update to esprima-fb

README.md

@@ -72,7 +72,7 @@ this module currently only supports transpilation between ES6 module and CommonJ
 
 ```js
 var recast = require('recast')
-var esprima = require('esprima')
+var esprima = require('esprima-fb')
 var Module = require('es6-module-crosspiler')
 
 // parse the code with recast

lib/common.js

@@ -7,6 +7,10 @@ var b = types.builders
 
 var Module = require('./module')
 
+/**
+ * Return a list of `require()`s.
+ */
+
 memo(Module.prototype, 'requires', function () {
   var requires = []
   types.visit(this.ast.program, {
@@ -26,7 +30,10 @@ memo(Module.prototype, 'requires', function () {
   return requires
 })
 
-// look for module.exports or exports.xxxx
+/**
+ * Look for `module.exports = ` or `exports[x] = `
+ */
+
 memo(Module.prototype, 'hasCommonExports', function () {
   var hasCommonExports = false
   types.visit(this.ast.program, {
@@ -43,6 +50,11 @@ memo(Module.prototype, 'hasCommonExports', function () {
   return hasCommonExports
 })
 
+/**
+ * Skip function traversals if a `require()` function is defined
+ * somewhere, because then we're not trying to use a CommonJS require.
+ */
+
 function skipFunctionTraversal(path) {
   // `require` is defined somewhere
   if (path.scope.lookup('require')) return true
@@ -53,6 +65,10 @@ function skipFunctionTraversal(path) {
   return false
 }
 
+/**
+ * Check whether a node is a `require()` expression.
+ */
+
 function isRequireExpression(path) {
   // only global `require`
   if (path.scope.lookup('require')) return false

lib/exports.js

@@ -26,7 +26,7 @@ Module.prototype.buildExports = function () {
 
     if (node.default) {
       var id
-      if (n.FunctionExpression.check(declaration) && declaration.id) {
+      if (n.FunctionDeclaration.check(declaration) && declaration.id) {
         id = node._varname = declaration.id.name
       } else {
         id = node._varname = this.sourceToVariableName('default')
@@ -35,7 +35,7 @@ Module.prototype.buildExports = function () {
       return
     }
 
-    if (node.specifiers) {
+    if (node.specifiers.length) {
       return node.specifiers.forEach(function (specifier) {
         var id = specifier.id.name
         exports.push([id, id])
@@ -74,14 +74,18 @@ Module.prototype.buildExports = function () {
   this.ast.program.body.unshift(b.expressionStatement(obj))
 }
 
+/**
+ * Remove all the `export` statements after
+ * converting them to CommonJS.
+ */
+
 Module.prototype.removeExports = function () {
   types.visit(this.ast.program, {
     visitExportDeclaration: function (path) {
       var declaration = path.node.declaration
       if (path.node.default) {
         // remove `export default`s
-        if (n.FunctionExpression.check(declaration) && declaration.id) {
-          declaration.type = 'FunctionDeclaration'
+        if (n.FunctionDeclaration.check(declaration) && declaration.id) {
           path.replace(declaration)
         } else {
           path.replace(b.variableDeclaration('var', [
@@ -91,7 +95,7 @@ Module.prototype.removeExports = function () {
             )
           ]))
         }
-      } else if (path.node.specifiers) {
+      } else if (path.node.specifiers.length) {
         // remove `export { x, y }`s
         path.replace()
       } else {

lib/imports.js

@@ -2,6 +2,7 @@
 var astUtils = require('ast-util')
 var memo = require('memorizer')
 var recast = require('recast')
+var assert = require('assert')
 
 var types = recast.types
 var n = types.namedTypes
@@ -36,7 +37,7 @@ Module.prototype.renameImports = function () {
 }
 
 /**
- * Build require() statements
+ * Build `require()` statements
  */
 
 Module.prototype.buildImports =
@@ -51,30 +52,36 @@ Module.prototype.buildRequires = function () {
     // import 'x' -> require('x')
     // don't need to check whether default is exported
     // or what type of module the dependency is here
-    if (node.kind === undefined)
-        return declarations.push(b.expressionStatement(buildRequire(value)))
+    if (!node.specifiers.length)
+      return declarations.push(b.expressionStatement(buildRequire(value)))
 
-    // import X from 'y' -> var X = require('y')
-    // this is a special case when the dependency is CJS
-    // to do: also check if it's renamed
     var dep = this.lookup(value) || {}
-    if (node.kind === 'default' && dep.type === 'commonjs') {
-      var name = node.specifiers[0].id.name
-      return declarations.push(buildRequireDeclaration(name, value))
-    }
+    node.specifiers.forEach(function (specifier) {
+      // import X from 'y' -> var X = require('y')
+      // this is a special case when the dependency is CJS
+      // to do: also check if it's renamed
+      if (specifier.type === 'ImportDefaultSpecifier' && dep.type === 'commonjs') {
+        var name = specifier.id.name
+        return declarations.push(buildRequireDeclaration(name, value))
+      }
 
-    // named exports, creates a unique variable name
-    // then exports that as the require
-    // import { x, y } from 'z' -> var __z = require('z')
-    // then the `x` and `y`s are done later
-    var name = node._varname = this.sourceToVariableName(value)
-    return declarations.push(buildRequireDeclaration(name, value))
+      // named exports, creates a unique variable name
+      // then exports that as the require
+      // import { x, y } from 'z' -> var __z = require('z')
+      // then the `x` and `y`s are done later
+      var name = node._varname = this.sourceToVariableName(value)
+      return declarations.push(buildRequireDeclaration(name, value))
+    }, this)
   }, this)
 
   // add it to the top
   this.ast.program.body = declarations.concat(this.ast.program.body)
 }
 
+/**
+ * var `variable` = require(`value`)
+ */
+
 function buildRequireDeclaration(variable, value) {
   return b.variableDeclaration('var', [
     b.variableDeclarator(
@@ -100,7 +107,7 @@ Module.prototype.buildReferences = function () {
     if (!varname) return
 
     node.specifiers.forEach(function (specifier) {
-      var id = node.kind === 'default'
+      var id = specifier.type === 'ImportDefaultSpecifier'
         ? 'default'
         : specifier.id.name
       var name = specifier.name
@@ -113,6 +120,7 @@ Module.prototype.buildReferences = function () {
     })
   })
 
+  // rewrite lookups
   types.visit(this.ast.program, {
     visitIdentifier: function (path) {
       // make sure it's a variable reference
@@ -135,6 +143,10 @@ Module.prototype.buildReferences = function () {
   })
 }
 
+/**
+ * Remove all `import` statements after converting them to `require()`s
+ */
+
 Module.prototype.removeImports = function () {
   var body = this.ast.program.body
   for (var i = 0; i < body.length; i++) {

package.json

@@ -11,9 +11,10 @@
   "license": "MIT",
   "repository": "polyfills/es6-module-crosspiler",
   "dependencies": {
+    "ast-util": "0",
     "debug": "*",
+    "esprima-fb": "*",
     "memorizer": "1",
-    "ast-util": "0",
     "recast": "0"
   },
   "devDependencies": {

test/index.js

@@ -5,7 +5,7 @@ fs = require('fs')
 path = require('path')
 recast = require('recast')
 assert = require('assert')
-esprima = require('esprima')
+esprima = require('esprima-fb')
 
 Module = require('..')