From 82969651c5d2e049d89e384bf8f04ff2f0e4fd9a Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 00:12:40 +0900
Subject: [PATCH 001/103] Add a spec mode to transform-es2015-modules-commonjs

---
 packages/babel-helpers/src/helpers.js         |  31 ++
 .../src/index.js                              | 347 ++++++++++++++----
 .../fixtures/spec/commonjs-shadow/actual.js   |   7 +
 .../fixtures/spec/commonjs-shadow/expected.js |  22 ++
 .../fixtures/spec/export-default/actual.js    |   3 +
 .../fixtures/spec/export-default/expected.js  |  24 ++
 .../test/fixtures/spec/exports/actual.js      |  13 +
 .../test/fixtures/spec/exports/expected.js    |  62 ++++
 .../test/fixtures/spec/import/actual.js       |  23 ++
 .../test/fixtures/spec/import/expected.js     |  23 ++
 .../test/fixtures/spec/options.json           |   3 +
 .../test/fixtures/spec/reexports/actual.js    |  11 +
 .../test/fixtures/spec/reexports/expected.js  |  58 +++
 13 files changed, 554 insertions(+), 73 deletions(-)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/options.json
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index 87a58c3dc957..b5733159978a 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -396,6 +396,9 @@ helpers.interopRequireDefault = template(`
   })
 `);
 
+// interopRequireDefault doesn't technically match spec,
+// but where it does not match is not observable
+
 helpers.interopRequireWildcard = template(`
   (function (obj) {
     if (obj && obj.__esModule) {
@@ -413,6 +416,34 @@ helpers.interopRequireWildcard = template(`
   })
 `);
 
+helpers.specRequireInterop = template(`
+  (function (obj) {
+    if (obj && obj.__esModule) {
+      return obj;
+    } else {
+      var newObj = Object.create
+        ? Object.create(null, {
+          default: {
+            value: obj,
+            writable: true,
+            enumerable: true
+          },
+          __esModule: {
+            value: true
+          }
+        })
+        : {
+          default: obj,
+          __esModule: true
+        };
+      if (Symbol && Symbol.toStringTag) {
+        Object.defineProperty(newObj, Symbol.toStringTag, { value: "Module" })
+      }
+      return (Object.freeze || Object)(newObj);
+    }
+  })
+`);
+
 helpers.newArrowCheck = template(`
   (function (innerThis, boundThis) {
     if (innerThis !== boundThis) {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 8d3351bfa92e..17235e77e280 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -43,20 +43,91 @@ let buildExportAll = template(`
   });
 `);
 
+const specBuildNamespace = template(`
+  $0 = $1 = Object.create(null, { __esModule: { value: true } });
+`);
+
+const specBuildFunctionNameWrapper = template(`
+  ({ default: $0 }).default
+`);
+
+const specBuildExportDefault = template(`
+  Object.defineProperty(EXPORTS, "default", { enumerable: true, value: VALUE });
+`);
+
+const specBuildTempExportDescriptor = template(`
+  const $0 = { enumerable: true, configurable: true, value: undefined };
+`);
+
+const specBuildTempExportProperty = (id, descriptorId) => t.objectProperty(id, descriptorId);
+
+// Being configurable is not spec compliant; but not doing this would prevent updating
+// the export with the true value later.
+const specBuildTempExport = template(`
+  Object.defineProperties($0, $1);
+`);
+
+const specBuildExport = template(`
+  Object.defineProperty(EXPORTS, NAME, { enumerable: true, get() { return VALUE; } });
+`);
+
+const specBuildNamespaceReexport = template(`
+  Object.defineProperty(EXPORTS, NAME, { enumerable: true, value: VALUE });
+`);
+
+const specBuildNamespaceSpread = template(`
+  Object.keys(OBJECT).forEach(function (key) {
+    if (key === "default" || key === "__esModule") return;
+    Object.defineProperty(EXPORTS, key, {
+      enumerable: true,
+      get: function () {
+        return OBJECT[key];
+      }
+    });
+  });
+`);
+
+const specFinishNamespaceExport = template(`
+  Object.freeze($0);
+`);
+
 const THIS_BREAK_KEYS = ["FunctionExpression", "FunctionDeclaration", "ClassProperty", "ClassMethod", "ObjectMethod"];
 
 export default function () {
   let REASSIGN_REMAP_SKIP = Symbol();
 
+  const moduleExports = t.memberExpression(t.identifier("module"), t.identifier("exports"));
+  moduleExports[REASSIGN_REMAP_SKIP] = true;
+  const exportsObj = t.identifier("exports");
+  exportsObj[REASSIGN_REMAP_SKIP] = true;
+
+  const isModuleExports = t.buildMatchMemberExpression("module.exports", true);
+
   let reassignmentVisitor = {
-    ReferencedIdentifier(path) {
+    ReferencedIdentifier(path, state) {
+      const spec = isSpec(state);
       let name = path.node.name;
       let remap = this.remaps[name];
-      if (!remap) return;
+      if (!spec && !remap) return;
 
       // redeclared in this scope
       if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
 
+      if (spec) {
+        if (name === "exports" && !path.node[REASSIGN_REMAP_SKIP]) {
+          remap = this.remaps[".exports"] = this.remaps[".exports"] || path.scope.generateUidIdentifier("exports");
+          path.replaceWith(remap);
+          return;
+        }
+        if (isModuleExports(path.parent) && !path.parent[REASSIGN_REMAP_SKIP]) {
+          remap = this.remaps[".module.exports"] = this.remaps[".module.exports"] || path.scope.generateUidIdentifier("module.exports");
+          path.parentPath.replaceWith(remap);
+          return;
+        }
+
+        if (!remap) return;
+      }
+
       if (path.parentPath.isCallExpression({ callee: path.node })) {
         path.replaceWith(t.sequenceExpression([t.numericLiteral(0), remap]));
       } else if (path.isJSXIdentifier() && t.isMemberExpression(remap)) {
@@ -68,7 +139,11 @@ export default function () {
       this.requeueInParent(path);
     },
 
-    AssignmentExpression(path) {
+    AssignmentExpression(path, state) {
+      if (isSpec(state)) {
+        return;
+      }
+
       let node = path.node;
       if (node[REASSIGN_REMAP_SKIP]) return;
 
@@ -92,7 +167,11 @@ export default function () {
       this.requeueInParent(path);
     },
 
-    UpdateExpression(path) {
+    UpdateExpression(path, state) {
+      if (isSpec(state)) {
+        return;
+      }
+
       let arg = path.get("argument");
       if (!arg.isIdentifier()) return;
 
@@ -146,10 +225,11 @@ export default function () {
       },
 
       Program: {
-        exit(path) {
+        exit(path, state) {
           this.ranCommonJS = true;
 
           let strict = !!this.opts.strict;
+          const spec = isSpec(state);
 
           let { scope } = path;
 
@@ -169,19 +249,26 @@ export default function () {
 
           let topNodes = [];
           let remaps = Object.create(null);
+          const namespaceImports = new Set();
 
           let requires = Object.create(null);
 
-          function addRequire(source, blockHoist) {
+          const addRequire = (source, spec, blockHoist) => {
             let cached = requires[source];
             if (cached) return cached;
 
             let ref = path.scope.generateUidIdentifier(basename(source, extname(source)));
 
+            const req = buildRequire(
+              t.stringLiteral(source)
+            ).expression;
+
             let varDecl = t.variableDeclaration("var", [
-              t.variableDeclarator(ref, buildRequire(
-                t.stringLiteral(source)
-              ).expression)
+              t.variableDeclarator(ref,
+                spec
+                ? t.callExpression(this.addHelper("specRequireInterop"), [req])
+                : req
+              )
             ]);
 
             // Copy location from the original import statement for sourcemap
@@ -197,7 +284,7 @@ export default function () {
             topNodes.push(varDecl);
 
             return requires[source] = ref;
-          }
+          };
 
           function addTo(obj, key, arr) {
             let existing = obj[key] || [];
@@ -229,6 +316,13 @@ export default function () {
 
               importsEntry.specifiers.push(...path.node.specifiers);
 
+              if (spec) {
+                path.node.specifiers
+                .filter((s) => t.isImportNamespaceSpecifier(s))
+                .map((specifier) => specifier.local.name)
+                .forEach((name) => { namespaceImports.add(name); });
+              }
+
               if (typeof path.node._blockHoist === "number") {
                 importsEntry.maxBlockHoist = Math.max(
                   path.node._blockHoist,
@@ -246,10 +340,15 @@ export default function () {
                 let defNode = t.identifier("default");
                 if (id) {
                   addTo(exports, id.name, defNode);
-                  topNodes.push(buildExportsAssignment(defNode, id));
+                  topNodes.push(spec ? specBuildExportDefault({ EXPORTS: exportsObj, VALUE: id }) : buildExportsAssignment(defNode, id));
                   path.replaceWith(declaration.node);
+                } else if (spec) {
+                  const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
+                  topNodes.push(specBuildExportDefault({ EXPORTS: exportsObj, VALUE: expr }));
+                  path.remove();
                 } else {
-                  topNodes.push(buildExportsAssignment(defNode, t.toExpression(declaration.node)));
+                  const expr = t.toExpression(declaration.node);
+                  topNodes.push(buildExportsAssignment(defNode, expr));
                   path.remove();
                 }
               } else if (declaration.isClassDeclaration()) {
@@ -259,10 +358,19 @@ export default function () {
                   addTo(exports, id.name, defNode);
                   path.replaceWithMultiple([
                     declaration.node,
-                    buildExportsAssignment(defNode, id)
+                    spec ? specBuildExportDefault({ EXPORTS: exportsObj, VALUE: id }) : buildExportsAssignment(defNode, id)
                   ]);
+                } else if (spec) {
+                  const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
+                  path.replaceWith(specBuildExportDefault({ EXPORTS: exportsObj, VALUE: expr }));
+
+                  // Manually re-queue the expression so other transforms can get to it.
+                  // Ideally this would happen automatically from the replaceWith above.
+                  // See #4140 for more info.
+                  path.parentPath.requeue(path.get("expression.arguments.2"));
                 } else {
-                  path.replaceWith(buildExportsAssignment(defNode, t.toExpression(declaration.node)));
+                  const expr = t.toExpression(declaration.node);
+                  path.replaceWith(buildExportsAssignment(defNode, expr));
 
                   // Manualy re-queue `export default class {}` expressions so that the ES3 transform
                   // has an opportunity to convert them. Ideally this would happen automatically from the
@@ -270,12 +378,22 @@ export default function () {
                   path.parentPath.requeue(path.get("expression.left"));
                 }
               } else {
-                path.replaceWith(buildExportsAssignment(t.identifier("default"), declaration.node));
+                const defNode = t.identifier("default");
+                if (spec) {
+                  path.replaceWith(specBuildExportDefault({ EXPORTS: exportsObj, VALUE: declaration.node }));
+
+                  // Manually re-queue the expression so other transforms can get to it.
+                  // Ideally this would happen automatically from the replaceWith above.
+                  // See #4140 for more info.
+                  path.parentPath.requeue(path.get("expression.arguments.2"));
+                } else {
+                  path.replaceWith(buildExportsAssignment(defNode, declaration.node));
 
-                // Manualy re-queue `export default foo;` expressions so that the ES3 transform
-                // has an opportunity to convert them. Ideally this would happen automatically from the
-                // replaceWith above. See #4140 for more info.
-                path.parentPath.requeue(path.get("expression.left"));
+                  // Manualy re-queue `export default foo;` expressions so that the ES3 transform
+                  // has an opportunity to convert them. Ideally this would happen automatically from the
+                  // replaceWith above. See #4140 for more info.
+                  path.parentPath.requeue(path.get("expression.left"));
+                }
               }
             } else if (path.isExportNamedDeclaration()) {
               let declaration = path.get("declaration");
@@ -283,33 +401,57 @@ export default function () {
                 if (declaration.isFunctionDeclaration()) {
                   let id = declaration.node.id;
                   addTo(exports, id.name, id);
-                  topNodes.push(buildExportsAssignment(id, id));
+                  topNodes.push(spec
+                    ? specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral(id.name), VALUE: id })
+                    : buildExportsAssignment(id, id));
                   path.replaceWith(declaration.node);
                 } else if (declaration.isClassDeclaration()) {
                   let id = declaration.node.id;
                   addTo(exports, id.name, id);
                   path.replaceWithMultiple([
                     declaration.node,
-                    buildExportsAssignment(id, id)
+                    spec
+                    ? specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral(id.name), VALUE: id })
+                    : buildExportsAssignment(id, id)
                   ]);
                   nonHoistedExportNames[id.name] = true;
                 } else if (declaration.isVariableDeclaration()) {
                   let declarators = declaration.get("declarations");
+                  const toExport = spec && new Set();
                   for (let decl of declarators) {
                     let id = decl.get("id");
 
                     let init = decl.get("init");
                     if (!init.node) init.replaceWith(t.identifier("undefined"));
 
+                    if (spec) {
+                      toExport.add(id.node);
+                      nonHoistedExportNames[id.node.name] = true;
+                      continue;
+                    }
+
                     if (id.isIdentifier()) {
                       addTo(exports, id.node.name, id.node);
-                      init.replaceWith(buildExportsAssignment(id.node, init.node).expression);
+                      if (spec) {
+                      } else {
+                        init.replaceWith(buildExportsAssignment(id.node, init.node).expression);
+                      }
                       nonHoistedExportNames[id.node.name] = true;
                     } else {
                       // todo
                     }
                   }
-                  path.replaceWith(declaration.node);
+                  if (spec) {
+                    path.replaceWithMultiple([
+                      declaration.node
+                    ].concat(
+                      Array.from(toExport)
+                      .map((id) => specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral(id.name), VALUE: id}))
+                    )
+                  );
+                  } else {
+                    path.replaceWith(declaration.node);
+                  }
                 }
                 continue;
               }
@@ -318,7 +460,7 @@ export default function () {
               let nodes = [];
               let source = path.node.source;
               if (source) {
-                let ref = addRequire(source.value, path.node._blockHoist);
+                let ref = addRequire(source.value, spec, path.node._blockHoist);
 
                 for (let specifier of specifiers) {
                   if (specifier.isExportNamespaceSpecifier()) {
@@ -326,7 +468,9 @@ export default function () {
                   } else if (specifier.isExportDefaultSpecifier()) {
                     // todo
                   } else if (specifier.isExportSpecifier()) {
-                    if (specifier.node.local.name === "default") {
+                    if (spec) {
+                      topNodes.push(specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral(specifier.node.exported.name), VALUE: t.memberExpression(ref, specifier.node.local) }));
+                    } else if (specifier.node.local.name === "default") {
                       topNodes.push(buildExportsFrom(t.stringLiteral(specifier.node.exported.name), t.memberExpression(t.callExpression(this.addHelper("interopRequireDefault"), [ref]), specifier.node.local)));
                     } else {
                       topNodes.push(buildExportsFrom(t.stringLiteral(specifier.node.exported.name), t.memberExpression(ref, specifier.node.local)));
@@ -339,15 +483,30 @@ export default function () {
                   if (specifier.isExportSpecifier()) {
                     addTo(exports, specifier.node.local.name, specifier.node.exported);
                     nonHoistedExportNames[specifier.node.exported.name] = true;
-                    nodes.push(buildExportsAssignment(specifier.node.exported, specifier.node.local));
+
+                    if (spec) {
+                      if (namespaceImports.has(specifier.node.local.name)) {
+                        // it's a namespace, doesn't go through a getter, safe to reexport as a value
+                        nodes.push(specBuildNamespaceReexport({ EXPORTS: exportsObj, NAME: t.stringLiteral(specifier.node.exported.name), VALUE: specifier.node.local }));
+                      } else {
+                        nodes.push(specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral(specifier.node.exported.name), VALUE: specifier.node.local }));
+                      }
+                    } else {
+                      nodes.push(buildExportsAssignment(specifier.node.exported, specifier.node.local));
+                    }
                   }
                 }
               }
               path.replaceWithMultiple(nodes);
             } else if (path.isExportAllDeclaration()) {
-              let exportNode = buildExportAll({
-                OBJECT: addRequire(path.node.source.value, path.node._blockHoist)
-              });
+              let exportNode = spec
+                ? specBuildNamespaceSpread({
+                  EXPORTS: exportsObj,
+                  OBJECT: addRequire(path.node.source.value, spec, path.node._blockHoist)
+                })
+                : buildExportAll({
+                  OBJECT: addRequire(path.node.source.value, spec, path.node._blockHoist)
+                });
               exportNode.loc = path.node.loc;
               topNodes.push(exportNode);
               path.remove();
@@ -357,51 +516,32 @@ export default function () {
           for (let source in imports) {
             let {specifiers, maxBlockHoist} = imports[source];
             if (specifiers.length) {
-              let uid = addRequire(source, maxBlockHoist);
+              const uid = addRequire(source, spec, maxBlockHoist);
 
-              let wildcard;
-
-              for (let i = 0; i < specifiers.length; i++) {
-                let specifier = specifiers[i];
-                if (t.isImportNamespaceSpecifier(specifier)) {
-                  if (strict) {
+              if (spec) {
+                for (const specifier of specifiers) {
+                  if (t.isImportNamespaceSpecifier(specifier)) {
                     remaps[specifier.local.name] = uid;
+                  } else if (t.isImportDefaultSpecifier(specifier)) {
+                    remaps[specifier.local.name] = t.memberExpression(uid, t.identifier("default"));
                   } else {
-                    const varDecl = t.variableDeclaration("var", [
-                      t.variableDeclarator(
-                        specifier.local,
-                        t.callExpression(
-                          this.addHelper("interopRequireWildcard"),
-                          [uid]
-                        )
-                      )
-                    ]);
-
-                    if (maxBlockHoist > 0) {
-                      varDecl._blockHoist = maxBlockHoist;
-                    }
-
-                    topNodes.push(varDecl);
+                    remaps[specifier.local.name] = t.memberExpression(uid, t.cloneWithoutLoc(specifier.imported));
                   }
-                  wildcard = specifier.local;
-                } else if (t.isImportDefaultSpecifier(specifier)) {
-                  specifiers[i] = t.importSpecifier(specifier.local, t.identifier("default"));
                 }
-              }
+              } else {
+                let wildcard;
 
-              for (let specifier of specifiers) {
-                if (t.isImportSpecifier(specifier)) {
-                  let target = uid;
-                  if (specifier.imported.name === "default") {
-                    if (wildcard) {
-                      target = wildcard;
+                for (let i = 0; i < specifiers.length; i++) {
+                  let specifier = specifiers[i];
+                  if (t.isImportNamespaceSpecifier(specifier)) {
+                    if (strict) {
+                      remaps[specifier.local.name] = uid;
                     } else {
-                      target = wildcard = path.scope.generateUidIdentifier(uid.name);
                       const varDecl = t.variableDeclaration("var", [
                         t.variableDeclarator(
-                          target,
+                          specifier.local,
                           t.callExpression(
-                            this.addHelper("interopRequireDefault"),
+                            this.addHelper("interopRequireWildcard"),
                             [uid]
                           )
                         )
@@ -413,8 +553,39 @@ export default function () {
 
                       topNodes.push(varDecl);
                     }
+                    wildcard = specifier.local;
+                  } else if (t.isImportDefaultSpecifier(specifier)) {
+                    specifiers[i] = t.importSpecifier(specifier.local, t.identifier("default"));
+                  }
+                }
+
+                for (let specifier of specifiers) {
+                  if (t.isImportSpecifier(specifier)) {
+                    let target = uid;
+                    if (specifier.imported.name === "default") {
+                      if (wildcard) {
+                        target = wildcard;
+                      } else {
+                        target = wildcard = path.scope.generateUidIdentifier(uid.name);
+                        const varDecl = t.variableDeclaration("var", [
+                          t.variableDeclarator(
+                            target,
+                            t.callExpression(
+                              this.addHelper("interopRequireDefault"),
+                              [uid]
+                            )
+                          )
+                        ]);
+
+                        if (maxBlockHoist > 0) {
+                          varDecl._blockHoist = maxBlockHoist;
+                        }
+
+                        topNodes.push(varDecl);
+                      }
+                    }
+                    remaps[specifier.local.name] = t.memberExpression(target, t.cloneWithoutLoc(specifier.imported));
                   }
-                  remaps[specifier.local.name] = t.memberExpression(target, t.cloneWithoutLoc(specifier.imported));
                 }
               }
             } else {
@@ -428,20 +599,37 @@ export default function () {
           if (hasImports && Object.keys(nonHoistedExportNames).length) {
             let hoistedExportsNode = t.identifier("undefined");
 
-            for (let name in nonHoistedExportNames) {
-              hoistedExportsNode = buildExportsAssignment(t.identifier(name), hoistedExportsNode).expression;
-            }
+            if (spec) {
+              const descId = path.scope.generateUidIdentifier("undefined");
+              const desc = specBuildTempExportDescriptor(descId);
+              desc._blockHoist = 3;
+
+              const expr = t.objectExpression(
+                Object.keys(nonHoistedExportNames).map((name) =>
+                  specBuildTempExportProperty(t.identifier(name), descId)
+                )
+              );
+              const node = specBuildTempExport(exportsObj, expr);
+              node._blockHoist = 3;
+
+              topNodes.unshift(node);
+              topNodes.unshift(desc);
+            } else {
+              for (let name in nonHoistedExportNames) {
+                hoistedExportsNode = buildExportsAssignment(t.identifier(name), hoistedExportsNode).expression;
+              }
 
-            const node = t.expressionStatement(hoistedExportsNode);
-            node._blockHoist = 3;
+              const node = t.expressionStatement(hoistedExportsNode);
+              node._blockHoist = 3;
 
-            topNodes.unshift(node);
+              topNodes.unshift(node);
+            }
           }
 
           // add __esModule declaration if this file has any exports
-          if (hasExports && !strict) {
+          if (hasExports && !strict && !spec) {
             let buildTemplate = buildExportsModuleDeclaration;
-            if (this.opts.loose) buildTemplate = buildLooseExportsModuleDeclaration;
+            if (state.opts.loose) buildTemplate = buildLooseExportsModuleDeclaration;
 
             const declar = buildTemplate();
             declar._blockHoist = 3;
@@ -449,11 +637,20 @@ export default function () {
             topNodes.unshift(declar);
           }
 
+          if (hasExports && spec) {
+            const decl = specBuildNamespace(moduleExports, exportsObj);
+            decl._blockHoist = 3;
+            topNodes.unshift(decl);
+
+            path.pushContainer("body", [specFinishNamespaceExport(exportsObj)]);
+          }
+
           path.unshiftContainer("body", topNodes);
           path.traverse(reassignmentVisitor, {
             remaps,
             scope,
             exports,
+            opts: state.opts,
             requeueInParent: (newPath) => path.requeue(newPath),
           });
         }
@@ -461,3 +658,7 @@ export default function () {
     }
   };
 }
+
+function isSpec (state) {
+  return state && state.opts && !!state.opts.spec;
+}
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/actual.js
new file mode 100644
index 000000000000..6b02231af737
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/actual.js
@@ -0,0 +1,7 @@
+import * as foo from 'bar';
+
+export default class {};
+
+// neither of these should be able to use or affect the real exports
+new exports.default();
+module.exports = {};
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
new file mode 100644
index 000000000000..019b8da432cc
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -0,0 +1,22 @@
+'use strict';
+
+module.exports = exports = Object.create(null, {
+  __esModule: {
+    value: true
+  }
+});
+
+var _bar = babelHelpers.specRequireInterop(require('bar'));
+
+Object.defineProperty(exports, "default", {
+  enumerable: true,
+  value: {
+    default: class {}
+  }.default
+});
+;
+
+// neither of these should be able to use or affect the real exports
+new _exports.default();
+_moduleExports = {};
+Object.freeze(exports);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/actual.js
new file mode 100644
index 000000000000..4d818cf550fb
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/actual.js
@@ -0,0 +1,3 @@
+export default function () {}
+export var unrelated;
+unrelated = "changed";
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
new file mode 100644
index 000000000000..2ae6c4e2a48d
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -0,0 +1,24 @@
+"use strict";
+
+module.exports = exports = Object.create(null, {
+  __esModule: {
+    value: true
+  }
+});
+Object.defineProperty(exports, "default", {
+  enumerable: true,
+  value: {
+    default: function () {}
+  }.default
+});
+var unrelated = undefined;
+Object.defineProperty(exports, "unrelated", {
+  enumerable: true,
+
+  get() {
+    return unrelated;
+  }
+
+});
+unrelated = "changed";
+Object.freeze(exports);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/actual.js
new file mode 100644
index 000000000000..4b5d9f387a6c
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/actual.js
@@ -0,0 +1,13 @@
+import { anything } from "outside"
+
+var def;
+export { def as default }
+
+export function foo () {
+  def = "export mutation";
+  return "foo";
+}
+
+export class Bar {}
+
+export const baz = foo();
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
new file mode 100644
index 000000000000..32839eed43e3
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -0,0 +1,62 @@
+"use strict";
+
+module.exports = exports = Object.create(null, {
+  __esModule: {
+    value: true
+  }
+});
+const _undefined = {
+  enumerable: true,
+  configurable: true,
+  value: undefined
+};
+Object.defineProperties(exports, {
+  default: _undefined,
+  Bar: _undefined,
+  baz: _undefined
+});
+Object.defineProperty(exports, "foo", {
+  enumerable: true,
+
+  get() {
+    return foo;
+  }
+
+});
+
+var _outside = babelHelpers.specRequireInterop(require("outside"));
+
+var def;
+Object.defineProperty(exports, "default", {
+  enumerable: true,
+
+  get() {
+    return def;
+  }
+
+});
+function foo() {
+  def = "export mutation";
+  return "foo";
+}
+
+class Bar {}
+
+Object.defineProperty(exports, "Bar", {
+  enumerable: true,
+
+  get() {
+    return Bar;
+  }
+
+});
+const baz = foo();
+Object.defineProperty(exports, "baz", {
+  enumerable: true,
+
+  get() {
+    return baz;
+  }
+
+});
+Object.freeze(exports);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/actual.js
new file mode 100644
index 000000000000..461824804461
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/actual.js
@@ -0,0 +1,23 @@
+import * as namespace from './elsewhere';
+
+import { default as outside, obj } from './outside';
+
+outside(obj.key);
+
+import something from './anywhere';
+
+something(namespace);
+
+import {} from './empty';
+
+import './imperative';
+
+import who, { what } from './i-dont-know';
+
+import why, * as because from './naturally';
+
+who[what](why, because.naturally);
+
+import { who as naturally } from './i-dont-know';
+
+naturally(because);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
new file mode 100644
index 000000000000..7287f81c3b9e
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
@@ -0,0 +1,23 @@
+'use strict';
+
+var _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
+
+var _outside = babelHelpers.specRequireInterop(require('./outside'));
+
+var _anywhere = babelHelpers.specRequireInterop(require('./anywhere'));
+
+require('./empty');
+
+require('./imperative');
+
+var _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
+
+var _naturally = babelHelpers.specRequireInterop(require('./naturally'));
+
+(0, _outside.default)(_outside.obj.key);
+
+(0, _anywhere.default)(_elsewhere);
+
+_iDontKnow.default[_iDontKnow.what](_naturally.default, _naturally.naturally);
+
+(0, _iDontKnow.who)(_naturally);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/options.json b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/options.json
new file mode 100644
index 000000000000..b213374a9332
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["external-helpers", ["transform-es2015-modules-commonjs", {"spec": true}]]
+}
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js
new file mode 100644
index 000000000000..97b540e2e809
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js
@@ -0,0 +1,11 @@
+import * as namespace from './somewhere';
+
+import { stuff } from './elsewhere';
+
+export { namespace };
+
+export { stuff as default };
+
+export * from './i-dont-know';
+
+export { default as why } from './because';
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
new file mode 100644
index 000000000000..be4b9bb2e183
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -0,0 +1,58 @@
+'use strict';
+
+module.exports = exports = Object.create(null, {
+  __esModule: {
+    value: true
+  }
+});
+const _undefined = {
+  enumerable: true,
+  configurable: true,
+  value: undefined
+};
+Object.defineProperties(exports, {
+  namespace: _undefined,
+  default: _undefined,
+  why: _undefined
+});
+
+var _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
+
+Object.keys(_iDontKnow).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+  Object.defineProperty(exports, key, {
+    enumerable: true,
+    get: function () {
+      return _iDontKnow[key];
+    }
+  });
+});
+
+var _because = babelHelpers.specRequireInterop(require('./because'));
+
+Object.defineProperty(exports, 'why', {
+  enumerable: true,
+
+  get() {
+    return _because.default;
+  }
+
+});
+
+var _somewhere = babelHelpers.specRequireInterop(require('./somewhere'));
+
+var _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
+
+Object.defineProperty(exports, 'namespace', {
+  enumerable: true,
+  value: _somewhere
+});
+Object.defineProperty(exports, 'default', {
+  enumerable: true,
+
+  get() {
+    return _elsewhere.stuff;
+  }
+
+});
+Object.freeze(exports);
\ No newline at end of file

From 4a746eebc7050c4afe8b6800bfa098acfeabca23 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 00:42:12 +0900
Subject: [PATCH 002/103] Correct the descriptors to have writable: true

---
 .../src/index.js                              | 34 ++++++++++---------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 17235e77e280..8b3cd98da754 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -51,28 +51,19 @@ const specBuildFunctionNameWrapper = template(`
   ({ default: $0 }).default
 `);
 
+// The descriptors are as specified in https://tc39.github.io/ecma262/#sec-module-namespace-exotic-objects-getownproperty-p
 const specBuildExportDefault = template(`
-  Object.defineProperty(EXPORTS, "default", { enumerable: true, value: VALUE });
-`);
-
-const specBuildTempExportDescriptor = template(`
-  const $0 = { enumerable: true, configurable: true, value: undefined };
-`);
-
-const specBuildTempExportProperty = (id, descriptorId) => t.objectProperty(id, descriptorId);
-
-// Being configurable is not spec compliant; but not doing this would prevent updating
-// the export with the true value later.
-const specBuildTempExport = template(`
-  Object.defineProperties($0, $1);
+  Object.defineProperty(EXPORTS, "default", { enumerable: true, writable: true, value: VALUE });
 `);
 
+// Unfortunately, regular objects can't synthesize a value descriptor every time they're read,
+// so a getter needs to be used for live bindings.
 const specBuildExport = template(`
-  Object.defineProperty(EXPORTS, NAME, { enumerable: true, get() { return VALUE; } });
+  Object.defineProperty(EXPORTS, NAME, { enumerable: true, writable: true, get() { return VALUE; } });
 `);
 
 const specBuildNamespaceReexport = template(`
-  Object.defineProperty(EXPORTS, NAME, { enumerable: true, value: VALUE });
+  Object.defineProperty(EXPORTS, NAME, { enumerable: true, writable: true, value: VALUE });
 `);
 
 const specBuildNamespaceSpread = template(`
@@ -80,13 +71,24 @@ const specBuildNamespaceSpread = template(`
     if (key === "default" || key === "__esModule") return;
     Object.defineProperty(EXPORTS, key, {
       enumerable: true,
-      get: function () {
+      writable: true,
+      get() {
         return OBJECT[key];
       }
     });
   });
 `);
 
+const specBuildTempExportDescriptor = template(`
+  const $0 = { enumerable: true, writable: true, value: undefined };
+`);
+
+const specBuildTempExportProperty = (id, descriptorId) => t.objectProperty(id, descriptorId);
+
+const specBuildTempExport = template(`
+  Object.defineProperties($0, $1);
+`);
+
 const specFinishNamespaceExport = template(`
   Object.freeze($0);
 `);

From 43bd0e92a143e8b81a5f47484373cf37c3b5668c Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 00:45:09 +0900
Subject: [PATCH 003/103] Update tests

---
 .../test/fixtures/spec/commonjs-shadow/expected.js     |  1 +
 .../test/fixtures/spec/export-default/expected.js      |  2 ++
 .../test/fixtures/spec/exports/expected.js             |  6 +++++-
 .../test/fixtures/spec/reexports/expected.js           | 10 ++++++++--
 4 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
index 019b8da432cc..2c310eae0a0c 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -10,6 +10,7 @@ var _bar = babelHelpers.specRequireInterop(require('bar'));
 
 Object.defineProperty(exports, "default", {
   enumerable: true,
+  writable: true,
   value: {
     default: class {}
   }.default
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index 2ae6c4e2a48d..3f66bbedf1ca 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -7,6 +7,7 @@ module.exports = exports = Object.create(null, {
 });
 Object.defineProperty(exports, "default", {
   enumerable: true,
+  writable: true,
   value: {
     default: function () {}
   }.default
@@ -14,6 +15,7 @@ Object.defineProperty(exports, "default", {
 var unrelated = undefined;
 Object.defineProperty(exports, "unrelated", {
   enumerable: true,
+  writable: true,
 
   get() {
     return unrelated;
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index 32839eed43e3..58ad9e96f22a 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -7,7 +7,7 @@ module.exports = exports = Object.create(null, {
 });
 const _undefined = {
   enumerable: true,
-  configurable: true,
+  writable: true,
   value: undefined
 };
 Object.defineProperties(exports, {
@@ -17,6 +17,7 @@ Object.defineProperties(exports, {
 });
 Object.defineProperty(exports, "foo", {
   enumerable: true,
+  writable: true,
 
   get() {
     return foo;
@@ -29,6 +30,7 @@ var _outside = babelHelpers.specRequireInterop(require("outside"));
 var def;
 Object.defineProperty(exports, "default", {
   enumerable: true,
+  writable: true,
 
   get() {
     return def;
@@ -44,6 +46,7 @@ class Bar {}
 
 Object.defineProperty(exports, "Bar", {
   enumerable: true,
+  writable: true,
 
   get() {
     return Bar;
@@ -53,6 +56,7 @@ Object.defineProperty(exports, "Bar", {
 const baz = foo();
 Object.defineProperty(exports, "baz", {
   enumerable: true,
+  writable: true,
 
   get() {
     return baz;
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index be4b9bb2e183..c6309cc1cb46 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -7,7 +7,7 @@ module.exports = exports = Object.create(null, {
 });
 const _undefined = {
   enumerable: true,
-  configurable: true,
+  writable: true,
   value: undefined
 };
 Object.defineProperties(exports, {
@@ -22,9 +22,12 @@ Object.keys(_iDontKnow).forEach(function (key) {
   if (key === "default" || key === "__esModule") return;
   Object.defineProperty(exports, key, {
     enumerable: true,
-    get: function () {
+    writable: true,
+
+    get() {
       return _iDontKnow[key];
     }
+
   });
 });
 
@@ -32,6 +35,7 @@ var _because = babelHelpers.specRequireInterop(require('./because'));
 
 Object.defineProperty(exports, 'why', {
   enumerable: true,
+  writable: true,
 
   get() {
     return _because.default;
@@ -45,10 +49,12 @@ var _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
 
 Object.defineProperty(exports, 'namespace', {
   enumerable: true,
+  writable: true,
   value: _somewhere
 });
 Object.defineProperty(exports, 'default', {
   enumerable: true,
+  writable: true,
 
   get() {
     return _elsewhere.stuff;

From 3389e9faf90588bbf7a0e5d19bd6bc7d0df1ecc8 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 00:47:47 +0900
Subject: [PATCH 004/103] Simplify the specRequireInterop helper; spec isn't
 ES3 compatible

---
 packages/babel-helpers/src/helpers.js | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index b5733159978a..6bce30779825 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -421,8 +421,7 @@ helpers.specRequireInterop = template(`
     if (obj && obj.__esModule) {
       return obj;
     } else {
-      var newObj = Object.create
-        ? Object.create(null, {
+      var newObj = Object.create(null, {
           default: {
             value: obj,
             writable: true,
@@ -431,15 +430,11 @@ helpers.specRequireInterop = template(`
           __esModule: {
             value: true
           }
-        })
-        : {
-          default: obj,
-          __esModule: true
-        };
+        });
       if (Symbol && Symbol.toStringTag) {
         Object.defineProperty(newObj, Symbol.toStringTag, { value: "Module" })
       }
-      return (Object.freeze || Object)(newObj);
+      return Object.freeze(newObj);
     }
   })
 `);

From 17cd0b985d30254d43737641a94b1a800e80dab9 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 00:48:55 +0900
Subject: [PATCH 005/103] Add missing @@toStringTag definition

---
 .../src/index.js                                               | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 8b3cd98da754..fd617b7ee7ec 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -45,6 +45,9 @@ let buildExportAll = template(`
 
 const specBuildNamespace = template(`
   $0 = $1 = Object.create(null, { __esModule: { value: true } });
+  if (Symbol && Symbol.toStringTag) {
+    Object.defineProperty($0, Symbol.toStringTag, { value: "Module" })
+  }
 `);
 
 const specBuildFunctionNameWrapper = template(`

From 42d870e1938cf89f944608ece0c38b520f6ff2eb Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 00:59:46 +0900
Subject: [PATCH 006/103] Fix broken AST attachment; update tests

---
 .../src/index.js                                      | 11 ++++++-----
 .../test/fixtures/spec/commonjs-shadow/expected.js    |  6 ++++++
 .../test/fixtures/spec/export-default/expected.js     |  7 +++++++
 .../test/fixtures/spec/exports/expected.js            |  7 +++++++
 .../test/fixtures/spec/reexports/expected.js          |  7 +++++++
 5 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index fd617b7ee7ec..a0a5ab43ee34 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -46,7 +46,7 @@ let buildExportAll = template(`
 const specBuildNamespace = template(`
   $0 = $1 = Object.create(null, { __esModule: { value: true } });
   if (Symbol && Symbol.toStringTag) {
-    Object.defineProperty($0, Symbol.toStringTag, { value: "Module" })
+    Object.defineProperty($0, Symbol.toStringTag, { value: "Module" });
   }
 `);
 
@@ -642,15 +642,16 @@ export default function () {
             topNodes.unshift(declar);
           }
 
+          path.unshiftContainer("body", topNodes);
+
           if (hasExports && spec) {
-            const decl = specBuildNamespace(moduleExports, exportsObj);
-            decl._blockHoist = 3;
-            topNodes.unshift(decl);
+            const decls = specBuildNamespace(moduleExports, exportsObj);
+            decls.forEach((decl) => { decl._blockHoist = 3; });
 
+            path.unshiftContainer("body", decls);
             path.pushContainer("body", [specFinishNamespaceExport(exportsObj)]);
           }
 
-          path.unshiftContainer("body", topNodes);
           path.traverse(reassignmentVisitor, {
             remaps,
             scope,
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
index 2c310eae0a0c..ca184036462f 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -6,6 +6,12 @@ module.exports = exports = Object.create(null, {
   }
 });
 
+if (Symbol && Symbol.toStringTag) {
+  Object.defineProperty(module.exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
 var _bar = babelHelpers.specRequireInterop(require('bar'));
 
 Object.defineProperty(exports, "default", {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index 3f66bbedf1ca..fe82b92852e7 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -5,6 +5,13 @@ module.exports = exports = Object.create(null, {
     value: true
   }
 });
+
+if (Symbol && Symbol.toStringTag) {
+  Object.defineProperty(module.exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
 Object.defineProperty(exports, "default", {
   enumerable: true,
   writable: true,
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index 58ad9e96f22a..cacf97e5ddae 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -5,6 +5,13 @@ module.exports = exports = Object.create(null, {
     value: true
   }
 });
+
+if (Symbol && Symbol.toStringTag) {
+  Object.defineProperty(module.exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
 const _undefined = {
   enumerable: true,
   writable: true,
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index c6309cc1cb46..e1e20a3a6a06 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -5,6 +5,13 @@ module.exports = exports = Object.create(null, {
     value: true
   }
 });
+
+if (Symbol && Symbol.toStringTag) {
+  Object.defineProperty(module.exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
 const _undefined = {
   enumerable: true,
   writable: true,

From 477cb99a13128232f358038651d299ab2f60909b Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 01:02:03 +0900
Subject: [PATCH 007/103] Use a check that won't actually throw in ES5 strict
 mode

---
 packages/babel-helpers/src/helpers.js                           | 2 +-
 .../babel-plugin-transform-es2015-modules-commonjs/src/index.js | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index 6bce30779825..ee7696ac41ea 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -431,7 +431,7 @@ helpers.specRequireInterop = template(`
             value: true
           }
         });
-      if (Symbol && Symbol.toStringTag) {
+      if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
         Object.defineProperty(newObj, Symbol.toStringTag, { value: "Module" })
       }
       return Object.freeze(newObj);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index a0a5ab43ee34..905059a35546 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -45,7 +45,7 @@ let buildExportAll = template(`
 
 const specBuildNamespace = template(`
   $0 = $1 = Object.create(null, { __esModule: { value: true } });
-  if (Symbol && Symbol.toStringTag) {
+  if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
     Object.defineProperty($0, Symbol.toStringTag, { value: "Module" });
   }
 `);

From 6fbf2ac824ca190bfa42124c274a85e05fc29bc2 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 01:02:50 +0900
Subject: [PATCH 008/103] Update fixtures

---
 .../test/fixtures/spec/commonjs-shadow/expected.js              | 2 +-
 .../test/fixtures/spec/export-default/expected.js               | 2 +-
 .../test/fixtures/spec/exports/expected.js                      | 2 +-
 .../test/fixtures/spec/reexports/expected.js                    | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
index ca184036462f..124eacdf2078 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -6,7 +6,7 @@ module.exports = exports = Object.create(null, {
   }
 });
 
-if (Symbol && Symbol.toStringTag) {
+if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
   Object.defineProperty(module.exports, Symbol.toStringTag, {
     value: "Module"
   });
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index fe82b92852e7..cdb801b00157 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -6,7 +6,7 @@ module.exports = exports = Object.create(null, {
   }
 });
 
-if (Symbol && Symbol.toStringTag) {
+if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
   Object.defineProperty(module.exports, Symbol.toStringTag, {
     value: "Module"
   });
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index cacf97e5ddae..cae265e1f14b 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -6,7 +6,7 @@ module.exports = exports = Object.create(null, {
   }
 });
 
-if (Symbol && Symbol.toStringTag) {
+if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
   Object.defineProperty(module.exports, Symbol.toStringTag, {
     value: "Module"
   });
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index e1e20a3a6a06..c6f4b0eaed9e 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -6,7 +6,7 @@ module.exports = exports = Object.create(null, {
   }
 });
 
-if (Symbol && Symbol.toStringTag) {
+if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
   Object.defineProperty(module.exports, Symbol.toStringTag, {
     value: "Module"
   });

From 906e8c12791d82f48b5d17dfa2e766c428452258 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 01:14:28 +0900
Subject: [PATCH 009/103] Don't set writable alongside getters

Throws in v8 with "Invalid property descriptor. Cannot both specify
accessors and a value or writable attribute"

I guess this is why the spec defines "magic changing values" instead of
getters :sweat_smile:
---
 .../src/index.js                                               | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 905059a35546..0c8b9249e04a 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -62,7 +62,7 @@ const specBuildExportDefault = template(`
 // Unfortunately, regular objects can't synthesize a value descriptor every time they're read,
 // so a getter needs to be used for live bindings.
 const specBuildExport = template(`
-  Object.defineProperty(EXPORTS, NAME, { enumerable: true, writable: true, get() { return VALUE; } });
+  Object.defineProperty(EXPORTS, NAME, { enumerable: true, get() { return VALUE; } });
 `);
 
 const specBuildNamespaceReexport = template(`
@@ -74,7 +74,6 @@ const specBuildNamespaceSpread = template(`
     if (key === "default" || key === "__esModule") return;
     Object.defineProperty(EXPORTS, key, {
       enumerable: true,
-      writable: true,
       get() {
         return OBJECT[key];
       }

From b88c6c54955839b72f6c78f8d4cf7f3826a79355 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 01:15:00 +0900
Subject: [PATCH 010/103] Shorten generated code

Repeat the shorter identifier in the block.
---
 .../src/index.js                                              | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 0c8b9249e04a..347a52c07173 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -44,7 +44,7 @@ let buildExportAll = template(`
 `);
 
 const specBuildNamespace = template(`
-  $0 = $1 = Object.create(null, { __esModule: { value: true } });
+  $1 = $0 = Object.create(null, { __esModule: { value: true } });
   if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
     Object.defineProperty($0, Symbol.toStringTag, { value: "Module" });
   }
@@ -644,7 +644,7 @@ export default function () {
           path.unshiftContainer("body", topNodes);
 
           if (hasExports && spec) {
-            const decls = specBuildNamespace(moduleExports, exportsObj);
+            const decls = specBuildNamespace(exportsObj, moduleExports);
             decls.forEach((decl) => { decl._blockHoist = 3; });
 
             path.unshiftContainer("body", decls);

From 8f18792789f10f5795202b1e9cdb0992e0f2206b Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 01:16:07 +0900
Subject: [PATCH 011/103] Update fixtures

---
 .../test/fixtures/spec/commonjs-shadow/expected.js          | 2 +-
 .../test/fixtures/spec/export-default/expected.js           | 3 +--
 .../test/fixtures/spec/exports/expected.js                  | 6 +-----
 .../test/fixtures/spec/reexports/expected.js                | 5 +----
 4 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
index 124eacdf2078..2d61482992b3 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -7,7 +7,7 @@ module.exports = exports = Object.create(null, {
 });
 
 if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
-  Object.defineProperty(module.exports, Symbol.toStringTag, {
+  Object.defineProperty(exports, Symbol.toStringTag, {
     value: "Module"
   });
 }
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index cdb801b00157..2e9f228fb494 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -7,7 +7,7 @@ module.exports = exports = Object.create(null, {
 });
 
 if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
-  Object.defineProperty(module.exports, Symbol.toStringTag, {
+  Object.defineProperty(exports, Symbol.toStringTag, {
     value: "Module"
   });
 }
@@ -22,7 +22,6 @@ Object.defineProperty(exports, "default", {
 var unrelated = undefined;
 Object.defineProperty(exports, "unrelated", {
   enumerable: true,
-  writable: true,
 
   get() {
     return unrelated;
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index cae265e1f14b..2a757b715dc2 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -7,7 +7,7 @@ module.exports = exports = Object.create(null, {
 });
 
 if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
-  Object.defineProperty(module.exports, Symbol.toStringTag, {
+  Object.defineProperty(exports, Symbol.toStringTag, {
     value: "Module"
   });
 }
@@ -24,7 +24,6 @@ Object.defineProperties(exports, {
 });
 Object.defineProperty(exports, "foo", {
   enumerable: true,
-  writable: true,
 
   get() {
     return foo;
@@ -37,7 +36,6 @@ var _outside = babelHelpers.specRequireInterop(require("outside"));
 var def;
 Object.defineProperty(exports, "default", {
   enumerable: true,
-  writable: true,
 
   get() {
     return def;
@@ -53,7 +51,6 @@ class Bar {}
 
 Object.defineProperty(exports, "Bar", {
   enumerable: true,
-  writable: true,
 
   get() {
     return Bar;
@@ -63,7 +60,6 @@ Object.defineProperty(exports, "Bar", {
 const baz = foo();
 Object.defineProperty(exports, "baz", {
   enumerable: true,
-  writable: true,
 
   get() {
     return baz;
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index c6f4b0eaed9e..375a1da63039 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -7,7 +7,7 @@ module.exports = exports = Object.create(null, {
 });
 
 if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
-  Object.defineProperty(module.exports, Symbol.toStringTag, {
+  Object.defineProperty(exports, Symbol.toStringTag, {
     value: "Module"
   });
 }
@@ -29,7 +29,6 @@ Object.keys(_iDontKnow).forEach(function (key) {
   if (key === "default" || key === "__esModule") return;
   Object.defineProperty(exports, key, {
     enumerable: true,
-    writable: true,
 
     get() {
       return _iDontKnow[key];
@@ -42,7 +41,6 @@ var _because = babelHelpers.specRequireInterop(require('./because'));
 
 Object.defineProperty(exports, 'why', {
   enumerable: true,
-  writable: true,
 
   get() {
     return _because.default;
@@ -61,7 +59,6 @@ Object.defineProperty(exports, 'namespace', {
 });
 Object.defineProperty(exports, 'default', {
   enumerable: true,
-  writable: true,
 
   get() {
     return _elsewhere.stuff;

From 60900bdc05adb8ac6ab141e34b848592449a9edf Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 02:09:05 +0900
Subject: [PATCH 012/103] Fix several corner cases in the commons shadowing

---
 .../src/index.js                              | 36 ++++++++++++++++---
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 347a52c07173..ccad4ff942b6 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -100,12 +100,14 @@ const THIS_BREAK_KEYS = ["FunctionExpression", "FunctionDeclaration", "ClassProp
 export default function () {
   let REASSIGN_REMAP_SKIP = Symbol();
 
-  const moduleExports = t.memberExpression(t.identifier("module"), t.identifier("exports"));
-  moduleExports[REASSIGN_REMAP_SKIP] = true;
   const exportsObj = t.identifier("exports");
   exportsObj[REASSIGN_REMAP_SKIP] = true;
+  const moduleExports = t.memberExpression(t.identifier("module"), exportsObj);
+  moduleExports[REASSIGN_REMAP_SKIP] = true;
 
   const isModuleExports = t.buildMatchMemberExpression("module.exports", true);
+  const isExports = t.buildMatchMemberExpression("exports", true);
+  let commonjsExportsMasked = null;
 
   let reassignmentVisitor = {
     ReferencedIdentifier(path, state) {
@@ -118,14 +120,20 @@ export default function () {
       if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
 
       if (spec) {
-        if (name === "exports" && !path.node[REASSIGN_REMAP_SKIP]) {
+        if (name === "exports" && !path.node[REASSIGN_REMAP_SKIP] &&
+          // Apparently replacing "module.exports" still visits the ".exports" here
+          !(this.remaps[".module.exports"] && t.isIdentifier(path.parent, this.remaps[".module.exports"])) &&
+          // Avoid entering when it's just some other object key named export
+          !(isExports(path.parent) && t.isMemberExpression(path.parent.parent))) {
           remap = this.remaps[".exports"] = this.remaps[".exports"] || path.scope.generateUidIdentifier("exports");
           path.replaceWith(remap);
+          commonjsExportsMasked.exports = remap;
           return;
         }
-        if (isModuleExports(path.parent) && !path.parent[REASSIGN_REMAP_SKIP]) {
+        if (isModuleExports(path.parent) && !path.parent[REASSIGN_REMAP_SKIP] && !t.isMemberExpression(path.parent.parent)) {
           remap = this.remaps[".module.exports"] = this.remaps[".module.exports"] || path.scope.generateUidIdentifier("module.exports");
           path.parentPath.replaceWith(remap);
+          commonjsExportsMasked.moduleExports = remap;
           return;
         }
 
@@ -145,6 +153,12 @@ export default function () {
 
     AssignmentExpression(path, state) {
       if (isSpec(state)) {
+        if (!path.node[REASSIGN_REMAP_SKIP] && t.isIdentifier(path.node.left, { name: "exports" }) &&
+          !path.node.left[REASSIGN_REMAP_SKIP] && this.scope.getBinding(name) === path.scope.getBinding(name)) {
+          let remap = this.remaps[".exports"] = this.remaps[".exports"] || path.scope.generateUidIdentifier("exports");
+          path.get("left").replaceWith(remap);
+          commonjsExportsMasked.exports = remap;
+        }
         return;
       }
 
@@ -651,6 +665,8 @@ export default function () {
             path.pushContainer("body", [specFinishNamespaceExport(exportsObj)]);
           }
 
+          commonjsExportsMasked = {};
+
           path.traverse(reassignmentVisitor, {
             remaps,
             scope,
@@ -658,6 +674,18 @@ export default function () {
             opts: state.opts,
             requeueInParent: (newPath) => path.requeue(newPath),
           });
+
+          if (spec && (commonjsExportsMasked.exports || commonjsExportsMasked.moduleExports)) {
+            path.unshiftContainer("body", [
+              t.variableDeclaration("var", [
+                commonjsExportsMasked.exports && t.variableDeclarator(commonjsExportsMasked.exports, t.objectExpression([])),
+                commonjsExportsMasked.moduleExports && commonjsExportsMasked.exports &&
+                  t.variableDeclarator(commonjsExportsMasked.moduleExports, commonjsExportsMasked.exports),
+                commonjsExportsMasked.moduleExports && !commonjsExportsMasked.exports &&
+                  t.variableDeclarator(commonjsExportsMasked.moduleExports, t.objectExpression([]))
+              ].filter(Boolean))
+            ]);
+          }
         }
       }
     }

From a57449f6db0082c13c67b67661bde480933f4994 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 02:09:17 +0900
Subject: [PATCH 013/103] Add more fixtures, update fixtures

---
 .../fixtures/spec/commonjs-shadow-1/actual.js |  3 +++
 .../spec/commonjs-shadow-1/expected.js        | 26 +++++++++++++++++++
 .../fixtures/spec/commonjs-shadow-2/actual.js |  3 +++
 .../spec/commonjs-shadow-2/expected.js        | 19 ++++++++++++++
 .../fixtures/spec/commonjs-shadow/expected.js |  3 +++
 5 files changed, 54 insertions(+)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/actual.js
new file mode 100644
index 000000000000..7e4fee02a3e1
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/actual.js
@@ -0,0 +1,3 @@
+export default function () {}
+
+exports = function () {};
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
new file mode 100644
index 000000000000..cda8436c1f19
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
@@ -0,0 +1,26 @@
+"use strict";
+
+module.exports = exports = Object.create(null, {
+  __esModule: {
+    value: true
+  }
+});
+
+if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+var _exports = {};
+Object.defineProperty(exports, "default", {
+  enumerable: true,
+  writable: true,
+  value: {
+    default: function () {}
+  }.default
+});
+
+
+_exports = function () {};
+Object.freeze(exports);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/actual.js
new file mode 100644
index 000000000000..1a6e3c5624ab
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/actual.js
@@ -0,0 +1,3 @@
+export {}
+
+module.exports = class {};
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
new file mode 100644
index 000000000000..2fce7f7d11f0
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
@@ -0,0 +1,19 @@
+"use strict";
+
+module.exports = exports = Object.create(null, {
+  __esModule: {
+    value: true
+  }
+});
+
+if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+var _moduleExports = {};
+
+
+_moduleExports = class {};
+Object.freeze(exports);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
index 2d61482992b3..4d4f2991cca6 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -12,6 +12,9 @@ if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
   });
 }
 
+var _exports = {},
+    _moduleExports = _exports;
+
 var _bar = babelHelpers.specRequireInterop(require('bar'));
 
 Object.defineProperty(exports, "default", {

From d09ac54a7ea93763c521174ba92c1c89cc2a5ac1 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 02:18:21 +0900
Subject: [PATCH 014/103] Better check for typeof Symbol

---
 packages/babel-helpers/src/helpers.js                           | 2 +-
 .../babel-plugin-transform-es2015-modules-commonjs/src/index.js | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index ee7696ac41ea..dc272edb4e6e 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -431,7 +431,7 @@ helpers.specRequireInterop = template(`
             value: true
           }
         });
-      if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
+      if (typeof Symbol === "function" && Symbol.toStringTag) {
         Object.defineProperty(newObj, Symbol.toStringTag, { value: "Module" })
       }
       return Object.freeze(newObj);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index ccad4ff942b6..42ccc9666525 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -45,7 +45,7 @@ let buildExportAll = template(`
 
 const specBuildNamespace = template(`
   $1 = $0 = Object.create(null, { __esModule: { value: true } });
-  if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
+  if (typeof Symbol === "function" && Symbol.toStringTag) {
     Object.defineProperty($0, Symbol.toStringTag, { value: "Module" });
   }
 `);

From cf5e102fd5c120b4d31d4a71b0b261ac2f5fb016 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 02:18:37 +0900
Subject: [PATCH 015/103] Avoid allocation on non-spec

---
 .../src/index.js                                              | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 42ccc9666525..d9051b8c1f01 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -665,7 +665,9 @@ export default function () {
             path.pushContainer("body", [specFinishNamespaceExport(exportsObj)]);
           }
 
-          commonjsExportsMasked = {};
+          if (spec) {
+            commonjsExportsMasked = {};
+          }
 
           path.traverse(reassignmentVisitor, {
             remaps,

From 538a5859bab966b8361607671e13ca840ca47d09 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 02:19:21 +0900
Subject: [PATCH 016/103] Update fixtures

---
 .../test/fixtures/spec/commonjs-shadow-1/expected.js            | 2 +-
 .../test/fixtures/spec/commonjs-shadow-2/expected.js            | 2 +-
 .../test/fixtures/spec/commonjs-shadow/expected.js              | 2 +-
 .../test/fixtures/spec/export-default/expected.js               | 2 +-
 .../test/fixtures/spec/exports/expected.js                      | 2 +-
 .../test/fixtures/spec/reexports/expected.js                    | 2 +-
 6 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
index cda8436c1f19..c38f1b8a5117 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
@@ -6,7 +6,7 @@ module.exports = exports = Object.create(null, {
   }
 });
 
-if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
+if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
     value: "Module"
   });
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
index 2fce7f7d11f0..15eea8814872 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
@@ -6,7 +6,7 @@ module.exports = exports = Object.create(null, {
   }
 });
 
-if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
+if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
     value: "Module"
   });
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
index 4d4f2991cca6..bdc244ee83da 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -6,7 +6,7 @@ module.exports = exports = Object.create(null, {
   }
 });
 
-if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
+if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
     value: "Module"
   });
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index 2e9f228fb494..39985281d780 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -6,7 +6,7 @@ module.exports = exports = Object.create(null, {
   }
 });
 
-if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
+if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
     value: "Module"
   });
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index 2a757b715dc2..1acc32f9801e 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -6,7 +6,7 @@ module.exports = exports = Object.create(null, {
   }
 });
 
-if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
+if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
     value: "Module"
   });
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index 375a1da63039..05394ca5d497 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -6,7 +6,7 @@ module.exports = exports = Object.create(null, {
   }
 });
 
-if (typeof Symbol !== "undefined" && Symbol.toStringTag) {
+if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
     value: "Module"
   });

From ba377a991b6256d5ddd1d2e4d76aa688194e4fc6 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 16:37:26 +0900
Subject: [PATCH 017/103] Try to be nicer to es5-sham

---
 packages/babel-helpers/src/helpers.js                    | 9 ++++++---
 .../src/index.js                                         | 5 +++--
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index dc272edb4e6e..ab33858da99b 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -421,7 +421,7 @@ helpers.specRequireInterop = template(`
     if (obj && obj.__esModule) {
       return obj;
     } else {
-      var newObj = Object.create(null, {
+      var newObj = Object.create ? Object.create(null, {
           default: {
             value: obj,
             writable: true,
@@ -430,11 +430,14 @@ helpers.specRequireInterop = template(`
           __esModule: {
             value: true
           }
-        });
+        }) : {
+          default: obj,
+          __esModule: true
+        };
       if (typeof Symbol === "function" && Symbol.toStringTag) {
         Object.defineProperty(newObj, Symbol.toStringTag, { value: "Module" })
       }
-      return Object.freeze(newObj);
+      return (Object.freeze || Object)(newObj);
     }
   })
 `);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index d9051b8c1f01..2fcec7e83373 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -44,7 +44,7 @@ let buildExportAll = template(`
 `);
 
 const specBuildNamespace = template(`
-  $1 = $0 = Object.create(null, { __esModule: { value: true } });
+  $1 = $0 = Object.create ? Object.create(null, { __esModule: { value: true } }) : { __esModule: true };
   if (typeof Symbol === "function" && Symbol.toStringTag) {
     Object.defineProperty($0, Symbol.toStringTag, { value: "Module" });
   }
@@ -61,6 +61,7 @@ const specBuildExportDefault = template(`
 
 // Unfortunately, regular objects can't synthesize a value descriptor every time they're read,
 // so a getter needs to be used for live bindings.
+// It's also not allowed to specify writable when using getters/setters.
 const specBuildExport = template(`
   Object.defineProperty(EXPORTS, NAME, { enumerable: true, get() { return VALUE; } });
 `);
@@ -92,7 +93,7 @@ const specBuildTempExport = template(`
 `);
 
 const specFinishNamespaceExport = template(`
-  Object.freeze($0);
+  !(Object.freeze || Object)($0);
 `);
 
 const THIS_BREAK_KEYS = ["FunctionExpression", "FunctionDeclaration", "ClassProperty", "ClassMethod", "ObjectMethod"];

From adea1878d462cccd871f4c31eb8c324bfd6d5396 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 16:59:02 +0900
Subject: [PATCH 018/103] Remove unneeded unary negation

---
 .../babel-plugin-transform-es2015-modules-commonjs/src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 2fcec7e83373..545c740310de 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -93,7 +93,7 @@ const specBuildTempExport = template(`
 `);
 
 const specFinishNamespaceExport = template(`
-  !(Object.freeze || Object)($0);
+  (Object.freeze || Object)($0);
 `);
 
 const THIS_BREAK_KEYS = ["FunctionExpression", "FunctionDeclaration", "ClassProperty", "ClassMethod", "ObjectMethod"];

From 62ade301ebc69378a6fe0d944b7b333275d68c78 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 16:59:36 +0900
Subject: [PATCH 019/103] Try to convert access to "global" exports / module
 into TDZ violations

---
 .../src/index.js                              | 67 +++++++++++++------
 1 file changed, 45 insertions(+), 22 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 545c740310de..3a6e2947e343 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -103,10 +103,12 @@ export default function () {
 
   const exportsObj = t.identifier("exports");
   exportsObj[REASSIGN_REMAP_SKIP] = true;
-  const moduleExports = t.memberExpression(t.identifier("module"), exportsObj);
-  moduleExports[REASSIGN_REMAP_SKIP] = true;
+  const moduleObj = t.identifier("module");
+  moduleObj[REASSIGN_REMAP_SKIP] = true;
+  const module = t.memberExpression(moduleObj, exportsObj);
+  module[REASSIGN_REMAP_SKIP] = true;
 
-  const isModuleExports = t.buildMatchMemberExpression("module.exports", true);
+  const isModuleObj = t.buildMatchMemberExpression("module", true);
   const isExports = t.buildMatchMemberExpression("exports", true);
   let commonjsExportsMasked = null;
 
@@ -123,7 +125,7 @@ export default function () {
       if (spec) {
         if (name === "exports" && !path.node[REASSIGN_REMAP_SKIP] &&
           // Apparently replacing "module.exports" still visits the ".exports" here
-          !(this.remaps[".module.exports"] && t.isIdentifier(path.parent, this.remaps[".module.exports"])) &&
+          !(this.remaps[".module"] && t.isIdentifier(path.parent, this.remaps[".module"])) &&
           // Avoid entering when it's just some other object key named export
           !(isExports(path.parent) && t.isMemberExpression(path.parent.parent))) {
           remap = this.remaps[".exports"] = this.remaps[".exports"] || path.scope.generateUidIdentifier("exports");
@@ -131,10 +133,11 @@ export default function () {
           commonjsExportsMasked.exports = remap;
           return;
         }
-        if (isModuleExports(path.parent) && !path.parent[REASSIGN_REMAP_SKIP] && !t.isMemberExpression(path.parent.parent)) {
-          remap = this.remaps[".module.exports"] = this.remaps[".module.exports"] || path.scope.generateUidIdentifier("module.exports");
-          path.parentPath.replaceWith(remap);
-          commonjsExportsMasked.moduleExports = remap;
+        if (name === "module" && !path.node[REASSIGN_REMAP_SKIP] &&
+          !(isModuleObj(path.parent) && !path.parent[REASSIGN_REMAP_SKIP] && !t.isMemberExpression(path.parent.parent))) {
+          remap = this.remaps[".module"] = this.remaps[".module"] || path.scope.generateUidIdentifier("module");
+          path.replaceWith(remap);
+          commonjsExportsMasked.module = remap;
           return;
         }
 
@@ -154,11 +157,34 @@ export default function () {
 
     AssignmentExpression(path, state) {
       if (isSpec(state)) {
-        if (!path.node[REASSIGN_REMAP_SKIP] && t.isIdentifier(path.node.left, { name: "exports" }) &&
-          !path.node.left[REASSIGN_REMAP_SKIP] && this.scope.getBinding(name) === path.scope.getBinding(name)) {
-          let remap = this.remaps[".exports"] = this.remaps[".exports"] || path.scope.generateUidIdentifier("exports");
-          path.get("left").replaceWith(remap);
-          commonjsExportsMasked.exports = remap;
+        if (!path.node[REASSIGN_REMAP_SKIP]) {
+          const target = t.isIdentifier(path.node.left)
+            ? path.node.left
+            : t.isMemberExpression(path.node.left) && t.isIdentifier(path.node.left.object)
+              ? path.node.left.object : null;
+          const name = target && target.name;
+
+          if (target[REASSIGN_REMAP_SKIP] || this.scope.getBinding(name) !== path.scope.getBinding(name)) {
+            return;
+          }
+
+          let remap = null;
+          if (name === "exports") {
+            remap = this.remaps[".exports"] = this.remaps[".exports"] || path.scope.generateUidIdentifier("exports");
+            commonjsExportsMasked.exports = remap;
+          }
+          if (name === "module") {
+            remap = this.remaps[".module"] = this.remaps[".module"] || path.scope.generateUidIdentifier("module");
+            commonjsExportsMasked.module = remap;
+          }
+
+          if (remap) {
+            if (t.isIdentifier(path.node.left)) {
+              path.get("left").replaceWith(remap);
+            } else {
+              path.get("left.object").replaceWith(remap);
+            }
+          }
         }
         return;
       }
@@ -659,7 +685,7 @@ export default function () {
           path.unshiftContainer("body", topNodes);
 
           if (hasExports && spec) {
-            const decls = specBuildNamespace(exportsObj, moduleExports);
+            const decls = specBuildNamespace(exportsObj, module);
             decls.forEach((decl) => { decl._blockHoist = 3; });
 
             path.unshiftContainer("body", decls);
@@ -678,14 +704,11 @@ export default function () {
             requeueInParent: (newPath) => path.requeue(newPath),
           });
 
-          if (spec && (commonjsExportsMasked.exports || commonjsExportsMasked.moduleExports)) {
-            path.unshiftContainer("body", [
-              t.variableDeclaration("var", [
-                commonjsExportsMasked.exports && t.variableDeclarator(commonjsExportsMasked.exports, t.objectExpression([])),
-                commonjsExportsMasked.moduleExports && commonjsExportsMasked.exports &&
-                  t.variableDeclarator(commonjsExportsMasked.moduleExports, commonjsExportsMasked.exports),
-                commonjsExportsMasked.moduleExports && !commonjsExportsMasked.exports &&
-                  t.variableDeclarator(commonjsExportsMasked.moduleExports, t.objectExpression([]))
+          if (spec && (commonjsExportsMasked.exports || commonjsExportsMasked.module)) {
+            path.pushContainer("body", [
+              t.variableDeclaration("let", [
+                commonjsExportsMasked.exports && t.variableDeclarator(commonjsExportsMasked.exports),
+                commonjsExportsMasked.module && t.variableDeclarator(commonjsExportsMasked.module)
               ].filter(Boolean))
             ]);
           }

From 418ee6b0b0fdf8ffc164ba47c927bcde11520941 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 17:00:10 +0900
Subject: [PATCH 020/103] Update fixtures

---
 .../fixtures/spec/commonjs-shadow-1/expected.js   | 11 +++++++----
 .../fixtures/spec/commonjs-shadow-2/expected.js   | 13 +++++++------
 .../fixtures/spec/commonjs-shadow/expected.js     | 15 ++++++++-------
 .../test/fixtures/spec/export-default/expected.js |  8 +++++---
 .../test/fixtures/spec/exports/expected.js        |  8 +++++---
 .../test/fixtures/spec/reexports/expected.js      |  8 +++++---
 6 files changed, 37 insertions(+), 26 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
index c38f1b8a5117..5094128117c9 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
@@ -1,10 +1,12 @@
 "use strict";
 
-module.exports = exports = Object.create(null, {
+module.exports = exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
-});
+}) : {
+  __esModule: true
+};
 
 if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
@@ -12,7 +14,6 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
   });
 }
 
-var _exports = {};
 Object.defineProperty(exports, "default", {
   enumerable: true,
   writable: true,
@@ -23,4 +24,6 @@ Object.defineProperty(exports, "default", {
 
 
 _exports = function () {};
-Object.freeze(exports);
\ No newline at end of file
+(Object.freeze || Object)(exports);
+
+let _exports;
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
index 15eea8814872..24da5d4fa9eb 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
@@ -1,10 +1,12 @@
 "use strict";
 
-module.exports = exports = Object.create(null, {
+module.exports = exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
-});
+}) : {
+  __esModule: true
+};
 
 if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
@@ -12,8 +14,7 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
   });
 }
 
-var _moduleExports = {};
+_module.exports = class {};
+(Object.freeze || Object)(exports);
 
-
-_moduleExports = class {};
-Object.freeze(exports);
\ No newline at end of file
+let _module;
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
index bdc244ee83da..b982216b3c58 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -1,10 +1,12 @@
 'use strict';
 
-module.exports = exports = Object.create(null, {
+module.exports = exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
-});
+}) : {
+  __esModule: true
+};
 
 if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
@@ -12,9 +14,6 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
   });
 }
 
-var _exports = {},
-    _moduleExports = _exports;
-
 var _bar = babelHelpers.specRequireInterop(require('bar'));
 
 Object.defineProperty(exports, "default", {
@@ -28,5 +27,7 @@ Object.defineProperty(exports, "default", {
 
 // neither of these should be able to use or affect the real exports
 new _exports.default();
-_moduleExports = {};
-Object.freeze(exports);
\ No newline at end of file
+_module.exports = {};
+(Object.freeze || Object)(exports);
+
+let _exports, _module;
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index 39985281d780..f720708f0bc5 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -1,10 +1,12 @@
 "use strict";
 
-module.exports = exports = Object.create(null, {
+module.exports = exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
-});
+}) : {
+  __esModule: true
+};
 
 if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
@@ -29,4 +31,4 @@ Object.defineProperty(exports, "unrelated", {
 
 });
 unrelated = "changed";
-Object.freeze(exports);
\ No newline at end of file
+(Object.freeze || Object)(exports);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index 1acc32f9801e..ede8a080c456 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -1,10 +1,12 @@
 "use strict";
 
-module.exports = exports = Object.create(null, {
+module.exports = exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
-});
+}) : {
+  __esModule: true
+};
 
 if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
@@ -66,4 +68,4 @@ Object.defineProperty(exports, "baz", {
   }
 
 });
-Object.freeze(exports);
\ No newline at end of file
+(Object.freeze || Object)(exports);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index 05394ca5d497..77cad80b471b 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -1,10 +1,12 @@
 'use strict';
 
-module.exports = exports = Object.create(null, {
+module.exports = exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
-});
+}) : {
+  __esModule: true
+};
 
 if (typeof Symbol === "function" && Symbol.toStringTag) {
   Object.defineProperty(exports, Symbol.toStringTag, {
@@ -65,4 +67,4 @@ Object.defineProperty(exports, 'default', {
   }
 
 });
-Object.freeze(exports);
\ No newline at end of file
+(Object.freeze || Object)(exports);
\ No newline at end of file

From 4afaba85da28e9e3237eba05001856cdbed033e8 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Fri, 9 Dec 2016 17:18:57 +0900
Subject: [PATCH 021/103] Add moduleSpec option to preset-es2015

Mostly for testing interaction of the transform with other es2015
plugins.
---
 packages/babel-preset-es2015/src/index.js     | 21 +++++++------
 .../modules-commonjs-spec/actual.js           |  2 ++
 .../modules-commonjs-spec/expected.js         | 31 +++++++++++++++++++
 .../modules-commonjs-spec/options.json        |  5 +++
 4 files changed, 49 insertions(+), 10 deletions(-)
 create mode 100644 packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/actual.js
 create mode 100644 packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
 create mode 100644 packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/options.json

diff --git a/packages/babel-preset-es2015/src/index.js b/packages/babel-preset-es2015/src/index.js
index 57d96082d120..721ec43d291c 100644
--- a/packages/babel-preset-es2015/src/index.js
+++ b/packages/babel-preset-es2015/src/index.js
@@ -33,22 +33,23 @@ import transformRegenerator from "babel-plugin-transform-regenerator";
 
 function preset(context, opts = {}) {
   const moduleTypes = ["commonjs", "amd", "umd", "systemjs"];
-  let loose = false;
-  let modules = "commonjs";
-  let spec = false;
-
-  if (opts !== undefined) {
-    if (opts.loose !== undefined) loose = opts.loose;
-    if (opts.modules !== undefined) modules = opts.modules;
-    if (opts.spec !== undefined) spec = opts.spec;
-  }
+  const {
+    loose = false,
+    modules = "commonjs",
+    spec = false,
+    moduleSpec = false
+  } = opts;
 
   if (typeof loose !== "boolean") throw new Error("Preset es2015 'loose' option must be a boolean.");
   if (typeof spec !== "boolean") throw new Error("Preset es2015 'spec' option must be a boolean.");
+  if (typeof moduleSpec !== "boolean") throw new Error("Preset es2015 'moduleSpec' option must be a boolean.");
   if (modules !== false && moduleTypes.indexOf(modules) === -1) {
     throw new Error("Preset es2015 'modules' option must be 'false' to indicate no modules\n" +
       "or a module type which be be one of: 'commonjs' (default), 'amd', 'umd', 'systemjs'");
   }
+  if (moduleSpec !== false && (modules !== false || modules !== "commonjs")) {
+    throw new Error("The 'moduleSpec' option is only supported with 'commonjs' modules");
+  }
 
   // be DRY
   const optsLoose = { loose };
@@ -74,7 +75,7 @@ function preset(context, opts = {}) {
       [transformES2015Destructuring, optsLoose],
       transformES2015BlockScoping,
       transformES2015TypeofSymbol,
-      modules === "commonjs" && [transformES2015ModulesCommonJS, optsLoose],
+      modules === "commonjs" && [transformES2015ModulesCommonJS, { loose, spec: moduleSpec }],
       modules === "systemjs" && [transformES2015ModulesSystemJS, optsLoose],
       modules === "amd" && [transformES2015ModulesAMD, optsLoose],
       modules === "umd" && [transformES2015ModulesUMD, optsLoose],
diff --git a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/actual.js b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/actual.js
new file mode 100644
index 000000000000..c3c69a6e6961
--- /dev/null
+++ b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/actual.js
@@ -0,0 +1,2 @@
+export default function () {}
+export function b () {}
diff --git a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
new file mode 100644
index 000000000000..7f834879d42a
--- /dev/null
+++ b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
@@ -0,0 +1,31 @@
+"use strict";
+
+module.exports = exports = Object.create ? Object.create(null, {
+  __esModule: {
+    value: true
+  }
+}) : {
+  __esModule: true
+};
+
+if (typeof Symbol === "function" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+Object.defineProperty(exports, "default", {
+  enumerable: true,
+  writable: true,
+  value: {
+    default: function _default() {}
+  }.default
+});
+Object.defineProperty(exports, "b", {
+  enumerable: true,
+  get: function get() {
+    return b;
+  }
+});
+function b() {}
+(Object.freeze || Object)(exports);
\ No newline at end of file
diff --git a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/options.json b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/options.json
new file mode 100644
index 000000000000..68b24a409796
--- /dev/null
+++ b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/options.json
@@ -0,0 +1,5 @@
+{
+  "presets": [
+    ["es2015", { "modules": "commonjs", "moduleSpec": true }]
+  ]
+}

From ad9fc26553c343a38cc7660a8c7e791ad581c914 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 00:48:53 +0900
Subject: [PATCH 022/103] Correct logic error

---
 packages/babel-preset-es2015/src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-preset-es2015/src/index.js b/packages/babel-preset-es2015/src/index.js
index 721ec43d291c..e7892f970a8d 100644
--- a/packages/babel-preset-es2015/src/index.js
+++ b/packages/babel-preset-es2015/src/index.js
@@ -47,7 +47,7 @@ function preset(context, opts = {}) {
     throw new Error("Preset es2015 'modules' option must be 'false' to indicate no modules\n" +
       "or a module type which be be one of: 'commonjs' (default), 'amd', 'umd', 'systemjs'");
   }
-  if (moduleSpec !== false && (modules !== false || modules !== "commonjs")) {
+  if (moduleSpec !== false && (modules !== false && modules !== "commonjs")) {
     throw new Error("The 'moduleSpec' option is only supported with 'commonjs' modules");
   }
 

From b37066feac0c0457166c6c98cb416cdbec8d1b74 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 02:22:09 +0900
Subject: [PATCH 023/103] Use getter on default export of named class or
 function

If they're named, they can be modified, so the binding has to be kept
live.
---
 .../src/index.js                              |  9 ++++--
 .../spec/export-default-named/actual.js       |  1 +
 .../spec/export-default-named/expected.js     | 28 +++++++++++++++++++
 3 files changed, 36 insertions(+), 2 deletions(-)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 3a6e2947e343..b18865a963d5 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -385,7 +385,10 @@ export default function () {
                 let defNode = t.identifier("default");
                 if (id) {
                   addTo(exports, id.name, defNode);
-                  topNodes.push(spec ? specBuildExportDefault({ EXPORTS: exportsObj, VALUE: id }) : buildExportsAssignment(defNode, id));
+                  topNodes.push(spec
+                    ? specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral("default"), VALUE: id })
+                    : buildExportsAssignment(defNode, id)
+                  );
                   path.replaceWith(declaration.node);
                 } else if (spec) {
                   const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
@@ -403,7 +406,9 @@ export default function () {
                   addTo(exports, id.name, defNode);
                   path.replaceWithMultiple([
                     declaration.node,
-                    spec ? specBuildExportDefault({ EXPORTS: exportsObj, VALUE: id }) : buildExportsAssignment(defNode, id)
+                    spec
+                      ? specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral("default"), VALUE: id })
+                      : buildExportsAssignment(defNode, id)
                   ]);
                 } else if (spec) {
                   const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/actual.js
new file mode 100644
index 000000000000..9cecd735acaf
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/actual.js
@@ -0,0 +1 @@
+export default function named () { named = function () {} }
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js
new file mode 100644
index 000000000000..828c2c40e315
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js
@@ -0,0 +1,28 @@
+"use strict";
+
+module.exports = exports = Object.create ? Object.create(null, {
+  __esModule: {
+    value: true
+  }
+}) : {
+  __esModule: true
+};
+
+if (typeof Symbol === "function" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+Object.defineProperty(exports, "default", {
+  enumerable: true,
+
+  get() {
+    return named;
+  }
+
+});
+function named() {
+  named = function () {};
+}
+(Object.freeze || Object)(exports);
\ No newline at end of file

From cf7a7e4e422b83e54e67db4062fb812de13883d8 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 02:23:11 +0900
Subject: [PATCH 024/103] Add an easy to read import test case with all import
 forms

---
 .../test/fixtures/spec/import-simple/actual.js    |  9 +++++++++
 .../test/fixtures/spec/import-simple/expected.js  | 15 +++++++++++++++
 2 files changed, 24 insertions(+)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/actual.js
new file mode 100644
index 000000000000..c9e476c2a46e
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/actual.js
@@ -0,0 +1,9 @@
+import 'a';
+import {} from 'b';
+import * as ns from 'c';
+import d from 'd'
+import {name} from 'e';
+
+ns.name;
+d;
+name;
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
new file mode 100644
index 000000000000..3aba3f2fdee8
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
@@ -0,0 +1,15 @@
+'use strict';
+
+require('a');
+
+require('b');
+
+var _c = babelHelpers.specRequireInterop(require('c'));
+
+var _d = babelHelpers.specRequireInterop(require('d'));
+
+var _e = babelHelpers.specRequireInterop(require('e'));
+
+_c.name;
+_d.default;
+_e.name;
\ No newline at end of file

From 0efc4386866198c211f83e0bbcf73482117ea67a Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 03:36:24 +0900
Subject: [PATCH 025/103] Add a test that actually executes the module body and
 inspects the exprots

---
 .../test/spec-import.js                       | 93 +++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import.js
new file mode 100644
index 000000000000..2cf16b41ac81
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import.js
@@ -0,0 +1,93 @@
+const assert = require("assert");
+const babel = require("../../babel-core");
+const vm = require("vm");
+
+test("spec Interop import", function () {
+  const src = "import * as ns from 'fs'\nimport fs from 'fs'\nexport { fs, ns }\n";
+
+  const fakeMod = { "fakeFs": true };
+  const context = {
+    module: {
+      exports: {}
+    },
+    require: function (id) {
+      if (id === "fs") return fakeMod;
+      throw new Error("Unmocked module " + id + " required");
+    }
+  };
+  context.exports = context.module.exports;
+
+  const code = babel.transform(src, {
+    "plugins": [
+      [require("../"), {spec: true}],
+    ],
+    "ast": false,
+  }).code;
+
+  vm.runInNewContext(code, context);
+
+  const exports = context.module.exports;
+
+  assert(Object.isFrozen(exports), "exports is frozen");
+  assert.strictEqual(Object.getPrototypeOf(exports), null, "exports has null prototype");
+
+  if (typeof Symbol === "function" && Symbol.toStringTag) {
+    assert.strictEqual(exports[Symbol.toStringTag], "Module", "exports is tagged as Module");
+  }
+
+  assert.deepStrictEqual(
+    Object.getOwnPropertyDescriptor(exports, "__esModule"),
+    { value: true, configurable: false, writable: false, enumerable: false },
+    "__esModule in top level Module"
+  );
+
+  const nsDesc = Object.getOwnPropertyDescriptor(exports, "ns");
+
+  assert(nsDesc.enumerable, "ns export is enumerable");
+  // This should be the actual observable behavior, but freezing the export
+  // makes this change to false.
+  // // assert(nsDesc.writable, "ns export is writable");
+  assert(!nsDesc.writable, "ns export happens to not be writable");
+  assert(!nsDesc.configurable,"ns export is not configurable");
+
+  const fsDesc = Object.getOwnPropertyDescriptor(exports, "fs");
+
+  assert(fsDesc.enumerable, "fs export is enumerable");
+  // fsDesc.writable cannot be true like the spec asks because...
+  // // assert.strictEqual(fsDesc.writable, true);
+  // ...fsDesc.get must be provided (and be a function)
+  assert.strictEqual(typeof fsDesc.get, "function", "fs export is a getter");
+  assert(!fsDesc.configurable, "fs export is not configurable");
+
+  const ns = exports.ns;
+
+  assert.deepStrictEqual(
+    Object.getOwnPropertyDescriptor(ns, "__esModule"),
+    { value: true, configurable: false, writable: false, enumerable: false },
+    "__esModule in the imported ns Module"
+  );
+
+  assert(Object.isFrozen(ns), "ns export is frozen");
+  assert.strictEqual(Object.getPrototypeOf(ns), null, "ns export has null prototype");
+
+  if (typeof Symbol === "function" && Symbol.toStringTag) {
+    assert.strictEqual(ns[Symbol.toStringTag], "Module", "ns export is tagged as Module");
+  }
+
+  const imported = Object.getOwnPropertyNames(ns).filter(function (name) { return name !== "__esModule"; });
+
+  assert.deepStrictEqual(imported, [ "default" ], "No exports other than 'default' in ns Module");
+
+  const defaultDesc = Object.getOwnPropertyDescriptor(ns, "default");
+
+  assert.strictEqual(defaultDesc.enumerable, true, "ns.default export is enumerable");
+  // This is also not writable for the same reason nsDesc.writable was false
+  // // assert.strictEqual(defaultDesc.writable, true, "ns.default export is writable");
+  assert.strictEqual(defaultDesc.writable, false, "ns export happens to not be writable");
+  assert.strictEqual(defaultDesc.configurable, false, "ns.default export is configurable");
+  assert.strictEqual("value" in defaultDesc, true, "ns.default export has a value");
+
+  assert(!("__esModule" in ns.default), "ns.default export is not a Module");
+  assert.strictEqual(ns.default, fakeMod, "ns.default export is the commonjs namespace");
+  assert.strictEqual(exports.fs, fakeMod, "fs reexport is the commonjs namespace");
+});

From ebfb27487e7df8ab9ec10c8e245f1682a47cfaed Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 03:37:43 +0900
Subject: [PATCH 026/103] Correct bugs found by the runtime test

---
 .../src/index.js                                           | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index b18865a963d5..abbb27b21f59 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -44,7 +44,7 @@ let buildExportAll = template(`
 `);
 
 const specBuildNamespace = template(`
-  $1 = $0 = Object.create ? Object.create(null, { __esModule: { value: true } }) : { __esModule: true };
+  const $0 = $1 = Object.create ? Object.create(null, { __esModule: { value: true } }) : { __esModule: true };
   if (typeof Symbol === "function" && Symbol.toStringTag) {
     Object.defineProperty($0, Symbol.toStringTag, { value: "Module" });
   }
@@ -82,8 +82,11 @@ const specBuildNamespaceSpread = template(`
   });
 `);
 
+// It should _not_ be configurable, but this is needed as referring to
+// the real export, even with a getter, may cause DMZ errors with circular
+// references.
 const specBuildTempExportDescriptor = template(`
-  const $0 = { enumerable: true, writable: true, value: undefined };
+  const $0 = { enumerable: true, writable: true, configurable: true, value: undefined };
 `);
 
 const specBuildTempExportProperty = (id, descriptorId) => t.objectProperty(id, descriptorId);

From c083987e89966e5c6a0613ee8846266eb4cc5d34 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 03:38:56 +0900
Subject: [PATCH 027/103] Update fixtures

---
 .../test/fixtures/spec/commonjs-shadow-1/expected.js           | 2 +-
 .../test/fixtures/spec/commonjs-shadow-2/expected.js           | 2 +-
 .../test/fixtures/spec/commonjs-shadow/expected.js             | 2 +-
 .../test/fixtures/spec/export-default-named/expected.js        | 2 +-
 .../test/fixtures/spec/export-default/expected.js              | 2 +-
 .../test/fixtures/spec/exports/expected.js                     | 3 ++-
 .../test/fixtures/spec/reexports/expected.js                   | 3 ++-
 7 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
index 5094128117c9..619d54bcfa6b 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-module.exports = exports = Object.create ? Object.create(null, {
+const exports = module.exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
index 24da5d4fa9eb..d208a7611eab 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-module.exports = exports = Object.create ? Object.create(null, {
+const exports = module.exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
index b982216b3c58..c3bad22fa1ff 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -1,6 +1,6 @@
 'use strict';
 
-module.exports = exports = Object.create ? Object.create(null, {
+const exports = module.exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js
index 828c2c40e315..45dc5d88fb26 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-module.exports = exports = Object.create ? Object.create(null, {
+const exports = module.exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index f720708f0bc5..3deadbfc2cd6 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-module.exports = exports = Object.create ? Object.create(null, {
+const exports = module.exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index ede8a080c456..7813011a89a6 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-module.exports = exports = Object.create ? Object.create(null, {
+const exports = module.exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
@@ -17,6 +17,7 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
 const _undefined = {
   enumerable: true,
   writable: true,
+  configurable: true,
   value: undefined
 };
 Object.defineProperties(exports, {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index 77cad80b471b..633ea62e6220 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -1,6 +1,6 @@
 'use strict';
 
-module.exports = exports = Object.create ? Object.create(null, {
+const exports = module.exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }
@@ -17,6 +17,7 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
 const _undefined = {
   enumerable: true,
   writable: true,
+  configurable: true,
   value: undefined
 };
 Object.defineProperties(exports, {

From 0c2bd667d60f83eb0a0993986d6cdac1406475db Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 16:04:38 +0900
Subject: [PATCH 028/103] Missing fixture update

---
 .../fixtures/preset-options/modules-commonjs-spec/expected.js   | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
index 7f834879d42a..e2156380ac58 100644
--- a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
+++ b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-module.exports = exports = Object.create ? Object.create(null, {
+var exports = module.exports = Object.create ? Object.create(null, {
   __esModule: {
     value: true
   }

From 6fd580d0862b8a61ac07bcc4850948e3e0620bed Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 16:33:26 +0900
Subject: [PATCH 029/103] Add (failing) reexport runtime tests

---
 .../test/spec-reexport.js                     | 63 +++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
new file mode 100644
index 000000000000..db90935dc033
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
@@ -0,0 +1,63 @@
+"use strict";
+
+const assert = require("assert");
+const babel = require("../../babel-core");
+const vm = require("vm");
+
+describe("spec star reexport", function () {
+  const modules = {
+    a: "export const name = {key: 'value'}",
+    b: "export const name = {key: 'value'}",
+    aSame: "export const name = 'name'",
+    bSame: "export const name = 'name'"
+  };
+
+  const cached = {};
+
+  function makeContext () {
+    const context = { module: { exports: {} }, require: contextRequire };
+    context.exports = context.module.exports;
+    return context;
+  }
+
+  function transformAndRunInNewContext (code, context) {
+    if (typeof context === "undefined") {
+      context = makeContext();
+    }
+
+    code = babel.transform(code, {
+      "plugins": [
+        [require("../"), {spec: true}],
+      ],
+      "ast": false,
+    }).code;
+    vm.runInNewContext(code, context);
+
+    return context.module.exports;
+  }
+
+  function contextRequire (id) {
+    if (id in modules) {
+      if (!cached[id]) {
+        cached[id] = makeContext();
+        transformAndRunInNewContext(modules[id], cached[id]);
+      }
+      return cached[id].module.exports;
+    }
+    throw new Error("Unmocked module " + id + " required");
+  }
+
+  it("throws when not shadowed and duplicate is not SameValue", function () {
+    assert.throws(function () {
+      transformAndRunInNewContext("export * from 'a'\nexport * from 'b'");
+    });
+  });
+
+  it("does not throw when not shadowed but is SameValue", function () {
+    transformAndRunInNewContext("export * from 'aSame'\nexport * from 'bSame'");
+  });
+
+  it("does not throw when shadowed even if it is not SameValue", function () {
+    transformAndRunInNewContext("export * from 'a'\nexport * from 'b'\nexport const name = {}");
+  });
+});

From 2e0f7402784ac4b358a15cb06059f62d02690e3d Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 18:01:44 +0900
Subject: [PATCH 030/103] Hoist all exports in spec mode, avoid name clashes on
 star reexport

---
 .../src/index.js                              | 187 ++++++++++--------
 1 file changed, 108 insertions(+), 79 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index abbb27b21f59..6e789b51f120 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -66,13 +66,14 @@ const specBuildExport = template(`
   Object.defineProperty(EXPORTS, NAME, { enumerable: true, get() { return VALUE; } });
 `);
 
-const specBuildNamespaceReexport = template(`
-  Object.defineProperty(EXPORTS, NAME, { enumerable: true, writable: true, value: VALUE });
+const specBuildOwnExports = template(`
+  const $0 = Object.keys($1)
 `);
 
 const specBuildNamespaceSpread = template(`
   Object.keys(OBJECT).forEach(function (key) {
-    if (key === "default" || key === "__esModule") return;
+    if (key === "__esModule" || key === "default" || OWN_EXPORTS.indexOf(key) >= 0) return;
+    if (key in EXPORTS && (EXPORTS[key] === OBJECT[key] || typeof EXPORTS[key] === 'number' && isNaN(EXPORTS[key]))) return;
     Object.defineProperty(EXPORTS, key, {
       enumerable: true,
       get() {
@@ -85,13 +86,14 @@ const specBuildNamespaceSpread = template(`
 // It should _not_ be configurable, but this is needed as referring to
 // the real export, even with a getter, may cause DMZ errors with circular
 // references.
-const specBuildTempExportDescriptor = template(`
-  const $0 = { enumerable: true, writable: true, configurable: true, value: undefined };
+const specBuildHoistedExportDescriptor = template(`
+  ({ enumerable: true, get() { return $0; } })
 `);
 
-const specBuildTempExportProperty = (id, descriptorId) => t.objectProperty(id, descriptorId);
+const specBuildHoistedExportProperty = (id, descriptorId) =>
+  t.objectProperty(id, specBuildHoistedExportDescriptor(descriptorId).expression);
 
-const specBuildTempExport = template(`
+const specBuildHoistedExport = template(`
   Object.defineProperties($0, $1);
 `);
 
@@ -297,7 +299,9 @@ export default function () {
 
           let topNodes = [];
           let remaps = Object.create(null);
-          const namespaceImports = new Set();
+
+          const hoistedExports = spec && new Map();
+          let ownExportsUid = null;
 
           let requires = Object.create(null);
 
@@ -364,13 +368,6 @@ export default function () {
 
               importsEntry.specifiers.push(...path.node.specifiers);
 
-              if (spec) {
-                path.node.specifiers
-                .filter((s) => t.isImportNamespaceSpecifier(s))
-                .map((specifier) => specifier.local.name)
-                .forEach((name) => { namespaceImports.add(name); });
-              }
-
               if (typeof path.node._blockHoist === "number") {
                 importsEntry.maxBlockHoist = Math.max(
                   path.node._blockHoist,
@@ -382,18 +379,24 @@ export default function () {
 
               path.remove();
             } else if (path.isExportDefaultDeclaration()) {
+              if (spec && hoistedExports.has("default")) {
+                let todo;
+              }
+
               let declaration = path.get("declaration");
               if (declaration.isFunctionDeclaration()) {
                 let id = declaration.node.id;
                 let defNode = t.identifier("default");
                 if (id) {
                   addTo(exports, id.name, defNode);
-                  topNodes.push(spec
-                    ? specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral("default"), VALUE: id })
-                    : buildExportsAssignment(defNode, id)
-                  );
+                  if (spec) {
+                    hoistedExports.set("default", id);
+                  } else {
+                    topNodes.push(spec, buildExportsAssignment(defNode, id));
+                  }
                   path.replaceWith(declaration.node);
                 } else if (spec) {
+                  hoistedExports.set("default", null);
                   const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
                   topNodes.push(specBuildExportDefault({ EXPORTS: exportsObj, VALUE: expr }));
                   path.remove();
@@ -407,13 +410,18 @@ export default function () {
                 let defNode = t.identifier("default");
                 if (id) {
                   addTo(exports, id.name, defNode);
-                  path.replaceWithMultiple([
-                    declaration.node,
-                    spec
-                      ? specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral("default"), VALUE: id })
-                      : buildExportsAssignment(defNode, id)
-                  ]);
+                  if (spec) {
+                    hoistedExports.set("default", id);
+                    path.replaceWith(declaration.node);
+                  } else {
+                    path.replaceWithMultiple([
+                      declaration.node,
+                      buildExportsAssignment(defNode, id)
+                    ]);
+                  }
                 } else if (spec) {
+                  hoistedExports.set("default", null);
+
                   const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
                   path.replaceWith(specBuildExportDefault({ EXPORTS: exportsObj, VALUE: expr }));
 
@@ -433,6 +441,7 @@ export default function () {
               } else {
                 const defNode = t.identifier("default");
                 if (spec) {
+                  hoistedExports.set("default", null);
                   path.replaceWith(specBuildExportDefault({ EXPORTS: exportsObj, VALUE: declaration.node }));
 
                   // Manually re-queue the expression so other transforms can get to it.
@@ -454,35 +463,45 @@ export default function () {
                 if (declaration.isFunctionDeclaration()) {
                   let id = declaration.node.id;
                   addTo(exports, id.name, id);
-                  topNodes.push(spec
-                    ? specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral(id.name), VALUE: id })
-                    : buildExportsAssignment(id, id));
+                  if (spec) {
+                    if (hoistedExports.has(id.name)) {
+                      let todo;
+                    }
+                    hoistedExports.set(id.name, id);
+                  } else {
+                    topNodes.push(buildExportsAssignment(id, id));
+                  }
                   path.replaceWith(declaration.node);
                 } else if (declaration.isClassDeclaration()) {
                   let id = declaration.node.id;
                   addTo(exports, id.name, id);
-                  path.replaceWithMultiple([
-                    declaration.node,
-                    spec
-                    ? specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral(id.name), VALUE: id })
-                    : buildExportsAssignment(id, id)
-                  ]);
-                  nonHoistedExportNames[id.name] = true;
+                  if (spec) {
+                    if (hoistedExports.has(id.name)) {
+                      let todo;
+                    }
+                    hoistedExports.set(id.name, id);
+                    path.replaceWith(declaration.node);
+                  } else {
+                    path.replaceWithMultiple([
+                      declaration.node,
+                      buildExportsAssignment(id, id)
+                    ]);
+                    nonHoistedExportNames[id.name] = true;
+                  }
                 } else if (declaration.isVariableDeclaration()) {
                   let declarators = declaration.get("declarations");
                   const toExport = spec && new Set();
                   for (let decl of declarators) {
                     let id = decl.get("id");
 
-                    let init = decl.get("init");
-                    if (!init.node) init.replaceWith(t.identifier("undefined"));
-
                     if (spec) {
                       toExport.add(id.node);
-                      nonHoistedExportNames[id.node.name] = true;
                       continue;
                     }
 
+                    let init = decl.get("init");
+                    if (!init.node) init.replaceWith(t.identifier("undefined"));
+
                     if (id.isIdentifier()) {
                       addTo(exports, id.node.name, id.node);
                       if (spec) {
@@ -495,16 +514,14 @@ export default function () {
                     }
                   }
                   if (spec) {
-                    path.replaceWithMultiple([
-                      declaration.node
-                    ].concat(
-                      Array.from(toExport)
-                      .map((id) => specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral(id.name), VALUE: id}))
-                    )
-                  );
-                  } else {
-                    path.replaceWith(declaration.node);
+                    Array.from(toExport).forEach((id) => {
+                      if (hoistedExports.has(id.name)) {
+                        let todo;
+                      }
+                      hoistedExports.set(id.name, id);
+                    });
                   }
+                  path.replaceWith(declaration.node);
                 }
                 continue;
               }
@@ -522,7 +539,10 @@ export default function () {
                     // todo
                   } else if (specifier.isExportSpecifier()) {
                     if (spec) {
-                      topNodes.push(specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral(specifier.node.exported.name), VALUE: t.memberExpression(ref, specifier.node.local) }));
+                      if (hoistedExports.has(specifier.node.exported.name)) {
+                        let todo;
+                      }
+                      hoistedExports.set(specifier.node.exported.name, t.memberExpression(ref, specifier.node.local));
                     } else if (specifier.node.local.name === "default") {
                       topNodes.push(buildExportsFrom(t.stringLiteral(specifier.node.exported.name), t.memberExpression(t.callExpression(this.addHelper("interopRequireDefault"), [ref]), specifier.node.local)));
                     } else {
@@ -538,12 +558,10 @@ export default function () {
                     nonHoistedExportNames[specifier.node.exported.name] = true;
 
                     if (spec) {
-                      if (namespaceImports.has(specifier.node.local.name)) {
-                        // it's a namespace, doesn't go through a getter, safe to reexport as a value
-                        nodes.push(specBuildNamespaceReexport({ EXPORTS: exportsObj, NAME: t.stringLiteral(specifier.node.exported.name), VALUE: specifier.node.local }));
-                      } else {
-                        nodes.push(specBuildExport({ EXPORTS: exportsObj, NAME: t.stringLiteral(specifier.node.exported.name), VALUE: specifier.node.local }));
+                      if (hoistedExports.has(specifier.node.exported.name)) {
+                        let todo;
                       }
+                      hoistedExports.set(specifier.node.exported.name, specifier.node.local);
                     } else {
                       nodes.push(buildExportsAssignment(specifier.node.exported, specifier.node.local));
                     }
@@ -552,14 +570,24 @@ export default function () {
               }
               path.replaceWithMultiple(nodes);
             } else if (path.isExportAllDeclaration()) {
-              let exportNode = spec
-                ? specBuildNamespaceSpread({
+              let exportNode;
+              if (spec) {
+                if (ownExportsUid == null) {
+                  ownExportsUid = path.scope.generateUidIdentifier("ownExports");
+                  const ownExportsNode = specBuildOwnExports(ownExportsUid, exportsObj);
+                  topNodes.push(ownExportsNode);
+                }
+
+                exportNode = specBuildNamespaceSpread({
                   EXPORTS: exportsObj,
+                  OWN_EXPORTS: ownExportsUid,
                   OBJECT: addRequire(path.node.source.value, spec, path.node._blockHoist)
-                })
-                : buildExportAll({
+                });
+              } else {
+                exportNode = buildExportAll({
                   OBJECT: addRequire(path.node.source.value, spec, path.node._blockHoist)
                 });
+              }
               exportNode.loc = path.node.loc;
               topNodes.push(exportNode);
               path.remove();
@@ -649,34 +677,35 @@ export default function () {
             }
           }
 
-          if (hasImports && Object.keys(nonHoistedExportNames).length) {
-            let hoistedExportsNode = t.identifier("undefined");
+          if (spec) {
+            const entries = Array.from(hoistedExports.entries()).map(([name, id]) => {
+              if (name === "default" && id === null) {
+                // explicit export is generated
+                return;
+              }
+              return specBuildHoistedExportProperty(t.identifier(name), id);
+            }).filter(Boolean);
 
-            if (spec) {
-              const descId = path.scope.generateUidIdentifier("undefined");
-              const desc = specBuildTempExportDescriptor(descId);
-              desc._blockHoist = 3;
-
-              const expr = t.objectExpression(
-                Object.keys(nonHoistedExportNames).map((name) =>
-                  specBuildTempExportProperty(t.identifier(name), descId)
-                )
-              );
-              const node = specBuildTempExport(exportsObj, expr);
+            if (entries.length > 0) {
+              const expr = t.objectExpression(entries);
+              const node = specBuildHoistedExport(exportsObj, expr);
               node._blockHoist = 3;
 
               topNodes.unshift(node);
-              topNodes.unshift(desc);
-            } else {
-              for (let name in nonHoistedExportNames) {
-                hoistedExportsNode = buildExportsAssignment(t.identifier(name), hoistedExportsNode).expression;
-              }
+            }
+          }
 
-              const node = t.expressionStatement(hoistedExportsNode);
-              node._blockHoist = 3;
+          if (!spec && hasImports && Object.keys(nonHoistedExportNames).length) {
+            let hoistedExportsNode = t.identifier("undefined");
 
-              topNodes.unshift(node);
+            for (let name in nonHoistedExportNames) {
+              hoistedExportsNode = buildExportsAssignment(t.identifier(name), hoistedExportsNode).expression;
             }
+
+            const node = t.expressionStatement(hoistedExportsNode);
+            node._blockHoist = 3;
+
+            topNodes.unshift(node);
           }
 
           // add __esModule declaration if this file has any exports

From c428c522dfab74c220fa7ba8359d5c8d2b0ee5b8 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 18:02:48 +0900
Subject: [PATCH 031/103] Update fixtures

---
 .../spec/export-default-named/expected.js     | 12 ++--
 .../fixtures/spec/export-default/expected.js  | 20 +++---
 .../test/fixtures/spec/exports/expected.js    | 69 ++++++++-----------
 .../test/fixtures/spec/reexports/expected.js  | 60 ++++++++--------
 4 files changed, 76 insertions(+), 85 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js
index 45dc5d88fb26..9bd50067ab04 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js
@@ -14,13 +14,15 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
   });
 }
 
-Object.defineProperty(exports, "default", {
-  enumerable: true,
+Object.defineProperties(exports, {
+  default: {
+    enumerable: true,
 
-  get() {
-    return named;
-  }
+    get() {
+      return named;
+    }
 
+  }
 });
 function named() {
   named = function () {};
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index 3deadbfc2cd6..3e2fb6e77433 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -14,6 +14,16 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
   });
 }
 
+Object.defineProperties(exports, {
+  unrelated: {
+    enumerable: true,
+
+    get() {
+      return unrelated;
+    }
+
+  }
+});
 Object.defineProperty(exports, "default", {
   enumerable: true,
   writable: true,
@@ -21,14 +31,6 @@ Object.defineProperty(exports, "default", {
     default: function () {}
   }.default
 });
-var unrelated = undefined;
-Object.defineProperty(exports, "unrelated", {
-  enumerable: true,
-
-  get() {
-    return unrelated;
-  }
-
-});
+var unrelated;
 unrelated = "changed";
 (Object.freeze || Object)(exports);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index 7813011a89a6..c85c8a9232cb 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -14,37 +14,44 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
   });
 }
 
-const _undefined = {
-  enumerable: true,
-  writable: true,
-  configurable: true,
-  value: undefined
-};
 Object.defineProperties(exports, {
-  default: _undefined,
-  Bar: _undefined,
-  baz: _undefined
-});
-Object.defineProperty(exports, "foo", {
-  enumerable: true,
+  default: {
+    enumerable: true,
 
-  get() {
-    return foo;
-  }
+    get() {
+      return def;
+    }
 
-});
+  },
+  foo: {
+    enumerable: true,
 
-var _outside = babelHelpers.specRequireInterop(require("outside"));
+    get() {
+      return foo;
+    }
 
-var def;
-Object.defineProperty(exports, "default", {
-  enumerable: true,
+  },
+  Bar: {
+    enumerable: true,
 
-  get() {
-    return def;
-  }
+    get() {
+      return Bar;
+    }
+
+  },
+  baz: {
+    enumerable: true,
+
+    get() {
+      return baz;
+    }
 
+  }
 });
+
+var _outside = babelHelpers.specRequireInterop(require("outside"));
+
+var def;
 function foo() {
   def = "export mutation";
   return "foo";
@@ -52,21 +59,5 @@ function foo() {
 
 class Bar {}
 
-Object.defineProperty(exports, "Bar", {
-  enumerable: true,
-
-  get() {
-    return Bar;
-  }
-
-});
 const baz = foo();
-Object.defineProperty(exports, "baz", {
-  enumerable: true,
-
-  get() {
-    return baz;
-  }
-
-});
 (Object.freeze || Object)(exports);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index 633ea62e6220..8191934da8bf 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -14,22 +14,40 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
   });
 }
 
-const _undefined = {
-  enumerable: true,
-  writable: true,
-  configurable: true,
-  value: undefined
-};
 Object.defineProperties(exports, {
-  namespace: _undefined,
-  default: _undefined,
-  why: _undefined
+  namespace: {
+    enumerable: true,
+
+    get() {
+      return _somewhere;
+    }
+
+  },
+  default: {
+    enumerable: true,
+
+    get() {
+      return _elsewhere.stuff;
+    }
+
+  },
+  why: {
+    enumerable: true,
+
+    get() {
+      return _because.default;
+    }
+
+  }
 });
 
+const _ownExports = Object.keys(exports);
+
 var _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
 
 Object.keys(_iDontKnow).forEach(function (key) {
-  if (key === "default" || key === "__esModule") return;
+  if (key === "__esModule" || key === "default" || _ownExports.indexOf(key) >= 0) return;
+  if (key in exports && (exports[key] === _iDontKnow[key] || typeof exports[key] === 'number' && isNaN(exports[key]))) return;
   Object.defineProperty(exports, key, {
     enumerable: true,
 
@@ -42,30 +60,8 @@ Object.keys(_iDontKnow).forEach(function (key) {
 
 var _because = babelHelpers.specRequireInterop(require('./because'));
 
-Object.defineProperty(exports, 'why', {
-  enumerable: true,
-
-  get() {
-    return _because.default;
-  }
-
-});
-
 var _somewhere = babelHelpers.specRequireInterop(require('./somewhere'));
 
 var _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
 
-Object.defineProperty(exports, 'namespace', {
-  enumerable: true,
-  writable: true,
-  value: _somewhere
-});
-Object.defineProperty(exports, 'default', {
-  enumerable: true,
-
-  get() {
-    return _elsewhere.stuff;
-  }
-
-});
 (Object.freeze || Object)(exports);
\ No newline at end of file

From f3b8e118dd0c95986536d5ee900e6eba96dbf756 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 18:03:12 +0900
Subject: [PATCH 032/103] Refactor runtime tests

---
 .../test/spec-import.js                       | 31 ++-------
 .../test/spec-reexport.js                     | 48 ++-----------
 .../test/spec-test-helpers.js                 | 69 +++++++++++++++++++
 3 files changed, 82 insertions(+), 66 deletions(-)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import.js
index 2cf16b41ac81..388f6ecf6093 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import.js
@@ -1,32 +1,15 @@
 const assert = require("assert");
-const babel = require("../../babel-core");
-const vm = require("vm");
+const helpers = require("./spec-test-helpers");
 
 test("spec Interop import", function () {
-  const src = "import * as ns from 'fs'\nimport fs from 'fs'\nexport { fs, ns }\n";
+  const runner = new helpers.Runner();
 
   const fakeMod = { "fakeFs": true };
-  const context = {
-    module: {
-      exports: {}
-    },
-    require: function (id) {
-      if (id === "fs") return fakeMod;
-      throw new Error("Unmocked module " + id + " required");
-    }
-  };
-  context.exports = context.module.exports;
-
-  const code = babel.transform(src, {
-    "plugins": [
-      [require("../"), {spec: true}],
-    ],
-    "ast": false,
-  }).code;
-
-  vm.runInNewContext(code, context);
-
-  const exports = context.module.exports;
+  runner.addToCache("fs", { module: { exports: fakeMod } });
+
+  const exports = runner.transformAndRun(
+    "import * as ns from 'fs'\nimport fs from 'fs'\nexport { fs, ns }\n"
+  );
 
   assert(Object.isFrozen(exports), "exports is frozen");
   assert.strictEqual(Object.getPrototypeOf(exports), null, "exports has null prototype");
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
index db90935dc033..67b46af3b9a3 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
@@ -1,63 +1,27 @@
 "use strict";
 
 const assert = require("assert");
-const babel = require("../../babel-core");
-const vm = require("vm");
+const helpers = require("./spec-test-helpers");
 
 describe("spec star reexport", function () {
-  const modules = {
+  const runner = new helpers.Runner({
     a: "export const name = {key: 'value'}",
     b: "export const name = {key: 'value'}",
     aSame: "export const name = 'name'",
     bSame: "export const name = 'name'"
-  };
-
-  const cached = {};
-
-  function makeContext () {
-    const context = { module: { exports: {} }, require: contextRequire };
-    context.exports = context.module.exports;
-    return context;
-  }
-
-  function transformAndRunInNewContext (code, context) {
-    if (typeof context === "undefined") {
-      context = makeContext();
-    }
-
-    code = babel.transform(code, {
-      "plugins": [
-        [require("../"), {spec: true}],
-      ],
-      "ast": false,
-    }).code;
-    vm.runInNewContext(code, context);
-
-    return context.module.exports;
-  }
-
-  function contextRequire (id) {
-    if (id in modules) {
-      if (!cached[id]) {
-        cached[id] = makeContext();
-        transformAndRunInNewContext(modules[id], cached[id]);
-      }
-      return cached[id].module.exports;
-    }
-    throw new Error("Unmocked module " + id + " required");
-  }
+  });
 
   it("throws when not shadowed and duplicate is not SameValue", function () {
     assert.throws(function () {
-      transformAndRunInNewContext("export * from 'a'\nexport * from 'b'");
+      runner.transformAndRun("export * from 'a'\nexport * from 'b'");
     });
   });
 
   it("does not throw when not shadowed but is SameValue", function () {
-    transformAndRunInNewContext("export * from 'aSame'\nexport * from 'bSame'");
+    runner.transformAndRun("export * from 'aSame'\nexport * from 'bSame'");
   });
 
   it("does not throw when shadowed even if it is not SameValue", function () {
-    transformAndRunInNewContext("export * from 'a'\nexport * from 'b'\nexport const name = {}");
+    runner.transformAndRun("export * from 'a'\nexport * from 'b'\nexport const name = {}");
   });
 });
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
new file mode 100644
index 000000000000..ef2f6cdd2b0b
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
@@ -0,0 +1,69 @@
+const babel = require("../../babel-core");
+const vm = require("vm");
+
+module.exports.Runner = function Runner (initialModules) {
+  if (!(this instanceof Runner)) {
+    throw new Error("Runner can only be instantiated");
+  }
+
+  this.modules = {};
+  this.cache = {};
+
+  if (initialModules != null) {
+    this.addModules(initialModules);
+  }
+};
+
+module.exports.Runner.prototype = {
+  addModule: function (name, code) {
+    this.modules[name] = code;
+  },
+
+  addModules: function (dict) {
+    for (const key in dict) {
+      if (!Object.prototype.hasOwnProperty.call(dict, key)) continue;
+      this.addModule(key, dict[key]);
+    }
+  },
+
+  addToCache: function (name, context) {
+    if (! (context && context.module && "exports" in context.module)) {
+      throw new Error("The context to cache must have a module.exports");
+    }
+    this.cache[name] = context;
+  },
+
+  transformAndRun: function (code) {
+    return this.transformAndRunInNewContext(code, this.makeContext());
+  },
+
+  transformAndRunInNewContext: function (code, context) {
+    code = babel.transform(code, {
+      "plugins": [
+        [require("../"), {spec: true}],
+      ],
+      "ast": false,
+    }).code;
+    vm.runInNewContext(code, context);
+
+    return context.module.exports;
+  },
+
+  makeContext: function () {
+    const context = { module: { exports: {} }, require: this.contextRequire.bind(this) };
+    context.exports = context.module.exports;
+    return context;
+  },
+
+  contextRequire: function (id) {
+    if (id in this.cache) {
+      return this.cache[id].module.exports;
+    }
+    if (id in this.modules) {
+      this.cache[id] = this.makeContext();
+      this.transformAndRunInNewContext(this.modules[id], this.cache[id]);
+      return this.cache[id].module.exports;
+    }
+    throw new Error("Unmocked module " + id + " required");
+  }
+};

From f18e5dc48c1429742b5e786fd2deb6ddacce307a Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 18:04:42 +0900
Subject: [PATCH 033/103] Remove unused template, update comments

---
 .../src/index.js                                 | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 6e789b51f120..26c32a279c2f 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -59,13 +59,6 @@ const specBuildExportDefault = template(`
   Object.defineProperty(EXPORTS, "default", { enumerable: true, writable: true, value: VALUE });
 `);
 
-// Unfortunately, regular objects can't synthesize a value descriptor every time they're read,
-// so a getter needs to be used for live bindings.
-// It's also not allowed to specify writable when using getters/setters.
-const specBuildExport = template(`
-  Object.defineProperty(EXPORTS, NAME, { enumerable: true, get() { return VALUE; } });
-`);
-
 const specBuildOwnExports = template(`
   const $0 = Object.keys($1)
 `);
@@ -83,9 +76,12 @@ const specBuildNamespaceSpread = template(`
   });
 `);
 
-// It should _not_ be configurable, but this is needed as referring to
-// the real export, even with a getter, may cause DMZ errors with circular
-// references.
+// Unfortunately, regular objects can't synthesize a value descriptor every time they're read,
+// so a getter needs to be used for live bindings.
+// It's also not allowed to specify writable when using getters/setters.
+//
+// Accessing a non-hoisted export should cause a DMZ error instead of just
+// returning undefined, so a getter is also needed for that.
 const specBuildHoistedExportDescriptor = template(`
   ({ enumerable: true, get() { return $0; } })
 `);

From 56164e7cde6629bb407b3960ea11d2fbdde721dc Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 18:41:17 +0900
Subject: [PATCH 034/103] Remove the hoistedExports.has checks; babylon already
 checks for this

---
 .../src/index.js                              | 27 +------------------
 1 file changed, 1 insertion(+), 26 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 26c32a279c2f..7747b6f302db 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -375,10 +375,6 @@ export default function () {
 
               path.remove();
             } else if (path.isExportDefaultDeclaration()) {
-              if (spec && hoistedExports.has("default")) {
-                let todo;
-              }
-
               let declaration = path.get("declaration");
               if (declaration.isFunctionDeclaration()) {
                 let id = declaration.node.id;
@@ -460,9 +456,6 @@ export default function () {
                   let id = declaration.node.id;
                   addTo(exports, id.name, id);
                   if (spec) {
-                    if (hoistedExports.has(id.name)) {
-                      let todo;
-                    }
                     hoistedExports.set(id.name, id);
                   } else {
                     topNodes.push(buildExportsAssignment(id, id));
@@ -472,9 +465,6 @@ export default function () {
                   let id = declaration.node.id;
                   addTo(exports, id.name, id);
                   if (spec) {
-                    if (hoistedExports.has(id.name)) {
-                      let todo;
-                    }
                     hoistedExports.set(id.name, id);
                     path.replaceWith(declaration.node);
                   } else {
@@ -486,12 +476,11 @@ export default function () {
                   }
                 } else if (declaration.isVariableDeclaration()) {
                   let declarators = declaration.get("declarations");
-                  const toExport = spec && new Set();
                   for (let decl of declarators) {
                     let id = decl.get("id");
 
                     if (spec) {
-                      toExport.add(id.node);
+                      hoistedExports.set(id.node.name, id.node);
                       continue;
                     }
 
@@ -509,14 +498,6 @@ export default function () {
                       // todo
                     }
                   }
-                  if (spec) {
-                    Array.from(toExport).forEach((id) => {
-                      if (hoistedExports.has(id.name)) {
-                        let todo;
-                      }
-                      hoistedExports.set(id.name, id);
-                    });
-                  }
                   path.replaceWith(declaration.node);
                 }
                 continue;
@@ -535,9 +516,6 @@ export default function () {
                     // todo
                   } else if (specifier.isExportSpecifier()) {
                     if (spec) {
-                      if (hoistedExports.has(specifier.node.exported.name)) {
-                        let todo;
-                      }
                       hoistedExports.set(specifier.node.exported.name, t.memberExpression(ref, specifier.node.local));
                     } else if (specifier.node.local.name === "default") {
                       topNodes.push(buildExportsFrom(t.stringLiteral(specifier.node.exported.name), t.memberExpression(t.callExpression(this.addHelper("interopRequireDefault"), [ref]), specifier.node.local)));
@@ -554,9 +532,6 @@ export default function () {
                     nonHoistedExportNames[specifier.node.exported.name] = true;
 
                     if (spec) {
-                      if (hoistedExports.has(specifier.node.exported.name)) {
-                        let todo;
-                      }
                       hoistedExports.set(specifier.node.exported.name, specifier.node.local);
                     } else {
                       nodes.push(buildExportsAssignment(specifier.node.exported, specifier.node.local));

From 6340b24bb65e563c25885d1a74808f0d94911a43 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 18:41:50 +0900
Subject: [PATCH 035/103] Add more specific runtime tests for the export shape

---
 .../test/spec-export.js                       | 140 ++++++++++++++++++
 ...{spec-import.js => spec-interop-import.js} |   0
 2 files changed, 140 insertions(+)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
 rename packages/babel-plugin-transform-es2015-modules-commonjs/test/{spec-import.js => spec-interop-import.js} (100%)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
new file mode 100644
index 000000000000..eca863b31330
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
@@ -0,0 +1,140 @@
+"use strict";
+
+const assert = require("assert");
+const helpers = require("./spec-test-helpers");
+
+describe("spec export", function () {
+  const runner = new helpers.Runner();
+
+  describe("basic shape", function () {
+    const exports = runner.transformAndRun("export {}");
+
+    it("is frozen", function () {
+      assert(Object.isFrozen(exports));
+    });
+
+    it("has a null prototype", function () {
+      assert.strictEqual(Object.getPrototypeOf(exports), null);
+    });
+
+    it("is tagged as Module", function () {
+      if (typeof Symbol === "function" && Symbol.toStringTag) {
+        assert.strictEqual(exports[Symbol.toStringTag], "Module");
+      } else {
+        this.skip();
+      }
+    });
+
+    it("has the __esModule flag", function () {
+      assert.deepStrictEqual(
+        Object.getOwnPropertyDescriptor(exports, "__esModule"),
+        { value: true, configurable: false, writable: false, enumerable: false }
+      );
+    });
+
+    it("has no exports", function () {
+      assert.deepStrictEqual(Object.keys(exports), []);
+    });
+  });
+
+  describe("default export", function () {
+    describe("of single value", function () {
+      const exports = runner.transformAndRun("const foo = 'foo';\nexport default foo");
+
+      it("has no exports other than 'default'", function () {
+        assert.deepStrictEqual(Object.keys(exports), ["default"]);
+      });
+
+      it("has the correct value", function () {
+        assert.strictEqual(exports.default, "foo");
+      });
+    });
+
+    describe("of anonymous function", function () {
+      const exports = runner.transformAndRun("export default function () {}");
+
+      it("has Function.name of 'default'", function () {
+        assert.strictEqual(exports.default.name, "default");
+      });
+    });
+
+    describe("of anonymous class", function () {
+      const exports = runner.transformAndRun("export default class {}");
+
+      it("has Function.name of 'default'", function () {
+        assert.strictEqual(exports.default.name, "default");
+      });
+    });
+  });
+
+  describe("named export", function () {
+    describe("of single value declaration", function () {
+      const exports = runner.transformAndRun("export const a = 'a'");
+
+      it("has no exports other than 'a'", function () {
+        assert.deepStrictEqual(Object.keys(exports), ["a"]);
+      });
+
+      it("has the correct value", function () {
+        assert.strictEqual(exports.a, "a");
+      });
+    });
+
+    describe("of multiple value declaration", function () {
+      const exports = runner.transformAndRun("export const a = 'a', b = 'b'");
+
+      it("has no exports other than 'a' and 'b'", function () {
+        const keys = Object.keys(exports);
+        assert.strictEqual(keys.length, 2);
+        assert(keys.indexOf("a") >= 0);
+        assert(keys.indexOf("b") >= 0);
+      });
+
+      it("has the correct values", function () {
+        assert.strictEqual(exports.a, "a");
+        assert.strictEqual(exports.b, "b");
+      });
+    });
+  });
+
+  describe("early errors", function () {
+    // it turns out that babylon already throws for us, but test just to make sure
+    it("throws when generating duplicate default exports", function () {
+      assert.throws(function () {
+        runner.transformAndRun("export default class {}\nexport default class {}");
+      });
+    });
+
+    it("throws when generating duplicate default export via renaming", function () {
+      assert.throws(function () {
+        runner.transformAndRun("var foo\nexport default foo\nexport { foo as default }");
+      });
+    });
+
+    it("throws when generating duplicate exports in the same specifier", function () {
+      assert.throws(function () {
+        runner.transformAndRun("export var foo, foo");
+      });
+    });
+
+    it("throws when generating duplicate named exports in the same specifier", function () {
+      assert.throws(function () {
+        runner.transformAndRun("const foo = 'foo'\nexport { foo, foo }");
+      });
+    });
+
+    it("throws when generating duplicate renamed exports", function () {
+      assert.throws(function () {
+        runner.transformAndRun("const foo = 'foo'\nconst bar = 'bar'\nexport { foo, bar as foo }");
+      });
+    });
+
+    // babel extension; check for the flag used to distinguish
+    // babel ES modules from regular commonjs modules
+    it("throws when attempting to export __esModule", function () {
+      assert.throws(function () {
+        runner.transformAndRun("const __esModule = false\nexport { __esModule }");
+      });
+    });
+  });
+});
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
similarity index 100%
rename from packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import.js
rename to packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js

From f6c014a052bb4ef106e2ceadb0420bd12918a8fb Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 19:00:50 +0900
Subject: [PATCH 036/103] Improve runtime tests

---
 .../test/spec-export.js                       | 77 +++++++++++++++++++
 .../test/spec-reexport.js                     | 18 +++--
 2 files changed, 90 insertions(+), 5 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
index eca863b31330..37c8f2864f88 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
@@ -95,6 +95,83 @@ describe("spec export", function () {
         assert.strictEqual(exports.b, "b");
       });
     });
+
+    describe("of function", function () {
+      const exports = runner.transformAndRun("export function foo () { return 'bar'; }");
+
+      it("has no exports other than 'foo'", function () {
+        assert.deepStrictEqual(Object.keys(exports), ["foo"]);
+      });
+
+      it("hass the correct Function.name", function () {
+        assert.strictEqual(exports.foo.name, "foo");
+      });
+
+      it("has the correct value", function () {
+        assert.strictEqual(typeof exports.foo, "function");
+        assert.strictEqual((0, exports).foo(), "bar");
+      });
+    });
+
+    describe("of class", function () {
+      const exports = runner.transformAndRun("export class Foo {}");
+
+      it("has no exports other than 'Foo'", function () {
+        assert.deepStrictEqual(Object.keys(exports), ["Foo"]);
+      });
+
+      it("has the correct Function.name", function () {
+        assert.strictEqual(exports.Foo.name, "Foo");
+      });
+    });
+
+    describe("of identifier", function () {
+      const exports = runner.transformAndRun("var foo\nexport { foo }");
+
+      it("has no exports other than 'foo'", function () {
+        assert.deepStrictEqual(Object.keys(exports), ["foo"]);
+      });
+    });
+
+    describe("of renamed identifier", function () {
+      const exports = runner.transformAndRun("function foo () {}\nexport { foo as bar }");
+
+      it("has no exports other than 'bar'", function () {
+        assert.deepStrictEqual(Object.keys(exports), ["bar"]);
+      });
+
+      it("has the correct Function.name", function () {
+        assert.strictEqual(exports.bar.name, "foo");
+      });
+    });
+  });
+
+  describe("live binding", function () {
+    describe("of default export", function () {
+      const exports = runner.transformAndRun("export default function foo () { foo = ':scream:' }");
+
+      it("has the correct initial value", function () {
+        assert.strictEqual(typeof exports.default, "function");
+      });
+
+      it("correctly updates when executed", function () {
+        (0, exports).default();
+        assert.strictEqual(exports.default, ":scream:");
+      });
+    });
+
+    describe("of named export", function () {
+      const exports = runner.transformAndRun("export let count = 0\nexport default function up () { count += 1 }");
+
+      it("has the correct initial value", function () {
+        assert.strictEqual(exports.count, 0);
+      });
+
+      it("correctly updates", function () {
+        (0, exports).default();
+        assert.strictEqual(exports.count, 1);
+      });
+    });
   });
 
   describe("early errors", function () {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
index 67b46af3b9a3..3f4a9287a360 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
@@ -14,14 +14,22 @@ describe("spec star reexport", function () {
   it("throws when not shadowed and duplicate is not SameValue", function () {
     assert.throws(function () {
       runner.transformAndRun("export * from 'a'\nexport * from 'b'");
-    });
+    }, "Cannot redefine property: name");
   });
 
-  it("does not throw when not shadowed but is SameValue", function () {
-    runner.transformAndRun("export * from 'aSame'\nexport * from 'bSame'");
+  describe("SameValue duplicate reexport", function () {
+    const exports = runner.transformAndRun("export * from 'aSame'\nexport * from 'bSame'");
+
+    it("has the correct value", function () {
+      assert.strictEqual(exports.name, "name");
+    });
   });
 
-  it("does not throw when shadowed even if it is not SameValue", function () {
-    runner.transformAndRun("export * from 'a'\nexport * from 'b'\nexport const name = {}");
+  describe("shadowed reexport", function () {
+    const exports = runner.transformAndRun("export * from 'a'\nexport * from 'b'\nexport const name = 'foo'");
+
+    it("has the correct value", function () {
+      assert.strictEqual(exports.name, "foo");
+    });
   });
 });

From a861f64c78b54782345f7d263dd2804147ea5b4d Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 19:17:08 +0900
Subject: [PATCH 037/103] Add reexport tests

---
 .../test/spec-reexport.js                     | 127 +++++++++++++++++-
 .../test/spec-test-helpers.js                 |   7 +
 2 files changed, 132 insertions(+), 2 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
index 3f4a9287a360..028f91f79322 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
@@ -3,7 +3,130 @@
 const assert = require("assert");
 const helpers = require("./spec-test-helpers");
 
-describe("spec star reexport", function () {
+describe("spec reexport", function () {
+  const runner = new helpers.Runner({
+    a: "export const a = 'a'",
+    b: "export const b = 'b'",
+    ab: "export { a } from 'a'\nexport { b } from 'b'",
+    ns: "import * as ab from 'ab'\nexport { ab }",
+    star: "export * from 'ab'\nexport * from 'ns'"
+  });
+
+  describe("individual reexports", function () {
+    const exports = runner.getExportsOf("ab");
+
+    it("is frozen", function () {
+      assert(Object.isFrozen(exports));
+    });
+
+    it("has a null prototype", function () {
+      assert.strictEqual(Object.getPrototypeOf(exports), null);
+    });
+
+    it("is tagged as Module", function () {
+      if (typeof Symbol === "function" && Symbol.toStringTag) {
+        assert.strictEqual(exports[Symbol.toStringTag], "Module");
+      } else {
+        this.skip();
+      }
+    });
+
+    it("has the __esModule flag", function () {
+      assert.deepStrictEqual(
+        Object.getOwnPropertyDescriptor(exports, "__esModule"),
+        { value: true, configurable: false, writable: false, enumerable: false }
+      );
+    });
+
+    it("has no exports other than 'a' and 'b'", function () {
+      const keys = Object.keys(exports);
+      assert.strictEqual(keys.length, 2);
+      assert(keys.indexOf("a") >= 0);
+      assert(keys.indexOf("b") >= 0);
+    });
+
+    it("has the correct values", function () {
+      assert.strictEqual(exports.a, "a");
+      assert.strictEqual(exports.b, "b");
+    });
+  });
+
+  describe("namespace reexport", function () {
+    const exports = runner.getExportsOf("ns");
+
+    it("the reexport is frozen", function () {
+      assert(Object.isFrozen(exports.ab));
+    });
+
+    it("the reexport has a null prototype", function () {
+      assert.strictEqual(Object.getPrototypeOf(exports.ab), null);
+    });
+
+    it("the reexport is tagged as Module", function () {
+      if (typeof Symbol === "function" && Symbol.toStringTag) {
+        assert.strictEqual(exports.ab[Symbol.toStringTag], "Module");
+      } else {
+        this.skip();
+      }
+    });
+
+    it("the reexport has the __esModule flag", function () {
+      assert.deepStrictEqual(
+        Object.getOwnPropertyDescriptor(exports.ab, "__esModule"),
+        { value: true, configurable: false, writable: false, enumerable: false }
+      );
+    });
+
+    it("the reexport has the correct values", function () {
+      assert.strictEqual(exports.ab.a, "a");
+      assert.strictEqual(exports.ab.b, "b");
+    });
+  });
+
+  describe("star reexport", function () {
+    const exports = runner.getExportsOf("star");
+
+
+    it("is frozen", function () {
+      assert(Object.isFrozen(exports));
+    });
+
+    it("has a null prototype", function () {
+      assert.strictEqual(Object.getPrototypeOf(exports), null);
+    });
+
+    it("is tagged as Module", function () {
+      if (typeof Symbol === "function" && Symbol.toStringTag) {
+        assert.strictEqual(exports[Symbol.toStringTag], "Module");
+      } else {
+        this.skip();
+      }
+    });
+
+    it("has the __esModule flag", function () {
+      assert.deepStrictEqual(
+        Object.getOwnPropertyDescriptor(exports, "__esModule"),
+        { value: true, configurable: false, writable: false, enumerable: false }
+      );
+    });
+
+    it("has no exports other than 'a', 'b' and 'ab'", function () {
+      const keys = Object.keys(exports);
+      assert.strictEqual(keys.length, 3);
+      assert(keys.indexOf("a") >= 0);
+      assert(keys.indexOf("b") >= 0);
+      assert(keys.indexOf("ab") >= 0);
+    });
+
+    it("has the correct values", function () {
+      assert.strictEqual(exports.a, "a");
+      assert.strictEqual(exports.b, "b");
+      assert.strictEqual(exports.ab, runner.getExportsOf("ab"));
+    });
+  });
+});
+
+describe("spec reexport star with duplicates", function () {
   const runner = new helpers.Runner({
     a: "export const name = {key: 'value'}",
     b: "export const name = {key: 'value'}",
@@ -17,7 +140,7 @@ describe("spec star reexport", function () {
     }, "Cannot redefine property: name");
   });
 
-  describe("SameValue duplicate reexport", function () {
+  describe("SameValue", function () {
     const exports = runner.transformAndRun("export * from 'aSame'\nexport * from 'bSame'");
 
     it("has the correct value", function () {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
index ef2f6cdd2b0b..f46b1c0b40d1 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
@@ -33,6 +33,13 @@ module.exports.Runner.prototype = {
     this.cache[name] = context;
   },
 
+  getExportsOf: function (name) {
+    if (! (name in this.cache || name in this.modules)) {
+      throw new Error("Unknown module " + name + " requested");
+    }
+    return this.contextRequire(name);
+  },
+
   transformAndRun: function (code) {
     return this.transformAndRunInNewContext(code, this.makeContext());
   },

From 9ec0147ccfbeccf925dfb8fb6975e61428acfe1f Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 19:18:16 +0900
Subject: [PATCH 038/103] Update fixtures

---
 .../modules-commonjs-spec/expected.js              | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
index e2156380ac58..3fafd2eeabdf 100644
--- a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
+++ b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
@@ -14,6 +14,14 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
   });
 }
 
+Object.defineProperties(exports, {
+  b: {
+    enumerable: true,
+    get: function get() {
+      return b;
+    }
+  }
+});
 Object.defineProperty(exports, "default", {
   enumerable: true,
   writable: true,
@@ -21,11 +29,5 @@ Object.defineProperty(exports, "default", {
     default: function _default() {}
   }.default
 });
-Object.defineProperty(exports, "b", {
-  enumerable: true,
-  get: function get() {
-    return b;
-  }
-});
 function b() {}
 (Object.freeze || Object)(exports);
\ No newline at end of file

From de10efb5dd891e212f128aa55fd932b1144fe7b9 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 19:28:16 +0900
Subject: [PATCH 039/103] Try to detect extra transforms needed for node 0.12

---
 .../test/spec-test-helpers.js                 | 31 +++++++++++++++----
 1 file changed, 25 insertions(+), 6 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
index f46b1c0b40d1..ca9688f1484d 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
@@ -1,6 +1,24 @@
 const babel = require("../../babel-core");
 const vm = require("vm");
 
+const extraPlugins = [];
+
+function prepareExtraPlugins () {
+  try {
+    eval("'use strict'; const foo = 'bar'");
+  } catch (e) {
+    extraPlugins.push(require("../../babel-plugin-transform-es2015-block-scoping"));
+  }
+
+  try {
+    eval("'use strict'; ({ get () {} })");
+  } catch (e) {
+    extraPlugins.push(require("../../babel-plugin-transform-es2015-shorthand-properties"));
+  }
+}
+
+prepareExtraPlugins();
+
 module.exports.Runner = function Runner (initialModules) {
   if (!(this instanceof Runner)) {
     throw new Error("Runner can only be instantiated");
@@ -8,6 +26,12 @@ module.exports.Runner = function Runner (initialModules) {
 
   this.modules = {};
   this.cache = {};
+  this.babelConfig = {
+    "plugins": [
+      [require("../"), {spec: true}].concat(extraPlugins),
+    ],
+    "ast": false,
+  };
 
   if (initialModules != null) {
     this.addModules(initialModules);
@@ -45,12 +69,7 @@ module.exports.Runner.prototype = {
   },
 
   transformAndRunInNewContext: function (code, context) {
-    code = babel.transform(code, {
-      "plugins": [
-        [require("../"), {spec: true}],
-      ],
-      "ast": false,
-    }).code;
+    code = babel.transform(code, this.babelConfig).code;
     vm.runInNewContext(code, context);
 
     return context.module.exports;

From 23382524dbf98215c51aab0a767524c58c028b3f Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 20:08:56 +0900
Subject: [PATCH 040/103] Actually fix tests to run in node 0.12

---
 .../test/spec-export.js                       | 35 +++++++++++++------
 .../test/spec-interop-import.js               | 14 +++++---
 .../test/spec-reexport.js                     | 12 +++----
 .../test/spec-test-helpers.js                 | 22 ++++++++++--
 4 files changed, 59 insertions(+), 24 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
index 37c8f2864f88..7a3910e1f376 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
@@ -18,7 +18,7 @@ describe("spec export", function () {
     });
 
     it("is tagged as Module", function () {
-      if (typeof Symbol === "function" && Symbol.toStringTag) {
+      if (helpers.hasToStringTag()) {
         assert.strictEqual(exports[Symbol.toStringTag], "Module");
       } else {
         this.skip();
@@ -26,14 +26,14 @@ describe("spec export", function () {
     });
 
     it("has the __esModule flag", function () {
-      assert.deepStrictEqual(
+      assert.deepEqual(
         Object.getOwnPropertyDescriptor(exports, "__esModule"),
         { value: true, configurable: false, writable: false, enumerable: false }
       );
     });
 
     it("has no exports", function () {
-      assert.deepStrictEqual(Object.keys(exports), []);
+      assert.deepEqual(Object.keys(exports), []);
     });
   });
 
@@ -42,7 +42,7 @@ describe("spec export", function () {
       const exports = runner.transformAndRun("const foo = 'foo';\nexport default foo");
 
       it("has no exports other than 'default'", function () {
-        assert.deepStrictEqual(Object.keys(exports), ["default"]);
+        assert.deepEqual(Object.keys(exports), ["default"]);
       });
 
       it("has the correct value", function () {
@@ -50,11 +50,20 @@ describe("spec export", function () {
       });
     });
 
+    // Use Function to make sure it is not transformed by babel-register
+    // Even with the function name transform, it would not be possible to get the correct
+    // Function.name to be generated, so use this to decide whether to skip tests
+    const hasFunctionName = Function("return { foo: function () {} }.foo")().name === "foo";
+
     describe("of anonymous function", function () {
       const exports = runner.transformAndRun("export default function () {}");
 
       it("has Function.name of 'default'", function () {
-        assert.strictEqual(exports.default.name, "default");
+        if (hasFunctionName) {
+          assert.strictEqual(exports.default.name, "default");
+        } else {
+          this.skip();
+        }
       });
     });
 
@@ -62,7 +71,11 @@ describe("spec export", function () {
       const exports = runner.transformAndRun("export default class {}");
 
       it("has Function.name of 'default'", function () {
-        assert.strictEqual(exports.default.name, "default");
+        if (hasFunctionName) {
+          assert.strictEqual(exports.default.name, "default");
+        } else {
+          this.skip();
+        }
       });
     });
   });
@@ -72,7 +85,7 @@ describe("spec export", function () {
       const exports = runner.transformAndRun("export const a = 'a'");
 
       it("has no exports other than 'a'", function () {
-        assert.deepStrictEqual(Object.keys(exports), ["a"]);
+        assert.deepEqual(Object.keys(exports), ["a"]);
       });
 
       it("has the correct value", function () {
@@ -100,7 +113,7 @@ describe("spec export", function () {
       const exports = runner.transformAndRun("export function foo () { return 'bar'; }");
 
       it("has no exports other than 'foo'", function () {
-        assert.deepStrictEqual(Object.keys(exports), ["foo"]);
+        assert.deepEqual(Object.keys(exports), ["foo"]);
       });
 
       it("hass the correct Function.name", function () {
@@ -117,7 +130,7 @@ describe("spec export", function () {
       const exports = runner.transformAndRun("export class Foo {}");
 
       it("has no exports other than 'Foo'", function () {
-        assert.deepStrictEqual(Object.keys(exports), ["Foo"]);
+        assert.deepEqual(Object.keys(exports), ["Foo"]);
       });
 
       it("has the correct Function.name", function () {
@@ -129,7 +142,7 @@ describe("spec export", function () {
       const exports = runner.transformAndRun("var foo\nexport { foo }");
 
       it("has no exports other than 'foo'", function () {
-        assert.deepStrictEqual(Object.keys(exports), ["foo"]);
+        assert.deepEqual(Object.keys(exports), ["foo"]);
       });
     });
 
@@ -137,7 +150,7 @@ describe("spec export", function () {
       const exports = runner.transformAndRun("function foo () {}\nexport { foo as bar }");
 
       it("has no exports other than 'bar'", function () {
-        assert.deepStrictEqual(Object.keys(exports), ["bar"]);
+        assert.deepEqual(Object.keys(exports), ["bar"]);
       });
 
       it("has the correct Function.name", function () {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
index 388f6ecf6093..6bc71fc28756 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
@@ -14,11 +14,13 @@ test("spec Interop import", function () {
   assert(Object.isFrozen(exports), "exports is frozen");
   assert.strictEqual(Object.getPrototypeOf(exports), null, "exports has null prototype");
 
-  if (typeof Symbol === "function" && Symbol.toStringTag) {
+  if (helpers.hasToStringTag()) {
     assert.strictEqual(exports[Symbol.toStringTag], "Module", "exports is tagged as Module");
+  } else {
+    it.skip("exports is tagged as Module");
   }
 
-  assert.deepStrictEqual(
+  assert.deepEqual(
     Object.getOwnPropertyDescriptor(exports, "__esModule"),
     { value: true, configurable: false, writable: false, enumerable: false },
     "__esModule in top level Module"
@@ -44,7 +46,7 @@ test("spec Interop import", function () {
 
   const ns = exports.ns;
 
-  assert.deepStrictEqual(
+  assert.deepEqual(
     Object.getOwnPropertyDescriptor(ns, "__esModule"),
     { value: true, configurable: false, writable: false, enumerable: false },
     "__esModule in the imported ns Module"
@@ -53,13 +55,15 @@ test("spec Interop import", function () {
   assert(Object.isFrozen(ns), "ns export is frozen");
   assert.strictEqual(Object.getPrototypeOf(ns), null, "ns export has null prototype");
 
-  if (typeof Symbol === "function" && Symbol.toStringTag) {
+  if (helpers.hasToStringTag()) {
     assert.strictEqual(ns[Symbol.toStringTag], "Module", "ns export is tagged as Module");
+  } else {
+    it.skip("ns export is tagged as Module");
   }
 
   const imported = Object.getOwnPropertyNames(ns).filter(function (name) { return name !== "__esModule"; });
 
-  assert.deepStrictEqual(imported, [ "default" ], "No exports other than 'default' in ns Module");
+  assert.deepEqual(imported, [ "default" ], "No exports other than 'default' in ns Module");
 
   const defaultDesc = Object.getOwnPropertyDescriptor(ns, "default");
 
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
index 028f91f79322..bc8170a2d5e5 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
@@ -24,7 +24,7 @@ describe("spec reexport", function () {
     });
 
     it("is tagged as Module", function () {
-      if (typeof Symbol === "function" && Symbol.toStringTag) {
+      if (helpers.hasToStringTag()) {
         assert.strictEqual(exports[Symbol.toStringTag], "Module");
       } else {
         this.skip();
@@ -32,7 +32,7 @@ describe("spec reexport", function () {
     });
 
     it("has the __esModule flag", function () {
-      assert.deepStrictEqual(
+      assert.deepEqual(
         Object.getOwnPropertyDescriptor(exports, "__esModule"),
         { value: true, configurable: false, writable: false, enumerable: false }
       );
@@ -63,7 +63,7 @@ describe("spec reexport", function () {
     });
 
     it("the reexport is tagged as Module", function () {
-      if (typeof Symbol === "function" && Symbol.toStringTag) {
+      if (helpers.hasToStringTag()) {
         assert.strictEqual(exports.ab[Symbol.toStringTag], "Module");
       } else {
         this.skip();
@@ -71,7 +71,7 @@ describe("spec reexport", function () {
     });
 
     it("the reexport has the __esModule flag", function () {
-      assert.deepStrictEqual(
+      assert.deepEqual(
         Object.getOwnPropertyDescriptor(exports.ab, "__esModule"),
         { value: true, configurable: false, writable: false, enumerable: false }
       );
@@ -96,7 +96,7 @@ describe("spec reexport", function () {
     });
 
     it("is tagged as Module", function () {
-      if (typeof Symbol === "function" && Symbol.toStringTag) {
+      if (helpers.hasToStringTag()) {
         assert.strictEqual(exports[Symbol.toStringTag], "Module");
       } else {
         this.skip();
@@ -104,7 +104,7 @@ describe("spec reexport", function () {
     });
 
     it("has the __esModule flag", function () {
-      assert.deepStrictEqual(
+      assert.deepEqual(
         Object.getOwnPropertyDescriptor(exports, "__esModule"),
         { value: true, configurable: false, writable: false, enumerable: false }
       );
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
index ca9688f1484d..57238b7de7eb 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
@@ -15,6 +15,12 @@ function prepareExtraPlugins () {
   } catch (e) {
     extraPlugins.push(require("../../babel-plugin-transform-es2015-shorthand-properties"));
   }
+
+  try {
+    eval("'use strict'; class Foo {}");
+  } catch (e) {
+    extraPlugins.push(require("../../babel-plugin-transform-es2015-classes"));
+  }
 }
 
 prepareExtraPlugins();
@@ -28,8 +34,8 @@ module.exports.Runner = function Runner (initialModules) {
   this.cache = {};
   this.babelConfig = {
     "plugins": [
-      [require("../"), {spec: true}].concat(extraPlugins),
-    ],
+      [require("../"), {spec: true}],
+    ].concat(extraPlugins),
     "ast": false,
   };
 
@@ -93,3 +99,15 @@ module.exports.Runner.prototype = {
     throw new Error("Unmocked module " + id + " required");
   }
 };
+
+let hasToStringTag = null;
+module.exports.hasToStringTag = function () {
+  if (hasToStringTag != null) {
+    return hasToStringTag;
+  }
+
+  const context = { module: { exports : {} } };
+  vm.runInNewContext("module.exports = typeof Symbol === 'function' && Symbol.toStringTag", context);
+  hasToStringTag = typeof context.module.exports === "symbol";
+  return hasToStringTag;
+};

From cd388c9fcefd9c90eb27f8a318d5d9bf5e037447 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 20:12:22 +0900
Subject: [PATCH 041/103] Fix incorrect arguments to array push

---
 .../babel-plugin-transform-es2015-modules-commonjs/src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 7747b6f302db..846d432b8ebb 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -384,7 +384,7 @@ export default function () {
                   if (spec) {
                     hoistedExports.set("default", id);
                   } else {
-                    topNodes.push(spec, buildExportsAssignment(defNode, id));
+                    topNodes.push(buildExportsAssignment(defNode, id));
                   }
                   path.replaceWith(declaration.node);
                 } else if (spec) {

From 3f2f1a7f21acbfcfb2fc18a1b34d0ae5f314e5b9 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 20:37:02 +0900
Subject: [PATCH 042/103] Refactor test/spec-interop-import

---
 .../test/spec-interop-import.js               | 181 +++++++++++-------
 1 file changed, 114 insertions(+), 67 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
index 6bc71fc28756..f91db6b728d0 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
@@ -1,7 +1,7 @@
 const assert = require("assert");
 const helpers = require("./spec-test-helpers");
 
-test("spec Interop import", function () {
+describe("spec Interop import", function () {
   const runner = new helpers.Runner();
 
   const fakeMod = { "fakeFs": true };
@@ -11,70 +11,117 @@ test("spec Interop import", function () {
     "import * as ns from 'fs'\nimport fs from 'fs'\nexport { fs, ns }\n"
   );
 
-  assert(Object.isFrozen(exports), "exports is frozen");
-  assert.strictEqual(Object.getPrototypeOf(exports), null, "exports has null prototype");
-
-  if (helpers.hasToStringTag()) {
-    assert.strictEqual(exports[Symbol.toStringTag], "Module", "exports is tagged as Module");
-  } else {
-    it.skip("exports is tagged as Module");
-  }
-
-  assert.deepEqual(
-    Object.getOwnPropertyDescriptor(exports, "__esModule"),
-    { value: true, configurable: false, writable: false, enumerable: false },
-    "__esModule in top level Module"
-  );
-
-  const nsDesc = Object.getOwnPropertyDescriptor(exports, "ns");
-
-  assert(nsDesc.enumerable, "ns export is enumerable");
-  // This should be the actual observable behavior, but freezing the export
-  // makes this change to false.
-  // // assert(nsDesc.writable, "ns export is writable");
-  assert(!nsDesc.writable, "ns export happens to not be writable");
-  assert(!nsDesc.configurable,"ns export is not configurable");
-
-  const fsDesc = Object.getOwnPropertyDescriptor(exports, "fs");
-
-  assert(fsDesc.enumerable, "fs export is enumerable");
-  // fsDesc.writable cannot be true like the spec asks because...
-  // // assert.strictEqual(fsDesc.writable, true);
-  // ...fsDesc.get must be provided (and be a function)
-  assert.strictEqual(typeof fsDesc.get, "function", "fs export is a getter");
-  assert(!fsDesc.configurable, "fs export is not configurable");
-
-  const ns = exports.ns;
-
-  assert.deepEqual(
-    Object.getOwnPropertyDescriptor(ns, "__esModule"),
-    { value: true, configurable: false, writable: false, enumerable: false },
-    "__esModule in the imported ns Module"
-  );
-
-  assert(Object.isFrozen(ns), "ns export is frozen");
-  assert.strictEqual(Object.getPrototypeOf(ns), null, "ns export has null prototype");
-
-  if (helpers.hasToStringTag()) {
-    assert.strictEqual(ns[Symbol.toStringTag], "Module", "ns export is tagged as Module");
-  } else {
-    it.skip("ns export is tagged as Module");
-  }
-
-  const imported = Object.getOwnPropertyNames(ns).filter(function (name) { return name !== "__esModule"; });
-
-  assert.deepEqual(imported, [ "default" ], "No exports other than 'default' in ns Module");
-
-  const defaultDesc = Object.getOwnPropertyDescriptor(ns, "default");
-
-  assert.strictEqual(defaultDesc.enumerable, true, "ns.default export is enumerable");
-  // This is also not writable for the same reason nsDesc.writable was false
-  // // assert.strictEqual(defaultDesc.writable, true, "ns.default export is writable");
-  assert.strictEqual(defaultDesc.writable, false, "ns export happens to not be writable");
-  assert.strictEqual(defaultDesc.configurable, false, "ns.default export is configurable");
-  assert.strictEqual("value" in defaultDesc, true, "ns.default export has a value");
-
-  assert(!("__esModule" in ns.default), "ns.default export is not a Module");
-  assert.strictEqual(ns.default, fakeMod, "ns.default export is the commonjs namespace");
-  assert.strictEqual(exports.fs, fakeMod, "fs reexport is the commonjs namespace");
+  describe("export descriptors", function () {
+    describe("ns", function () {
+      const nsDesc = Object.getOwnPropertyDescriptor(exports, "ns");
+
+      it("is enumerable", function () {
+        assert(nsDesc.enumerable);
+      });
+
+      it("is writable", function () {
+        // This should be the actual observable behavior, but getters
+        // are being used, which forbids setting writable.
+        // Even if it was a value descriptor, freezing the export
+        // forces the result of getOwnPropertyDescriptor to have writable: false
+        // // assert(nsDesc.writable);
+        this.skip();
+      });
+
+      it("happens to be a getter", function () {
+        assert.strictEqual(typeof nsDesc.get, "function");
+      });
+
+      it("is not configurable", function () {
+        assert(!nsDesc.configurable);
+      });
+    });
+
+    describe("fs", function () {
+      const fsDesc = Object.getOwnPropertyDescriptor(exports, "fs");
+
+      it("is enumerable", function () {
+        assert(fsDesc.enumerable);
+      });
+
+      it("is writable", function () {
+        // fsDesc.writable cannot be true for the same reason nsDesc.writable could not
+        // // assert(fsDesc.writable);
+      });
+
+      it("happens to be a getter", function () {
+        assert.strictEqual(typeof fsDesc.get, "function");
+      });
+
+      it("is not configurable", function () {
+        assert(!fsDesc.configurable);
+      });
+    });
+  });
+
+  describe("synthetic namespace", function () {
+    const ns = exports.ns;
+
+    it("is frozen", function () {
+      assert(Object.isFrozen(ns));
+    });
+
+    it("has a null prototype", function () {
+      assert.strictEqual(Object.getPrototypeOf(ns), null);
+    });
+
+    it("is tagged as Module", function () {
+      if (helpers.hasToStringTag()) {
+        assert.strictEqual(ns[Symbol.toStringTag], "Module");
+      } else {
+        this.skip();
+      }
+    });
+
+    it("has the __esModule flag", function () {
+      assert.deepEqual(
+        Object.getOwnPropertyDescriptor(ns, "__esModule"),
+        { value: true, configurable: false, writable: false, enumerable: false }
+      );
+    });
+
+    it("has no exports other than 'default'", function () {
+      assert.deepEqual(Object.keys(ns), ["default"]);
+    });
+
+    describe("'default' descriptor", function () {
+      const defaultDesc = Object.getOwnPropertyDescriptor(ns, "default");
+
+      it("is enumerable", function () {
+        assert(defaultDesc.enumerable);
+      });
+      it("is writable", function () {
+        // Unfortunately, when the namespace is frozen, all value descriptors
+        // returned by getOwnPropertyDescriptors have writable: false
+        // // assert(defaultDesc.writable)
+        this.skip();
+      });
+      it("happens to not be writable", function () {
+        assert(!defaultDesc.writable);
+      });
+      it("has a value", function () {
+        assert("value" in defaultDesc);
+      });
+    });
+  });
+
+  describe("ns export", function () {
+    it("is not a Module", function () {
+      assert(!("__esModule" in exports.ns.default));
+    });
+    it("is the original commonjs namespace", function () {
+      assert.strictEqual(exports.ns.default, fakeMod);
+    });
+  });
+
+  describe("fs reexport", function () {
+    it("is the original commonjs namespace", function() {
+      assert.strictEqual(exports.fs, fakeMod);
+    });
+  });
 });

From f9dd48504bcc20f43d2b1e14ab1a33558f5d81e1 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 20:37:47 +0900
Subject: [PATCH 043/103] Add missing this.skip()

---
 .../test/spec-interop-import.js                                  | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
index f91db6b728d0..284589bc0063 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
@@ -47,6 +47,7 @@ describe("spec Interop import", function () {
       it("is writable", function () {
         // fsDesc.writable cannot be true for the same reason nsDesc.writable could not
         // // assert(fsDesc.writable);
+        this.skip();
       });
 
       it("happens to be a getter", function () {

From f27fe0883942e05568c42645c2c4f9431a9f9053 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 20:51:57 +0900
Subject: [PATCH 044/103] Also hoist the declaration of the default export

Use `let` to ensure it will be in TDZ if something goes horribly wrong
and the initialization doesn't happen.
---
 .../src/index.js                              | 37 ++++++++++++-------
 1 file changed, 24 insertions(+), 13 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 846d432b8ebb..55aeb240ea8f 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -54,11 +54,6 @@ const specBuildFunctionNameWrapper = template(`
   ({ default: $0 }).default
 `);
 
-// The descriptors are as specified in https://tc39.github.io/ecma262/#sec-module-namespace-exotic-objects-getownproperty-p
-const specBuildExportDefault = template(`
-  Object.defineProperty(EXPORTS, "default", { enumerable: true, writable: true, value: VALUE });
-`);
-
 const specBuildOwnExports = template(`
   const $0 = Object.keys($1)
 `);
@@ -79,9 +74,13 @@ const specBuildNamespaceSpread = template(`
 // Unfortunately, regular objects can't synthesize a value descriptor every time they're read,
 // so a getter needs to be used for live bindings.
 // It's also not allowed to specify writable when using getters/setters.
+// Even if it was a value, getOwnPropertyDescriptor would return writable: false after
+// the exports are frozen by specFinishNamespaceExport.
 //
 // Accessing a non-hoisted export should cause a DMZ error instead of just
 // returning undefined, so a getter is also needed for that.
+//
+// This is as close as we can get to https://tc39.github.io/ecma262/#sec-module-namespace-exotic-objects-getownproperty-p
 const specBuildHoistedExportDescriptor = template(`
   ({ enumerable: true, get() { return $0; } })
 `);
@@ -297,6 +296,7 @@ export default function () {
           let remaps = Object.create(null);
 
           const hoistedExports = spec && new Map();
+          let defaultExportUid = null;
           let ownExportsUid = null;
 
           let requires = Object.create(null);
@@ -388,9 +388,12 @@ export default function () {
                   }
                   path.replaceWith(declaration.node);
                 } else if (spec) {
-                  hoistedExports.set("default", null);
+                  defaultExportUid = path.scope.generateUidIdentifier("default");
+                  hoistedExports.set("default", defaultExportUid);
                   const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
-                  topNodes.push(specBuildExportDefault({ EXPORTS: exportsObj, VALUE: expr }));
+                  topNodes.push(t.variableDeclaration("let", [
+                    t.variableDeclarator(defaultExportUid, expr)
+                  ]));
                   path.remove();
                 } else {
                   const expr = t.toExpression(declaration.node);
@@ -412,15 +415,19 @@ export default function () {
                     ]);
                   }
                 } else if (spec) {
-                  hoistedExports.set("default", null);
+                  defaultExportUid = path.scope.generateUidIdentifier("default");
+                  hoistedExports.set("default", defaultExportUid);
 
                   const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
-                  path.replaceWith(specBuildExportDefault({ EXPORTS: exportsObj, VALUE: expr }));
+
+                  path.replaceWith(t.variableDeclaration("let", [
+                    t.variableDeclarator(defaultExportUid, expr)
+                  ]));
 
                   // Manually re-queue the expression so other transforms can get to it.
                   // Ideally this would happen automatically from the replaceWith above.
                   // See #4140 for more info.
-                  path.parentPath.requeue(path.get("expression.arguments.2"));
+                  path.parentPath.requeue(path.get("declarations.init"));
                 } else {
                   const expr = t.toExpression(declaration.node);
                   path.replaceWith(buildExportsAssignment(defNode, expr));
@@ -433,13 +440,17 @@ export default function () {
               } else {
                 const defNode = t.identifier("default");
                 if (spec) {
-                  hoistedExports.set("default", null);
-                  path.replaceWith(specBuildExportDefault({ EXPORTS: exportsObj, VALUE: declaration.node }));
+                  defaultExportUid = path.scope.generateUidIdentifier("default");
+                  hoistedExports.set("default", defaultExportUid);
+
+                  path.replaceWith(t.variableDeclaration("let", [
+                    t.variableDeclarator(defaultExportUid, declaration.node)
+                  ]));
 
                   // Manually re-queue the expression so other transforms can get to it.
                   // Ideally this would happen automatically from the replaceWith above.
                   // See #4140 for more info.
-                  path.parentPath.requeue(path.get("expression.arguments.2"));
+                  path.parentPath.requeue(path.get("declarations.init"));
                 } else {
                   path.replaceWith(buildExportsAssignment(defNode, declaration.node));
 

From 2fddb7af3d9aaa8b36fe0dd673abf4d5d64b4852 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 20:53:52 +0900
Subject: [PATCH 045/103] Update fixtures

---
 .../spec/commonjs-shadow-1/expected.js        | 18 ++++++++++------
 .../fixtures/spec/commonjs-shadow/expected.js | 21 ++++++++++++-------
 .../fixtures/spec/export-default/expected.js  | 18 +++++++++-------
 .../modules-commonjs-spec/expected.js         | 16 +++++++-------
 4 files changed, 46 insertions(+), 27 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
index 619d54bcfa6b..f81646fd5ef6 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
@@ -14,13 +14,19 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
   });
 }
 
-Object.defineProperty(exports, "default", {
-  enumerable: true,
-  writable: true,
-  value: {
-    default: function () {}
-  }.default
+Object.defineProperties(exports, {
+  default: {
+    enumerable: true,
+
+    get() {
+      return _default;
+    }
+
+  }
 });
+let _default = {
+  default: function () {}
+}.default;
 
 
 _exports = function () {};
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
index c3bad22fa1ff..e3c410416a4c 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -14,15 +14,22 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
   });
 }
 
-var _bar = babelHelpers.specRequireInterop(require('bar'));
+Object.defineProperties(exports, {
+  default: {
+    enumerable: true,
+
+    get() {
+      return _default;
+    }
 
-Object.defineProperty(exports, "default", {
-  enumerable: true,
-  writable: true,
-  value: {
-    default: class {}
-  }.default
+  }
 });
+
+var _bar = babelHelpers.specRequireInterop(require('bar'));
+
+let _default = {
+  default: class {}
+}.default;
 ;
 
 // neither of these should be able to use or affect the real exports
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index 3e2fb6e77433..7e62ec78167b 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -15,6 +15,14 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
 }
 
 Object.defineProperties(exports, {
+  default: {
+    enumerable: true,
+
+    get() {
+      return _default;
+    }
+
+  },
   unrelated: {
     enumerable: true,
 
@@ -24,13 +32,9 @@ Object.defineProperties(exports, {
 
   }
 });
-Object.defineProperty(exports, "default", {
-  enumerable: true,
-  writable: true,
-  value: {
-    default: function () {}
-  }.default
-});
+let _default = {
+  default: function () {}
+}.default;
 var unrelated;
 unrelated = "changed";
 (Object.freeze || Object)(exports);
\ No newline at end of file
diff --git a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
index 3fafd2eeabdf..263730f3babc 100644
--- a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
+++ b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
@@ -15,6 +15,12 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
 }
 
 Object.defineProperties(exports, {
+  default: {
+    enumerable: true,
+    get: function get() {
+      return _default;
+    }
+  },
   b: {
     enumerable: true,
     get: function get() {
@@ -22,12 +28,8 @@ Object.defineProperties(exports, {
     }
   }
 });
-Object.defineProperty(exports, "default", {
-  enumerable: true,
-  writable: true,
-  value: {
-    default: function _default() {}
-  }.default
-});
+var _default = {
+  default: function _default() {}
+}.default;
 function b() {}
 (Object.freeze || Object)(exports);
\ No newline at end of file

From ba4d3d64328646594c85284a85f1686ab2169a5d Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 21:30:57 +0900
Subject: [PATCH 046/103] Also hoist the Object.freeze call

---
 .../src/index.js                              | 50 ++++++++++++-------
 1 file changed, 31 insertions(+), 19 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 55aeb240ea8f..9e02bc732540 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -557,14 +557,21 @@ export default function () {
                 if (ownExportsUid == null) {
                   ownExportsUid = path.scope.generateUidIdentifier("ownExports");
                   const ownExportsNode = specBuildOwnExports(ownExportsUid, exportsObj);
+                  ownExportsNode._blockHoist = 3;
                   topNodes.push(ownExportsNode);
                 }
 
+                // Unfortunately, the namespace spread needs to happen _before_
+                // the namespace is frozen. This _will_ result in out-of-order
+                // imports, with the 'export * from' imports all running before
+                // any of the other imports.
+
                 exportNode = specBuildNamespaceSpread({
                   EXPORTS: exportsObj,
                   OWN_EXPORTS: ownExportsUid,
-                  OBJECT: addRequire(path.node.source.value, spec, path.node._blockHoist)
+                  OBJECT: addRequire(path.node.source.value, spec, 3)
                 });
+                exportNode._blockHoist = 3;
               } else {
                 exportNode = buildExportAll({
                   OBJECT: addRequire(path.node.source.value, spec, path.node._blockHoist)
@@ -675,30 +682,36 @@ export default function () {
 
               topNodes.unshift(node);
             }
-          }
 
-          if (!spec && hasImports && Object.keys(nonHoistedExportNames).length) {
-            let hoistedExportsNode = t.identifier("undefined");
-
-            for (let name in nonHoistedExportNames) {
-              hoistedExportsNode = buildExportsAssignment(t.identifier(name), hoistedExportsNode).expression;
+            if (hasExports) {
+              const node = specFinishNamespaceExport(exportsObj);
+              node._blockHoist = 3;
+              topNodes.push(node);
             }
+          } else {
+            if (hasImports && Object.keys(nonHoistedExportNames).length) {
+              let hoistedExportsNode = t.identifier("undefined");
+
+              for (let name in nonHoistedExportNames) {
+                hoistedExportsNode = buildExportsAssignment(t.identifier(name), hoistedExportsNode).expression;
+              }
 
-            const node = t.expressionStatement(hoistedExportsNode);
-            node._blockHoist = 3;
+              const node = t.expressionStatement(hoistedExportsNode);
+              node._blockHoist = 3;
 
-            topNodes.unshift(node);
-          }
+              topNodes.unshift(node);
+            }
 
-          // add __esModule declaration if this file has any exports
-          if (hasExports && !strict && !spec) {
-            let buildTemplate = buildExportsModuleDeclaration;
-            if (state.opts.loose) buildTemplate = buildLooseExportsModuleDeclaration;
+            // add __esModule declaration if this file has any exports
+            if (hasExports && !strict) {
+              let buildTemplate = buildExportsModuleDeclaration;
+              if (state.opts.loose) buildTemplate = buildLooseExportsModuleDeclaration;
 
-            const declar = buildTemplate();
-            declar._blockHoist = 3;
+              const declar = buildTemplate();
+              declar._blockHoist = 3;
 
-            topNodes.unshift(declar);
+              topNodes.unshift(declar);
+            }
           }
 
           path.unshiftContainer("body", topNodes);
@@ -708,7 +721,6 @@ export default function () {
             decls.forEach((decl) => { decl._blockHoist = 3; });
 
             path.unshiftContainer("body", decls);
-            path.pushContainer("body", [specFinishNamespaceExport(exportsObj)]);
           }
 
           if (spec) {

From 82455bc9bab98f44a3cf887c01527fa5bf52cf6f Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 21:31:04 +0900
Subject: [PATCH 047/103] Update fixtures

---
 .../test/fixtures/spec/commonjs-shadow-1/expected.js         | 2 +-
 .../test/fixtures/spec/commonjs-shadow-2/expected.js         | 4 +++-
 .../test/fixtures/spec/commonjs-shadow/expected.js           | 2 +-
 .../test/fixtures/spec/export-default-named/expected.js      | 4 ++--
 .../test/fixtures/spec/export-default/expected.js            | 4 ++--
 .../test/fixtures/spec/exports/expected.js                   | 4 ++--
 .../test/fixtures/spec/reexports/expected.js                 | 5 ++---
 .../preset-options/modules-commonjs-spec/expected.js         | 4 ++--
 8 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
index f81646fd5ef6..f1248c6fc7a5 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
@@ -24,12 +24,12 @@ Object.defineProperties(exports, {
 
   }
 });
+(Object.freeze || Object)(exports);
 let _default = {
   default: function () {}
 }.default;
 
 
 _exports = function () {};
-(Object.freeze || Object)(exports);
 
 let _exports;
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
index d208a7611eab..9c127fe38a3e 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-2/expected.js
@@ -14,7 +14,9 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
   });
 }
 
-_module.exports = class {};
 (Object.freeze || Object)(exports);
 
+
+_module.exports = class {};
+
 let _module;
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
index e3c410416a4c..a63986d16f52 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -24,6 +24,7 @@ Object.defineProperties(exports, {
 
   }
 });
+(Object.freeze || Object)(exports);
 
 var _bar = babelHelpers.specRequireInterop(require('bar'));
 
@@ -35,6 +36,5 @@ let _default = {
 // neither of these should be able to use or affect the real exports
 new _exports.default();
 _module.exports = {};
-(Object.freeze || Object)(exports);
 
 let _exports, _module;
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js
index 9bd50067ab04..dd98228d8edb 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-named/expected.js
@@ -24,7 +24,7 @@ Object.defineProperties(exports, {
 
   }
 });
+(Object.freeze || Object)(exports);
 function named() {
   named = function () {};
-}
-(Object.freeze || Object)(exports);
\ No newline at end of file
+}
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index 7e62ec78167b..6809a8bcf691 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -32,9 +32,9 @@ Object.defineProperties(exports, {
 
   }
 });
+(Object.freeze || Object)(exports);
 let _default = {
   default: function () {}
 }.default;
 var unrelated;
-unrelated = "changed";
-(Object.freeze || Object)(exports);
\ No newline at end of file
+unrelated = "changed";
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index c85c8a9232cb..3a3d5d1beee0 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -48,6 +48,7 @@ Object.defineProperties(exports, {
 
   }
 });
+(Object.freeze || Object)(exports);
 
 var _outside = babelHelpers.specRequireInterop(require("outside"));
 
@@ -59,5 +60,4 @@ function foo() {
 
 class Bar {}
 
-const baz = foo();
-(Object.freeze || Object)(exports);
\ No newline at end of file
+const baz = foo();
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index 8191934da8bf..c48b9a418f7b 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -57,11 +57,10 @@ Object.keys(_iDontKnow).forEach(function (key) {
 
   });
 });
+(Object.freeze || Object)(exports);
 
 var _because = babelHelpers.specRequireInterop(require('./because'));
 
 var _somewhere = babelHelpers.specRequireInterop(require('./somewhere'));
 
-var _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
-
-(Object.freeze || Object)(exports);
\ No newline at end of file
+var _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
\ No newline at end of file
diff --git a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
index 263730f3babc..5da0ef4e0201 100644
--- a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
+++ b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
@@ -28,8 +28,8 @@ Object.defineProperties(exports, {
     }
   }
 });
+(Object.freeze || Object)(exports);
 var _default = {
   default: function _default() {}
 }.default;
-function b() {}
-(Object.freeze || Object)(exports);
\ No newline at end of file
+function b() {}
\ No newline at end of file

From 33a956d6202fbb36761f46c3bf4004d602c78c82 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 21:31:33 +0900
Subject: [PATCH 048/103] Use before hooks to run less code during TEST_GREP

---
 .../test/spec-export.js                       | 72 +++++++++++++++----
 .../test/spec-interop-import.js               | 34 +++++++--
 .../test/spec-reexport.js                     | 17 ++++-
 3 files changed, 101 insertions(+), 22 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
index 7a3910e1f376..f14059dcbd3b 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
@@ -7,7 +7,11 @@ describe("spec export", function () {
   const runner = new helpers.Runner();
 
   describe("basic shape", function () {
-    const exports = runner.transformAndRun("export {}");
+    let exports;
+
+    before(function () {
+      exports = runner.transformAndRun("export {}");
+    });
 
     it("is frozen", function () {
       assert(Object.isFrozen(exports));
@@ -39,7 +43,11 @@ describe("spec export", function () {
 
   describe("default export", function () {
     describe("of single value", function () {
-      const exports = runner.transformAndRun("const foo = 'foo';\nexport default foo");
+      let exports;
+
+      before(function () {
+        exports = runner.transformAndRun("const foo = 'foo';\nexport default foo");
+      });
 
       it("has no exports other than 'default'", function () {
         assert.deepEqual(Object.keys(exports), ["default"]);
@@ -56,7 +64,11 @@ describe("spec export", function () {
     const hasFunctionName = Function("return { foo: function () {} }.foo")().name === "foo";
 
     describe("of anonymous function", function () {
-      const exports = runner.transformAndRun("export default function () {}");
+      let exports;
+
+      before(function () {
+        exports = runner.transformAndRun("export default function () {}");
+      });
 
       it("has Function.name of 'default'", function () {
         if (hasFunctionName) {
@@ -68,7 +80,11 @@ describe("spec export", function () {
     });
 
     describe("of anonymous class", function () {
-      const exports = runner.transformAndRun("export default class {}");
+      let exports;
+
+      before(function () {
+        exports = runner.transformAndRun("export default class {}");
+      });
 
       it("has Function.name of 'default'", function () {
         if (hasFunctionName) {
@@ -82,7 +98,11 @@ describe("spec export", function () {
 
   describe("named export", function () {
     describe("of single value declaration", function () {
-      const exports = runner.transformAndRun("export const a = 'a'");
+      let exports;
+
+      before(function () {
+        exports = runner.transformAndRun("export const a = 'a'");
+      });
 
       it("has no exports other than 'a'", function () {
         assert.deepEqual(Object.keys(exports), ["a"]);
@@ -94,7 +114,11 @@ describe("spec export", function () {
     });
 
     describe("of multiple value declaration", function () {
-      const exports = runner.transformAndRun("export const a = 'a', b = 'b'");
+      let exports;
+
+      before(function () {
+        exports = runner.transformAndRun("export const a = 'a', b = 'b'");
+      });
 
       it("has no exports other than 'a' and 'b'", function () {
         const keys = Object.keys(exports);
@@ -110,7 +134,11 @@ describe("spec export", function () {
     });
 
     describe("of function", function () {
-      const exports = runner.transformAndRun("export function foo () { return 'bar'; }");
+      let exports;
+
+      before(function () {
+        exports = runner.transformAndRun("export function foo () { return 'bar'; }");
+      });
 
       it("has no exports other than 'foo'", function () {
         assert.deepEqual(Object.keys(exports), ["foo"]);
@@ -127,7 +155,11 @@ describe("spec export", function () {
     });
 
     describe("of class", function () {
-      const exports = runner.transformAndRun("export class Foo {}");
+      let exports;
+
+      before(function () {
+        exports = runner.transformAndRun("export class Foo {}");
+      });
 
       it("has no exports other than 'Foo'", function () {
         assert.deepEqual(Object.keys(exports), ["Foo"]);
@@ -139,7 +171,11 @@ describe("spec export", function () {
     });
 
     describe("of identifier", function () {
-      const exports = runner.transformAndRun("var foo\nexport { foo }");
+      let exports;
+
+      before(function () {
+        exports = runner.transformAndRun("var foo\nexport { foo }");
+      });
 
       it("has no exports other than 'foo'", function () {
         assert.deepEqual(Object.keys(exports), ["foo"]);
@@ -147,7 +183,11 @@ describe("spec export", function () {
     });
 
     describe("of renamed identifier", function () {
-      const exports = runner.transformAndRun("function foo () {}\nexport { foo as bar }");
+      let exports;
+
+      before(function () {
+        exports = runner.transformAndRun("function foo () {}\nexport { foo as bar }");
+      });
 
       it("has no exports other than 'bar'", function () {
         assert.deepEqual(Object.keys(exports), ["bar"]);
@@ -161,7 +201,11 @@ describe("spec export", function () {
 
   describe("live binding", function () {
     describe("of default export", function () {
-      const exports = runner.transformAndRun("export default function foo () { foo = ':scream:' }");
+      let exports;
+
+      before(function () {
+        exports = runner.transformAndRun("export default function foo () { foo = ':scream:' }");
+      });
 
       it("has the correct initial value", function () {
         assert.strictEqual(typeof exports.default, "function");
@@ -174,7 +218,11 @@ describe("spec export", function () {
     });
 
     describe("of named export", function () {
-      const exports = runner.transformAndRun("export let count = 0\nexport default function up () { count += 1 }");
+      let exports;
+
+      before(function () {
+        exports = runner.transformAndRun("export let count = 0\nexport default function up () { count += 1 }");
+      });
 
       it("has the correct initial value", function () {
         assert.strictEqual(exports.count, 0);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
index 284589bc0063..c3dd85e83e46 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-interop-import.js
@@ -7,13 +7,21 @@ describe("spec Interop import", function () {
   const fakeMod = { "fakeFs": true };
   runner.addToCache("fs", { module: { exports: fakeMod } });
 
-  const exports = runner.transformAndRun(
-    "import * as ns from 'fs'\nimport fs from 'fs'\nexport { fs, ns }\n"
-  );
+  let exports;
+
+  before(function () {
+    exports = runner.transformAndRun(
+      "import * as ns from 'fs'\nimport fs from 'fs'\nexport { fs, ns }\n"
+    );
+  });
 
   describe("export descriptors", function () {
     describe("ns", function () {
-      const nsDesc = Object.getOwnPropertyDescriptor(exports, "ns");
+      let nsDesc;
+
+      before(function () {
+        nsDesc = Object.getOwnPropertyDescriptor(exports, "ns");
+      });
 
       it("is enumerable", function () {
         assert(nsDesc.enumerable);
@@ -38,7 +46,11 @@ describe("spec Interop import", function () {
     });
 
     describe("fs", function () {
-      const fsDesc = Object.getOwnPropertyDescriptor(exports, "fs");
+      let fsDesc;
+
+      before(function () {
+        fsDesc = Object.getOwnPropertyDescriptor(exports, "fs");
+      });
 
       it("is enumerable", function () {
         assert(fsDesc.enumerable);
@@ -61,7 +73,11 @@ describe("spec Interop import", function () {
   });
 
   describe("synthetic namespace", function () {
-    const ns = exports.ns;
+    let ns;
+
+    before(function () {
+      ns = exports.ns;
+    });
 
     it("is frozen", function () {
       assert(Object.isFrozen(ns));
@@ -91,7 +107,11 @@ describe("spec Interop import", function () {
     });
 
     describe("'default' descriptor", function () {
-      const defaultDesc = Object.getOwnPropertyDescriptor(ns, "default");
+      let defaultDesc;
+
+      before(function () {
+        defaultDesc = Object.getOwnPropertyDescriptor(ns, "default");
+      });
 
       it("is enumerable", function () {
         assert(defaultDesc.enumerable);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
index bc8170a2d5e5..c924a2026fc8 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
@@ -13,7 +13,11 @@ describe("spec reexport", function () {
   });
 
   describe("individual reexports", function () {
-    const exports = runner.getExportsOf("ab");
+    let exports;
+
+    before(function () {
+      exports = runner.getExportsOf("ab");
+    });
 
     it("is frozen", function () {
       assert(Object.isFrozen(exports));
@@ -52,7 +56,11 @@ describe("spec reexport", function () {
   });
 
   describe("namespace reexport", function () {
-    const exports = runner.getExportsOf("ns");
+    let exports;
+
+    before(function () {
+      exports = runner.getExportsOf("ns");
+    });
 
     it("the reexport is frozen", function () {
       assert(Object.isFrozen(exports.ab));
@@ -84,8 +92,11 @@ describe("spec reexport", function () {
   });
 
   describe("star reexport", function () {
-    const exports = runner.getExportsOf("star");
+    let exports;
 
+    before(function () {
+      exports = runner.getExportsOf("star");
+    });
 
     it("is frozen", function () {
       assert(Object.isFrozen(exports));

From db72c8719f88bfe73a7913ea66c1716a0f84d145 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 21:51:15 +0900
Subject: [PATCH 049/103] Hoist the initialization of the default func if it's
 inside the function name wrapper

---
 .../src/index.js                                           | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 9e02bc732540..6aa48f974424 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -391,9 +391,12 @@ export default function () {
                   defaultExportUid = path.scope.generateUidIdentifier("default");
                   hoistedExports.set("default", defaultExportUid);
                   const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
-                  topNodes.push(t.variableDeclaration("let", [
+                  const decl = t.variableDeclaration("let", [
                     t.variableDeclarator(defaultExportUid, expr)
-                  ]));
+                  ]);
+                  decl.loc = declaration.node.loc;
+                  decl._blockHoist = 3;
+                  topNodes.unshift(decl);
                   path.remove();
                 } else {
                   const expr = t.toExpression(declaration.node);

From 8ba476d670276d3f719f7ac023c984fd133d827f Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sat, 10 Dec 2016 21:51:39 +0900
Subject: [PATCH 050/103] Add default func hoisting fixture, update fixtures

---
 .../spec/commonjs-shadow-1/expected.js        |  2 +-
 .../export-default-func-hoisting/actual.js    |  3 ++
 .../export-default-func-hoisting/expected.js  | 51 +++++++++++++++++++
 .../fixtures/spec/export-default/expected.js  |  2 +-
 .../modules-commonjs-spec/expected.js         |  2 +-
 5 files changed, 57 insertions(+), 3 deletions(-)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
index f1248c6fc7a5..d89d44cb86c1 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
@@ -24,10 +24,10 @@ Object.defineProperties(exports, {
 
   }
 });
-(Object.freeze || Object)(exports);
 let _default = {
   default: function () {}
 }.default;
+(Object.freeze || Object)(exports);
 
 
 _exports = function () {};
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/actual.js
new file mode 100644
index 000000000000..cbbd0b626777
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/actual.js
@@ -0,0 +1,3 @@
+import * as foo from 'foo'
+export * from 'bar'
+export default function () { return foo }
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
new file mode 100644
index 000000000000..dafc334fb2be
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
@@ -0,0 +1,51 @@
+'use strict';
+
+const exports = module.exports = Object.create ? Object.create(null, {
+  __esModule: {
+    value: true
+  }
+}) : {
+  __esModule: true
+};
+
+if (typeof Symbol === "function" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+Object.defineProperties(exports, {
+  default: {
+    enumerable: true,
+
+    get() {
+      return _default;
+    }
+
+  }
+});
+let _default = {
+  default: function () {
+    return _foo;
+  }
+}.default;
+
+const _ownExports = Object.keys(exports);
+
+var _bar = babelHelpers.specRequireInterop(require('bar'));
+
+Object.keys(_bar).forEach(function (key) {
+  if (key === "__esModule" || key === "default" || _ownExports.indexOf(key) >= 0) return;
+  if (key in exports && (exports[key] === _bar[key] || typeof exports[key] === 'number' && isNaN(exports[key]))) return;
+  Object.defineProperty(exports, key, {
+    enumerable: true,
+
+    get() {
+      return _bar[key];
+    }
+
+  });
+});
+(Object.freeze || Object)(exports);
+
+var _foo = babelHelpers.specRequireInterop(require('foo'));
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index 6809a8bcf691..721df9030725 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -32,9 +32,9 @@ Object.defineProperties(exports, {
 
   }
 });
-(Object.freeze || Object)(exports);
 let _default = {
   default: function () {}
 }.default;
+(Object.freeze || Object)(exports);
 var unrelated;
 unrelated = "changed";
\ No newline at end of file
diff --git a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
index 5da0ef4e0201..57432694d213 100644
--- a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
+++ b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
@@ -28,8 +28,8 @@ Object.defineProperties(exports, {
     }
   }
 });
-(Object.freeze || Object)(exports);
 var _default = {
   default: function _default() {}
 }.default;
+(Object.freeze || Object)(exports);
 function b() {}
\ No newline at end of file

From 97db049030d8cd36017dee262fe26343daca6ddc Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 16:01:02 +0900
Subject: [PATCH 051/103] Add documentation for spec mode

---
 .../README.md                                 | 65 +++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
index 0693b91f07d6..8415cabc2901 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
@@ -62,6 +62,69 @@ require("babel-core").transform("code", {
 });
 ```
 
+## Options `spec`
+
+By default, `babel` actually implements importing very loosely, by
+supporting treating a commonjs export as if it was a namespace export.
+The exported namespace is also not frozen and has an incorrect prototype.
+
+The `spec` option, when set to `true`, tries to generate code that is as
+close as possible to what is required by the ECMA262 spec without relying
+on `Proxy`. The exports will be frozen, and imports will always be treated
+like ES modules.
+
+Importing a commonjs module (say, the standard `fs` module) will always
+wrap it in an ES module that has a single `default` export. This means that
+some imports that work in non-`spec` mode, like `import { readFile } from 'fs'`,
+will result in `undefined` in `spec` mode.
+
+Note that exports, under this mode, always require runtime support for
+getters. It also is not possible to access or write to the commonjs
+`exports` or `module` objects; attempts to access them will result in
+TDZ errors at runtime.
+
+```javascript
+import 'module1';
+import defaultImport from 'module2';
+import * as namespace from 'module3';
+import { pick } from 'module4';
+
+defaultImport(namespace, pick);
+
+export { pick }
+export default function () {}
+```
+
+```javascript
+const exports = module.exports = Object.create ? Object.create(null, {
+  __esModule: { value: true }
+}) : { __esModule: true }
+Object.defineProperties(exports, {
+  default: {
+    enumerable: true,
+    get() { return _default; }
+  },
+  pick: {
+    enumerable: true,
+    get() { return _module4.pick; }
+  }
+})
+let _default = {
+  default: function () {}
+}.default;
+(Object.freeze || Object)(exports);
+
+require('module1');
+
+const _module2 = babelHelpers._specInteropImport(require('module2'));
+
+const _module3 = babelHelpers._specInteropImport(require('module3'));
+
+const _module4 = babelHelpers._specInteropImport(require('module4'));
+
+_module2.default(_module3, _module4.pick);
+```
+
 ## Options `loose`
 
 As per the spec, `import` and `export` are only allowed to be used at the top
@@ -85,3 +148,5 @@ and instead of using `Object.defineProperty` an assignment will be used instead.
 var foo = exports.foo = 5;
 exports.__esModule = true;
 ```
+
+The `loose` option is **ignored** if used in combination with `spec`.
\ No newline at end of file

From 31205a8b07bd09fd78eccd99f5190ed42052a73c Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 16:14:22 +0900
Subject: [PATCH 052/103] Add a 'specImport' option to only enable the import
 half of spec mode

---
 .../src/index.js                              |  9 +++++++--
 .../specImport/commonjs-no-shadow/actual.js   |  5 +++++
 .../specImport/commonjs-no-shadow/exec.js     |  3 +++
 .../specImport/commonjs-no-shadow/expected.js |  9 +++++++++
 .../specImport/import-and-export/actual.js    |  8 ++++++++
 .../specImport/import-and-export/expected.js  | 19 +++++++++++++++++++
 .../test/fixtures/specImport/options.json     |  3 +++
 7 files changed, 54 insertions(+), 2 deletions(-)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/exec.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/options.json

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 6aa48f974424..b1fd0c02a22f 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -275,6 +275,7 @@ export default function () {
 
           let strict = !!this.opts.strict;
           const spec = isSpec(state);
+          const specImport = isSpecImport(state);
 
           let { scope } = path;
 
@@ -313,7 +314,7 @@ export default function () {
 
             let varDecl = t.variableDeclaration("var", [
               t.variableDeclarator(ref,
-                spec
+                specImport
                 ? t.callExpression(this.addHelper("specRequireInterop"), [req])
                 : req
               )
@@ -591,7 +592,7 @@ export default function () {
             if (specifiers.length) {
               const uid = addRequire(source, spec, maxBlockHoist);
 
-              if (spec) {
+              if (specImport) {
                 for (const specifier of specifiers) {
                   if (t.isImportNamespaceSpecifier(specifier)) {
                     remaps[specifier.local.name] = uid;
@@ -755,3 +756,7 @@ export default function () {
 function isSpec (state) {
   return state && state.opts && !!state.opts.spec;
 }
+
+function isSpecImport (state) {
+  return state && state.opts && (!!state.opts.spec || !!state.opts.specImport);
+}
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/actual.js
new file mode 100644
index 000000000000..6551aeb215ec
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/actual.js
@@ -0,0 +1,5 @@
+import foo from 'bar'
+
+export {}
+
+module.exports = exports = {};
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/exec.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/exec.js
new file mode 100644
index 000000000000..80b3abf6ebdb
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/exec.js
@@ -0,0 +1,3 @@
+export {}
+
+assert.notStrictEqual(typeof exports, 'undefined')
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
new file mode 100644
index 000000000000..ebf14257e902
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
@@ -0,0 +1,9 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+var _bar = babelHelpers.specRequireInterop(require('bar'));
+
+module.exports = exports = {};
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/actual.js
new file mode 100644
index 000000000000..b2823a779ea6
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/actual.js
@@ -0,0 +1,8 @@
+import 'module1'
+import * as module2 from 'module2'
+import module3 from 'module3'
+import { default as module4 } from 'module4'
+
+module2.default(module3, module4)
+
+export { module2, module3 }
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
new file mode 100644
index 000000000000..a3e60ebba4cd
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
@@ -0,0 +1,19 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.module3 = exports.module2 = undefined;
+
+require('module1');
+
+var _module = babelHelpers.specRequireInterop(require('module2'));
+
+var _module2 = babelHelpers.specRequireInterop(require('module3'));
+
+var _module3 = babelHelpers.specRequireInterop(require('module4'));
+
+_module.default(_module2.default, _module3.default);
+
+exports.module2 = _module;
+exports.module3 = _module2.default;
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/options.json b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/options.json
new file mode 100644
index 000000000000..47949d470d56
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["external-helpers", ["transform-es2015-modules-commonjs", {"spec": false, "specImport": true}]]
+}

From f6f291f3845e1288187451d22fdcf6cc1ff74144 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 16:30:05 +0900
Subject: [PATCH 053/103] Improve README

---
 .../README.md                                 | 44 ++++++++++++++++++-
 1 file changed, 42 insertions(+), 2 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
index 8415cabc2901..e0114486344f 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
@@ -83,6 +83,8 @@ getters. It also is not possible to access or write to the commonjs
 `exports` or `module` objects; attempts to access them will result in
 TDZ errors at runtime.
 
+### Input
+
 ```javascript
 import 'module1';
 import defaultImport from 'module2';
@@ -95,10 +97,14 @@ export { pick }
 export default function () {}
 ```
 
+### Output
+
 ```javascript
+'use strict';
+
 const exports = module.exports = Object.create ? Object.create(null, {
   __esModule: { value: true }
-}) : { __esModule: true }
+}) : { __esModule: true };
 Object.defineProperties(exports, {
   default: {
     enumerable: true,
@@ -108,7 +114,7 @@ Object.defineProperties(exports, {
     enumerable: true,
     get() { return _module4.pick; }
   }
-})
+});
 let _default = {
   default: function () {}
 }.default;
@@ -125,6 +131,40 @@ const _module4 = babelHelpers._specInteropImport(require('module4'));
 _module2.default(_module3, _module4.pick);
 ```
 
+## Options `specImport`
+
+This option enables only the half of `spec` mode that affects the imports, without
+changing how exports are generated. This would allow the generation of code that
+may still be compatible with engines that do not support getters.
+
+Note that the require helper does use `Object.defineProperty`, so when running on
+an old engine that does not support it, a polyfill like `es5-sham` is still required.
+
+This option is **ignored** if `spec` is enabled. Enabling `spec` implies that this
+option is also enabled.
+
+### Input
+
+```javascript
+import { pick } from 'module'
+
+export default pick()
+```
+
+### Output
+
+```javascript
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+var _module = babelHelpers.specRequireInterop(require('module'));
+
+exports.default = (0, _module.pick)();
+```
+
 ## Options `loose`
 
 As per the spec, `import` and `export` are only allowed to be used at the top

From 1861e4d37e187a66b56c9f28c907b9e8026689dc Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 16:32:26 +0900
Subject: [PATCH 054/103] Use const for specImport namespaces to ensure TDZ in
 circular references

---
 .../babel-plugin-transform-es2015-modules-commonjs/src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index b1fd0c02a22f..c2d65695adb7 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -312,7 +312,7 @@ export default function () {
               t.stringLiteral(source)
             ).expression;
 
-            let varDecl = t.variableDeclaration("var", [
+            let varDecl = t.variableDeclaration(specImport ? "const" : "var", [
               t.variableDeclarator(ref,
                 specImport
                 ? t.callExpression(this.addHelper("specRequireInterop"), [req])

From a371bb17ce361e79e359345d59f2d262802fc42a Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 16:32:39 +0900
Subject: [PATCH 055/103] Add more specImport tests, update fixtures

---
 .../fixtures/spec/commonjs-shadow/expected.js |  2 +-
 .../export-default-func-hoisting/expected.js  |  4 +--
 .../test/fixtures/spec/exports/expected.js    |  2 +-
 .../fixtures/spec/import-simple/expected.js   |  6 ++--
 .../test/fixtures/spec/import/expected.js     | 10 +++----
 .../test/fixtures/spec/reexports/expected.js  |  8 ++---
 .../specImport/commonjs-no-shadow/expected.js |  2 +-
 .../specImport/export-default/actual.js       |  3 ++
 .../specImport/export-default/expected.js     |  9 ++++++
 .../specImport/import-and-export/expected.js  |  6 ++--
 .../fixtures/specImport/reexport/actual.js    |  7 +++++
 .../fixtures/specImport/reexport/expected.js  | 29 +++++++++++++++++++
 12 files changed, 68 insertions(+), 20 deletions(-)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
index a63986d16f52..7168f20e7137 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow/expected.js
@@ -26,7 +26,7 @@ Object.defineProperties(exports, {
 });
 (Object.freeze || Object)(exports);
 
-var _bar = babelHelpers.specRequireInterop(require('bar'));
+const _bar = babelHelpers.specRequireInterop(require('bar'));
 
 let _default = {
   default: class {}
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
index dafc334fb2be..926ec213203a 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
@@ -32,7 +32,7 @@ let _default = {
 
 const _ownExports = Object.keys(exports);
 
-var _bar = babelHelpers.specRequireInterop(require('bar'));
+const _bar = babelHelpers.specRequireInterop(require('bar'));
 
 Object.keys(_bar).forEach(function (key) {
   if (key === "__esModule" || key === "default" || _ownExports.indexOf(key) >= 0) return;
@@ -48,4 +48,4 @@ Object.keys(_bar).forEach(function (key) {
 });
 (Object.freeze || Object)(exports);
 
-var _foo = babelHelpers.specRequireInterop(require('foo'));
\ No newline at end of file
+const _foo = babelHelpers.specRequireInterop(require('foo'));
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index 3a3d5d1beee0..62390aa3d09d 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -50,7 +50,7 @@ Object.defineProperties(exports, {
 });
 (Object.freeze || Object)(exports);
 
-var _outside = babelHelpers.specRequireInterop(require("outside"));
+const _outside = babelHelpers.specRequireInterop(require("outside"));
 
 var def;
 function foo() {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
index 3aba3f2fdee8..a2207ce5af09 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
@@ -4,11 +4,11 @@ require('a');
 
 require('b');
 
-var _c = babelHelpers.specRequireInterop(require('c'));
+const _c = babelHelpers.specRequireInterop(require('c'));
 
-var _d = babelHelpers.specRequireInterop(require('d'));
+const _d = babelHelpers.specRequireInterop(require('d'));
 
-var _e = babelHelpers.specRequireInterop(require('e'));
+const _e = babelHelpers.specRequireInterop(require('e'));
 
 _c.name;
 _d.default;
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
index 7287f81c3b9e..2b2633b12fe1 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
@@ -1,18 +1,18 @@
 'use strict';
 
-var _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
+const _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
 
-var _outside = babelHelpers.specRequireInterop(require('./outside'));
+const _outside = babelHelpers.specRequireInterop(require('./outside'));
 
-var _anywhere = babelHelpers.specRequireInterop(require('./anywhere'));
+const _anywhere = babelHelpers.specRequireInterop(require('./anywhere'));
 
 require('./empty');
 
 require('./imperative');
 
-var _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
+const _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
 
-var _naturally = babelHelpers.specRequireInterop(require('./naturally'));
+const _naturally = babelHelpers.specRequireInterop(require('./naturally'));
 
 (0, _outside.default)(_outside.obj.key);
 
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index c48b9a418f7b..96571bc6f667 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -43,7 +43,7 @@ Object.defineProperties(exports, {
 
 const _ownExports = Object.keys(exports);
 
-var _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
+const _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
 
 Object.keys(_iDontKnow).forEach(function (key) {
   if (key === "__esModule" || key === "default" || _ownExports.indexOf(key) >= 0) return;
@@ -59,8 +59,8 @@ Object.keys(_iDontKnow).forEach(function (key) {
 });
 (Object.freeze || Object)(exports);
 
-var _because = babelHelpers.specRequireInterop(require('./because'));
+const _because = babelHelpers.specRequireInterop(require('./because'));
 
-var _somewhere = babelHelpers.specRequireInterop(require('./somewhere'));
+const _somewhere = babelHelpers.specRequireInterop(require('./somewhere'));
 
-var _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
\ No newline at end of file
+const _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
index ebf14257e902..7b49a4b2a3f2 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
@@ -4,6 +4,6 @@ Object.defineProperty(exports, "__esModule", {
   value: true
 });
 
-var _bar = babelHelpers.specRequireInterop(require('bar'));
+const _bar = babelHelpers.specRequireInterop(require('bar'));
 
 module.exports = exports = {};
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/actual.js
new file mode 100644
index 000000000000..b50c286043a4
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/actual.js
@@ -0,0 +1,3 @@
+import { pick } from 'module';
+
+export default pick()
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js
new file mode 100644
index 000000000000..290cb9600aae
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js
@@ -0,0 +1,9 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+const _module = babelHelpers.specRequireInterop(require('module'));
+
+exports.default = (0, _module.pick)();
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
index a3e60ebba4cd..417861debc50 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
@@ -7,11 +7,11 @@ exports.module3 = exports.module2 = undefined;
 
 require('module1');
 
-var _module = babelHelpers.specRequireInterop(require('module2'));
+const _module = babelHelpers.specRequireInterop(require('module2'));
 
-var _module2 = babelHelpers.specRequireInterop(require('module3'));
+const _module2 = babelHelpers.specRequireInterop(require('module3'));
 
-var _module3 = babelHelpers.specRequireInterop(require('module4'));
+const _module3 = babelHelpers.specRequireInterop(require('module4'));
 
 _module.default(_module2.default, _module3.default);
 
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/actual.js
new file mode 100644
index 000000000000..d5df151b640f
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/actual.js
@@ -0,0 +1,7 @@
+import * as ns from 'module1'
+import def from 'module2'
+import { pick } from 'module3'
+
+export default ns
+export { ns, def, pick }
+export * from 'module4'
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js
new file mode 100644
index 000000000000..b2c80d773501
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js
@@ -0,0 +1,29 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.pick = exports.def = exports.ns = undefined;
+
+const _module = babelHelpers.specRequireInterop(require('module4'));
+
+Object.keys(_module).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+  Object.defineProperty(exports, key, {
+    enumerable: true,
+    get: function () {
+      return _module[key];
+    }
+  });
+});
+
+const _module2 = babelHelpers.specRequireInterop(require('module1'));
+
+const _module3 = babelHelpers.specRequireInterop(require('module2'));
+
+const _module4 = babelHelpers.specRequireInterop(require('module3'));
+
+exports.default = _module2;
+exports.ns = _module2;
+exports.def = _module3.default;
+exports.pick = _module4.pick;
\ No newline at end of file

From d8c8e8609fbff2f3fc191d486cc98d80abc60b71 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 18:59:19 +0900
Subject: [PATCH 056/103] Keep track of used import names; assert that they
 exist at import time

---
 packages/babel-helpers/src/helpers.js         |  15 ++
 .../src/index.js                              | 178 +++++++++++++++++-
 2 files changed, 184 insertions(+), 9 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index ab33858da99b..f728134fe796 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -442,6 +442,21 @@ helpers.specRequireInterop = template(`
   })
 `);
 
+helpers.specImportCheck = template(`
+  (function (module, moduleName, imports) {
+    if (!module.__esModule) throw new Error("Only ES modules can be checked");
+    const realImports = Object.keys(module);
+    const invalid = imports.filter(function (i) { return realImports.indexOf(i) < 0; });
+    if (invalid.length > 0) {
+      throw new Error(
+        "Unknown imports (" +
+        invalid.map(function (i) { return "'" + i + "'"; }).join(', ') +
+        ") used from module '" + moduleName + "'"
+      );
+    }
+  })
+`);
+
 helpers.newArrowCheck = template(`
   (function (innerThis, boundThis) {
     if (innerThis !== boundThis) {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index c2d65695adb7..183935649a9c 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -110,6 +110,7 @@ export default function () {
 
   const isModuleObj = t.buildMatchMemberExpression("module", true);
   const isExports = t.buildMatchMemberExpression("exports", true);
+
   let commonjsExportsMasked = null;
 
   let reassignmentVisitor = {
@@ -150,6 +151,29 @@ export default function () {
         const { object, property } = remap;
         path.replaceWith(t.JSXMemberExpression(t.JSXIdentifier(object.name), t.JSXIdentifier(property.name)));
       } else {
+        if (remap.nameSet) {
+          if (t.isMemberExpression(remap)) {
+            const name = t.isIdentifier(remap.property)
+              ? remap.property.name
+              : t.isStringLiteral(remap.property)
+              ? remap.property.value
+              : undefined;
+            if (name == null) {
+              throw new Error(`Unexpected ${remap.type}`);
+            }
+            remap.nameSet.add(name);
+          } else if (t.isIdentifier(remap)) {
+            if (t.isMemberExpression(path.parent) && !path.parent.computed) {
+              const name = t.isIdentifier(path.parent.property)
+                ? path.parent.property.name
+                : t.isStringLiteral(path.parent.property)
+                ? path.parent.property.value
+                : undefined;
+
+              remap.nameSet.add(name);
+            }
+          }
+        }
         path.replaceWith(remap);
       }
       this.requeueInParent(path);
@@ -302,7 +326,7 @@ export default function () {
 
           let requires = Object.create(null);
 
-          const addRequire = (source, spec, blockHoist) => {
+          const addRequire = (source, specImport, blockHoist) => {
             let cached = requires[source];
             if (cached) return cached;
 
@@ -326,10 +350,16 @@ export default function () {
               varDecl.loc = imports[source].loc;
             }
 
+            if (specImport) {
+              blockHoist = Math.max(
+                imports[source] && imports[source].maxBlockHoist || 0,
+                blockHoist || 0
+              );
+            }
+
             if (typeof blockHoist === "number" && blockHoist > 0) {
               varDecl._blockHoist = blockHoist;
             }
-
             topNodes.push(varDecl);
 
             return requires[source] = ref;
@@ -359,7 +389,7 @@ export default function () {
               let key = path.node.source.value;
               let importsEntry = imports[key] || {
                 specifiers: [],
-                maxBlockHoist: 0,
+                maxBlockHoist: specImport ? 2 : 0,
                 loc: path.node.loc,
               };
 
@@ -522,7 +552,29 @@ export default function () {
               let nodes = [];
               let source = path.node.source;
               if (source) {
-                let ref = addRequire(source.value, spec, path.node._blockHoist);
+                let ref, importsEntry;
+                if (specImport) {
+                  let key = path.node.source.value;
+                  importsEntry = imports[key] || {
+                    specifiers: [],
+                    maxBlockHoist: 2,
+                    loc: path.node.loc,
+                  };
+                  importsEntry.reexports = importsEntry.reexports || new Map(),
+
+                  importsEntry.specifiers.push(...path.node.specifiers);
+
+                  if (typeof path.node._blockHoist === "number") {
+                    importsEntry.maxBlockHoist = Math.max(
+                      path.node._blockHoist,
+                      importsEntry.maxBlockHoist
+                    );
+                  }
+
+                  imports[key] = importsEntry;
+                } else {
+                  ref = addRequire(source.value, specImport, path.node._blockHoist);
+                }
 
                 for (let specifier of specifiers) {
                   if (specifier.isExportNamespaceSpecifier()) {
@@ -530,8 +582,8 @@ export default function () {
                   } else if (specifier.isExportDefaultSpecifier()) {
                     // todo
                   } else if (specifier.isExportSpecifier()) {
-                    if (spec) {
-                      hoistedExports.set(specifier.node.exported.name, t.memberExpression(ref, specifier.node.local));
+                    if (specImport) {
+                      importsEntry.reexports.set(specifier.node.exported.name, specifier.node.local);
                     } else if (specifier.node.local.name === "default") {
                       topNodes.push(buildExportsFrom(t.stringLiteral(specifier.node.exported.name), t.memberExpression(t.callExpression(this.addHelper("interopRequireDefault"), [ref]), specifier.node.local)));
                     } else {
@@ -573,12 +625,12 @@ export default function () {
                 exportNode = specBuildNamespaceSpread({
                   EXPORTS: exportsObj,
                   OWN_EXPORTS: ownExportsUid,
-                  OBJECT: addRequire(path.node.source.value, spec, 3)
+                  OBJECT: addRequire(path.node.source.value, specImport, 3)
                 });
                 exportNode._blockHoist = 3;
               } else {
                 exportNode = buildExportAll({
-                  OBJECT: addRequire(path.node.source.value, spec, path.node._blockHoist)
+                  OBJECT: addRequire(path.node.source.value, specImport, path.node._blockHoist)
                 });
               }
               exportNode.loc = path.node.loc;
@@ -587,20 +639,83 @@ export default function () {
             }
           }
 
+          const checkedImportMap = specImport && new Map();
           for (let source in imports) {
             let {specifiers, maxBlockHoist} = imports[source];
             if (specifiers.length) {
-              const uid = addRequire(source, spec, maxBlockHoist);
+              const uid = addRequire(source, specImport, maxBlockHoist);
+
+              if (imports[source].reexports) {
+                if (!spec) {
+                  for (const [name, local] of imports[source].reexports.entries()) {
+                    if (name === "default") {
+                      topNodes.push(buildExportsFrom(t.stringLiteral(name), t.memberExpression(t.callExpression(this.addHelper("interopRequireDefault"), [uid]), local)));
+                    } else {
+                      topNodes.push(buildExportsFrom(t.stringLiteral(name), t.memberExpression(uid, local)));
+                    }
+                  }
+                } else {
+                  for (const [name, local] of imports[source].reexports.entries()) {
+                    hoistedExports.set(name, t.memberExpression(uid, local));
+                  }
+                }
+              }
 
               if (specImport) {
+                if (!checkedImportMap.has(uid)) {
+                  const nameSet = new Set(
+                    Array.from(new Set(specifiers))
+                    .filter((specifier) => !t.isImportNamespaceSpecifier(specifier))
+                    .map((specifier) => {
+                      if (t.isImportDefaultSpecifier(specifier)) {
+                        return "default";
+                      }
+                      if (t.isExportSpecifier(specifier)) {
+                        return specifier.local.name;
+                      }
+                      return specifier.imported.name;
+                    })
+                  );
+                  nameSet.source = source;
+
+                  checkedImportMap.set(uid, nameSet);
+
+                  if (nameSet.size > 0) {
+                    nameSet.generated = Array.from(nameSet).map((name) => t.stringLiteral(name));
+                    const names = t.arrayExpression(nameSet.generated);
+
+                    const stmt =
+                      t.expressionStatement(
+                        t.callExpression(
+                          this.addHelper("specImportCheck"),
+                          [
+                            uid,
+                            t.stringLiteral(nameSet.source),
+                            names
+                          ]
+                        )
+                      );
+
+                    stmt.loc = imports[source].loc;
+                    stmt._blockHoist = Math.max(imports[source].maxBlockHoist, 2);
+
+                    topNodes.push(stmt);
+                  }
+                }
+
                 for (const specifier of specifiers) {
                   if (t.isImportNamespaceSpecifier(specifier)) {
                     remaps[specifier.local.name] = uid;
                   } else if (t.isImportDefaultSpecifier(specifier)) {
                     remaps[specifier.local.name] = t.memberExpression(uid, t.identifier("default"));
+                  } else if (specImport && t.isExportSpecifier(specifier)) {
+                    // do nothing
                   } else {
                     remaps[specifier.local.name] = t.memberExpression(uid, t.cloneWithoutLoc(specifier.imported));
                   }
+                  if (specImport && !t.isExportSpecifier(specifier)) {
+                    remaps[specifier.local.name].nameSet = checkedImportMap.get(uid);
+                  }
                 }
               } else {
                 let wildcard;
@@ -665,6 +780,9 @@ export default function () {
             } else {
               // bare import
               let requireNode = buildRequire(t.stringLiteral(source));
+              if (specImport) {
+                requireNode._blockHoist = 2;
+              }
               requireNode.loc = imports[source].loc;
               topNodes.push(requireNode);
             }
@@ -739,6 +857,48 @@ export default function () {
             requeueInParent: (newPath) => path.requeue(newPath),
           });
 
+          if (specImport && hasImports) {
+            const checks = Array.from(checkedImportMap.entries())
+            .map(([uid, nameSet]) => {
+              if (nameSet.size < 1) return;
+
+              if (nameSet.generated) {
+                if (nameSet.generated.length === nameSet.generated.size) return;
+                // nameSet.generated must be modified in-place
+                // to update the nodes of the pre-existing nameSet check
+                for (const name of nameSet) {
+                  if (!nameSet.generated.some((existing) => existing.value === name)) {
+                    nameSet.generated.push(t.stringLiteral(name));
+                  }
+                }
+                return;
+              }
+
+              const names = t.arrayExpression(Array.from(nameSet).map((name) => t.stringLiteral(name)));
+
+              const stmt =
+                t.expressionStatement(
+                  t.callExpression(
+                    this.addHelper("specImportCheck"),
+                    [
+                      uid,
+                      t.stringLiteral(nameSet.source),
+                      names
+                    ]
+                  )
+                );
+
+              stmt.loc = imports[nameSet.source].loc;
+              stmt._blockHoist = Math.max(imports[nameSet.source].maxBlockHoist, 1);
+
+              return stmt;
+            }).filter(Boolean);
+
+            if (checks.length > 0) {
+              path.pushContainer("body", checks);
+            }
+          }
+
           if (spec && (commonjsExportsMasked.exports || commonjsExportsMasked.module)) {
             path.pushContainer("body", [
               t.variableDeclaration("let", [

From c920f266dbf6d4180238f755a7ec6d1446f6d6d4 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 18:59:32 +0900
Subject: [PATCH 057/103] Update tests and fixtures

---
 .../test/fixtures/spec/exports/expected.js    |  3 ++
 .../fixtures/spec/import-simple/expected.js   |  6 +++
 .../test/fixtures/spec/import/expected.js     |  9 +++++
 .../test/fixtures/spec/reexports/actual.js    |  4 +-
 .../test/fixtures/spec/reexports/expected.js  | 22 +++++++++--
 .../specImport/commonjs-no-shadow/expected.js |  3 ++
 .../specImport/export-default/expected.js     |  1 +
 .../specImport/import-and-export/expected.js  |  6 +++
 .../fixtures/specImport/reexport/actual.js    |  6 ++-
 .../fixtures/specImport/reexport/expected.js  | 37 +++++++++++++++----
 10 files changed, 84 insertions(+), 13 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index 62390aa3d09d..49dba7c4e42a 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -52,6 +52,9 @@ Object.defineProperties(exports, {
 
 const _outside = babelHelpers.specRequireInterop(require("outside"));
 
+babelHelpers.specImportCheck(_outside, "outside", ["anything"]);
+
+
 var def;
 function foo() {
   def = "export mutation";
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
index a2207ce5af09..56c8efaefc9f 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
@@ -8,8 +8,14 @@ const _c = babelHelpers.specRequireInterop(require('c'));
 
 const _d = babelHelpers.specRequireInterop(require('d'));
 
+babelHelpers.specImportCheck(_d, 'd', ['default']);
+
 const _e = babelHelpers.specRequireInterop(require('e'));
 
+babelHelpers.specImportCheck(_e, 'e', ['name']);
+babelHelpers.specImportCheck(_c, 'c', ['name']);
+
+
 _c.name;
 _d.default;
 _e.name;
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
index 2b2633b12fe1..73c02875303a 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
@@ -4,16 +4,25 @@ const _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
 
 const _outside = babelHelpers.specRequireInterop(require('./outside'));
 
+babelHelpers.specImportCheck(_outside, './outside', ['default', 'obj']);
+
 const _anywhere = babelHelpers.specRequireInterop(require('./anywhere'));
 
+babelHelpers.specImportCheck(_anywhere, './anywhere', ['default']);
+
 require('./empty');
 
 require('./imperative');
 
 const _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
 
+babelHelpers.specImportCheck(_iDontKnow, './i-dont-know', ['default', 'what', 'who']);
+
 const _naturally = babelHelpers.specRequireInterop(require('./naturally'));
 
+babelHelpers.specImportCheck(_naturally, './naturally', ['default', 'naturally']);
+
+
 (0, _outside.default)(_outside.obj.key);
 
 (0, _anywhere.default)(_elsewhere);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js
index 97b540e2e809..78e00fcd9f4d 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js
@@ -1,6 +1,8 @@
 import * as namespace from './somewhere';
 
-import { stuff } from './elsewhere';
+export { stuff } from './elsewhere'
+
+import { stuff } from './somewhereElse';
 
 export { namespace };
 
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index 96571bc6f667..6b78725db960 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -26,6 +26,14 @@ Object.defineProperties(exports, {
   default: {
     enumerable: true,
 
+    get() {
+      return _somewhereElse.stuff;
+    }
+
+  },
+  stuff: {
+    enumerable: true,
+
     get() {
       return _elsewhere.stuff;
     }
@@ -59,8 +67,16 @@ Object.keys(_iDontKnow).forEach(function (key) {
 });
 (Object.freeze || Object)(exports);
 
-const _because = babelHelpers.specRequireInterop(require('./because'));
-
 const _somewhere = babelHelpers.specRequireInterop(require('./somewhere'));
 
-const _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
\ No newline at end of file
+const _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
+
+babelHelpers.specImportCheck(_elsewhere, './elsewhere', ['stuff']);
+
+const _somewhereElse = babelHelpers.specRequireInterop(require('./somewhereElse'));
+
+babelHelpers.specImportCheck(_somewhereElse, './somewhereElse', ['stuff']);
+
+const _because = babelHelpers.specRequireInterop(require('./because'));
+
+babelHelpers.specImportCheck(_because, './because', ['default']);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
index 7b49a4b2a3f2..b63f73a1e786 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
@@ -6,4 +6,7 @@ Object.defineProperty(exports, "__esModule", {
 
 const _bar = babelHelpers.specRequireInterop(require('bar'));
 
+babelHelpers.specImportCheck(_bar, 'bar', ['default']);
+
+
 module.exports = exports = {};
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js
index 290cb9600aae..dee5129ff66b 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js
@@ -6,4 +6,5 @@ Object.defineProperty(exports, "__esModule", {
 
 const _module = babelHelpers.specRequireInterop(require('module'));
 
+babelHelpers.specImportCheck(_module, 'module', ['pick']);
 exports.default = (0, _module.pick)();
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
index 417861debc50..43acc9a1dcf5 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
@@ -11,8 +11,14 @@ const _module = babelHelpers.specRequireInterop(require('module2'));
 
 const _module2 = babelHelpers.specRequireInterop(require('module3'));
 
+babelHelpers.specImportCheck(_module2, 'module3', ['default']);
+
 const _module3 = babelHelpers.specRequireInterop(require('module4'));
 
+babelHelpers.specImportCheck(_module3, 'module4', ['default']);
+babelHelpers.specImportCheck(_module, 'module2', ['default']);
+
+
 _module.default(_module2.default, _module3.default);
 
 exports.module2 = _module;
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/actual.js
index d5df151b640f..04d951f02101 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/actual.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/actual.js
@@ -4,4 +4,8 @@ import { pick } from 'module3'
 
 export default ns
 export { ns, def, pick }
-export * from 'module4'
\ No newline at end of file
+export * from 'module4'
+
+export { foo, bar as baz } from 'module5'
+
+import 'module6'
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js
index b2c80d773501..19fff6a4ff6e 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js
@@ -3,7 +3,23 @@
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
-exports.pick = exports.def = exports.ns = undefined;
+exports.baz = exports.foo = exports.pick = exports.def = exports.ns = undefined;
+
+const _module2 = babelHelpers.specRequireInterop(require('module1'));
+
+const _module3 = babelHelpers.specRequireInterop(require('module2'));
+
+babelHelpers.specImportCheck(_module3, 'module2', ['default']);
+
+const _module4 = babelHelpers.specRequireInterop(require('module3'));
+
+babelHelpers.specImportCheck(_module4, 'module3', ['pick']);
+
+const _module5 = babelHelpers.specRequireInterop(require('module5'));
+
+babelHelpers.specImportCheck(_module5, 'module5', ['foo', 'bar']);
+
+require('module6');
 
 const _module = babelHelpers.specRequireInterop(require('module4'));
 
@@ -16,13 +32,18 @@ Object.keys(_module).forEach(function (key) {
     }
   });
 });
-
-const _module2 = babelHelpers.specRequireInterop(require('module1'));
-
-const _module3 = babelHelpers.specRequireInterop(require('module2'));
-
-const _module4 = babelHelpers.specRequireInterop(require('module3'));
-
+Object.defineProperty(exports, 'foo', {
+  enumerable: true,
+  get: function () {
+    return _module5.foo;
+  }
+});
+Object.defineProperty(exports, 'baz', {
+  enumerable: true,
+  get: function () {
+    return _module5.bar;
+  }
+});
 exports.default = _module2;
 exports.ns = _module2;
 exports.def = _module3.default;

From 03c6ef996e70d35cd766cd9b86b7d965be5f3697 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 18:59:39 +0900
Subject: [PATCH 058/103] Add missing before handlers

---
 .../test/spec-reexport.js                            | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
index c924a2026fc8..6dc40a68bd90 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
@@ -152,7 +152,11 @@ describe("spec reexport star with duplicates", function () {
   });
 
   describe("SameValue", function () {
-    const exports = runner.transformAndRun("export * from 'aSame'\nexport * from 'bSame'");
+    let exports;
+
+    before(function () {
+      exports = runner.transformAndRun("export * from 'aSame'\nexport * from 'bSame'");
+    });
 
     it("has the correct value", function () {
       assert.strictEqual(exports.name, "name");
@@ -160,7 +164,11 @@ describe("spec reexport star with duplicates", function () {
   });
 
   describe("shadowed reexport", function () {
-    const exports = runner.transformAndRun("export * from 'a'\nexport * from 'b'\nexport const name = 'foo'");
+    let exports;
+
+    before(function () {
+      exports = runner.transformAndRun("export * from 'a'\nexport * from 'b'\nexport const name = 'foo'");
+    });
 
     it("has the correct value", function () {
       assert.strictEqual(exports.name, "foo");

From 4d54fdc703631165b7d20c046b36b3c317de6cbb Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 19:11:25 +0900
Subject: [PATCH 059/103] Don't give the module name as argument to helper;
 would have prevented minification

---
 packages/babel-helpers/src/helpers.js                  | 10 ++++++----
 .../src/index.js                                       |  2 --
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index f728134fe796..31a1615bb5aa 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -443,16 +443,18 @@ helpers.specRequireInterop = template(`
 `);
 
 helpers.specImportCheck = template(`
-  (function (module, moduleName, imports) {
+  (function (module, imports) {
     if (!module.__esModule) throw new Error("Only ES modules can be checked");
     const realImports = Object.keys(module);
     const invalid = imports.filter(function (i) { return realImports.indexOf(i) < 0; });
     if (invalid.length > 0) {
-      throw new Error(
-        "Unknown imports (" +
+      const error = new Error(
+        "Unknown exports" + (invalid.length > 1 ? "s " : " ") +
         invalid.map(function (i) { return "'" + i + "'"; }).join(', ') +
-        ") used from module '" + moduleName + "'"
+        " imported"
       );
+      error.module = module;
+      throw error;
     }
   })
 `);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 183935649a9c..a3b2c863e842 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -690,7 +690,6 @@ export default function () {
                           this.addHelper("specImportCheck"),
                           [
                             uid,
-                            t.stringLiteral(nameSet.source),
                             names
                           ]
                         )
@@ -882,7 +881,6 @@ export default function () {
                     this.addHelper("specImportCheck"),
                     [
                       uid,
-                      t.stringLiteral(nameSet.source),
                       names
                     ]
                   )

From 76eea108f74a4a56d2145c332b3011c147f88917 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 19:11:46 +0900
Subject: [PATCH 060/103] Update README

---
 .../README.md                                 | 27 ++++++++++++-------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
index e0114486344f..21c2ca8db813 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
@@ -71,12 +71,13 @@ The exported namespace is also not frozen and has an incorrect prototype.
 The `spec` option, when set to `true`, tries to generate code that is as
 close as possible to what is required by the ECMA262 spec without relying
 on `Proxy`. The exports will be frozen, and imports will always be treated
-like ES modules.
+like ES modules. All imported names will be checked, at import time, if
+they exist in the exports of the imported module.
 
 Importing a commonjs module (say, the standard `fs` module) will always
 wrap it in an ES module that has a single `default` export. This means that
 some imports that work in non-`spec` mode, like `import { readFile } from 'fs'`,
-will result in `undefined` in `spec` mode.
+will result errors in `spec` mode.
 
 Note that exports, under this mode, always require runtime support for
 getters. It also is not possible to access or write to the commonjs
@@ -91,7 +92,7 @@ import defaultImport from 'module2';
 import * as namespace from 'module3';
 import { pick } from 'module4';
 
-defaultImport(namespace, pick);
+defaultImport(namespace.foo, pick);
 
 export { pick }
 export default function () {}
@@ -122,13 +123,18 @@ let _default = {
 
 require('module1');
 
-const _module2 = babelHelpers._specInteropImport(require('module2'));
+const _module2 = babelHelpers.specInteropImport(require('module2'));
 
-const _module3 = babelHelpers._specInteropImport(require('module3'));
+babelHelpers.specImportCheck(_module2, [ 'default' ]);
 
-const _module4 = babelHelpers._specInteropImport(require('module4'));
+const _module3 = babelHelpers.specInteropImport(require('module3'));
 
-_module2.default(_module3, _module4.pick);
+const _module4 = babelHelpers.specInteropImport(require('module4'));
+
+babelHelpers.specImportCheck(_module4, [ 'pick' ]);
+babelHelpers.specImportCheck(_module3, [ 'foo' ]);
+
+_module2.default(_module3.foo, _module4.pick);
 ```
 
 ## Options `specImport`
@@ -137,8 +143,9 @@ This option enables only the half of `spec` mode that affects the imports, witho
 changing how exports are generated. This would allow the generation of code that
 may still be compatible with engines that do not support getters.
 
-Note that the require helper does use `Object.defineProperty`, so when running on
-an old engine that does not support it, a polyfill like `es5-sham` is still required.
+Note that the require helpers do use `Object.keys` and `Object.defineProperty`, so
+ES5 polyfills may still be required. When running on an old engine that does not support
+`Object.defineProperty`, a polyfill to fake it like `es5-sham` is still required.
 
 This option is **ignored** if `spec` is enabled. Enabling `spec` implies that this
 option is also enabled.
@@ -162,6 +169,8 @@ Object.defineProperty(exports, "__esModule", {
 
 var _module = babelHelpers.specRequireInterop(require('module'));
 
+babelHelpers.specImportCheck(_module, [ 'pick' ]);
+
 exports.default = (0, _module.pick)();
 ```
 

From 8aa75b51289e20d345717501a1ae3238bdc1f003 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 19:27:49 +0900
Subject: [PATCH 061/103] Fix typo in helper

---
 packages/babel-helpers/src/helpers.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index 31a1615bb5aa..cb7a369405da 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -449,7 +449,7 @@ helpers.specImportCheck = template(`
     const invalid = imports.filter(function (i) { return realImports.indexOf(i) < 0; });
     if (invalid.length > 0) {
       const error = new Error(
-        "Unknown exports" + (invalid.length > 1 ? "s " : " ") +
+        "Unknown export" + (invalid.length > 1 ? "s " : " ") +
         invalid.map(function (i) { return "'" + i + "'"; }).join(', ') +
         " imported"
       );

From a8b094cd9f8d9cc44bd760571fa492f423dd732c Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 19:28:53 +0900
Subject: [PATCH 062/103] Add runtime tests for the import name checker

---
 .../test/spec-import-check.js                 | 70 +++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
new file mode 100644
index 000000000000..0c777b39f73f
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
@@ -0,0 +1,70 @@
+"use strict";
+
+const assert = require("assert");
+const helpers = require("./spec-test-helpers");
+
+describe("spec import", function () {
+  const runner = new helpers.Runner({
+    a: "export const a = 'a'",
+    b: "export const b = 'b'"
+  });
+  runner.addToCache("cjs", { module: { exports: { cjs: true } } });
+
+  describe("error checking", function () {
+    it("throws when directly importing unknown name", function () {
+      assert.throws(function () {
+        runner.transformAndRun("import { b } from 'a'");
+      }, "Unknown export 'b' imported");
+    });
+
+    it("throws when importing renamed unknown name", function () {
+      assert.throws(function () {
+        runner.transformAndRun("import { b as a } from 'a'");
+      }, "Unknown export 'b' imported");
+    });
+
+    it("throws when using unknown name from namespace", function () {
+      assert.throws(function () {
+        runner.transformAndRun("import * as b from 'b'\nb.a");
+      }, "Unknown export 'a' imported");
+    });
+
+    it("throws when using multiple unknown names", function () {
+      assert.throws(function () {
+        runner.transformAndRun("import { a, b, c, d } from 'a'");
+      }, "Unknown exports 'b', 'c', 'd' imported");
+    });
+
+    it("throws when using default export of module without default export", function () {
+      assert.throws(function () {
+        runner.transformAndRun("import a from 'a'");
+      }, "Unknown export 'default' imported");
+    });
+
+    it("throws when namespace and name imports are combined", function () {
+      assert.throws(function () {
+        runner.transformAndRun("import * as a, { b } from 'a'\na.c");
+      }, "Unknown exports 'b', 'c' imported");
+    });
+
+    it("does not throw when only known imports are used", function () {
+      runner.transformAndRun("import * as a from 'a'\nimport { b } from 'b'\na.a");
+    });
+  });
+
+  describe("error checking with commonjs", function () {
+    it("throws when any name other than default is used", function () {
+      assert.throws(function () {
+        runner.transformAndRun("import { cjs } from 'cjs'");
+      }, "Unknown export 'cjs' imported");
+    });
+
+    it("does not throw when default import of commonjs module is used", function () {
+      runner.transformAndRun("import cjs from 'cjs'");
+    });
+
+    it("does not throw when only default is used from namespace import of commonjs module", function () {
+      runner.transformAndRun("import * as ns from 'cjs'\nns.default");
+    });
+  });
+});

From 157ab451ac23ef5888717dfff9e31609bc5e421b Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 19:29:34 +0900
Subject: [PATCH 063/103] Update fixtures

---
 .../test/fixtures/spec/exports/expected.js                | 2 +-
 .../test/fixtures/spec/import-simple/expected.js          | 6 +++---
 .../test/fixtures/spec/import/expected.js                 | 8 ++++----
 .../test/fixtures/spec/reexports/expected.js              | 6 +++---
 .../fixtures/specImport/commonjs-no-shadow/expected.js    | 2 +-
 .../test/fixtures/specImport/export-default/expected.js   | 2 +-
 .../fixtures/specImport/import-and-export/expected.js     | 6 +++---
 .../test/fixtures/specImport/reexport/expected.js         | 6 +++---
 8 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
index 49dba7c4e42a..f7370da00c39 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/exports/expected.js
@@ -52,7 +52,7 @@ Object.defineProperties(exports, {
 
 const _outside = babelHelpers.specRequireInterop(require("outside"));
 
-babelHelpers.specImportCheck(_outside, "outside", ["anything"]);
+babelHelpers.specImportCheck(_outside, ["anything"]);
 
 
 var def;
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
index 56c8efaefc9f..386d7c9fd916 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
@@ -8,12 +8,12 @@ const _c = babelHelpers.specRequireInterop(require('c'));
 
 const _d = babelHelpers.specRequireInterop(require('d'));
 
-babelHelpers.specImportCheck(_d, 'd', ['default']);
+babelHelpers.specImportCheck(_d, ['default']);
 
 const _e = babelHelpers.specRequireInterop(require('e'));
 
-babelHelpers.specImportCheck(_e, 'e', ['name']);
-babelHelpers.specImportCheck(_c, 'c', ['name']);
+babelHelpers.specImportCheck(_e, ['name']);
+babelHelpers.specImportCheck(_c, ['name']);
 
 
 _c.name;
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
index 73c02875303a..6e85d8f8b66f 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
@@ -4,11 +4,11 @@ const _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
 
 const _outside = babelHelpers.specRequireInterop(require('./outside'));
 
-babelHelpers.specImportCheck(_outside, './outside', ['default', 'obj']);
+babelHelpers.specImportCheck(_outside, ['default', 'obj']);
 
 const _anywhere = babelHelpers.specRequireInterop(require('./anywhere'));
 
-babelHelpers.specImportCheck(_anywhere, './anywhere', ['default']);
+babelHelpers.specImportCheck(_anywhere, ['default']);
 
 require('./empty');
 
@@ -16,11 +16,11 @@ require('./imperative');
 
 const _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
 
-babelHelpers.specImportCheck(_iDontKnow, './i-dont-know', ['default', 'what', 'who']);
+babelHelpers.specImportCheck(_iDontKnow, ['default', 'what', 'who']);
 
 const _naturally = babelHelpers.specRequireInterop(require('./naturally'));
 
-babelHelpers.specImportCheck(_naturally, './naturally', ['default', 'naturally']);
+babelHelpers.specImportCheck(_naturally, ['default', 'naturally']);
 
 
 (0, _outside.default)(_outside.obj.key);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index 6b78725db960..d2e82b2f1836 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -71,12 +71,12 @@ const _somewhere = babelHelpers.specRequireInterop(require('./somewhere'));
 
 const _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
 
-babelHelpers.specImportCheck(_elsewhere, './elsewhere', ['stuff']);
+babelHelpers.specImportCheck(_elsewhere, ['stuff']);
 
 const _somewhereElse = babelHelpers.specRequireInterop(require('./somewhereElse'));
 
-babelHelpers.specImportCheck(_somewhereElse, './somewhereElse', ['stuff']);
+babelHelpers.specImportCheck(_somewhereElse, ['stuff']);
 
 const _because = babelHelpers.specRequireInterop(require('./because'));
 
-babelHelpers.specImportCheck(_because, './because', ['default']);
\ No newline at end of file
+babelHelpers.specImportCheck(_because, ['default']);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
index b63f73a1e786..47f7ba1314e6 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/commonjs-no-shadow/expected.js
@@ -6,7 +6,7 @@ Object.defineProperty(exports, "__esModule", {
 
 const _bar = babelHelpers.specRequireInterop(require('bar'));
 
-babelHelpers.specImportCheck(_bar, 'bar', ['default']);
+babelHelpers.specImportCheck(_bar, ['default']);
 
 
 module.exports = exports = {};
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js
index dee5129ff66b..a3a5a635d46d 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/export-default/expected.js
@@ -6,5 +6,5 @@ Object.defineProperty(exports, "__esModule", {
 
 const _module = babelHelpers.specRequireInterop(require('module'));
 
-babelHelpers.specImportCheck(_module, 'module', ['pick']);
+babelHelpers.specImportCheck(_module, ['pick']);
 exports.default = (0, _module.pick)();
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
index 43acc9a1dcf5..19fe13456355 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
@@ -11,12 +11,12 @@ const _module = babelHelpers.specRequireInterop(require('module2'));
 
 const _module2 = babelHelpers.specRequireInterop(require('module3'));
 
-babelHelpers.specImportCheck(_module2, 'module3', ['default']);
+babelHelpers.specImportCheck(_module2, ['default']);
 
 const _module3 = babelHelpers.specRequireInterop(require('module4'));
 
-babelHelpers.specImportCheck(_module3, 'module4', ['default']);
-babelHelpers.specImportCheck(_module, 'module2', ['default']);
+babelHelpers.specImportCheck(_module3, ['default']);
+babelHelpers.specImportCheck(_module, ['default']);
 
 
 _module.default(_module2.default, _module3.default);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js
index 19fff6a4ff6e..2abcf7d0eed1 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js
@@ -9,15 +9,15 @@ const _module2 = babelHelpers.specRequireInterop(require('module1'));
 
 const _module3 = babelHelpers.specRequireInterop(require('module2'));
 
-babelHelpers.specImportCheck(_module3, 'module2', ['default']);
+babelHelpers.specImportCheck(_module3, ['default']);
 
 const _module4 = babelHelpers.specRequireInterop(require('module3'));
 
-babelHelpers.specImportCheck(_module4, 'module3', ['pick']);
+babelHelpers.specImportCheck(_module4, ['pick']);
 
 const _module5 = babelHelpers.specRequireInterop(require('module5'));
 
-babelHelpers.specImportCheck(_module5, 'module5', ['foo', 'bar']);
+babelHelpers.specImportCheck(_module5, ['foo', 'bar']);
 
 require('module6');
 

From 79a87ca6ba293a14956075ced2816a6fe215313f Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 19:34:26 +0900
Subject: [PATCH 064/103] Copy the _blockHoist in non-spec specImport mode,
 just to make sure

---
 .../src/index.js                                            | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index a3b2c863e842..477ce749fe9c 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -629,9 +629,13 @@ export default function () {
                 });
                 exportNode._blockHoist = 3;
               } else {
+                const ref = addRequire(path.node.source.value, specImport, path.node._blockHoist);
                 exportNode = buildExportAll({
-                  OBJECT: addRequire(path.node.source.value, specImport, path.node._blockHoist)
+                  OBJECT: ref
                 });
+                if (specImport) {
+                  exportNode._blockHoist = ref._blockHoist;
+                }
               }
               exportNode.loc = path.node.loc;
               topNodes.push(exportNode);

From 0a6ead9d6c0fc16cf022bb82440142f2907e4725 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 19:42:24 +0900
Subject: [PATCH 065/103] Helpers can't use const

---
 packages/babel-helpers/src/helpers.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index cb7a369405da..ed3226c6d14d 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -445,10 +445,10 @@ helpers.specRequireInterop = template(`
 helpers.specImportCheck = template(`
   (function (module, imports) {
     if (!module.__esModule) throw new Error("Only ES modules can be checked");
-    const realImports = Object.keys(module);
-    const invalid = imports.filter(function (i) { return realImports.indexOf(i) < 0; });
+    var realImports = Object.keys(module);
+    var invalid = imports.filter(function (i) { return realImports.indexOf(i) < 0; });
     if (invalid.length > 0) {
-      const error = new Error(
+      var error = new Error(
         "Unknown export" + (invalid.length > 1 ? "s " : " ") +
         invalid.map(function (i) { return "'" + i + "'"; }).join(', ') +
         " imported"

From b2cb5294e7b00ed1aa44c4a79b98d1848b2e58f7 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 19:55:46 +0900
Subject: [PATCH 066/103] Add a section about star reexports to the README

---
 .../README.md                                       | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
index 21c2ca8db813..8cb5bfaebfc5 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
@@ -198,4 +198,15 @@ var foo = exports.foo = 5;
 exports.__esModule = true;
 ```
 
-The `loose` option is **ignored** if used in combination with `spec`.
\ No newline at end of file
+The `loose` option is **ignored** if used in combination with `spec`.
+
+## Caveats
+
+Star reexports (`export * from 'module'`) always run before other imports or
+reexports, as this module's exports must be known before other modules execute.
+That is, they behave as if there was an `import 'module'` that runs before any
+of the other imports.
+
+This is particularly hard to avoid in the `spec` / `specImport` mode, as the
+exports must be frozen before importing other modules. Star reexports are the
+only exception.

From 5eb912f5cfa2ee471c86a77ae76e0c2f4b360862 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 20:05:35 +0900
Subject: [PATCH 067/103] Add the README snippets as fixtures; use
 (reformatted) output in the README

---
 .../README.md                                 | 44 ++++++++-------
 .../test/fixtures/spec/readme/actual.js       |  9 ++++
 .../test/fixtures/spec/readme/expected.js     | 54 +++++++++++++++++++
 .../test/fixtures/specImport/readme/actual.js |  3 ++
 .../fixtures/specImport/readme/expected.js    | 10 ++++
 5 files changed, 100 insertions(+), 20 deletions(-)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/readme/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/readme/expected.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
index 8cb5bfaebfc5..12375e6e47c5 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
@@ -104,17 +104,21 @@ export default function () {}
 'use strict';
 
 const exports = module.exports = Object.create ? Object.create(null, {
-  __esModule: { value: true }
-}) : { __esModule: true };
-Object.defineProperties(exports, {
-  default: {
-    enumerable: true,
-    get() { return _default; }
-  },
-  pick: {
-    enumerable: true,
-    get() { return _module4.pick; }
+  __esModule: {
+    value: true
   }
+}) : {
+  __esModule: true
+};
+if (typeof Symbol === "function" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+Object.defineProperties(exports, {
+  pick: { enumerable: true, get() { return _module4.pick; } },
+  default: { enumerable: true, get() { return _default; } }
 });
 let _default = {
   default: function () {}
@@ -123,18 +127,19 @@ let _default = {
 
 require('module1');
 
-const _module2 = babelHelpers.specInteropImport(require('module2'));
+const _module2 = babelHelpers.specRequireInterop(require('module2'));
+
+babelHelpers.specImportCheck(_module2, ['default']);
 
-babelHelpers.specImportCheck(_module2, [ 'default' ]);
+const _module3 = babelHelpers.specRequireInterop(require('module3'));
 
-const _module3 = babelHelpers.specInteropImport(require('module3'));
+const _module4 = babelHelpers.specRequireInterop(require('module4'));
 
-const _module4 = babelHelpers.specInteropImport(require('module4'));
+babelHelpers.specImportCheck(_module4, ['pick']);
+babelHelpers.specImportCheck(_module3, ['foo']);
 
-babelHelpers.specImportCheck(_module4, [ 'pick' ]);
-babelHelpers.specImportCheck(_module3, [ 'foo' ]);
 
-_module2.default(_module3.foo, _module4.pick);
+(0, _module2.default)(_module3.foo, _module4.pick);
 ```
 
 ## Options `specImport`
@@ -167,10 +172,9 @@ Object.defineProperty(exports, "__esModule", {
   value: true
 });
 
-var _module = babelHelpers.specRequireInterop(require('module'));
-
-babelHelpers.specImportCheck(_module, [ 'pick' ]);
+const _module = babelHelpers.specRequireInterop(require('module'));
 
+babelHelpers.specImportCheck(_module, ['pick']);
 exports.default = (0, _module.pick)();
 ```
 
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/actual.js
new file mode 100644
index 000000000000..7da03f672c52
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/actual.js
@@ -0,0 +1,9 @@
+import 'module1';
+import defaultImport from 'module2';
+import * as namespace from 'module3';
+import { pick } from 'module4';
+
+defaultImport(namespace.foo, pick);
+
+export { pick }
+export default function () {}
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
new file mode 100644
index 000000000000..7d906d6c96ac
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
@@ -0,0 +1,54 @@
+'use strict';
+
+const exports = module.exports = Object.create ? Object.create(null, {
+  __esModule: {
+    value: true
+  }
+}) : {
+  __esModule: true
+};
+
+if (typeof Symbol === "function" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+Object.defineProperties(exports, {
+  pick: {
+    enumerable: true,
+
+    get() {
+      return _module3.pick;
+    }
+
+  },
+  default: {
+    enumerable: true,
+
+    get() {
+      return _default;
+    }
+
+  }
+});
+let _default = {
+  default: function () {}
+}.default;
+(Object.freeze || Object)(exports);
+
+require('module1');
+
+const _module = babelHelpers.specRequireInterop(require('module2'));
+
+babelHelpers.specImportCheck(_module, ['default']);
+
+const _module2 = babelHelpers.specRequireInterop(require('module3'));
+
+const _module3 = babelHelpers.specRequireInterop(require('module4'));
+
+babelHelpers.specImportCheck(_module3, ['pick']);
+babelHelpers.specImportCheck(_module2, ['foo']);
+
+
+(0, _module.default)(_module2.foo, _module3.pick);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/readme/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/readme/actual.js
new file mode 100644
index 000000000000..03d53e791329
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/readme/actual.js
@@ -0,0 +1,3 @@
+import { pick } from 'module'
+
+export default pick()
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/readme/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/readme/expected.js
new file mode 100644
index 000000000000..a3a5a635d46d
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/readme/expected.js
@@ -0,0 +1,10 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+const _module = babelHelpers.specRequireInterop(require('module'));
+
+babelHelpers.specImportCheck(_module, ['pick']);
+exports.default = (0, _module.pick)();
\ No newline at end of file

From 52f9b5b2710e75754944fce0a810fc0b50bbedaa Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 20:11:26 +0900
Subject: [PATCH 068/103] Give a better example for the options :blush:

---
 .../babel-plugin-transform-es2015-modules-commonjs/README.md    | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
index 12375e6e47c5..25ae2f39a536 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
@@ -42,7 +42,7 @@ npm install --save-dev babel-plugin-transform-es2015-modules-commonjs
 {
   "plugins": [
     ["transform-es2015-modules-commonjs", {
-      "allowTopLevelThis": true
+      "spec": true
     }]
   ]
 }

From 60c0e9c73c58dadd127df28e78a6d19b0d7adf48 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Sun, 11 Dec 2016 20:17:45 +0900
Subject: [PATCH 069/103] Add note about TDZ

---
 .../babel-plugin-transform-es2015-modules-commonjs/README.md   | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
index 25ae2f39a536..393b65dec433 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
@@ -72,7 +72,8 @@ The `spec` option, when set to `true`, tries to generate code that is as
 close as possible to what is required by the ECMA262 spec without relying
 on `Proxy`. The exports will be frozen, and imports will always be treated
 like ES modules. All imported names will be checked, at import time, if
-they exist in the exports of the imported module.
+they exist in the exports of the imported module. If `let` and `const` are
+not transformed to `var`, the exports will also implement TDZ.
 
 Importing a commonjs module (say, the standard `fs` module) will always
 wrap it in an ES module that has a single `default` export. This means that

From 79941d842d090566e8a426e7d70132cebceebbc1 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 07:17:05 +0900
Subject: [PATCH 070/103] Use faster filter, use JSON.stringify for the list of
 invalid imports

---
 packages/babel-helpers/src/helpers.js | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index ed3226c6d14d..8c948c6cb7a4 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -445,12 +445,11 @@ helpers.specRequireInterop = template(`
 helpers.specImportCheck = template(`
   (function (module, imports) {
     if (!module.__esModule) throw new Error("Only ES modules can be checked");
-    var realImports = Object.keys(module);
-    var invalid = imports.filter(function (i) { return realImports.indexOf(i) < 0; });
+    var invalid = imports.filter(function (i) { var d = Object.getOwnPropertyDescriptor(module, i); return !d || !d.enumerable; });
     if (invalid.length > 0) {
       var error = new Error(
         "Unknown export" + (invalid.length > 1 ? "s " : " ") +
-        invalid.map(function (i) { return "'" + i + "'"; }).join(', ') +
+        JSON.stringify(invalid) +
         " imported"
       );
       error.module = module;

From a95a651b8f403bd09945b0a55c74dddc1315ff05 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 07:24:47 +0900
Subject: [PATCH 071/103] Update tests, correct invalid second argument

---
 .../test/spec-import-check.js                          | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
index 0c777b39f73f..29323b6302f0 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
@@ -14,31 +14,31 @@ describe("spec import", function () {
     it("throws when directly importing unknown name", function () {
       assert.throws(function () {
         runner.transformAndRun("import { b } from 'a'");
-      }, "Unknown export 'b' imported");
+      }, /Unknown export \["b"] imported$/);
     });
 
     it("throws when importing renamed unknown name", function () {
       assert.throws(function () {
         runner.transformAndRun("import { b as a } from 'a'");
-      }, "Unknown export 'b' imported");
+      }, /Unknown export \["b"] imported$/);
     });
 
     it("throws when using unknown name from namespace", function () {
       assert.throws(function () {
         runner.transformAndRun("import * as b from 'b'\nb.a");
-      }, "Unknown export 'a' imported");
+      }, /Unknown export \["a"] imported$/);
     });
 
     it("throws when using multiple unknown names", function () {
       assert.throws(function () {
         runner.transformAndRun("import { a, b, c, d } from 'a'");
-      }, "Unknown exports 'b', 'c', 'd' imported");
+      }, /Unknown exports \["b","c","d"] imported$/);
     });
 
     it("throws when using default export of module without default export", function () {
       assert.throws(function () {
         runner.transformAndRun("import a from 'a'");
-      }, "Unknown export 'default' imported");
+      }, /Unknown export \["default"] imported$/);
     });
 
     it("throws when namespace and name imports are combined", function () {

From a77935c69e6270a57d5a4a017f0b17eb9dd81cd7 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 07:28:12 +0900
Subject: [PATCH 072/103] Fix incorrect second argument to assert.throws in
 tests

---
 .../test/spec-export.js                              | 12 ++++++------
 .../test/spec-import-check.js                        |  4 ++--
 .../test/spec-reexport.js                            |  2 +-
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
index f14059dcbd3b..bca03e5af020 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-export.js
@@ -240,31 +240,31 @@ describe("spec export", function () {
     it("throws when generating duplicate default exports", function () {
       assert.throws(function () {
         runner.transformAndRun("export default class {}\nexport default class {}");
-      });
+      }, SyntaxError);
     });
 
     it("throws when generating duplicate default export via renaming", function () {
       assert.throws(function () {
         runner.transformAndRun("var foo\nexport default foo\nexport { foo as default }");
-      });
+      }, SyntaxError);
     });
 
     it("throws when generating duplicate exports in the same specifier", function () {
       assert.throws(function () {
         runner.transformAndRun("export var foo, foo");
-      });
+      }, SyntaxError);
     });
 
     it("throws when generating duplicate named exports in the same specifier", function () {
       assert.throws(function () {
         runner.transformAndRun("const foo = 'foo'\nexport { foo, foo }");
-      });
+      }, SyntaxError);
     });
 
     it("throws when generating duplicate renamed exports", function () {
       assert.throws(function () {
         runner.transformAndRun("const foo = 'foo'\nconst bar = 'bar'\nexport { foo, bar as foo }");
-      });
+      }, SyntaxError);
     });
 
     // babel extension; check for the flag used to distinguish
@@ -272,7 +272,7 @@ describe("spec export", function () {
     it("throws when attempting to export __esModule", function () {
       assert.throws(function () {
         runner.transformAndRun("const __esModule = false\nexport { __esModule }");
-      });
+      }, SyntaxError);
     });
   });
 });
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
index 29323b6302f0..0d29513874f3 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
@@ -43,8 +43,8 @@ describe("spec import", function () {
 
     it("throws when namespace and name imports are combined", function () {
       assert.throws(function () {
-        runner.transformAndRun("import * as a, { b } from 'a'\na.c");
-      }, "Unknown exports 'b', 'c' imported");
+        runner.transformAndRun("import * as a from 'a'\nimport { b } from 'a'\na.c");
+      }, /Unknown exports \["b","c"] imported$/);
     });
 
     it("does not throw when only known imports are used", function () {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
index 6dc40a68bd90..50dba486d498 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-reexport.js
@@ -148,7 +148,7 @@ describe("spec reexport star with duplicates", function () {
   it("throws when not shadowed and duplicate is not SameValue", function () {
     assert.throws(function () {
       runner.transformAndRun("export * from 'a'\nexport * from 'b'");
-    }, "Cannot redefine property: name");
+    }, /Cannot redefine property: name$/);
   });
 
   describe("SameValue", function () {

From 6dbd22897146d9100a24714fceb0e63681e484bb Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 08:26:49 +0900
Subject: [PATCH 073/103] Add specNamespaceGet helper, use when doing computed
 access to namespace

---
 packages/babel-helpers/src/helpers.js         | 18 +++++++++++++
 .../src/index.js                              | 27 ++++++++++++++-----
 2 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index 8c948c6cb7a4..7065d31fb2ff 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -458,6 +458,24 @@ helpers.specImportCheck = template(`
   })
 `);
 
+// The name && typeof Symbol === "function" && ... line is from helpers.typeof, which may be needed
+// when polyfilled. Helpers might not be transformed when using external-helpers, so can't rely on
+// the typeof being augmented when targeting ES5.
+helpers.specNamespaceGet = template(`
+  (function (module, name) {
+    if (!module.__esModule) throw new Error("Only ES modules can be checked");
+    if (
+      typeof name === "symbol" ||
+      name && typeof Symbol === "function" && name.constructor === Symbol && name !== Symbol.prototype
+    ) {
+      return module[name];
+    }
+    var d = Object.getOwnPropertyDescriptor(module, name);
+    if (!d || !d.enumerable) throw new Error("Unknown export " + JSON.stringify(name) + " imported");
+    return module[name];
+  })
+`);
+
 helpers.newArrowCheck = template(`
   (function (innerThis, boundThis) {
     if (innerThis !== boundThis) {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 477ce749fe9c..b2c58236e31d 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -163,15 +163,29 @@ export default function () {
             }
             remap.nameSet.add(name);
           } else if (t.isIdentifier(remap)) {
-            if (t.isMemberExpression(path.parent) && !path.parent.computed) {
-              const name = t.isIdentifier(path.parent.property)
-                ? path.parent.property.name
-                : t.isStringLiteral(path.parent.property)
-                ? path.parent.property.value
+            if (t.isMemberExpression(path.parent)) {
+              const { property, computed } = path.parent;
+
+              const name = !computed && t.isIdentifier(property)
+                ? property.name
+                : t.isStringLiteral(property)
+                ? property.value
                 : undefined;
 
-              remap.nameSet.add(name);
+              if (name !== undefined) {
+                remap.nameSet.add(name);
+              } else {
+                path.parentPath.replaceWith(
+                  t.callExpression(
+                    this.addHelper("specNamespaceGet"),
+                    [ remap, property ]
+                  )
+                );
+                return;
+              }
             }
+          } else {
+            throw new Error(`Unexpected ${remap.type}`);
           }
         }
         path.replaceWith(remap);
@@ -857,6 +871,7 @@ export default function () {
             scope,
             exports,
             opts: state.opts,
+            addHelper: this.addHelper.bind(this),
             requeueInParent: (newPath) => path.requeue(newPath),
           });
 

From 789aeae70431c9a39360f09bd97819616bb5107c Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 08:28:22 +0900
Subject: [PATCH 074/103] Add fixture and runtime tests

---
 .../fixtures/spec/namespace-get/actual.js     |  9 +++
 .../fixtures/spec/namespace-get/expected.js   | 14 +++++
 .../test/spec-import-check.js                 | 58 +++++++++++++++++++
 3 files changed, 81 insertions(+)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/expected.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/actual.js
new file mode 100644
index 000000000000..2ea7e0a33e24
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/actual.js
@@ -0,0 +1,9 @@
+import * as a from 'a'
+
+const name = 'a'
+
+const ident = a.a
+const literal = a['a']
+const computed = a[name]
+const recursive = a[a[name]]
+const symbol = a[Symbol.toStringTag]
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/expected.js
new file mode 100644
index 000000000000..b1970e9da86e
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/expected.js
@@ -0,0 +1,14 @@
+'use strict';
+
+const _a = babelHelpers.specRequireInterop(require('a'));
+
+babelHelpers.specImportCheck(_a, ['a']);
+
+
+const name = 'a';
+
+const ident = _a.a;
+const literal = _a['a'];
+const computed = babelHelpers.specNamespaceGet(_a, name);
+const recursive = babelHelpers.specNamespaceGet(_a, babelHelpers.specNamespaceGet(_a, name));
+const symbol = babelHelpers.specNamespaceGet(_a, Symbol.toStringTag);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
index 0d29513874f3..fecf5de8b9b3 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
@@ -47,9 +47,67 @@ describe("spec import", function () {
       }, /Unknown exports \["b","c"] imported$/);
     });
 
+    it("throws when using indexed access with constant string", function () {
+      assert.throws(function () {
+        runner.transformAndRun("import * as a from 'a'; a['b']");
+      }, /Unknown export \["b"] imported$/);
+    });
+
+    it("throws when using indexed access with null", function () {
+      assert.throws(function () {
+        runner.transformAndRun("import * as a from 'a'; a[null]");
+      }, /Unknown export null imported$/);
+    });
+
+    it("throws when using indexed access with variable", function () {
+      assert.throws(function () {
+        exports = runner.transformAndRun("import * as a from 'a'; const name = 'b'; a[name]");
+      }, /Unknown export "b" imported$/);
+    });
+
     it("does not throw when only known imports are used", function () {
       runner.transformAndRun("import * as a from 'a'\nimport { b } from 'b'\na.a");
     });
+
+    describe("with variable", function () {
+      runner.addModule("variable", "import * as a from 'a'\nconst name = 'a'\nexport const simple = a[name]\nexport const recursive = a[a[name]]");
+
+      it("does not throw", function () {
+        runner.getExportsOf("variable");
+      });
+
+      describe("has the correct result", function () {
+        const exports = runner.getExportsOf("variable");
+
+        it("simple", function () {
+          assert.strictEqual(exports.simple, "a");
+        });
+
+        it("recursive", function () {
+          assert.strictEqual(exports.recursive, "a");
+        });
+      });
+    });
+
+    describe("with Symbol", function () {
+      runner.addModule("symbol", "import * as a from 'a'\nexport default a[Symbol.toStringTag]");
+      if (!helpers.hasToStringTag()) {
+        this.skip();
+      }
+
+      it("does not throw", function () {
+        runner.getExportsOf("symbol");
+      });
+
+      it("has the correct result", function () {
+        const exports = runner.getExportsOf("symbol");
+        assert.strictEqual(exports.default, "Module");
+      });
+
+      it("does not throw with unknown symbols either", function () {
+        runner.transformAndRun("import * as a from 'a'\na[Symbol('foo')]");
+      });
+    });
   });
 
   describe("error checking with commonjs", function () {

From 5f6206199d5228e8328c02162c29fd3773364598 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 08:41:34 +0900
Subject: [PATCH 075/103] Add test to verify __esModule is considered an
 unknown export

---
 .../test/spec-import-check.js                              | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
index fecf5de8b9b3..9eb387639d80 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
@@ -47,6 +47,13 @@ describe("spec import", function () {
       }, /Unknown exports \["b","c"] imported$/);
     });
 
+    it("throws when attempting to import __esModule", function () {
+      // This one unfortunately won't work with { spec: false, specImport: true, loose: true } :cry:
+      assert.throws(function () {
+        runner.transformAndRun("import { __esModule } from 'b'");
+      }, /Unknown export \["__esModule"] imported$/);
+    });
+
     it("throws when using indexed access with constant string", function () {
       assert.throws(function () {
         runner.transformAndRun("import * as a from 'a'; a['b']");

From 3b7f44351e2509762135cabff24f9506cf20c997 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 08:48:47 +0900
Subject: [PATCH 076/103] Add test to document the namespace get wrapping can't
 be perfect

---
 .../test/spec-import-check.js                             | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
index 9eb387639d80..7fb64b5885f7 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
@@ -72,6 +72,14 @@ describe("spec import", function () {
       }, /Unknown export "b" imported$/);
     });
 
+    it("throws when accessing unknown import when aliased", function () {
+      this.skip("would require a Proxy-based implementation to work");
+
+      assert.throws(function () {
+        runner.transformAndRun("import * as a from 'a'; function get (ns, key) { return ns[key]; }; get(a, 'b')");
+      }, /Unknown export "b" imported$/);
+    });
+
     it("does not throw when only known imports are used", function () {
       runner.transformAndRun("import * as a from 'a'\nimport { b } from 'b'\na.a");
     });

From c6aec5f25831950004fa95edf59c331ac770bf4a Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 10:17:28 +0900
Subject: [PATCH 077/103] Add non-spec test to verify export * from ordering
 behavior

---
 .../fixtures/interop/export-from-8/actual.js  |  3 ++
 .../interop/export-from-8/expected.js         | 31 +++++++++++++++++++
 2 files changed, 34 insertions(+)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-8/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-8/expected.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-8/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-8/actual.js
new file mode 100644
index 000000000000..c7dddff6227d
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-8/actual.js
@@ -0,0 +1,3 @@
+export * from 'a'
+import 'b'
+export * from 'c'
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-8/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-8/expected.js
new file mode 100644
index 000000000000..d007f4c2829d
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-8/expected.js
@@ -0,0 +1,31 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+var _a = require('a');
+
+Object.keys(_a).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+  Object.defineProperty(exports, key, {
+    enumerable: true,
+    get: function () {
+      return _a[key];
+    }
+  });
+});
+
+var _c = require('c');
+
+Object.keys(_c).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+  Object.defineProperty(exports, key, {
+    enumerable: true,
+    get: function () {
+      return _c[key];
+    }
+  });
+});
+
+require('b');
\ No newline at end of file

From d212a375c88fd38cb46b81a9e84c9e805fe1756b Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 10:27:52 +0900
Subject: [PATCH 078/103] Remove _blockHoist hack for imports; just remove
 check later if it's empty

---
 .../src/index.js                              | 143 +++++++++---------
 1 file changed, 69 insertions(+), 74 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index b2c58236e31d..04cd8a6e2a5a 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -403,7 +403,7 @@ export default function () {
               let key = path.node.source.value;
               let importsEntry = imports[key] || {
                 specifiers: [],
-                maxBlockHoist: specImport ? 2 : 0,
+                maxBlockHoist: 0,
                 loc: path.node.loc,
               };
 
@@ -571,7 +571,7 @@ export default function () {
                   let key = path.node.source.value;
                   importsEntry = imports[key] || {
                     specifiers: [],
-                    maxBlockHoist: 2,
+                    maxBlockHoist: 0,
                     loc: path.node.loc,
                   };
                   importsEntry.reexports = importsEntry.reexports || new Map(),
@@ -663,22 +663,6 @@ export default function () {
             if (specifiers.length) {
               const uid = addRequire(source, specImport, maxBlockHoist);
 
-              if (imports[source].reexports) {
-                if (!spec) {
-                  for (const [name, local] of imports[source].reexports.entries()) {
-                    if (name === "default") {
-                      topNodes.push(buildExportsFrom(t.stringLiteral(name), t.memberExpression(t.callExpression(this.addHelper("interopRequireDefault"), [uid]), local)));
-                    } else {
-                      topNodes.push(buildExportsFrom(t.stringLiteral(name), t.memberExpression(uid, local)));
-                    }
-                  }
-                } else {
-                  for (const [name, local] of imports[source].reexports.entries()) {
-                    hoistedExports.set(name, t.memberExpression(uid, local));
-                  }
-                }
-              }
-
               if (specImport) {
                 if (!checkedImportMap.has(uid)) {
                   const nameSet = new Set(
@@ -696,30 +680,62 @@ export default function () {
                   );
                   nameSet.source = source;
 
-                  checkedImportMap.set(uid, nameSet);
+                  const names = Array.from(nameSet).map((name) => t.stringLiteral(name));
+                  const namesExpr = t.arrayExpression(names);
+
+                  const node =
+                    t.expressionStatement(
+                      t.callExpression(
+                        this.addHelper("specImportCheck"),
+                        [
+                          uid,
+                          namesExpr
+                        ]
+                      )
+                    );
 
-                  if (nameSet.size > 0) {
-                    nameSet.generated = Array.from(nameSet).map((name) => t.stringLiteral(name));
-                    const names = t.arrayExpression(nameSet.generated);
+                  node.loc = imports[source].loc;
 
-                    const stmt =
-                      t.expressionStatement(
-                        t.callExpression(
-                          this.addHelper("specImportCheck"),
-                          [
-                            uid,
-                            names
-                          ]
-                        )
-                      );
+                  checkedImportMap.set(uid, {
+                    nameSet,
+                    node,
+                    updateNode: () => {
+                      if (nameSet.size === names.length) return;
+
+                      const current = new Set(names.map((name) => name.value));
+
+                      for (const name of nameSet) {
+                        if (!current.has(name)) {
+                          names.push(t.stringLiteral(name));
+                        }
+                      }
+                    },
+                    isEmpty: () => {
+                      return names.length < 1;
+                    }
+                  });
 
-                    stmt.loc = imports[source].loc;
-                    stmt._blockHoist = Math.max(imports[source].maxBlockHoist, 2);
+                  topNodes.push(node);
+                }
+              }
 
-                    topNodes.push(stmt);
+              if (imports[source].reexports) {
+                if (!spec) {
+                  for (const [name, local] of imports[source].reexports.entries()) {
+                    if (name === "default") {
+                      topNodes.push(buildExportsFrom(t.stringLiteral(name), t.memberExpression(t.callExpression(this.addHelper("interopRequireDefault"), [uid]), local)));
+                    } else {
+                      topNodes.push(buildExportsFrom(t.stringLiteral(name), t.memberExpression(uid, local)));
+                    }
+                  }
+                } else {
+                  for (const [name, local] of imports[source].reexports.entries()) {
+                    hoistedExports.set(name, t.memberExpression(uid, local));
                   }
                 }
+              }
 
+              if (specImport) {
                 for (const specifier of specifiers) {
                   if (t.isImportNamespaceSpecifier(specifier)) {
                     remaps[specifier.local.name] = uid;
@@ -731,7 +747,7 @@ export default function () {
                     remaps[specifier.local.name] = t.memberExpression(uid, t.cloneWithoutLoc(specifier.imported));
                   }
                   if (specImport && !t.isExportSpecifier(specifier)) {
-                    remaps[specifier.local.name].nameSet = checkedImportMap.get(uid);
+                    remaps[specifier.local.name].nameSet = checkedImportMap.get(uid).nameSet;
                   }
                 }
               } else {
@@ -797,9 +813,6 @@ export default function () {
             } else {
               // bare import
               let requireNode = buildRequire(t.stringLiteral(source));
-              if (specImport) {
-                requireNode._blockHoist = 2;
-              }
               requireNode.loc = imports[source].loc;
               topNodes.push(requireNode);
             }
@@ -876,43 +889,25 @@ export default function () {
           });
 
           if (specImport && hasImports) {
-            const checks = Array.from(checkedImportMap.entries())
-            .map(([uid, nameSet]) => {
-              if (nameSet.size < 1) return;
-
-              if (nameSet.generated) {
-                if (nameSet.generated.length === nameSet.generated.size) return;
-                // nameSet.generated must be modified in-place
-                // to update the nodes of the pre-existing nameSet check
-                for (const name of nameSet) {
-                  if (!nameSet.generated.some((existing) => existing.value === name)) {
-                    nameSet.generated.push(t.stringLiteral(name));
-                  }
-                }
-                return;
-              }
-
-              const names = t.arrayExpression(Array.from(nameSet).map((name) => t.stringLiteral(name)));
-
-              const stmt =
-                t.expressionStatement(
-                  t.callExpression(
-                    this.addHelper("specImportCheck"),
-                    [
-                      uid,
-                      names
-                    ]
-                  )
-                );
-
-              stmt.loc = imports[nameSet.source].loc;
-              stmt._blockHoist = Math.max(imports[nameSet.source].maxBlockHoist, 1);
+            const toRemove = new Set();
+            for (const check of checkedImportMap.values()) {
+              check.updateNode();
 
-              return stmt;
-            }).filter(Boolean);
+              if (check.isEmpty()) {
+                toRemove.add(check.node);
+              }
+            }
 
-            if (checks.length > 0) {
-              path.pushContainer("body", checks);
+            if (toRemove.size) {
+              path.traverse({
+                ExpressionStatement (path) {
+                  if (toRemove.has(path.node)) {
+                    path.remove();
+                    return;
+                  }
+                  path.skip();
+                }
+              });
             }
           }
 

From 77ae14188b71577a77640fe73ad1d6a3299a9fac Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 10:28:06 +0900
Subject: [PATCH 079/103] Update fixtures

---
 .../fixtures/spec/import-simple/expected.js   |  3 +-
 .../test/fixtures/spec/readme/expected.js     |  3 +-
 .../specImport/import-and-export/expected.js  |  3 +-
 .../fixtures/specImport/reexport/expected.js  | 29 ++++++++++---------
 4 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
index 386d7c9fd916..5f03bec21402 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
@@ -6,6 +6,8 @@ require('b');
 
 const _c = babelHelpers.specRequireInterop(require('c'));
 
+babelHelpers.specImportCheck(_c, ['name']);
+
 const _d = babelHelpers.specRequireInterop(require('d'));
 
 babelHelpers.specImportCheck(_d, ['default']);
@@ -13,7 +15,6 @@ babelHelpers.specImportCheck(_d, ['default']);
 const _e = babelHelpers.specRequireInterop(require('e'));
 
 babelHelpers.specImportCheck(_e, ['name']);
-babelHelpers.specImportCheck(_c, ['name']);
 
 
 _c.name;
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
index 7d906d6c96ac..719eeff3ab04 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
@@ -45,10 +45,11 @@ babelHelpers.specImportCheck(_module, ['default']);
 
 const _module2 = babelHelpers.specRequireInterop(require('module3'));
 
+babelHelpers.specImportCheck(_module2, ['foo']);
+
 const _module3 = babelHelpers.specRequireInterop(require('module4'));
 
 babelHelpers.specImportCheck(_module3, ['pick']);
-babelHelpers.specImportCheck(_module2, ['foo']);
 
 
 (0, _module.default)(_module2.foo, _module3.pick);
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
index 19fe13456355..00405de335a1 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/import-and-export/expected.js
@@ -9,6 +9,8 @@ require('module1');
 
 const _module = babelHelpers.specRequireInterop(require('module2'));
 
+babelHelpers.specImportCheck(_module, ['default']);
+
 const _module2 = babelHelpers.specRequireInterop(require('module3'));
 
 babelHelpers.specImportCheck(_module2, ['default']);
@@ -16,7 +18,6 @@ babelHelpers.specImportCheck(_module2, ['default']);
 const _module3 = babelHelpers.specRequireInterop(require('module4'));
 
 babelHelpers.specImportCheck(_module3, ['default']);
-babelHelpers.specImportCheck(_module, ['default']);
 
 
 _module.default(_module2.default, _module3.default);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js
index 2abcf7d0eed1..a3dc349ed815 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/reexport/expected.js
@@ -5,6 +5,18 @@ Object.defineProperty(exports, "__esModule", {
 });
 exports.baz = exports.foo = exports.pick = exports.def = exports.ns = undefined;
 
+const _module = babelHelpers.specRequireInterop(require('module4'));
+
+Object.keys(_module).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+  Object.defineProperty(exports, key, {
+    enumerable: true,
+    get: function () {
+      return _module[key];
+    }
+  });
+});
+
 const _module2 = babelHelpers.specRequireInterop(require('module1'));
 
 const _module3 = babelHelpers.specRequireInterop(require('module2'));
@@ -18,20 +30,6 @@ babelHelpers.specImportCheck(_module4, ['pick']);
 const _module5 = babelHelpers.specRequireInterop(require('module5'));
 
 babelHelpers.specImportCheck(_module5, ['foo', 'bar']);
-
-require('module6');
-
-const _module = babelHelpers.specRequireInterop(require('module4'));
-
-Object.keys(_module).forEach(function (key) {
-  if (key === "default" || key === "__esModule") return;
-  Object.defineProperty(exports, key, {
-    enumerable: true,
-    get: function () {
-      return _module[key];
-    }
-  });
-});
 Object.defineProperty(exports, 'foo', {
   enumerable: true,
   get: function () {
@@ -44,6 +42,9 @@ Object.defineProperty(exports, 'baz', {
     return _module5.bar;
   }
 });
+
+require('module6');
+
 exports.default = _module2;
 exports.ns = _module2;
 exports.def = _module3.default;

From fe39f70d76d30552d4d7664e49180271d2043a0a Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 10:29:22 +0900
Subject: [PATCH 080/103] Use names in readme snippet that
 generateUidIdentifier likes better

---
 .../test/fixtures/spec/readme/actual.js        |  8 ++++----
 .../test/fixtures/spec/readme/expected.js      | 18 +++++++++---------
 2 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/actual.js
index 7da03f672c52..03c18c5535b4 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/actual.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/actual.js
@@ -1,7 +1,7 @@
-import 'module1';
-import defaultImport from 'module2';
-import * as namespace from 'module3';
-import { pick } from 'module4';
+import 'a';
+import defaultImport from 'b';
+import * as namespace from 'c';
+import { pick } from 'd';
 
 defaultImport(namespace.foo, pick);
 
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
index 719eeff3ab04..628f4f5986d8 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
@@ -19,7 +19,7 @@ Object.defineProperties(exports, {
     enumerable: true,
 
     get() {
-      return _module3.pick;
+      return _d.pick;
     }
 
   },
@@ -37,19 +37,19 @@ let _default = {
 }.default;
 (Object.freeze || Object)(exports);
 
-require('module1');
+require('a');
 
-const _module = babelHelpers.specRequireInterop(require('module2'));
+const _b = babelHelpers.specRequireInterop(require('b'));
 
-babelHelpers.specImportCheck(_module, ['default']);
+babelHelpers.specImportCheck(_b, ['default']);
 
-const _module2 = babelHelpers.specRequireInterop(require('module3'));
+const _c = babelHelpers.specRequireInterop(require('c'));
 
-babelHelpers.specImportCheck(_module2, ['foo']);
+babelHelpers.specImportCheck(_c, ['foo']);
 
-const _module3 = babelHelpers.specRequireInterop(require('module4'));
+const _d = babelHelpers.specRequireInterop(require('d'));
 
-babelHelpers.specImportCheck(_module3, ['pick']);
+babelHelpers.specImportCheck(_d, ['pick']);
 
 
-(0, _module.default)(_module2.foo, _module3.pick);
\ No newline at end of file
+(0, _b.default)(_c.foo, _d.pick);
\ No newline at end of file

From d6ce6ab5758508981d8396907759522d856bb30e Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 10:33:07 +0900
Subject: [PATCH 081/103] Update README

---
 .../README.md                                 | 34 ++++++++++---------
 1 file changed, 18 insertions(+), 16 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
index 393b65dec433..af35ee7d3007 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/README.md
@@ -88,10 +88,10 @@ TDZ errors at runtime.
 ### Input
 
 ```javascript
-import 'module1';
-import defaultImport from 'module2';
-import * as namespace from 'module3';
-import { pick } from 'module4';
+import 'a';
+import defaultImport from 'b';
+import * as namespace from 'c';
+import { pick } from 'd';
 
 defaultImport(namespace.foo, pick);
 
@@ -118,7 +118,7 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
 }
 
 Object.defineProperties(exports, {
-  pick: { enumerable: true, get() { return _module4.pick; } },
+  pick: { enumerable: true, get() { return _d.pick; } },
   default: { enumerable: true, get() { return _default; } }
 });
 let _default = {
@@ -126,21 +126,22 @@ let _default = {
 }.default;
 (Object.freeze || Object)(exports);
 
-require('module1');
+require('a');
 
-const _module2 = babelHelpers.specRequireInterop(require('module2'));
+const _b = babelHelpers.specRequireInterop(require('b'));
 
-babelHelpers.specImportCheck(_module2, ['default']);
+babelHelpers.specImportCheck(_b, ['default']);
 
-const _module3 = babelHelpers.specRequireInterop(require('module3'));
+const _c = babelHelpers.specRequireInterop(require('c'));
 
-const _module4 = babelHelpers.specRequireInterop(require('module4'));
+babelHelpers.specImportCheck(_c, ['foo']);
 
-babelHelpers.specImportCheck(_module4, ['pick']);
-babelHelpers.specImportCheck(_module3, ['foo']);
+const _d = babelHelpers.specRequireInterop(require('d'));
 
+babelHelpers.specImportCheck(_d, ['pick']);
 
-(0, _module2.default)(_module3.foo, _module4.pick);
+
+(0, _b.default)(_c.foo, _d.pick);
 ```
 
 ## Options `specImport`
@@ -149,9 +150,10 @@ This option enables only the half of `spec` mode that affects the imports, witho
 changing how exports are generated. This would allow the generation of code that
 may still be compatible with engines that do not support getters.
 
-Note that the require helpers do use `Object.keys` and `Object.defineProperty`, so
-ES5 polyfills may still be required. When running on an old engine that does not support
-`Object.defineProperty`, a polyfill to fake it like `es5-sham` is still required.
+Note that the require helpers do use `Object.getOwnPropertyDescriptor` and
+`Object.defineProperty`, so ES5 polyfills may still be required. When running on an
+old engine that does not support `Object.defineProperty`, a polyfill to fake it like
+`es5-sham` is required.
 
 This option is **ignored** if `spec` is enabled. Enabling `spec` implies that this
 option is also enabled.

From df80908e3ab7ee9490883d27bce62682a1329b07 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 10:47:54 +0900
Subject: [PATCH 082/103] Remove unneeded argument

---
 .../src/index.js                                       | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 04cd8a6e2a5a..4cab15faeafc 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -340,7 +340,7 @@ export default function () {
 
           let requires = Object.create(null);
 
-          const addRequire = (source, specImport, blockHoist) => {
+          const addRequire = (source, blockHoist) => {
             let cached = requires[source];
             if (cached) return cached;
 
@@ -587,7 +587,7 @@ export default function () {
 
                   imports[key] = importsEntry;
                 } else {
-                  ref = addRequire(source.value, specImport, path.node._blockHoist);
+                  ref = addRequire(source.value, path.node._blockHoist);
                 }
 
                 for (let specifier of specifiers) {
@@ -639,11 +639,11 @@ export default function () {
                 exportNode = specBuildNamespaceSpread({
                   EXPORTS: exportsObj,
                   OWN_EXPORTS: ownExportsUid,
-                  OBJECT: addRequire(path.node.source.value, specImport, 3)
+                  OBJECT: addRequire(path.node.source.value, 3)
                 });
                 exportNode._blockHoist = 3;
               } else {
-                const ref = addRequire(path.node.source.value, specImport, path.node._blockHoist);
+                const ref = addRequire(path.node.source.value, path.node._blockHoist);
                 exportNode = buildExportAll({
                   OBJECT: ref
                 });
@@ -661,7 +661,7 @@ export default function () {
           for (let source in imports) {
             let {specifiers, maxBlockHoist} = imports[source];
             if (specifiers.length) {
-              const uid = addRequire(source, specImport, maxBlockHoist);
+              const uid = addRequire(source, maxBlockHoist);
 
               if (specImport) {
                 if (!checkedImportMap.has(uid)) {

From 2241a880a0b69cf1524e51d1dbbb85ae3603e000 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 11:04:03 +0900
Subject: [PATCH 083/103] Check if renamed reexports are correctly exported

---
 .../test/fixtures/spec/reexports/actual.js                      | 2 +-
 .../test/fixtures/spec/reexports/expected.js                    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js
index 78e00fcd9f4d..ce30528464c2 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/actual.js
@@ -1,6 +1,6 @@
 import * as namespace from './somewhere';
 
-export { stuff } from './elsewhere'
+export { stuff as renamed } from './elsewhere'
 
 import { stuff } from './somewhereElse';
 
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index d2e82b2f1836..985698f907d1 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -31,7 +31,7 @@ Object.defineProperties(exports, {
     }
 
   },
-  stuff: {
+  renamed: {
     enumerable: true,
 
     get() {

From 9989e97a126846ab2535c3eb14ad101a84586172 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 11:19:27 +0900
Subject: [PATCH 084/103] Add missing before hooks; fix tests failing on Node <
 6

---
 .../test/spec-import-check.js                 | 25 +++++++++++++------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
index 7fb64b5885f7..6e2eb8820c09 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-import-check.js
@@ -85,14 +85,20 @@ describe("spec import", function () {
     });
 
     describe("with variable", function () {
-      runner.addModule("variable", "import * as a from 'a'\nconst name = 'a'\nexport const simple = a[name]\nexport const recursive = a[a[name]]");
+      before(function () {
+        runner.addModule("variable", "import * as a from 'a'\nconst name = 'a'\nexport const simple = a[name]\nexport const recursive = a[a[name]]");
 
-      it("does not throw", function () {
-        runner.getExportsOf("variable");
+        it("does not throw", function () {
+          runner.getExportsOf("variable");
+        });
       });
 
       describe("has the correct result", function () {
-        const exports = runner.getExportsOf("variable");
+        let exports;
+
+        before(function () {
+          exports = runner.getExportsOf("variable");
+        });
 
         it("simple", function () {
           assert.strictEqual(exports.simple, "a");
@@ -105,10 +111,13 @@ describe("spec import", function () {
     });
 
     describe("with Symbol", function () {
-      runner.addModule("symbol", "import * as a from 'a'\nexport default a[Symbol.toStringTag]");
-      if (!helpers.hasToStringTag()) {
-        this.skip();
-      }
+      before(function () {
+        runner.addModule("symbol", "import * as a from 'a'\nexport default a[Symbol.toStringTag]");
+
+        if (!helpers.hasToStringTag()) {
+          this.skip();
+        }
+      });
 
       it("does not throw", function () {
         runner.getExportsOf("symbol");

From 33f2325360c9dfa710517ddf5e262071a5d5dab8 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 11:44:21 +0900
Subject: [PATCH 085/103] Use propertyIsEnumerable instead of
 getOwnPropertyDescriptor

---
 packages/babel-helpers/src/helpers.js | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index 7065d31fb2ff..e5b566a36e26 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -445,7 +445,7 @@ helpers.specRequireInterop = template(`
 helpers.specImportCheck = template(`
   (function (module, imports) {
     if (!module.__esModule) throw new Error("Only ES modules can be checked");
-    var invalid = imports.filter(function (i) { var d = Object.getOwnPropertyDescriptor(module, i); return !d || !d.enumerable; });
+    var invalid = imports.filter(function (i) { return !Object.prototype.propertyIsEnumerable.call(module, i) });
     if (invalid.length > 0) {
       var error = new Error(
         "Unknown export" + (invalid.length > 1 ? "s " : " ") +
@@ -470,8 +470,9 @@ helpers.specNamespaceGet = template(`
     ) {
       return module[name];
     }
-    var d = Object.getOwnPropertyDescriptor(module, name);
-    if (!d || !d.enumerable) throw new Error("Unknown export " + JSON.stringify(name) + " imported");
+    if (!Object.prototype.propertyIsEnumerable.call(module, name)) {
+      throw new Error("Unknown export " + JSON.stringify(name) + " imported");
+    }
     return module[name];
   })
 `);

From ca4b63b33205ff3f13a4561b8bea83b677b61aa9 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 11:44:56 +0900
Subject: [PATCH 086/103] Use better SameValue algorithm

---
 .../src/index.js                                          | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 4cab15faeafc..1d6fa1b4b143 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -58,10 +58,16 @@ const specBuildOwnExports = template(`
   const $0 = Object.keys($1)
 `);
 
+// The SameValue check between own and other was adapted from core-js's
+// Object.is implementation.
+// https://github.com/zloirock/core-js/blob/master/modules/_same-value.js
 const specBuildNamespaceSpread = template(`
   Object.keys(OBJECT).forEach(function (key) {
     if (key === "__esModule" || key === "default" || OWN_EXPORTS.indexOf(key) >= 0) return;
-    if (key in EXPORTS && (EXPORTS[key] === OBJECT[key] || typeof EXPORTS[key] === 'number' && isNaN(EXPORTS[key]))) return;
+    if (key in EXPORTS) {
+      var own = EXPORTS[key], other = OBJECT[key]
+      if (own === other ? own !== 0 || 1 / own === 1 / other : own != own && other != other) return;
+    }
     Object.defineProperty(EXPORTS, key, {
       enumerable: true,
       get() {

From 65680c9b8036e74c07572839d6250e47e38b88b4 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 11:46:04 +0900
Subject: [PATCH 087/103] Update fixtures

---
 .../spec/export-default-func-hoisting/expected.js         | 8 +++++++-
 .../test/fixtures/spec/reexports/expected.js              | 8 +++++++-
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
index 926ec213203a..d24d24791e39 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
@@ -36,7 +36,13 @@ const _bar = babelHelpers.specRequireInterop(require('bar'));
 
 Object.keys(_bar).forEach(function (key) {
   if (key === "__esModule" || key === "default" || _ownExports.indexOf(key) >= 0) return;
-  if (key in exports && (exports[key] === _bar[key] || typeof exports[key] === 'number' && isNaN(exports[key]))) return;
+
+  if (key in exports) {
+    var own = exports[key],
+        other = _bar[key];
+    if (own === other ? own !== 0 || 1 / own === 1 / other : own != own && other != other) return;
+  }
+
   Object.defineProperty(exports, key, {
     enumerable: true,
 
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index 985698f907d1..f15a403de471 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -55,7 +55,13 @@ const _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
 
 Object.keys(_iDontKnow).forEach(function (key) {
   if (key === "__esModule" || key === "default" || _ownExports.indexOf(key) >= 0) return;
-  if (key in exports && (exports[key] === _iDontKnow[key] || typeof exports[key] === 'number' && isNaN(exports[key]))) return;
+
+  if (key in exports) {
+    var own = exports[key],
+        other = _iDontKnow[key];
+    if (own === other ? own !== 0 || 1 / own === 1 / other : own != own && other != other) return;
+  }
+
   Object.defineProperty(exports, key, {
     enumerable: true,
 

From 70d0f9aec0f4d8f49c0481b82673765da24e22ce Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 11:52:11 +0900
Subject: [PATCH 088/103] Use a helper for the SameValue check

---
 packages/babel-helpers/src/helpers.js                    | 8 ++++++++
 .../src/index.js                                         | 9 ++-------
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index e5b566a36e26..00c81c2d03aa 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -416,6 +416,14 @@ helpers.interopRequireWildcard = template(`
   })
 `);
 
+// based on core-js's SameValue implementation
+// https://github.com/zloirock/core-js/blob/693767b/modules/_same-value.js
+helpers.sameValue = template(`
+  (function (x, y) {
+    return x === y ? x !== 0 || 1 / x === 1 / y : x != x && y != y;
+  })
+`);
+
 helpers.specRequireInterop = template(`
   (function (obj) {
     if (obj && obj.__esModule) {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 1d6fa1b4b143..c71aee758b2a 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -58,16 +58,10 @@ const specBuildOwnExports = template(`
   const $0 = Object.keys($1)
 `);
 
-// The SameValue check between own and other was adapted from core-js's
-// Object.is implementation.
-// https://github.com/zloirock/core-js/blob/master/modules/_same-value.js
 const specBuildNamespaceSpread = template(`
   Object.keys(OBJECT).forEach(function (key) {
     if (key === "__esModule" || key === "default" || OWN_EXPORTS.indexOf(key) >= 0) return;
-    if (key in EXPORTS) {
-      var own = EXPORTS[key], other = OBJECT[key]
-      if (own === other ? own !== 0 || 1 / own === 1 / other : own != own && other != other) return;
-    }
+    if (key in EXPORTS && SAME_VALUE(EXPORTS[key], OBJECT[key])) return;
     Object.defineProperty(EXPORTS, key, {
       enumerable: true,
       get() {
@@ -645,6 +639,7 @@ export default function () {
                 exportNode = specBuildNamespaceSpread({
                   EXPORTS: exportsObj,
                   OWN_EXPORTS: ownExportsUid,
+                  SAME_VALUE: this.addHelper("sameValue"),
                   OBJECT: addRequire(path.node.source.value, 3)
                 });
                 exportNode._blockHoist = 3;

From e233d40c3a8cc05fdff3b76f0032eadc6ba44d93 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 11:52:22 +0900
Subject: [PATCH 089/103] Update fixtures

---
 .../spec/export-default-func-hoisting/expected.js         | 8 +-------
 .../test/fixtures/spec/reexports/expected.js              | 8 +-------
 2 files changed, 2 insertions(+), 14 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
index d24d24791e39..2bacdc7c2267 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
@@ -36,13 +36,7 @@ const _bar = babelHelpers.specRequireInterop(require('bar'));
 
 Object.keys(_bar).forEach(function (key) {
   if (key === "__esModule" || key === "default" || _ownExports.indexOf(key) >= 0) return;
-
-  if (key in exports) {
-    var own = exports[key],
-        other = _bar[key];
-    if (own === other ? own !== 0 || 1 / own === 1 / other : own != own && other != other) return;
-  }
-
+  if (key in exports && babelHelpers.sameValue(exports[key], _bar[key])) return;
   Object.defineProperty(exports, key, {
     enumerable: true,
 
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index f15a403de471..11c61e6ebbf7 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -55,13 +55,7 @@ const _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
 
 Object.keys(_iDontKnow).forEach(function (key) {
   if (key === "__esModule" || key === "default" || _ownExports.indexOf(key) >= 0) return;
-
-  if (key in exports) {
-    var own = exports[key],
-        other = _iDontKnow[key];
-    if (own === other ? own !== 0 || 1 / own === 1 / other : own != own && other != other) return;
-  }
-
+  if (key in exports && babelHelpers.sameValue(exports[key], _iDontKnow[key])) return;
   Object.defineProperty(exports, key, {
     enumerable: true,
 

From 1d63392554bf352ac6dbdb610d15ab8c10ff25df Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 14:41:16 +0900
Subject: [PATCH 090/103] Fix crash when processing ThisExpression

---
 .../src/index.js                              | 18 ++++-----
 .../fixtures/spec/commonjs-shadow-3/actual.js |  9 +++++
 .../spec/commonjs-shadow-3/expected.js        | 40 +++++++++++++++++++
 3 files changed, 56 insertions(+), 11 deletions(-)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-3/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-3/expected.js

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index c71aee758b2a..03b2804eeb3e 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -196,13 +196,13 @@ export default function () {
     AssignmentExpression(path, state) {
       if (isSpec(state)) {
         if (!path.node[REASSIGN_REMAP_SKIP]) {
-          const target = t.isIdentifier(path.node.left)
-            ? path.node.left
-            : t.isMemberExpression(path.node.left) && t.isIdentifier(path.node.left.object)
-              ? path.node.left.object : null;
-          const name = target && target.name;
+          const left = path.get("left");
+          if (!left.isIdentifier() && !left.isMemberExpression()) return;
+          const target = left.isIdentifier() ? left : left.get("object");
+          if (!target.isIdentifier()) return;
+          const name = target.node.name;
 
-          if (target[REASSIGN_REMAP_SKIP] || this.scope.getBinding(name) !== path.scope.getBinding(name)) {
+          if (target.node[REASSIGN_REMAP_SKIP] || this.scope.getBinding(name) !== path.scope.getBinding(name)) {
             return;
           }
 
@@ -217,11 +217,7 @@ export default function () {
           }
 
           if (remap) {
-            if (t.isIdentifier(path.node.left)) {
-              path.get("left").replaceWith(remap);
-            } else {
-              path.get("left.object").replaceWith(remap);
-            }
+            target.replaceWith(remap);
           }
         }
         return;
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-3/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-3/actual.js
new file mode 100644
index 000000000000..4c4bb8a3ff02
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-3/actual.js
@@ -0,0 +1,9 @@
+export default class {
+  noShadow (exports) {
+    this.shadow(exports)
+  }
+
+  shadow () {
+    exports
+  }
+}
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-3/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-3/expected.js
new file mode 100644
index 000000000000..1529431091e9
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-3/expected.js
@@ -0,0 +1,40 @@
+"use strict";
+
+const exports = module.exports = Object.create ? Object.create(null, {
+  __esModule: {
+    value: true
+  }
+}) : {
+  __esModule: true
+};
+
+if (typeof Symbol === "function" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+Object.defineProperties(exports, {
+  default: {
+    enumerable: true,
+
+    get() {
+      return _default;
+    }
+
+  }
+});
+(Object.freeze || Object)(exports);
+let _default = {
+  default: class {
+    noShadow(exports) {
+      this.shadow(exports);
+    }
+
+    shadow() {
+      _exports;
+    }
+  }
+}.default;
+
+let _exports;
\ No newline at end of file

From ccd3895fd82bc7d94eea14a9d518e2b74e4213b8 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 14:41:44 +0900
Subject: [PATCH 091/103] Add failing test (fix TODO)

---
 .../specImport/transform-runtime/actual.js    |  5 +++
 .../specImport/transform-runtime/expected.js  | 32 +++++++++++++++++++
 .../specImport/transform-runtime/options.json |  3 ++
 3 files changed, 40 insertions(+)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/options.json

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/actual.js
new file mode 100644
index 000000000000..ff1f7dfa1590
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/actual.js
@@ -0,0 +1,5 @@
+import { foo } from 'foo'
+import * as ns from 'bar'
+export * from 'baz'
+
+ns[true && 'bar']
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/expected.js
new file mode 100644
index 000000000000..d0a9f34abfba
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/expected.js
@@ -0,0 +1,32 @@
+'use strict';
+
+// definitely not this
+import _Object$defineProperty from 'babel-runtime/core-js/object/define-property';
+import _Object$keys from 'babel-runtime/core-js/object/keys';
+import _specNamespaceGet from 'babel-runtime/helpers/specNamespaceGet';
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+import _specImportCheck from 'babel-runtime/helpers/specImportCheck';
+import _specRequireInterop from 'babel-runtime/helpers/specRequireInterop';
+
+const _baz = _specRequireInterop(require('baz'));
+
+_Object$keys(_baz).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+
+  _Object$defineProperty(exports, key, {
+    enumerable: true,
+    get: function () {
+      return _baz[key];
+    }
+  });
+});
+
+const _foo = _specRequireInterop(require('foo'));
+
+_specImportCheck(_foo, ['foo']);
+
+const _bar = _specRequireInterop(require('bar'));
+
+_specNamespaceGet(_bar, true && 'bar');
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/options.json b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/options.json
new file mode 100644
index 000000000000..71386e610d89
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": [["transform-es2015-modules-commonjs", {"spec": false, "specImport": true}], "transform-runtime"]
+}

From ba417599aa880905f74a4abf47090bdd2d635220 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Mon, 12 Dec 2016 14:43:42 +0900
Subject: [PATCH 092/103] Fix order in options.json; test still failing

---
 .../test/fixtures/specImport/transform-runtime/options.json     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/options.json b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/options.json
index 71386e610d89..74e1870801be 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/options.json
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/options.json
@@ -1,3 +1,3 @@
 {
-  "plugins": [["transform-es2015-modules-commonjs", {"spec": false, "specImport": true}], "transform-runtime"]
+  "plugins": ["transform-runtime", ["transform-es2015-modules-commonjs", {"spec": false, "specImport": true}]]
 }

From 838fb7b8ef68d022cf5e0b2d771f36d8fe7efbd2 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Tue, 13 Dec 2016 02:46:19 +0900
Subject: [PATCH 093/103] Allow the helperGenerator hook to return the helper
 itself

---
 packages/babel-core/src/transformation/file/index.js | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/packages/babel-core/src/transformation/file/index.js b/packages/babel-core/src/transformation/file/index.js
index 01d5b7efc9d3..88abbf288585 100644
--- a/packages/babel-core/src/transformation/file/index.js
+++ b/packages/babel-core/src/transformation/file/index.js
@@ -288,14 +288,15 @@ export default class File extends Store {
 
     let generator = this.get("helperGenerator");
     let runtime   = this.get("helpersNamespace");
+    let res = null;
     if (generator) {
-      let res = generator(name);
-      if (res) return res;
+      res = generator(name);
+      if (res && t.isIdentifier(res)) return res;
     } else if (runtime) {
       return t.memberExpression(runtime, t.identifier(name));
     }
 
-    let ref = getHelper(name);
+    let ref = res || getHelper(name);
     let uid = this.declarations[name] = this.scope.generateUidIdentifier(name);
 
     if (t.isFunctionExpression(ref) && !ref.id) {

From 60973721938d5d889ffd3ae14379d504e1133046 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Tue, 13 Dec 2016 02:47:02 +0900
Subject: [PATCH 094/103] transform-runtime: flag blacklisted helpers for
 skipping transform

---
 .../package.json                              |  3 ++-
 .../src/index.js                              | 19 ++++++++++++++++++-
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/packages/babel-plugin-transform-runtime/package.json b/packages/babel-plugin-transform-runtime/package.json
index eb6ef08fbfcf..ad5c9a9c8d26 100644
--- a/packages/babel-plugin-transform-runtime/package.json
+++ b/packages/babel-plugin-transform-runtime/package.json
@@ -9,7 +9,8 @@
     "babel-plugin"
   ],
   "dependencies": {
-    "babel-runtime": "^6.9.0"
+    "babel-runtime": "^6.9.0",
+    "babel-helpers": "^6.16.0"
   },
   "devDependencies": {
     "babel-helper-plugin-test-runner": "^6.8.0"
diff --git a/packages/babel-plugin-transform-runtime/src/index.js b/packages/babel-plugin-transform-runtime/src/index.js
index 805df686ae10..25e525f47f04 100644
--- a/packages/babel-plugin-transform-runtime/src/index.js
+++ b/packages/babel-plugin-transform-runtime/src/index.js
@@ -1,4 +1,5 @@
 import definitions from "./definitions";
+import getHelper from "babel-helpers";
 
 export default function ({ types: t }) {
   function getRuntimeModuleName(opts) {
@@ -9,7 +10,14 @@ export default function ({ types: t }) {
     return Object.prototype.hasOwnProperty.call(obj, key);
   }
 
-  let HELPER_BLACKLIST = ["interopRequireWildcard", "interopRequireDefault"];
+  let HELPER_BLACKLIST = [
+    "interopRequireWildcard", "interopRequireDefault",
+    "specRequireInterop", "specImportCheck"
+  ];
+
+  function shouldSkipTransform(path) {
+    return !!path.find((p) => p.node._noTransform);
+  }
 
   return {
     pre(file) {
@@ -19,6 +27,10 @@ export default function ({ types: t }) {
         file.set("helperGenerator", function (name) {
           if (HELPER_BLACKLIST.indexOf(name) < 0) {
             return file.addImport(`${moduleName}/helpers/${name}`, "default", name);
+          } else {
+            const node = getHelper(name);
+            node._noTransform = true;
+            return node;
           }
         });
       }
@@ -42,6 +54,7 @@ export default function ({ types: t }) {
         if (t.isMemberExpression(parent)) return;
         if (!has(definitions.builtins, node.name)) return;
         if (scope.getBindingIdentifier(node.name)) return;
+        if (shouldSkipTransform(path)) return;
 
         // Symbol() -> _core.Symbol(); new Promise -> new _core.Promise
         const moduleName = getRuntimeModuleName(state.opts);
@@ -63,6 +76,7 @@ export default function ({ types: t }) {
         if (!t.isMemberExpression(callee)) return;
         if (!callee.computed) return;
         if (!path.get("callee.property").matchesPattern("Symbol.iterator")) return;
+        if (shouldSkipTransform(path)) return;
 
         const moduleName = getRuntimeModuleName(state.opts);
         path.replaceWith(t.callExpression(
@@ -81,6 +95,7 @@ export default function ({ types: t }) {
 
         if (path.node.operator !== "in") return;
         if (!path.get("left").matchesPattern("Symbol.iterator")) return;
+        if (shouldSkipTransform(path)) return;
 
         const moduleName = getRuntimeModuleName(state.opts);
         path.replaceWith(t.callExpression(
@@ -118,6 +133,7 @@ export default function ({ types: t }) {
             let call = path.parentPath.node;
             if (call.arguments.length === 3 && t.isLiteral(call.arguments[1])) return;
           }
+          if (shouldSkipTransform(path)) return;
 
           const moduleName = getRuntimeModuleName(state.opts);
           path.replaceWith(state.addImport(
@@ -136,6 +152,7 @@ export default function ({ types: t }) {
 
           if (!has(definitions.builtins, obj.name)) return;
           if (path.scope.getBindingIdentifier(obj.name)) return;
+          if (shouldSkipTransform(path)) return;
 
           const moduleName = getRuntimeModuleName(state.opts);
           path.replaceWith(t.memberExpression(

From ba6dda001f75fb7e5dc6cada5b0eb0cab22567ca Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Tue, 13 Dec 2016 02:48:16 +0900
Subject: [PATCH 095/103] Build the babel-runtime dist scripts from current
 code

---
 packages/babel-runtime/scripts/build-dist.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-runtime/scripts/build-dist.js b/packages/babel-runtime/scripts/build-dist.js
index 25799b68c613..baa27038a378 100644
--- a/packages/babel-runtime/scripts/build-dist.js
+++ b/packages/babel-runtime/scripts/build-dist.js
@@ -31,7 +31,7 @@ each(legacy, function (value, key) {
   writeFile("core-js/" + key + ".js", defaultify('require("core-js/library/fn/' + value + '")'));
 });
 
-var helpers    = require("babel-helpers");
+var helpers    = require("../../babel-helpers");
 var babel      = require("../../babel-core");
 var util       = require("../../babel-core/lib/util");
 var t          = require("../../babel-types");

From 1c5bbcc21e51be7eeac839b0a7a042fd106c0e27 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Tue, 13 Dec 2016 02:50:42 +0900
Subject: [PATCH 096/103] Huge refactoring; reimplement spec / specImport modes
 with visitors

---
 packages/babel-helpers/src/helpers.js         |  34 +-
 .../src/index.js                              | 836 +++++++++++-------
 .../actual.js                                 |   5 +
 .../expected.js                               |  35 +
 .../options.json                              |   3 +
 .../spec/commonjs-shadow-1/expected.js        |   2 +-
 .../export-default-func-hoisting/expected.js  |  23 +-
 .../fixtures/spec/export-default/expected.js  |   2 +-
 .../fixtures/spec/import-simple/expected.js   |  16 +
 .../test/fixtures/spec/import/expected.js     |  16 +
 .../fixtures/spec/namespace-get/expected.js   |  16 +
 .../test/fixtures/spec/readme/expected.js     |   2 +-
 .../test/fixtures/spec/reexports/expected.js  |  25 +-
 .../fixtures/spec/transform-runtime/actual.js |   5 +
 .../spec/transform-runtime/expected.js        |  70 ++
 .../spec/transform-runtime/options.json       |   3 +
 .../specImport/transform-runtime/actual.js    |   5 +-
 .../specImport/transform-runtime/expected.js  |  33 +-
 .../test/spec-test-helpers.js                 |  12 +-
 .../test/spec-with-transform-runtime.js       |  54 ++
 20 files changed, 802 insertions(+), 395 deletions(-)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/options.json
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/options.json
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-with-transform-runtime.js

diff --git a/packages/babel-helpers/src/helpers.js b/packages/babel-helpers/src/helpers.js
index 00c81c2d03aa..921c700eba85 100644
--- a/packages/babel-helpers/src/helpers.js
+++ b/packages/babel-helpers/src/helpers.js
@@ -416,14 +416,6 @@ helpers.interopRequireWildcard = template(`
   })
 `);
 
-// based on core-js's SameValue implementation
-// https://github.com/zloirock/core-js/blob/693767b/modules/_same-value.js
-helpers.sameValue = template(`
-  (function (x, y) {
-    return x === y ? x !== 0 || 1 / x === 1 / y : x != x && y != y;
-  })
-`);
-
 helpers.specRequireInterop = template(`
   (function (obj) {
     if (obj && obj.__esModule) {
@@ -485,6 +477,32 @@ helpers.specNamespaceGet = template(`
   })
 `);
 
+// sameValue function based on core-js's SameValue implementation
+// https://github.com/zloirock/core-js/blob/693767b/modules/_same-value.js
+helpers.specNamespaceSpread = template(`
+  (function (exports, ownExports, module) {
+    if (!module.__esModule) throw new Error("Only ES modules can be spread");
+    for (var key in module) {
+      if (!Object.prototype.hasOwnProperty.call(module, key)) continue;
+      if (key === "__esModule" || key === "default" || ownExports.indexOf(key) >= 0) continue;
+      if (key in exports && sameValue(exports[key], module[key])) continue;
+
+      Object.defineProperty(exports, key, {
+        enumerable: true,
+        get: (function (key) {
+          return function () {
+            return module[key];
+          }
+        })(key)
+      });
+    }
+
+    function sameValue(x, y) {
+      return x === y ? x !== 0 || 1 / x === 1 / y : x != x && y != y;
+    }
+  })
+`);
+
 helpers.newArrowCheck = template(`
   (function (innerThis, boundThis) {
     if (innerThis !== boundThis) {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 03b2804eeb3e..9b6c3089c418 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -58,19 +58,6 @@ const specBuildOwnExports = template(`
   const $0 = Object.keys($1)
 `);
 
-const specBuildNamespaceSpread = template(`
-  Object.keys(OBJECT).forEach(function (key) {
-    if (key === "__esModule" || key === "default" || OWN_EXPORTS.indexOf(key) >= 0) return;
-    if (key in EXPORTS && SAME_VALUE(EXPORTS[key], OBJECT[key])) return;
-    Object.defineProperty(EXPORTS, key, {
-      enumerable: true,
-      get() {
-        return OBJECT[key];
-      }
-    });
-  });
-`);
-
 // Unfortunately, regular objects can't synthesize a value descriptor every time they're read,
 // so a getter needs to be used for live bindings.
 // It's also not allowed to specify writable when using getters/setters.
@@ -284,6 +271,67 @@ export default function () {
     }
   };
 
+  function addImportDependency(path, state) {
+    const { dependencySet, importMap, exportAllSet } = state;
+    const source = path.node.source.value;
+    dependencySet.add(source);
+    if (!importMap.has(source)) {
+      importMap.set(source, {
+        specifiers: new Set(),
+        reexports: new Map(),
+        maxBlockHoist: 0,
+        loc: path.node.loc
+      });
+    }
+    const entry = importMap.get(source);
+
+    if (path.isExportAllDeclaration()) {
+      exportAllSet.add(source);
+    } else {
+      for (const specifier of path.node.specifiers) {
+        if (t.isExportDefaultSpecifier(specifier)) {
+          // not ES2015
+        } else if (t.isExportNamespaceSpecifier(specifier)) {
+          // not ES2015
+        } else if (t.isExportSpecifier(specifier)) {
+          entry.reexports.set(specifier.exported.name, specifier.local);
+        }
+        entry.specifiers.add(specifier);
+      }
+    }
+
+    if (typeof path.node._blockHoist === "number") {
+      entry.maxBlockHoist = Math.max(
+        path.node._blockHoist,
+        entry.maxBlockHoist
+      );
+    }
+
+    return entry;
+  }
+
+  function addExportDeclaration(path, state) {
+    if (isSpec(state)) {
+      if (!path.isExportAllDeclaration()) {
+        const specifiers = [].concat(path.get("declaration"), path.get("specifiers"));
+        for (const specifier of specifiers) {
+          const ids = specifier.getBindingIdentifiers();
+          if (ids.__esModule) {
+            throw specifier.buildCodeFrameError("Illegal export \"__esModule\"");
+          }
+        }
+      }
+    }
+
+    if (isSpecImport(state)) {
+      if (path.node.source) {
+        state.addHelper("specRequireInterop");
+        state.addHelper("specImportCheck");
+        addImportDependency(path, state);
+      }
+    }
+  }
+
   return {
     inherits: require("babel-plugin-transform-strict-mode"),
 
@@ -303,7 +351,209 @@ export default function () {
         }
       },
 
+      ImportDeclaration(path, state) {
+        if (isSpecImport(state)) {
+          this.addHelper("specRequireInterop");
+          this.addHelper("specImportCheck");
+
+          addImportDependency(path, state);
+
+          try {
+            path.remove();
+          } catch (e) {
+            throw new Error(
+              `Invalid import ${JSON.stringify(path.node.source.value)} created after commonjs transform finished executing`
+            );
+          }
+        }
+      },
+
+      ExportDefaultDeclaration(path, state) {
+        addExportDeclaration(path, state);
+
+        if (isSpec(state)) {
+          const { exportMap } = state;
+          const declaration = path.get("declaration");
+          if (declaration.isFunctionDeclaration()) {
+            const id = declaration.node.id;
+            if (id) {
+              exportMap.set("default", id);
+              path.replaceWith(declaration.node);
+            } else {
+              const defaultExportUid = path.scope.generateUidIdentifier("default");
+              exportMap.set("default", defaultExportUid);
+
+              const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
+              const decl = t.variableDeclaration("let", [
+                t.variableDeclarator(defaultExportUid, expr)
+              ]);
+              decl.loc = declaration.node.loc;
+              decl._blockHoist = 3;
+
+              path.parentPath.pushContainer("body", [decl]);
+              path.remove();
+            }
+          } else if (declaration.isClassDeclaration()) {
+            const id = declaration.node.id;
+            if (id) {
+              exportMap.set("default", id);
+              path.replaceWith(declaration.node);
+            } else {
+              const defaultExportUid = path.scope.generateUidIdentifier("default");
+              exportMap.set("default", defaultExportUid);
+
+              const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
+              path.replaceWith(t.variableDeclaration("let", [
+                t.variableDeclarator(defaultExportUid, expr)
+              ]));
+            }
+          } else {
+            const defaultExportUid = path.scope.generateUidIdentifier("default");
+            exportMap.set("default", defaultExportUid);
+
+            path.replaceWith(t.variableDeclaration("let", [
+              t.variableDeclarator(defaultExportUid, declaration.node)
+            ]));
+          }
+        }
+      },
+
+      ExportAllDeclaration(path, state) {
+        addExportDeclaration(path, state);
+
+        if (isSpecImport(state)) {
+          this.addHelper("specRequireInterop");
+          this.addHelper("specImportCheck");
+          path.remove();
+        }
+        if (isSpec(state)) {
+          this.addHelper("specNamespaceSpread");
+        }
+      },
+
+      ExportNamedDeclaration(path, state) {
+        addExportDeclaration(path, state);
+
+        if (isSpec(state)) {
+          const { exportMap } = state;
+          const declaration = path.get("declaration");
+          if (declaration.node) {
+            if (declaration.isFunctionDeclaration() || declaration.isClassDeclaration()) {
+              const id = declaration.node.id;
+              exportMap.set(id.name, id);
+            } else if (declaration.isVariableDeclaration()) {
+              const declarations = declaration.get("declarations");
+              for (const decl of declarations) {
+                const id = decl.node.id;
+                exportMap.set(id.name, id);
+              }
+            }
+            path.replaceWith(declaration.node);
+          } else {
+            for (const specifier of path.node.specifiers) {
+              exportMap.set(specifier.exported.name, specifier.local);
+            }
+            path.remove();
+          }
+        }
+      },
+
       Program: {
+        enter(path, state) {
+          if (isSpec(state)) {
+            state.exportMap = new Map();
+
+            const decls = specBuildNamespace(exportsObj, module);
+            const exportPropertyList = [];
+            const node = specBuildHoistedExport(exportsObj, t.objectExpression(exportPropertyList));
+            decls.push(node);
+            const freeze = specFinishNamespaceExport(exportsObj);
+            decls.push(freeze);
+
+            decls.forEach((decl) => { decl._blockHoist = 3; });
+
+            path.unshiftContainer("body", decls);
+
+            state.exportPath = path.get("body").find((path) => path.node === node);
+            state.freezePath = path.get("body").find((path) => path.node === freeze);
+
+            state.updateExports = () => {
+              const { exportMap } = state;
+
+              const current = new Set(exportPropertyList.map((prop) => prop.key.name));
+
+              const entries = Array.from(exportMap.entries())
+              .filter(([name]) => !current.has(name))
+              .map(([name, id]) =>
+                specBuildHoistedExportProperty(t.identifier(name), id)
+              )
+              .filter(Boolean);
+
+              for (const entry of entries) {
+                exportPropertyList.push(entry);
+              }
+            };
+
+            state.removeHoistedExports = () => {
+              path.get("body").find((path) => path.node === node).remove();
+            };
+          }
+
+          if (isSpecImport(state)) {
+            state.dependencySet = new Set();
+            state.importMap = new Map();
+            state.exportAllSet = new Set();
+
+            const namespaceImportSet = new Set();
+
+            // two fast traversals to check whether the specNamespaceGet
+            // or the specNamespaceSpread helpers will be needed and request
+            // them beforehand
+
+            const { scope } = path;
+            const addHelper = this.addHelper.bind(this);
+
+            path.traverse({
+              ExportAllDeclaration() {
+                if (isSpec(state)) {
+                  addHelper("specNamespaceSpread");
+                  if (!state.ownExportsUid) {
+                    state.ownExportsUid = path.scope.generateUidIdentifier("ownExports");
+                    const node = specBuildOwnExports(state.ownExportsUid, exportsObj);
+                    node._blockHoist = 3;
+                    state.freezePath.insertBefore([node]);
+                    state.ownExportsPath = state.exportPath.parentPath.get("body").find((path) => path.node === node);
+                  }
+                }
+              },
+              ImportNamespaceSpecifier(path) {
+                namespaceImportSet.add(path.node.local.name);
+              }
+            });
+            if (namespaceImportSet.size > 0) {
+              path.traverse({
+                ReferencedIdentifier(path) {
+                  const name = path.node.name;
+
+                  // redeclared in this scope
+                  if (scope.getBinding(name) !== path.scope.getBinding(name)) return;
+
+                  if (
+                    t.isMemberExpression(path.parent) &&
+                    t.isIdentifier(path.parent.object) &&
+                    namespaceImportSet.has(path.parent.object.name)
+                  ) {
+                    const { property, computed } = path.parent;
+
+                    if (computed && !t.isStringLiteral(property)) {
+                      addHelper("specNamespaceGet");
+                    }
+                  }
+                }
+              });
+            }
+          }
+        },
         exit(path, state) {
           this.ranCommonJS = true;
 
@@ -330,10 +580,6 @@ export default function () {
           let topNodes = [];
           let remaps = Object.create(null);
 
-          const hoistedExports = spec && new Map();
-          let defaultExportUid = null;
-          let ownExportsUid = null;
-
           let requires = Object.create(null);
 
           const addRequire = (source, blockHoist) => {
@@ -393,7 +639,7 @@ export default function () {
               }
             }
 
-            if (path.isImportDeclaration()) {
+            if (!specImport && path.isImportDeclaration()) {
               hasImports = true;
 
               let key = path.node.source.value;
@@ -415,87 +661,42 @@ export default function () {
               imports[key] = importsEntry;
 
               path.remove();
-            } else if (path.isExportDefaultDeclaration()) {
-              let declaration = path.get("declaration");
-              if (declaration.isFunctionDeclaration()) {
-                let id = declaration.node.id;
-                let defNode = t.identifier("default");
-                if (id) {
-                  addTo(exports, id.name, defNode);
-                  if (spec) {
-                    hoistedExports.set("default", id);
-                  } else {
+            } else if (!spec) {
+              if (path.isExportDefaultDeclaration()) {
+                let declaration = path.get("declaration");
+                if (declaration.isFunctionDeclaration()) {
+                  let id = declaration.node.id;
+                  let defNode = t.identifier("default");
+                  if (id) {
+                    addTo(exports, id.name, defNode);
                     topNodes.push(buildExportsAssignment(defNode, id));
-                  }
-                  path.replaceWith(declaration.node);
-                } else if (spec) {
-                  defaultExportUid = path.scope.generateUidIdentifier("default");
-                  hoistedExports.set("default", defaultExportUid);
-                  const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
-                  const decl = t.variableDeclaration("let", [
-                    t.variableDeclarator(defaultExportUid, expr)
-                  ]);
-                  decl.loc = declaration.node.loc;
-                  decl._blockHoist = 3;
-                  topNodes.unshift(decl);
-                  path.remove();
-                } else {
-                  const expr = t.toExpression(declaration.node);
-                  topNodes.push(buildExportsAssignment(defNode, expr));
-                  path.remove();
-                }
-              } else if (declaration.isClassDeclaration()) {
-                let id = declaration.node.id;
-                let defNode = t.identifier("default");
-                if (id) {
-                  addTo(exports, id.name, defNode);
-                  if (spec) {
-                    hoistedExports.set("default", id);
                     path.replaceWith(declaration.node);
                   } else {
+                    const expr = t.toExpression(declaration.node);
+                    topNodes.push(buildExportsAssignment(defNode, expr));
+                    path.remove();
+                  }
+                } else if (declaration.isClassDeclaration()) {
+                  let id = declaration.node.id;
+                  let defNode = t.identifier("default");
+                  if (id) {
+                    addTo(exports, id.name, defNode);
                     path.replaceWithMultiple([
                       declaration.node,
                       buildExportsAssignment(defNode, id)
                     ]);
-                  }
-                } else if (spec) {
-                  defaultExportUid = path.scope.generateUidIdentifier("default");
-                  hoistedExports.set("default", defaultExportUid);
-
-                  const expr = specBuildFunctionNameWrapper(t.toExpression(declaration.node)).expression;
-
-                  path.replaceWith(t.variableDeclaration("let", [
-                    t.variableDeclarator(defaultExportUid, expr)
-                  ]));
+                  } else {
+                    const expr = t.toExpression(declaration.node);
+                    path.replaceWith(buildExportsAssignment(defNode, expr));
 
-                  // Manually re-queue the expression so other transforms can get to it.
-                  // Ideally this would happen automatically from the replaceWith above.
-                  // See #4140 for more info.
-                  path.parentPath.requeue(path.get("declarations.init"));
+                    // Manualy re-queue `export default class {}` expressions so that the ES3 transform
+                    // has an opportunity to convert them. Ideally this would happen automatically from the
+                    // replaceWith above. See #4140 for more info.
+                    path.parentPath.requeue(path.get("expression.left"));
+                  }
                 } else {
-                  const expr = t.toExpression(declaration.node);
-                  path.replaceWith(buildExportsAssignment(defNode, expr));
+                  const defNode = t.identifier("default");
 
-                  // Manualy re-queue `export default class {}` expressions so that the ES3 transform
-                  // has an opportunity to convert them. Ideally this would happen automatically from the
-                  // replaceWith above. See #4140 for more info.
-                  path.parentPath.requeue(path.get("expression.left"));
-                }
-              } else {
-                const defNode = t.identifier("default");
-                if (spec) {
-                  defaultExportUid = path.scope.generateUidIdentifier("default");
-                  hoistedExports.set("default", defaultExportUid);
-
-                  path.replaceWith(t.variableDeclaration("let", [
-                    t.variableDeclarator(defaultExportUid, declaration.node)
-                  ]));
-
-                  // Manually re-queue the expression so other transforms can get to it.
-                  // Ideally this would happen automatically from the replaceWith above.
-                  // See #4140 for more info.
-                  path.parentPath.requeue(path.get("declarations.init"));
-                } else {
                   path.replaceWith(buildExportsAssignment(defNode, declaration.node));
 
                   // Manualy re-queue `export default foo;` expressions so that the ES3 transform
@@ -503,251 +704,209 @@ export default function () {
                   // replaceWith above. See #4140 for more info.
                   path.parentPath.requeue(path.get("expression.left"));
                 }
-              }
-            } else if (path.isExportNamedDeclaration()) {
-              let declaration = path.get("declaration");
-              if (declaration.node) {
-                if (declaration.isFunctionDeclaration()) {
-                  let id = declaration.node.id;
-                  addTo(exports, id.name, id);
-                  if (spec) {
-                    hoistedExports.set(id.name, id);
-                  } else {
+              } else if (path.isExportNamedDeclaration()) {
+                let declaration = path.get("declaration");
+                if (declaration.node) {
+                  if (declaration.isFunctionDeclaration()) {
+                    let id = declaration.node.id;
+                    addTo(exports, id.name, id);
                     topNodes.push(buildExportsAssignment(id, id));
-                  }
-                  path.replaceWith(declaration.node);
-                } else if (declaration.isClassDeclaration()) {
-                  let id = declaration.node.id;
-                  addTo(exports, id.name, id);
-                  if (spec) {
-                    hoistedExports.set(id.name, id);
                     path.replaceWith(declaration.node);
-                  } else {
+                  } else if (declaration.isClassDeclaration()) {
+                    let id = declaration.node.id;
+                    addTo(exports, id.name, id);
                     path.replaceWithMultiple([
                       declaration.node,
                       buildExportsAssignment(id, id)
                     ]);
                     nonHoistedExportNames[id.name] = true;
-                  }
-                } else if (declaration.isVariableDeclaration()) {
-                  let declarators = declaration.get("declarations");
-                  for (let decl of declarators) {
-                    let id = decl.get("id");
-
-                    if (spec) {
-                      hoistedExports.set(id.node.name, id.node);
-                      continue;
-                    }
-
-                    let init = decl.get("init");
-                    if (!init.node) init.replaceWith(t.identifier("undefined"));
-
-                    if (id.isIdentifier()) {
-                      addTo(exports, id.node.name, id.node);
-                      if (spec) {
-                      } else {
+                  } else if (declaration.isVariableDeclaration()) {
+                    let declarators = declaration.get("declarations");
+                    for (let decl of declarators) {
+                      let id = decl.get("id");
+                      let init = decl.get("init");
+                      if (!init.node) init.replaceWith(t.identifier("undefined"));
+
+                      if (id.isIdentifier()) {
+                        addTo(exports, id.node.name, id.node);
                         init.replaceWith(buildExportsAssignment(id.node, init.node).expression);
+                        nonHoistedExportNames[id.node.name] = true;
+                      } else {
+                        // todo
                       }
-                      nonHoistedExportNames[id.node.name] = true;
-                    } else {
-                      // todo
                     }
+                    path.replaceWith(declaration.node);
                   }
-                  path.replaceWith(declaration.node);
+                  continue;
                 }
-                continue;
-              }
 
-              let specifiers = path.get("specifiers");
-              let nodes = [];
-              let source = path.node.source;
-              if (source) {
-                let ref, importsEntry;
-                if (specImport) {
-                  let key = path.node.source.value;
-                  importsEntry = imports[key] || {
-                    specifiers: [],
-                    maxBlockHoist: 0,
-                    loc: path.node.loc,
-                  };
-                  importsEntry.reexports = importsEntry.reexports || new Map(),
-
-                  importsEntry.specifiers.push(...path.node.specifiers);
-
-                  if (typeof path.node._blockHoist === "number") {
-                    importsEntry.maxBlockHoist = Math.max(
-                      path.node._blockHoist,
-                      importsEntry.maxBlockHoist
-                    );
-                  }
+                let specifiers = path.get("specifiers");
+                let nodes = [];
+                let source = path.node.source;
+                if (source && !specImport) {
+                  let ref = addRequire(source.value, path.node._blockHoist);
 
-                  imports[key] = importsEntry;
-                } else {
-                  ref = addRequire(source.value, path.node._blockHoist);
-                }
-
-                for (let specifier of specifiers) {
-                  if (specifier.isExportNamespaceSpecifier()) {
-                    // todo
-                  } else if (specifier.isExportDefaultSpecifier()) {
-                    // todo
-                  } else if (specifier.isExportSpecifier()) {
-                    if (specImport) {
-                      importsEntry.reexports.set(specifier.node.exported.name, specifier.node.local);
-                    } else if (specifier.node.local.name === "default") {
-                      topNodes.push(buildExportsFrom(t.stringLiteral(specifier.node.exported.name), t.memberExpression(t.callExpression(this.addHelper("interopRequireDefault"), [ref]), specifier.node.local)));
-                    } else {
-                      topNodes.push(buildExportsFrom(t.stringLiteral(specifier.node.exported.name), t.memberExpression(ref, specifier.node.local)));
+                  for (let specifier of specifiers) {
+                    if (specifier.isExportNamespaceSpecifier()) {
+                      // todo
+                    } else if (specifier.isExportDefaultSpecifier()) {
+                      // todo
+                    } else if (specifier.isExportSpecifier()) {
+                      if (specifier.node.local.name === "default") {
+                        topNodes.push(buildExportsFrom(t.stringLiteral(specifier.node.exported.name), t.memberExpression(t.callExpression(this.addHelper("interopRequireDefault"), [ref]), specifier.node.local)));
+                      } else {
+                        topNodes.push(buildExportsFrom(t.stringLiteral(specifier.node.exported.name), t.memberExpression(ref, specifier.node.local)));
+                      }
+                      nonHoistedExportNames[specifier.node.exported.name] = true;
                     }
-                    nonHoistedExportNames[specifier.node.exported.name] = true;
                   }
-                }
-              } else {
-                for (let specifier of specifiers) {
-                  if (specifier.isExportSpecifier()) {
-                    addTo(exports, specifier.node.local.name, specifier.node.exported);
-                    nonHoistedExportNames[specifier.node.exported.name] = true;
+                } else if (!source) {
+                  for (let specifier of specifiers) {
+                    if (specifier.isExportSpecifier()) {
+                      addTo(exports, specifier.node.local.name, specifier.node.exported);
+                      nonHoistedExportNames[specifier.node.exported.name] = true;
 
-                    if (spec) {
-                      hoistedExports.set(specifier.node.exported.name, specifier.node.local);
-                    } else {
                       nodes.push(buildExportsAssignment(specifier.node.exported, specifier.node.local));
                     }
                   }
                 }
-              }
-              path.replaceWithMultiple(nodes);
-            } else if (path.isExportAllDeclaration()) {
-              let exportNode;
-              if (spec) {
-                if (ownExportsUid == null) {
-                  ownExportsUid = path.scope.generateUidIdentifier("ownExports");
-                  const ownExportsNode = specBuildOwnExports(ownExportsUid, exportsObj);
-                  ownExportsNode._blockHoist = 3;
-                  topNodes.push(ownExportsNode);
-                }
-
-                // Unfortunately, the namespace spread needs to happen _before_
-                // the namespace is frozen. This _will_ result in out-of-order
-                // imports, with the 'export * from' imports all running before
-                // any of the other imports.
-
-                exportNode = specBuildNamespaceSpread({
-                  EXPORTS: exportsObj,
-                  OWN_EXPORTS: ownExportsUid,
-                  SAME_VALUE: this.addHelper("sameValue"),
-                  OBJECT: addRequire(path.node.source.value, 3)
-                });
-                exportNode._blockHoist = 3;
-              } else {
+                path.replaceWithMultiple(nodes);
+              } else if (path.isExportAllDeclaration() && !specImport) {
                 const ref = addRequire(path.node.source.value, path.node._blockHoist);
-                exportNode = buildExportAll({
+                const exportNode = buildExportAll({
                   OBJECT: ref
                 });
-                if (specImport) {
-                  exportNode._blockHoist = ref._blockHoist;
-                }
+                exportNode.loc = path.node.loc;
+                topNodes.push(exportNode);
+                path.remove();
               }
-              exportNode.loc = path.node.loc;
-              topNodes.push(exportNode);
-              path.remove();
             }
           }
 
           const checkedImportMap = specImport && new Map();
-          for (let source in imports) {
-            let {specifiers, maxBlockHoist} = imports[source];
-            if (specifiers.length) {
-              const uid = addRequire(source, maxBlockHoist);
-
-              if (specImport) {
-                if (!checkedImportMap.has(uid)) {
-                  const nameSet = new Set(
-                    Array.from(new Set(specifiers))
-                    .filter((specifier) => !t.isImportNamespaceSpecifier(specifier))
-                    .map((specifier) => {
-                      if (t.isImportDefaultSpecifier(specifier)) {
-                        return "default";
-                      }
-                      if (t.isExportSpecifier(specifier)) {
-                        return specifier.local.name;
-                      }
-                      return specifier.imported.name;
-                    })
-                  );
-                  nameSet.source = source;
-
-                  const names = Array.from(nameSet).map((name) => t.stringLiteral(name));
-                  const namesExpr = t.arrayExpression(names);
-
-                  const node =
-                    t.expressionStatement(
-                      t.callExpression(
-                        this.addHelper("specImportCheck"),
-                        [
-                          uid,
-                          namesExpr
-                        ]
-                      )
-                    );
-
-                  node.loc = imports[source].loc;
-
-                  checkedImportMap.set(uid, {
-                    nameSet,
-                    node,
-                    updateNode: () => {
-                      if (nameSet.size === names.length) return;
-
-                      const current = new Set(names.map((name) => name.value));
-
-                      for (const name of nameSet) {
-                        if (!current.has(name)) {
-                          names.push(t.stringLiteral(name));
-                        }
-                      }
-                    },
-                    isEmpty: () => {
-                      return names.length < 1;
-                    }
-                  });
 
-                  topNodes.push(node);
-                }
+          if (specImport) {
+            const { importMap, exportAllSet, dependencySet } = state;
+
+            if (!spec) {
+              for (const star of exportAllSet) {
+                const entry = importMap.get(star);
+                const maxBlockHoist = Math.max(entry.maxBlockHoist, 3);
+                const ref = addRequire(star, maxBlockHoist);
+                const exportNode = buildExportAll({
+                  OBJECT: ref
+                });
+                exportNode._blockHoist = maxBlockHoist;
+                exportNode.loc = entry.loc;
+                topNodes.push(exportNode);
               }
+            }
+            for (const dep of dependencySet) {
+              if (exportAllSet.has(dep)) continue;
 
-              if (imports[source].reexports) {
-                if (!spec) {
-                  for (const [name, local] of imports[source].reexports.entries()) {
-                    if (name === "default") {
-                      topNodes.push(buildExportsFrom(t.stringLiteral(name), t.memberExpression(t.callExpression(this.addHelper("interopRequireDefault"), [uid]), local)));
-                    } else {
-                      topNodes.push(buildExportsFrom(t.stringLiteral(name), t.memberExpression(uid, local)));
+              const entry = importMap.get(dep);
+              const { specifiers } = entry;
+
+              if (specifiers.size == 0) {
+                const node = buildRequire(t.stringLiteral(dep));
+                node.loc = entry.loc;
+                topNodes.push(node);
+                continue;
+              }
+
+              const uid = addRequire(dep, entry.maxBlockHoist || undefined);
+
+              if (!checkedImportMap.has(uid)) {
+                const nameSet = new Set(
+                  Array.from(new Set(specifiers))
+                  .filter((specifier) => !t.isImportNamespaceSpecifier(specifier))
+                  .map((specifier) => {
+                    if (t.isImportDefaultSpecifier(specifier)) {
+                      return "default";
                     }
+                    if (t.isExportSpecifier(specifier)) {
+                      return specifier.local.name;
+                    }
+                    return specifier.imported.name;
+                  })
+                );
+                nameSet.source = dep;
+
+                const names = Array.from(nameSet).map((name) => t.stringLiteral(name));
+                const namesExpr = t.arrayExpression(names);
+
+                const node =
+                  t.expressionStatement(
+                    t.callExpression(
+                      this.addHelper("specImportCheck"),
+                      [
+                        uid,
+                        namesExpr
+                      ]
+                    )
+                  );
+
+                node.loc = entry.loc;
+                node._blockHoist = entry.maxBlockHoist || undefined;
+
+                checkedImportMap.set(uid, {
+                  nameSet,
+                  node,
+                  updateNode: () => {
+                    if (nameSet.size === names.length) return;
+
+                    const current = new Set(names.map((name) => name.value));
+
+                    for (const name of nameSet) {
+                      if (!current.has(name)) {
+                        names.push(t.stringLiteral(name));
+                      }
+                    }
+                  },
+                  isEmpty: () => {
+                    return names.length < 1;
                   }
-                } else {
-                  for (const [name, local] of imports[source].reexports.entries()) {
-                    hoistedExports.set(name, t.memberExpression(uid, local));
-                  }
-                }
+                });
+
+                topNodes.push(node);
               }
 
-              if (specImport) {
-                for (const specifier of specifiers) {
-                  if (t.isImportNamespaceSpecifier(specifier)) {
-                    remaps[specifier.local.name] = uid;
-                  } else if (t.isImportDefaultSpecifier(specifier)) {
-                    remaps[specifier.local.name] = t.memberExpression(uid, t.identifier("default"));
-                  } else if (specImport && t.isExportSpecifier(specifier)) {
-                    // do nothing
+              if (!spec) {
+                for (const [name, local] of entry.reexports.entries()) {
+                  if (name === "default") {
+                    topNodes.push(buildExportsFrom(t.stringLiteral(name), t.memberExpression(t.callExpression(this.addHelper("interopRequireDefault"), [uid]), local)));
                   } else {
-                    remaps[specifier.local.name] = t.memberExpression(uid, t.cloneWithoutLoc(specifier.imported));
-                  }
-                  if (specImport && !t.isExportSpecifier(specifier)) {
-                    remaps[specifier.local.name].nameSet = checkedImportMap.get(uid).nameSet;
+                    topNodes.push(buildExportsFrom(t.stringLiteral(name), t.memberExpression(uid, local)));
                   }
                 }
               } else {
+                const { exportMap } = state;
+                for (const [name, local] of entry.reexports.entries()) {
+                  exportMap.set(name, t.memberExpression(uid, local));
+                }
+              }
+
+              // all specifiers
+              for (const specifier of specifiers) {
+                if (t.isExportSpecifier(specifier)) {
+                  continue;
+                } if (t.isImportNamespaceSpecifier(specifier)) {
+                  remaps[specifier.local.name] = uid;
+                } else if (t.isImportDefaultSpecifier(specifier)) {
+                  remaps[specifier.local.name] = t.memberExpression(uid, t.identifier("default"));
+                } else {
+                  remaps[specifier.local.name] = t.memberExpression(uid, t.cloneWithoutLoc(specifier.imported));
+                }
+
+                remaps[specifier.local.name].nameSet = checkedImportMap.get(uid).nameSet;
+              }
+            }
+          } else {
+            for (let source in imports) {
+              let {specifiers, maxBlockHoist} = imports[source];
+              if (specifiers.length) {
+                const uid = addRequire(source, maxBlockHoist);
+
                 let wildcard;
 
                 for (let i = 0; i < specifiers.length; i++) {
@@ -806,38 +965,27 @@ export default function () {
                     remaps[specifier.local.name] = t.memberExpression(target, t.cloneWithoutLoc(specifier.imported));
                   }
                 }
+              } else {
+                // bare import
+                let requireNode = buildRequire(t.stringLiteral(source));
+                requireNode.loc = imports[source].loc;
+                topNodes.push(requireNode);
               }
-            } else {
-              // bare import
-              let requireNode = buildRequire(t.stringLiteral(source));
-              requireNode.loc = imports[source].loc;
-              topNodes.push(requireNode);
             }
           }
 
-          if (spec) {
-            const entries = Array.from(hoistedExports.entries()).map(([name, id]) => {
-              if (name === "default" && id === null) {
-                // explicit export is generated
-                return;
-              }
-              return specBuildHoistedExportProperty(t.identifier(name), id);
-            }).filter(Boolean);
+          if (!spec) {
+            const { importMap } = state;
+            hasImports = specImport ? importMap.size > 0 : hasImports;
 
-            if (entries.length > 0) {
-              const expr = t.objectExpression(entries);
-              const node = specBuildHoistedExport(exportsObj, expr);
-              node._blockHoist = 3;
-
-              topNodes.unshift(node);
+            if (specImport) {
+              for (const entry of importMap.values()) {
+                for (const name of entry.reexports.keys()) {
+                  nonHoistedExportNames[name] = true;
+                }
+              }
             }
 
-            if (hasExports) {
-              const node = specFinishNamespaceExport(exportsObj);
-              node._blockHoist = 3;
-              topNodes.push(node);
-            }
-          } else {
             if (hasImports && Object.keys(nonHoistedExportNames).length) {
               let hoistedExportsNode = t.identifier("undefined");
 
@@ -865,14 +1013,50 @@ export default function () {
 
           path.unshiftContainer("body", topNodes);
 
-          if (hasExports && spec) {
-            const decls = specBuildNamespace(exportsObj, module);
-            decls.forEach((decl) => { decl._blockHoist = 3; });
+          if (spec) {
+            const { exportAllSet } = state;
+            let tail = state.exportPath;
 
-            path.unshiftContainer("body", decls);
-          }
+            if (exportAllSet.size > 0) {
+              const toAdd = new Set();
+
+              for (const star of exportAllSet) {
+                const ref = path.scope.generateUidIdentifier(basename(star, extname(star)));
+
+                const req = buildRequire(
+                  t.stringLiteral(star)
+                ).expression;
+
+                const decl = t.variableDeclaration("const", [
+                  t.variableDeclarator(ref,
+                    t.callExpression(this.addHelper("specRequireInterop"), [req])
+                  )
+                ]);
+                decl._blockHoist = 3;
+                toAdd.add(decl);
+
+                const node = t.expressionStatement(
+                  t.callExpression(
+                    this.addHelper("specNamespaceSpread"),
+                    [
+                      exportsObj, state.ownExportsUid, ref
+                    ]
+                  )
+                );
+                node._blockHoist = 3;
+                toAdd.add(node);
+              }
+
+              state.ownExportsPath.insertAfter(Array.from(toAdd));
+              tail = state.ownExportsPath.getSibling(state.ownExportsPath.key + toAdd.size);
+            }
+
+            if (state.exportMap.size > 0) {
+              state.updateExports();
+            } else {
+              state.removeHoistedExports();
+            }
 
-          if (spec) {
             commonjsExportsMasked = {};
           }
 
@@ -885,7 +1069,7 @@ export default function () {
             requeueInParent: (newPath) => path.requeue(newPath),
           });
 
-          if (specImport && hasImports) {
+          if (specImport && checkedImportMap.size > 0) {
             const toRemove = new Set();
             for (const check of checkedImportMap.values()) {
               check.updateNode();
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/actual.js
new file mode 100644
index 000000000000..d36f3711f1c6
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/actual.js
@@ -0,0 +1,5 @@
+// NOTE: this is _broken_
+
+export * from 'a'
+import 'b'
+export * from 'c'
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/expected.js
new file mode 100644
index 000000000000..3f5bff0264f9
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/expected.js
@@ -0,0 +1,35 @@
+'use strict';
+
+import _Object$defineProperty from 'babel-runtime/core-js/object/define-property';
+import _Object$keys from 'babel-runtime/core-js/object/keys';
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+var _a = require('a');
+
+_Object$keys(_a).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+
+  _Object$defineProperty(exports, key, {
+    enumerable: true,
+    get: function () {
+      return _a[key];
+    }
+  });
+});
+
+var _c = require('c');
+
+_Object$keys(_c).forEach(function (key) {
+  if (key === "default" || key === "__esModule") return;
+
+  _Object$defineProperty(exports, key, {
+    enumerable: true,
+    get: function () {
+      return _c[key];
+    }
+  });
+});
+
+require('b');
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/options.json b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/options.json
new file mode 100644
index 000000000000..50123bb50eb4
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/interop/export-from-with-transform-runtime/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["external-helpers", "transform-es2015-modules-commonjs", "transform-runtime"]
+}
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
index d89d44cb86c1..f1248c6fc7a5 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/commonjs-shadow-1/expected.js
@@ -24,10 +24,10 @@ Object.defineProperties(exports, {
 
   }
 });
+(Object.freeze || Object)(exports);
 let _default = {
   default: function () {}
 }.default;
-(Object.freeze || Object)(exports);
 
 
 _exports = function () {};
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
index 2bacdc7c2267..576e822e9a42 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default-func-hoisting/expected.js
@@ -24,28 +24,17 @@ Object.defineProperties(exports, {
 
   }
 });
-let _default = {
-  default: function () {
-    return _foo;
-  }
-}.default;
 
 const _ownExports = Object.keys(exports);
 
 const _bar = babelHelpers.specRequireInterop(require('bar'));
 
-Object.keys(_bar).forEach(function (key) {
-  if (key === "__esModule" || key === "default" || _ownExports.indexOf(key) >= 0) return;
-  if (key in exports && babelHelpers.sameValue(exports[key], _bar[key])) return;
-  Object.defineProperty(exports, key, {
-    enumerable: true,
-
-    get() {
-      return _bar[key];
-    }
-
-  });
-});
+babelHelpers.specNamespaceSpread(exports, _ownExports, _bar);
 (Object.freeze || Object)(exports);
+let _default = {
+  default: function () {
+    return _foo;
+  }
+}.default;
 
 const _foo = babelHelpers.specRequireInterop(require('foo'));
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
index 721df9030725..6809a8bcf691 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/export-default/expected.js
@@ -32,9 +32,9 @@ Object.defineProperties(exports, {
 
   }
 });
+(Object.freeze || Object)(exports);
 let _default = {
   default: function () {}
 }.default;
-(Object.freeze || Object)(exports);
 var unrelated;
 unrelated = "changed";
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
index 5f03bec21402..11c6b4718e83 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import-simple/expected.js
@@ -1,5 +1,21 @@
 'use strict';
 
+const exports = module.exports = Object.create ? Object.create(null, {
+  __esModule: {
+    value: true
+  }
+}) : {
+  __esModule: true
+};
+
+if (typeof Symbol === "function" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+(Object.freeze || Object)(exports);
+
 require('a');
 
 require('b');
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
index 6e85d8f8b66f..13d212d3381b 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/import/expected.js
@@ -1,5 +1,21 @@
 'use strict';
 
+const exports = module.exports = Object.create ? Object.create(null, {
+  __esModule: {
+    value: true
+  }
+}) : {
+  __esModule: true
+};
+
+if (typeof Symbol === "function" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+(Object.freeze || Object)(exports);
+
 const _elsewhere = babelHelpers.specRequireInterop(require('./elsewhere'));
 
 const _outside = babelHelpers.specRequireInterop(require('./outside'));
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/expected.js
index b1970e9da86e..d1e02c1eba49 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/namespace-get/expected.js
@@ -1,5 +1,21 @@
 'use strict';
 
+const exports = module.exports = Object.create ? Object.create(null, {
+  __esModule: {
+    value: true
+  }
+}) : {
+  __esModule: true
+};
+
+if (typeof Symbol === "function" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+(Object.freeze || Object)(exports);
+
 const _a = babelHelpers.specRequireInterop(require('a'));
 
 babelHelpers.specImportCheck(_a, ['a']);
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
index 628f4f5986d8..e37be1862631 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/readme/expected.js
@@ -32,10 +32,10 @@ Object.defineProperties(exports, {
 
   }
 });
+(Object.freeze || Object)(exports);
 let _default = {
   default: function () {}
 }.default;
-(Object.freeze || Object)(exports);
 
 require('a');
 
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
index 11c61e6ebbf7..a1510c85f98a 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/reexports/expected.js
@@ -15,27 +15,27 @@ if (typeof Symbol === "function" && Symbol.toStringTag) {
 }
 
 Object.defineProperties(exports, {
-  namespace: {
+  renamed: {
     enumerable: true,
 
     get() {
-      return _somewhere;
+      return _elsewhere.stuff;
     }
 
   },
-  default: {
+  namespace: {
     enumerable: true,
 
     get() {
-      return _somewhereElse.stuff;
+      return _somewhere;
     }
 
   },
-  renamed: {
+  default: {
     enumerable: true,
 
     get() {
-      return _elsewhere.stuff;
+      return _somewhereElse.stuff;
     }
 
   },
@@ -53,18 +53,7 @@ const _ownExports = Object.keys(exports);
 
 const _iDontKnow = babelHelpers.specRequireInterop(require('./i-dont-know'));
 
-Object.keys(_iDontKnow).forEach(function (key) {
-  if (key === "__esModule" || key === "default" || _ownExports.indexOf(key) >= 0) return;
-  if (key in exports && babelHelpers.sameValue(exports[key], _iDontKnow[key])) return;
-  Object.defineProperty(exports, key, {
-    enumerable: true,
-
-    get() {
-      return _iDontKnow[key];
-    }
-
-  });
-});
+babelHelpers.specNamespaceSpread(exports, _ownExports, _iDontKnow);
 (Object.freeze || Object)(exports);
 
 const _somewhere = babelHelpers.specRequireInterop(require('./somewhere'));
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/actual.js
new file mode 100644
index 000000000000..ff1f7dfa1590
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/actual.js
@@ -0,0 +1,5 @@
+import { foo } from 'foo'
+import * as ns from 'bar'
+export * from 'baz'
+
+ns[true && 'bar']
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/expected.js
new file mode 100644
index 000000000000..4099ee1003eb
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/expected.js
@@ -0,0 +1,70 @@
+'use strict';
+
+const _specNamespaceGet2 = _specRequireInterop(require('babel-runtime/helpers/specNamespaceGet'));
+
+_specImportCheck(_specNamespaceGet2, ['default']);
+
+const _specNamespaceSpread2 = _specRequireInterop(require('babel-runtime/helpers/specNamespaceSpread'));
+
+_specImportCheck(_specNamespaceSpread2, ['default']);
+
+const _create = _specRequireInterop(require('babel-runtime/core-js/object/create'));
+
+_specImportCheck(_create, ['default']);
+
+const _symbol = _specRequireInterop(require('babel-runtime/core-js/symbol'));
+
+_specImportCheck(_symbol, ['default']);
+
+const _toStringTag = _specRequireInterop(require('babel-runtime/core-js/symbol/to-string-tag'));
+
+_specImportCheck(_toStringTag, ['default']);
+
+const _defineProperty = _specRequireInterop(require('babel-runtime/core-js/object/define-property'));
+
+_specImportCheck(_defineProperty, ['default']);
+
+const _defineProperties = _specRequireInterop(require('babel-runtime/core-js/object/define-properties'));
+
+_specImportCheck(_defineProperties, ['default']);
+
+const _keys = _specRequireInterop(require('babel-runtime/core-js/object/keys'));
+
+_specImportCheck(_keys, ['default']);
+
+const _freeze = _specRequireInterop(require('babel-runtime/core-js/object/freeze'));
+
+_specImportCheck(_freeze, ['default']);
+
+const exports = module.exports = _create.default ? (0, _create.default)(null, {
+  __esModule: {
+    value: true
+  }
+}) : {
+  __esModule: true
+};
+
+if (typeof _symbol.default === "function" && _toStringTag.default) {
+  (0, _defineProperty.default)(exports, _toStringTag.default, {
+    value: "Module"
+  });
+}
+
+const _ownExports = (0, _keys.default)(exports);
+
+const _baz = _specRequireInterop(require('baz'));
+
+(0, _specNamespaceSpread2.default)(exports, _ownExports, _baz);
+(_freeze.default || Object)(exports);
+
+const _foo = _specRequireInterop(require('foo'));
+
+_specImportCheck(_foo, ['foo']);
+
+const _bar = _specRequireInterop(require('bar'));
+
+function _specImportCheck(module, imports) { if (!module.__esModule) throw new Error("Only ES modules can be checked"); var invalid = imports.filter(function (i) { return !Object.prototype.propertyIsEnumerable.call(module, i); }); if (invalid.length > 0) { var error = new Error("Unknown export" + (invalid.length > 1 ? "s " : " ") + JSON.stringify(invalid) + " imported"); error.module = module; throw error; } }
+
+function _specRequireInterop(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = Object.create ? Object.create(null, { default: { value: obj, writable: true, enumerable: true }, __esModule: { value: true } }) : { default: obj, __esModule: true }; if (typeof Symbol === "function" && Symbol.toStringTag) { Object.defineProperty(newObj, Symbol.toStringTag, { value: "Module" }); } return (Object.freeze || Object)(newObj); } }
+
+(0, _specNamespaceGet2.default)(_bar, true && 'bar');
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/options.json b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/options.json
new file mode 100644
index 000000000000..f0f17f52ca96
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/transform-runtime/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["transform-runtime", ["transform-es2015-modules-commonjs", {"spec": true}]]
+}
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/actual.js
index ff1f7dfa1590..7bf6c93f17b7 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/actual.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/actual.js
@@ -1,5 +1,6 @@
-import { foo } from 'foo'
+// NOTE: star reexports are completely broken, but they also are broken in non-spec mode
+
+export { foo } from 'foo'
 import * as ns from 'bar'
-export * from 'baz'
 
 ns[true && 'bar']
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/expected.js
index d0a9f34abfba..b427a9e1c055 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/expected.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/specImport/transform-runtime/expected.js
@@ -1,32 +1,29 @@
 'use strict';
 
-// definitely not this
-import _Object$defineProperty from 'babel-runtime/core-js/object/define-property';
-import _Object$keys from 'babel-runtime/core-js/object/keys';
-import _specNamespaceGet from 'babel-runtime/helpers/specNamespaceGet';
 Object.defineProperty(exports, "__esModule", {
   value: true
 });
-import _specImportCheck from 'babel-runtime/helpers/specImportCheck';
-import _specRequireInterop from 'babel-runtime/helpers/specRequireInterop';
+exports.foo = undefined;
 
-const _baz = _specRequireInterop(require('baz'));
+const _specNamespaceGet2 = _specRequireInterop(require('babel-runtime/helpers/specNamespaceGet'));
 
-_Object$keys(_baz).forEach(function (key) {
-  if (key === "default" || key === "__esModule") return;
-
-  _Object$defineProperty(exports, key, {
-    enumerable: true,
-    get: function () {
-      return _baz[key];
-    }
-  });
-});
+_specImportCheck(_specNamespaceGet2, ['default']);
 
 const _foo = _specRequireInterop(require('foo'));
 
 _specImportCheck(_foo, ['foo']);
 
+Object.defineProperty(exports, 'foo', {
+  enumerable: true,
+  get: function () {
+    return _foo.foo;
+  }
+});
+
 const _bar = _specRequireInterop(require('bar'));
 
-_specNamespaceGet(_bar, true && 'bar');
\ No newline at end of file
+function _specImportCheck(module, imports) { if (!module.__esModule) throw new Error("Only ES modules can be checked"); var invalid = imports.filter(function (i) { return !Object.prototype.propertyIsEnumerable.call(module, i); }); if (invalid.length > 0) { var error = new Error("Unknown export" + (invalid.length > 1 ? "s " : " ") + JSON.stringify(invalid) + " imported"); error.module = module; throw error; } }
+
+function _specRequireInterop(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = Object.create ? Object.create(null, { default: { value: obj, writable: true, enumerable: true }, __esModule: { value: true } }) : { default: obj, __esModule: true }; if (typeof Symbol === "function" && Symbol.toStringTag) { Object.defineProperty(newObj, Symbol.toStringTag, { value: "Module" }); } return (Object.freeze || Object)(newObj); } }
+
+(0, _specNamespaceGet2.default)(_bar, true && 'bar');
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
index 57238b7de7eb..ee0aa1f6d928 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
@@ -38,6 +38,7 @@ module.exports.Runner = function Runner (initialModules) {
     ].concat(extraPlugins),
     "ast": false,
   };
+  this.fallbackRequire = null;
 
   if (initialModules != null) {
     this.addModules(initialModules);
@@ -92,9 +93,14 @@ module.exports.Runner.prototype = {
       return this.cache[id].module.exports;
     }
     if (id in this.modules) {
-      this.cache[id] = this.makeContext();
-      this.transformAndRunInNewContext(this.modules[id], this.cache[id]);
-      return this.cache[id].module.exports;
+      const cache = this.makeContext();
+      this.transformAndRunInNewContext(this.modules[id], cache);
+      this.cache[id] = cache;
+      return cache.module.exports;
+    }
+    if (this.fallbackRequire) {
+      const res = this.fallbackRequire(id);
+      if (res) return res;
     }
     throw new Error("Unmocked module " + id + " required");
   }
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-with-transform-runtime.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-with-transform-runtime.js
new file mode 100644
index 000000000000..cc77247ccbfc
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-with-transform-runtime.js
@@ -0,0 +1,54 @@
+"use strict";
+
+const path = require("path");
+const assert = require("assert");
+const helpers = require("./spec-test-helpers");
+
+describe("spec with transform runtime", function () {
+  const runner = new helpers.Runner({
+    a: "export default 'a'",
+    b: "export const b = 'b'",
+    ab: "export { default as a } from 'a'\nexport { b } from 'b'",
+    star: "export * from 'a'\nexport * from 'b'"
+  });
+  runner.babelConfig.plugins.push(require("../../babel-plugin-transform-runtime"));
+  runner.fallbackRequire = function req(id) {
+    if (id.startsWith("babel-runtime")) {
+      id = path.resolve(__dirname, "../../", id);
+    }
+    return require(id);
+  };
+
+  it("throws without fallbackRequire", function () {
+    const fallback = runner.fallbackRequire;
+    try {
+      runner.fallbackRequire = null;
+      assert.throws(function () {
+        runner.getExportsOf("a");
+      }, /: Unmocked module.*\bbabel-runtime\b/);
+    } finally {
+      runner.fallbackRequire = fallback;
+    }
+  });
+
+  it("has correct default exports", function () {
+    assert.strictEqual(runner.getExportsOf("a").default, "a");
+  });
+
+  it("has correct named exports", function () {
+    assert.strictEqual(runner.getExportsOf("b").b, "b");
+  });
+
+  it("has correct named reexports", function () {
+    const exports = runner.getExportsOf("ab");
+    assert.strictEqual(exports.a, "a");
+    assert.strictEqual(exports.b, "b");
+  });
+
+  it("has correct star reexports", function () {
+    const exports = runner.getExportsOf("star");
+
+    assert.deepEqual(Object.keys(exports), [ "b" ]);
+    assert.strictEqual(exports.b, "b");
+  });
+});

From d9336f7fc45b6ada6988938b3e491045b393ddf0 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Tue, 13 Dec 2016 03:01:35 +0900
Subject: [PATCH 097/103] Remove unused variable, update fixture

---
 .../babel-plugin-transform-es2015-modules-commonjs/src/index.js | 2 --
 .../fixtures/preset-options/modules-commonjs-spec/expected.js   | 2 +-
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 9b6c3089c418..78892809fd41 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -1015,7 +1015,6 @@ export default function () {
 
           if (spec) {
             const { exportAllSet } = state;
-            let tail = state.exportPath;
 
             if (exportAllSet.size > 0) {
               const toAdd = new Set();
@@ -1048,7 +1047,6 @@ export default function () {
               }
 
               state.ownExportsPath.insertAfter(Array.from(toAdd));
-              tail = state.ownExportsPath.getSibling(state.ownExportsPath.key + toAdd.size);
             }
 
             if (state.exportMap.size > 0) {
diff --git a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
index 57432694d213..5da0ef4e0201 100644
--- a/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
+++ b/packages/babel-preset-es2015/test/fixtures/preset-options/modules-commonjs-spec/expected.js
@@ -28,8 +28,8 @@ Object.defineProperties(exports, {
     }
   }
 });
+(Object.freeze || Object)(exports);
 var _default = {
   default: function _default() {}
 }.default;
-(Object.freeze || Object)(exports);
 function b() {}
\ No newline at end of file

From 6066a222f5f4ec61fa3aa4537c7d06f105b1537a Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Wed, 14 Dec 2016 17:01:53 +0900
Subject: [PATCH 098/103] Avoid calling scope.getBinding on Flow types

---
 .../src/index.js                              | 24 +++++++-----
 .../test/fixtures/spec/flow/actual.js         | 13 +++++++
 .../test/fixtures/spec/flow/expected.js       | 38 +++++++++++++++++++
 .../test/fixtures/spec/flow/options.json      |  6 +++
 4 files changed, 71 insertions(+), 10 deletions(-)
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/actual.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/expected.js
 create mode 100644 packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/options.json

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index 78892809fd41..b14380040c61 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -107,22 +107,23 @@ export default function () {
       let remap = this.remaps[name];
       if (!spec && !remap) return;
 
-      // redeclared in this scope
-      if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
-
       if (spec) {
         if (name === "exports" && !path.node[REASSIGN_REMAP_SKIP] &&
           // Apparently replacing "module.exports" still visits the ".exports" here
           !(this.remaps[".module"] && t.isIdentifier(path.parent, this.remaps[".module"])) &&
           // Avoid entering when it's just some other object key named export
-          !(isExports(path.parent) && t.isMemberExpression(path.parent.parent))) {
+          !(isExports(path.parent) && t.isMemberExpression(path.parent.parent)) &&
+          // not shadowed
+          this.scope.getBinding(name) === path.scope.getBinding(name)
+        ) {
           remap = this.remaps[".exports"] = this.remaps[".exports"] || path.scope.generateUidIdentifier("exports");
           path.replaceWith(remap);
           commonjsExportsMasked.exports = remap;
           return;
         }
         if (name === "module" && !path.node[REASSIGN_REMAP_SKIP] &&
-          !(isModuleObj(path.parent) && !path.parent[REASSIGN_REMAP_SKIP] && !t.isMemberExpression(path.parent.parent))) {
+          !(isModuleObj(path.parent) && !path.parent[REASSIGN_REMAP_SKIP] && !t.isMemberExpression(path.parent.parent)) &&
+          this.scope.getBinding(name) === path.scope.getBinding(name)) {
           remap = this.remaps[".module"] = this.remaps[".module"] || path.scope.generateUidIdentifier("module");
           path.replaceWith(remap);
           commonjsExportsMasked.module = remap;
@@ -132,6 +133,9 @@ export default function () {
         if (!remap) return;
       }
 
+      // redeclared in this scope
+      if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
+
       if (path.parentPath.isCallExpression({ callee: path.node })) {
         path.replaceWith(t.sequenceExpression([t.numericLiteral(0), remap]));
       } else if (path.isJSXIdentifier() && t.isMemberExpression(remap)) {
@@ -533,16 +537,16 @@ export default function () {
             if (namespaceImportSet.size > 0) {
               path.traverse({
                 ReferencedIdentifier(path) {
-                  const name = path.node.name;
-
-                  // redeclared in this scope
-                  if (scope.getBinding(name) !== path.scope.getBinding(name)) return;
-
                   if (
                     t.isMemberExpression(path.parent) &&
                     t.isIdentifier(path.parent.object) &&
                     namespaceImportSet.has(path.parent.object.name)
                   ) {
+                    const name = path.parent.object.name;
+
+                    // redeclared in this scope
+                    if (!scope.getBinding(name) !== path.scope.getBinding(name)) return;
+
                     const { property, computed } = path.parent;
 
                     if (computed && !t.isStringLiteral(property)) {
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/actual.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/actual.js
new file mode 100644
index 000000000000..f1e526aa2a60
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/actual.js
@@ -0,0 +1,13 @@
+export type ElementState = {
+  tagExpr: Object; // tag node
+  tagName: string; // raw string tag name
+  args: Array<Object>; // array of call arguments
+  call?: Object; // optional call property that can be set to override the call expression returned
+  pre?: Function; // function called with (state: ElementState) before building attribs
+  post?: Function; // function called with (state: ElementState) after building attribs
+};
+
+import * as types from 'foo'
+export type Foo = types.Foo
+
+exports
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/expected.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/expected.js
new file mode 100644
index 000000000000..be9475e0b67b
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/expected.js
@@ -0,0 +1,38 @@
+'use strict';
+
+const exports = module.exports = Object.create ? Object.create(null, {
+  __esModule: {
+    value: true
+  }
+}) : {
+  __esModule: true
+};
+
+if (typeof Symbol === "function" && Symbol.toStringTag) {
+  Object.defineProperty(exports, Symbol.toStringTag, {
+    value: "Module"
+  });
+}
+
+(Object.freeze || Object)(exports);
+
+const _foo = _specRequireInterop(require('foo'));
+
+function _specImportCheck(module, imports) { if (!module.__esModule) throw new Error("Only ES modules can be checked"); var invalid = imports.filter(function (i) { return !Object.prototype.propertyIsEnumerable.call(module, i); }); if (invalid.length > 0) { var error = new Error("Unknown export" + (invalid.length > 1 ? "s " : " ") + JSON.stringify(invalid) + " imported"); error.module = module; throw error; } }
+
+function _specRequireInterop(obj) { if (obj && obj.__esModule) { return obj; } else { var newObj = Object.create ? Object.create(null, { default: { value: obj, writable: true, enumerable: true }, __esModule: { value: true } }) : { default: obj, __esModule: true }; if (typeof Symbol === "function" && Symbol.toStringTag) { Object.defineProperty(newObj, Symbol.toStringTag, { value: "Module" }); } return (Object.freeze || Object)(newObj); } }
+
+type ElementState = {
+  tagExpr: Object // tag node
+  ; tagName: string // raw string tag name
+  ; args: Array<Object> // array of call arguments
+  ; call?: Object // optional call property that can be set to override the call expression returned
+  ; pre?: Function // function called with (state: ElementState) before building attribs
+  ; post?: Function // function called with (state: ElementState) after building attribs
+  ; };
+
+type Foo = _foo.Foo;
+
+_exports;
+
+let _exports;
\ No newline at end of file
diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/options.json b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/options.json
new file mode 100644
index 000000000000..634c4c8da959
--- /dev/null
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/fixtures/spec/flow/options.json
@@ -0,0 +1,6 @@
+{
+  "plugins": [
+    "syntax-flow",
+    [ "transform-es2015-modules-commonjs", { "spec": true } ]
+  ]
+}

From 6fa02a8ed9f1267d82322aa130381ea25cb5ef49 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Wed, 14 Dec 2016 17:02:50 +0900
Subject: [PATCH 099/103] Convert spec-test-helpers to ES6

---
 .../test/spec-test-helpers.js                 | 85 +++++++++----------
 1 file changed, 41 insertions(+), 44 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
index ee0aa1f6d928..b4e753fd86dd 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/test/spec-test-helpers.js
@@ -1,5 +1,5 @@
-const babel = require("../../babel-core");
-const vm = require("vm");
+import * as babel from "../../babel-core";
+import vm from "vm";
 
 const extraPlugins = [];
 
@@ -25,70 +25,67 @@ function prepareExtraPlugins () {
 
 prepareExtraPlugins();
 
-module.exports.Runner = function Runner (initialModules) {
-  if (!(this instanceof Runner)) {
-    throw new Error("Runner can only be instantiated");
-  }
-
-  this.modules = {};
-  this.cache = {};
-  this.babelConfig = {
-    "plugins": [
-      [require("../"), {spec: true}],
-    ].concat(extraPlugins),
-    "ast": false,
-  };
-  this.fallbackRequire = null;
-
-  if (initialModules != null) {
-    this.addModules(initialModules);
+export class Runner {
+
+  constructor (initialModules) {
+    this.modules = {};
+    this.cache = {};
+    this.babelConfig = {
+      "plugins": [
+        [require("../"), {spec: true}],
+      ].concat(extraPlugins),
+      "ast": false,
+    };
+    this.fallbackRequire = null;
+
+    if (initialModules != null) {
+      this.addModules(initialModules);
+    }
   }
-};
 
-module.exports.Runner.prototype = {
-  addModule: function (name, code) {
+  addModule (name, code) {
     this.modules[name] = code;
-  },
+  }
 
-  addModules: function (dict) {
+  addModules (dict) {
     for (const key in dict) {
       if (!Object.prototype.hasOwnProperty.call(dict, key)) continue;
       this.addModule(key, dict[key]);
     }
-  },
+  }
 
-  addToCache: function (name, context) {
+  addToCache (name, context) {
     if (! (context && context.module && "exports" in context.module)) {
       throw new Error("The context to cache must have a module.exports");
     }
     this.cache[name] = context;
-  },
+  }
 
-  getExportsOf: function (name) {
+  getExportsOf (name) {
     if (! (name in this.cache || name in this.modules)) {
       throw new Error("Unknown module " + name + " requested");
     }
     return this.contextRequire(name);
-  },
+  }
 
-  transformAndRun: function (code) {
+  transformAndRun (code) {
     return this.transformAndRunInNewContext(code, this.makeContext());
-  },
+  }
 
-  transformAndRunInNewContext: function (code, context) {
+  transformAndRunInNewContext (code, context) {
     code = babel.transform(code, this.babelConfig).code;
     vm.runInNewContext(code, context);
 
     return context.module.exports;
-  },
+  }
 
-  makeContext: function () {
+  makeContext () {
     const context = { module: { exports: {} }, require: this.contextRequire.bind(this) };
     context.exports = context.module.exports;
     return context;
-  },
+  }
 
-  contextRequire: function (id) {
+  contextRequire (id) {
     if (id in this.cache) {
       return this.cache[id].module.exports;
     }
@@ -104,16 +101,16 @@ module.exports.Runner.prototype = {
     }
     throw new Error("Unmocked module " + id + " required");
   }
-};
+}
 
-let hasToStringTag = null;
-module.exports.hasToStringTag = function () {
-  if (hasToStringTag != null) {
-    return hasToStringTag;
+let hasToStringTagResult = null;
+export function hasToStringTag () {
+  if (hasToStringTagResult != null) {
+    return hasToStringTagResult;
   }
 
   const context = { module: { exports : {} } };
   vm.runInNewContext("module.exports = typeof Symbol === 'function' && Symbol.toStringTag", context);
-  hasToStringTag = typeof context.module.exports === "symbol";
-  return hasToStringTag;
-};
+  hasToStringTagResult = typeof context.module.exports === "symbol";
+  return hasToStringTagResult;
+}

From d50b59d3840ec72c3000ab8e9e74adb4b54f58ea Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Wed, 14 Dec 2016 20:32:05 +0900
Subject: [PATCH 100/103] Be more proactive with the Invalid import throw

Even if the path.remove did work, the import would have been deleted
without generating the corresponding require.
---
 .../src/index.js                                       | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index b14380040c61..fce5305f9f7d 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -360,15 +360,15 @@ export default function () {
           this.addHelper("specRequireInterop");
           this.addHelper("specImportCheck");
 
-          addImportDependency(path, state);
-
-          try {
-            path.remove();
-          } catch (e) {
+          if (state.ranCommonJS && !state.importMap.has(path.node.source.value)) {
             throw new Error(
               `Invalid import ${JSON.stringify(path.node.source.value)} created after commonjs transform finished executing`
             );
           }
+
+          addImportDependency(path, state);
+
+          path.remove();
         }
       },
 

From 4d9671926c4543a65f05306f7f169cc1c2158549 Mon Sep 17 00:00:00 2001
From: "Diogo Franco (Kovensky)" <diogomfranco@gmail.com>
Date: Thu, 15 Dec 2016 10:12:55 +0900
Subject: [PATCH 101/103] Remove accidental !

---
 .../babel-plugin-transform-es2015-modules-commonjs/src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index fce5305f9f7d..4f04588ff7af 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -545,7 +545,7 @@ export default function () {
                     const name = path.parent.object.name;
 
                     // redeclared in this scope
-                    if (!scope.getBinding(name) !== path.scope.getBinding(name)) return;
+                    if (scope.getBinding(name) !== path.scope.getBinding(name)) return;
 
                     const { property, computed } = path.parent;
 

From 7b222ac1cb9fe11d0229f2695d3715d1b1ead40e Mon Sep 17 00:00:00 2001
From: Diogo Franco <diogomfranco@gmail.com>
Date: Thu, 19 Jan 2017 11:54:18 +0900
Subject: [PATCH 102/103] Fix SyntaxError

---
 .../src/index.js                                              | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index bc6a40232bec..d992db23c047 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -104,7 +104,7 @@ export default function () {
     ReferencedIdentifier(path, state) {
       const spec = isSpec(state);
       const name = path.node.name;
-      const remap = this.remaps[name];
+      let remap = this.remaps[name];
       if (!spec && !remap) return;
 
       if (spec) {
@@ -1113,4 +1113,4 @@ function isSpec (state) {
 
 function isSpecImport (state) {
   return state && state.opts && (!!state.opts.spec || !!state.opts.specImport);
-}
\ No newline at end of file
+}

From 195d824e8cd5a571bb1479333b901b24d6501711 Mon Sep 17 00:00:00 2001
From: Diogo Franco <diogomfranco@gmail.com>
Date: Thu, 19 Jan 2017 12:10:14 +0900
Subject: [PATCH 103/103] Fix invalid this

---
 .../babel-plugin-transform-es2015-modules-commonjs/src/index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
index d992db23c047..7d5bef81f6c9 100644
--- a/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
+++ b/packages/babel-plugin-transform-es2015-modules-commonjs/src/index.js
@@ -599,7 +599,7 @@ export default function () {
             const varDecl = t.variableDeclaration(specImport ? "const" : "var", [
               t.variableDeclarator(ref,
                 specImport
-                ? t.callExpression(this.addHelper("specRequireInterop"), [req])
+                ? t.callExpression(state.addHelper("specRequireInterop"), [req])
                 : req
               )
             ]);