clean up module formatters and fix interopRequireWildcard helper

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

@@ -12,6 +12,8 @@ function DefaultFormatter(file) {
   this.file = file;
   this.ids  = object();
 
+  this.hasNonDefaultExports = false;
+
   this.hasLocalExports = false;
   this.hasLocalImports = false;
 
@@ -27,8 +29,9 @@ function DefaultFormatter(file) {
 
 DefaultFormatter.prototype.bumpImportOccurences = function (node) {
   var source = node.source.value;
-  this.localImportOccurences[source] = this.localImportOccurences[source] || 0;
-  this.localImportOccurences[source] += node.specifiers.length;
+  var occurs = this.localImportOccurences;
+  occurs[source] = occurs[source] || 0;
+  occurs[source] += node.specifiers.length;
 };
 
 var exportsVisitor = {
@@ -36,10 +39,15 @@ var exportsVisitor = {
     var declar = node && node.declaration;
     if (t.isExportDeclaration(node)) {
       formatter.hasLocalImports = true;
+
       if (declar && t.isStatement(declar)) {
         _.extend(formatter.localExports, t.getIds(declar, true));
       }
 
+      if (!node.default) {
+        formatter.hasNonDefaultExports = true;
+      }
+
       if (node.source) {
         formatter.bumpImportOccurences(node);
       }
@@ -189,14 +197,14 @@ DefaultFormatter.prototype._hoistExport = function (declar, assign, priority) {
   return assign;
 };
 
-DefaultFormatter.prototype.push = function (node, nodes) {
+DefaultFormatter.prototype.getExternalReference = function (node, nodes) {
   var ids = this.ids;
   var id = node.source.value;
 
   if (ids[id]) {
     return ids[id];
   } else {
-    return this.ids[id] = this._push(node, nodes);
+    return this.ids[id] = this._getExternalReference(node, nodes);
   }
 };
 
@@ -205,11 +213,11 @@ DefaultFormatter.prototype.exportSpecifier = function (specifier, node, nodes) {
   if (node.specifiers.length === 1) inherits = node;
 
   if (node.source) {
-    var ref = this.push(node, nodes);
+    var ref = this.getExternalReference(node, nodes);
 
     if (t.isExportBatchSpecifier(specifier)) {
       // export * from "foo";
-      nodes.push(this._exportsWildcard(ref, node));
+      nodes.push(this.buildExportsWildcard(ref, node));
     } else {
       var ref;
       if (t.isSpecifierDefault(specifier) && !this.noInteropRequire) {
@@ -220,7 +228,7 @@ DefaultFormatter.prototype.exportSpecifier = function (specifier, node, nodes) {
       }
 
       // export { foo } from "test";
-      nodes.push(this._exportsAssign(
+      nodes.push(this.buildExportsAssignment(
         t.getSpecifierName(specifier),
         ref,
         node
@@ -228,18 +236,18 @@ DefaultFormatter.prototype.exportSpecifier = function (specifier, node, nodes) {
     }
   } else {
     // export { foo };
-    nodes.push(this._exportsAssign(t.getSpecifierName(specifier), specifier.id, node));
+    nodes.push(this.buildExportsAssignment(t.getSpecifierName(specifier), specifier.id, node));
   }
 };
 
-DefaultFormatter.prototype._exportsWildcard = function (objectIdentifier) {
+DefaultFormatter.prototype.buildExportsWildcard = function (objectIdentifier) {
   return t.expressionStatement(t.callExpression(this.file.addHelper("defaults"), [
     t.identifier("exports"),
     t.callExpression(this.file.addHelper("interop-require-wildcard"), [objectIdentifier])
   ]));
 };
 
-DefaultFormatter.prototype._exportsAssign = function (id, init) {
+DefaultFormatter.prototype.buildExportsAssignment = function (id, init) {
   return util.template("exports-assign", {
     VALUE: init,
     KEY:   id
@@ -261,7 +269,7 @@ DefaultFormatter.prototype.exportDeclaration = function (node, nodes) {
     for (var i = 0; i < declar.declarations.length; i++) {
       var decl = declar.declarations[i];
 
-      decl.init = this._exportsAssign(decl.id, decl.init, node).expression;
+      decl.init = this.buildExportsAssignment(decl.id, decl.init, node).expression;
 
       var newDeclar = t.variableDeclaration(declar.kind, [decl]);
       if (i === 0) t.inherits(newDeclar, declar);
@@ -275,7 +283,7 @@ DefaultFormatter.prototype.exportDeclaration = function (node, nodes) {
       nodes.push(declar);
     }
 
-    assign = this._exportsAssign(id, ref, node);
+    assign = this.buildExportsAssignment(id, ref, node);
 
     nodes.push(assign);
 

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

@@ -67,17 +67,17 @@ AMDFormatter.prototype.getModuleName = function () {
   }
 };
 
-AMDFormatter.prototype._push = function (node) {
+AMDFormatter.prototype._getExternalReference = function (node) {
   return this.file.generateUidIdentifier(node.source.value);
 };
 
 AMDFormatter.prototype.importDeclaration = function (node) {
-  this.push(node);
+  this.getExternalReference(node);
 };
 
 AMDFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
   var key = t.getSpecifierName(specifier);
-  var ref = this.push(node);
+  var ref = this.getExternalReference(node);
 
   if (_.contains(this.file.dynamicImported, node)) {
     // Prevent unnecessary renaming of dynamic imports.
@@ -99,7 +99,7 @@ AMDFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
 };
 
 AMDFormatter.prototype.exportDeclaration = function (node) {
-  if (node.default && !this.noInteropRequire) {
+  if (node.default && !this.noInteropRequire && !this.hasNonDefaultExports) {
     this.passModuleArg = true;
   }
 

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

@@ -8,23 +8,13 @@ var util             = require("../../util");
 var t                = require("../../types");
 var _                = require("lodash");
 
-var visitor = {
-  enter: function (node, parent, scope, context, state) {
-    if (t.isExportDeclaration(node) && !node.default) {
-      state.hasNonDefaultExports = true;
-      context.stop();
-    }
-  }
-};
 
 function CommonJSFormatter(file) {
   DefaultFormatter.apply(this, arguments);
 
-  var state = { hasNonDefaultExports: false };
-  traverse(file.ast, visitor, file.scope, state);
-
-  this.insertedModuleDeclaration = false;
-  this.hasNonDefaultExports = state.hasNonDefaultExports;
+  if (this.hasNonDefaultExports) {
+    file.ast.program.body.push(util.template("exports-module-declaration", true));
+  }
 }
 
 util.inherits(CommonJSFormatter, DefaultFormatter);
@@ -32,7 +22,7 @@ util.inherits(CommonJSFormatter, DefaultFormatter);
 CommonJSFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
   var variableName = t.getSpecifierName(specifier);
 
-  var ref = this.push(node, nodes);
+  var ref = this.getExternalReference(node, nodes);
 
   // import foo from "foo";
   if (t.isSpecifierDefault(specifier)) {
@@ -71,34 +61,25 @@ CommonJSFormatter.prototype.importDeclaration = function (node, nodes) {
 };
 
 CommonJSFormatter.prototype.exportDeclaration = function (node, nodes) {
-  if (node.default && !this.noInteropRequire) {
+  if (node.default && !this.noInteropRequire && !this.hasNonDefaultExports) {
     var declar = node.declaration;
-    var assign;
+    var assign = util.template("exports-default-assign", {
+      VALUE: this._pushStatement(declar, nodes)
+    }, true);
 
-    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);
-
-      if (t.isFunctionDeclaration(declar)) {
-        // we can hoist this assignment to the top of the file
-        assign._blockHoist = 3;
-      }
-
-      nodes.push(assign);
-      return;
+    if (t.isFunctionDeclaration(declar)) {
+      // we can hoist this assignment to the top of the file
+      assign._blockHoist = 3;
     }
+
+    nodes.push(assign);
+    return;
   }
 
   DefaultFormatter.prototype.exportDeclaration.apply(this, arguments);
 };
 
-CommonJSFormatter.prototype._push = function (node, nodes) {
+CommonJSFormatter.prototype._getExternalReference = function (node, nodes) {
   var source = node.source.value;
   var call = t.callExpression(t.identifier("require"), [node.source]);
 

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

@@ -23,7 +23,7 @@ SystemFormatter.prototype._addImportSource = function (node, exportNode) {
   return node;
 };
 
-SystemFormatter.prototype._exportsWildcard = function (objectIdentifier, node) {
+SystemFormatter.prototype.buildExportsWildcard = function (objectIdentifier, node) {
   var leftIdentifier = this.file.generateUidIdentifier("key");
   var valIdentifier  = t.memberExpression(objectIdentifier, leftIdentifier, true);
 
@@ -40,7 +40,7 @@ SystemFormatter.prototype._exportsWildcard = function (objectIdentifier, node) {
   return this._addImportSource(t.forInStatement(left, right, block), node);
 };
 
-SystemFormatter.prototype._exportsAssign = function (id, init, node) {
+SystemFormatter.prototype.buildExportsAssignment = function (id, init, node) {
   var call = this.buildExportCall(t.literal(id.name), init, true);
   return this._addImportSource(call, node);
 };

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

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