safer common interop - closes #493

lib/6to5/transformation/modules/amd-strict.js

@@ -1,3 +0,0 @@
-"use strict";
-
-module.exports = require("./_strict")(require("./amd"));

lib/6to5/transformation/modules/amd.js

@@ -107,7 +107,7 @@ AMDFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
 };
 
 AMDFormatter.prototype.exportDeclaration = function (node) {
-  if (node.default) {
+  if (node.default && !this.noInteropRequire) {
     this.passModuleArg = true;
   }
 

lib/6to5/transformation/modules/common.js

@@ -20,6 +20,7 @@ function CommonJSFormatter(file) {
   var state = { hasNonDefaultExports: false };
   traverse(file.ast, visitor, file.scope, state);
 
+  this.insertedModuleDeclaration = false;
   this.hasNonDefaultExports = state.hasNonDefaultExports;
 }
 
@@ -71,33 +72,23 @@ CommonJSFormatter.prototype.exportDeclaration = function (node, nodes) {
     var declar = node.declaration;
     var assign;
 
-    // module.exports = VALUE;
-    var templateName = "exports-default-module";
-
-    // exports = module.exports = VALUE;
-    if (this.hasNonDefaultExports) templateName = "exports-default-module-override";
-
-    if (t.isFunctionDeclaration(declar) || !this.hasNonDefaultExports) {
-      assign = util.template(templateName, {
+    if (this.hasNonDefaultExports) {
+      if (!this.insertedModuleDeclaration) {
+        nodes.push(util.template("exports-module-declaration", true));
+        this.insertedModuleDeclaration = true;
+      }
+    } else {
+      var assign = util.template("exports-default-assign", {
         VALUE: this._pushStatement(declar, nodes)
       }, true);
 
-      // hoist to the top if this default is a function
-      nodes.push(this._hoistExport(declar, assign, 3));
-      return;
-    } else {
-      // this export isn't a function so we can't hoist it to the top so we need to set it
-      // at the very end of the file with something like:
-      //
-      //   module.exports = _extends(exports["default"], exports)
-      //
-
-      assign = util.template("common-export-default-assign", {
-        EXTENDS_HELPER: this.file.addHelper("extends")
-      }, true);
-      assign._blockHoist = 0;
+      if (t.isFunctionDeclaration(declar)) {
+        // we can hoist this assignment to the top of the file
+        assign._blockHoist = 3;
+      }
 
       nodes.push(assign);
+      return;
     }
   }
 

lib/6to5/transformation/templates/common-export-default-assign.js

@@ -1 +0,0 @@
-module.exports = EXTENDS_HELPER(exports["default"], exports);

lib/6to5/transformation/templates/exports-default-module-override.js

@@ -1 +0,0 @@
-exports = module.exports = VALUE;

lib/6to5/transformation/templates/exports-module-declaration.js

@@ -0,0 +1 @@
+exports.__esModule = true;

lib/6to5/transformation/templates/interop-require-wildcard.js

@@ -1,3 +1,3 @@
 (function (obj) {
-  return obj && obj.constructor === Object ? obj : { default: obj };
+  return obj && obj.__esModule ? obj.default : { default: obj };
 })

lib/6to5/transformation/templates/interop-require.js

@@ -1,3 +1,3 @@
 (function (obj) {
-  return obj && (obj["default"] || obj);
+  return obj && obj.__esModule ? obj.default : obj;
 })