Limit file-based plugins/presets to only exporting functions.

packages/babel-core/src/config/option-manager.js

@@ -556,6 +556,15 @@ function normalizePair(
     );
   }
 
+  if (filepath !== null && typeof value === "object" && value) {
+    // We allow object values for plugins/presets nested directly within a
+    // config object, because it can be useful to define them in nested
+    // configuration contexts.
+    throw new Error(
+      "Plugin/Preset files are not allowed to export objects, only functions.",
+    );
+  }
+
   if (options != null && typeof options !== "object") {
     throw new Error(
       "Plugin/Preset options must be an object, null, or undefined",

packages/babel-core/test/fixtures/option-manager/presets/es2015_default_object.js

@@ -7,6 +7,8 @@
 'use strict';
 
 exports.__esModule = true;
-exports.default = {
-  plugins: [require('../../../../../babel-plugin-syntax-decorators')]
+module.exports = function() {
+  return {
+    plugins: [require('../../../../../babel-plugin-syntax-decorators')]
+  };
 };

packages/babel-core/test/fixtures/option-manager/presets/es5_object.js

@@ -1,5 +1,7 @@
-module.exports = {
-  plugins: [
-    require('../../../../../babel-plugin-syntax-decorators'),
-  ]
+module.exports = function() {
+  return {
+    plugins: [
+      require('../../../../../babel-plugin-syntax-decorators'),
+    ]
+  };
 };

packages/babel-core/test/fixtures/resolution/relative-paths/dir/plugin.js

@@ -0,0 +1,3 @@
+module.exports = function() {
+  return {};
+};

packages/babel-core/test/fixtures/resolution/relative-paths/dir/preset.js

@@ -0,0 +1,3 @@
+module.exports = function() {
+  return {};
+};

packages/babel-helpers/test/fixtures/dependencies/basic/plugin.js

@@ -12,12 +12,14 @@ const main = defineHelper(__dirname, "main", `
   }
 `);
 
-module.exports = {
-  visitor: {
-    Identifier(path) {
-      if (path.node.name !== "REPLACE_ME") return;
-      const helper = this.addHelper(main);
-      path.replaceWith(helper);
+module.exports = function() {
+  return {
+    visitor: {
+      Identifier(path) {
+        if (path.node.name !== "REPLACE_ME") return;
+        const helper = this.addHelper(main);
+        path.replaceWith(helper);
+      },
     },
-  },
+  };
 };

packages/babel-helpers/test/fixtures/dependencies/deep/plugin.js

@@ -17,12 +17,14 @@ const main = defineHelper(__dirname, "main", `
   }
 `);
 
-module.exports = {
-  visitor: {
-    Identifier(path) {
-      if (path.node.name !== "REPLACE_ME") return;
-      const helper = this.addHelper(main);
-      path.replaceWith(helper);
+module.exports = function() {
+  return {
+    visitor: {
+      Identifier(path) {
+        if (path.node.name !== "REPLACE_ME") return;
+        const helper = this.addHelper(main);
+        path.replaceWith(helper);
+      },
     },
-  },
+  };
 };

packages/babel-helpers/test/fixtures/dependencies/missing/plugin.js

@@ -8,12 +8,14 @@ const main = defineHelper(__dirname, "main", `
   }
 `);
 
-module.exports = {
-  visitor: {
-    Identifier(path) {
-      if (path.node.name !== "REPLACE_ME") return;
-      const helper = this.addHelper(main);
-      path.replaceWith(helper);
+module.exports = function() {
+  return {
+    visitor: {
+      Identifier(path) {
+        if (path.node.name !== "REPLACE_ME") return;
+        const helper = this.addHelper(main);
+        path.replaceWith(helper);
+      },
     },
-  },
+  };
 };

packages/babel-helpers/test/fixtures/dependencies/multiple/plugin.js

@@ -17,12 +17,14 @@ const main = defineHelper(__dirname, "main", `
   }
 `);
 
-module.exports = {
-  visitor: {
-    Identifier(path) {
-      if (path.node.name !== "REPLACE_ME") return;
-      const helper = this.addHelper(main);
-      path.replaceWith(helper);
+module.exports = function() {
+  return {
+    visitor: {
+      Identifier(path) {
+        if (path.node.name !== "REPLACE_ME") return;
+        const helper = this.addHelper(main);
+        path.replaceWith(helper);
+      },
     },
-  },
+  };
 };

packages/babel-helpers/test/fixtures/dependencies/rename-binding-equal/plugin.js

@@ -15,12 +15,14 @@ const main = defineHelper(__dirname, "main", `
   }
 `);
 
-module.exports = {
-  visitor: {
-    Identifier(path) {
-      if (path.node.name !== "REPLACE_ME") return;
-      const helper = this.addHelper(main);
-      path.replaceWith(helper);
+module.exports = function() {
+  return {
+    visitor: {
+      Identifier(path) {
+        if (path.node.name !== "REPLACE_ME") return;
+        const helper = this.addHelper(main);
+        path.replaceWith(helper);
+      },
     },
-  },
+  };
 };

packages/babel-helpers/test/fixtures/dependencies/rename-deep-global/plugin.js

@@ -14,12 +14,14 @@ const main = defineHelper(__dirname, "main", `
   }
 `);
 
-module.exports = {
-  visitor: {
-    Identifier(path) {
-      if (path.node.name !== "REPLACE_ME") return;
-      const helper = this.addHelper(main);
-      path.replaceWith(helper);
+module.exports = function() {
+  return {
+    visitor: {
+      Identifier(path) {
+        if (path.node.name !== "REPLACE_ME") return;
+        const helper = this.addHelper(main);
+        path.replaceWith(helper);
+      },
     },
-  },
+  };
 };

packages/babel-helpers/test/fixtures/dependencies/reuse-dependency/plugin.js

@@ -12,16 +12,18 @@ const main = defineHelper(__dirname, "main", `
   }
 `);
 
-module.exports = {
-  visitor: {
-    Identifier(path) {
-      if (path.node.name === "REPLACE_ME_1") {
-        const mainHelper = this.addHelper(main);
-        path.replaceWith(mainHelper);
-      } else if (path.node.name === "REPLACE_ME_2") {
-        const dependencyHelper = this.addHelper(dependency);
-        path.replaceWith(dependencyHelper);
-      }
+module.exports = function() {
+  return {
+    visitor: {
+      Identifier(path) {
+        if (path.node.name === "REPLACE_ME_1") {
+          const mainHelper = this.addHelper(main);
+          path.replaceWith(mainHelper);
+        } else if (path.node.name === "REPLACE_ME_2") {
+          const dependencyHelper = this.addHelper(dependency);
+          path.replaceWith(dependencyHelper);
+        }
+      },
     },
-  },
+  };
 };

packages/babel-helpers/test/fixtures/dependencies/variable-same-name-dependency/plugin.js

@@ -15,12 +15,14 @@ const main = defineHelper(__dirname, "main", `
   }
 `);
 
-module.exports = {
-  visitor: {
-    Identifier(path) {
-      if (path.node.name !== "REPLACE_ME") return;
-      const helper = this.addHelper(main);
-      path.replaceWith(helper);
+module.exports = function() {
+  return {
+    visitor: {
+      Identifier(path) {
+        if (path.node.name !== "REPLACE_ME") return;
+        const helper = this.addHelper(main);
+        path.replaceWith(helper);
+      },
     },
-  },
+  };
 };