change the way modules handle default exports and function declaration exports

lib/6to5/transformation/transform.js

@@ -109,10 +109,9 @@ _.each({
   "playground.memoizationOperator":     require("./transformers/playground/memoization-operator"),
   "playground.objectGetterMemoization": require("./transformers/playground/object-getter-memoization"),
 
-  react:                              require("./transformers/other/react"),
+  react:                                require("./transformers/other/react"),
 
-  // needs to be before `_blockHoist` due to function hoisting etc
-  "es6.modules":                      require("./transformers/es6/modules"),
+  _modulesSplit: require("./transformers/_modules-split"),
 
   // needs to be before `regenerator` due to generator comprehensions
   // needs to be before `_aliasFunction`
@@ -164,6 +163,9 @@ _.each({
   // needs to be before `es6.modules` due to dynamic imports
   selfContained:                      require("./transformers/other/self-contained"),
 
+  // needs to be before `_blockHoist` due to function hoisting etc
+  "es6.modules":                      require("./transformers/es6/modules"),
+
   _blockHoist:                        require("./transformers/_block-hoist"),
 
   "spec.protoToAssign":               require("./transformers/spec/proto-to-assign"),

lib/6to5/transformation/transformers/_modules-split.js

@@ -0,0 +1,29 @@
+"use strict";
+
+var t = require("../../types");
+
+exports.ExportDeclaration = function (node, parent, scope, context, file) {
+  var declar = node.declaration;
+
+  if (node.default) {
+    if (t.isClassDeclaration(declar)) {
+      // we need to replace default class declarations with an assignment
+      // because VariableDeclaration nodes aren't allowed in `export default`
+      node.declaration = t.assignmentExpression("=", declar.id, t.toExpression(declar));
+
+      return [
+        t.variableDeclaration("let", [
+          t.variableDeclarator(declar.id)
+        ]),
+        node
+      ];
+    }
+  } else {
+    if (t.isFunctionDeclaration(declar)) {
+      node.declaration = null;
+      node.specifiers = [t.importSpecifier(declar.id, declar.id)];
+      node._blockHoist = 2;
+      return [declar, node];
+    }
+  }
+};

lib/6to5/transformation/transformers/es6/modules.js

@@ -23,6 +23,7 @@ exports.ImportDeclaration = function (node, parent, scope, context, file) {
 
 exports.ExportDeclaration = function (node, parent, scope, context, file) {
   var nodes = [];
+  var i;
 
   if (node.declaration) {
     // make sure variable exports have an initialiser
@@ -34,10 +35,16 @@ exports.ExportDeclaration = function (node, parent, scope, context, file) {
 
     file.moduleFormatter.exportDeclaration(node, nodes, parent);
   } else if (node.specifiers) {
-    for (var i = 0; i < node.specifiers.length; i++) {
+    for (i = 0; i < node.specifiers.length; i++) {
       file.moduleFormatter.exportSpecifier(node.specifiers[i], node, nodes, parent);
     }
   }
 
+  if (node._blockHoist) {
+    for (i = 0; i < nodes.length; i++) {
+      nodes[i]._blockHoist = node._blockHoist;
+    }
+  }
+
   return nodes;
 };

lib/6to5/types/index.js

@@ -364,6 +364,8 @@ t.toStatement = function (node, ignore) {
   } else if (t.isFunction(node)) {
     mustHaveId = true;
     newType = "FunctionDeclaration";
+  } else if (t.isAssignmentExpression(node)) {
+    return t.expressionStatement(node);
   }
 
   if (mustHaveId && !node.id) {