better circular references in amd/umd/system module formatter

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 Gaps between patch versions are faulty/broken releases.
 
+## 2.0.3
+
+ * Hoist function declarations in system module formatter for circular references.
+ * Hoist default function declarations in umd and amd module formatters for circular references.
+
 ## 2.0.2
 
  * Inherit comments in `for-of` transformer.

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

@@ -169,30 +169,36 @@ DefaultFormatter.prototype._exportsAssign = function (id, init) {
 DefaultFormatter.prototype.exportDeclaration = function (node, nodes) {
   var declar = node.declaration;
 
+  var id = declar.id;
+
   if (node.default) {
-    nodes.push(
-      this._exportsAssign(t.identifier("default"), this._pushStatement(declar, nodes))
-    );
-  } else {
-    var assign;
+    id = t.identifier("default");
+  }
 
-    if (t.isVariableDeclaration(declar)) {
-      for (var i in declar.declarations) {
-        var decl = declar.declarations[i];
+  var assign;
 
-        decl.init = this._exportsAssign(decl.id, decl.init).expression;
+  if (t.isVariableDeclaration(declar)) {
+    for (var i in declar.declarations) {
+      var decl = declar.declarations[i];
 
-        var newDeclar = t.variableDeclaration(declar.kind, [decl]);
-        if (i === "0") t.inherits(newDeclar, declar);
-        nodes.push(newDeclar);
-      }
-    } else {
-      assign = this._exportsAssign(declar.id, declar.id);
+      decl.init = this._exportsAssign(decl.id, decl.init).expression;
 
-      nodes.push(t.toStatement(declar));
-      nodes.push(assign);
-
-      this._hoistExport(declar, assign);
+      var newDeclar = t.variableDeclaration(declar.kind, [decl]);
+      if (i === "0") t.inherits(newDeclar, declar);
+      nodes.push(newDeclar);
     }
+  } else {
+    var ref = declar;
+
+    if (t.isFunctionDeclaration(declar) || t.isClassDeclaration(declar)) {
+      ref = declar.id;
+      nodes.push(declar);
+    }
+
+    assign = this._exportsAssign(id, ref);
+
+    nodes.push(assign);
+
+    this._hoistExport(declar, assign);
   }
 };

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

@@ -2,6 +2,7 @@ module.exports = SystemFormatter;
 
 var DefaultFormatter = require("./_default");
 var AMDFormatter     = require("./amd");
+var traverse         = require("../../traverse");
 var util             = require("../../util");
 var t                = require("../../types");
 var _                = require("lodash");
@@ -74,12 +75,28 @@ SystemFormatter.prototype.transform = function (ast) {
     EXECUTE: t.functionExpression(null, [], t.blockStatement(program.body))
   }, true);
 
+  var handlerBody = runner.expression.arguments[2].body.body;
+  var returnStatement = handlerBody.pop();
+
+  // hoist up function declarations for circular references
+  traverse(program, {
+    enter: function (node, parent) {
+      if (t.isFunction(node)) this.stop();
+
+      if (t.isFunctionDeclaration(node) || node._blockHoist) {
+        handlerBody.push(node);
+        this.remove();
+      }
+    }
+  });
+
   if (!_.isEmpty(this.ids)) {
-    var handlerBody = runner.expression.arguments[2].body.body;
-    handlerBody.unshift(t.variableDeclaration("var", _.map(this.ids, function (uid) {
+    handlerBody.push(t.variableDeclaration("var", _.map(this.ids, function (uid) {
       return t.variableDeclarator(uid);
     })));
   }
 
+  handlerBody.push(returnStatement);
+
   program.body = [runner];
 };

lib/6to5/traverse/index.js

@@ -50,11 +50,16 @@ function traverse(parent, opts, scope) {
         }
       };
 
-      var stop = false;
+      var stopped = false;
+      var removed = false;
 
       var context = {
         stop: function () {
-          stop = true;
+          stopped = true;
+        },
+
+        remove: function () {
+          stopped = removed = true;
         }
       };
 
@@ -67,8 +72,13 @@ function traverse(parent, opts, scope) {
         var result = opts.enter.call(context, node, parent, ourScope);
         maybeReplace(result);
 
+        if (removed) {
+          delete obj[key];
+          updated = true;
+        }
+
         // stop iteration
-        if (stop || result === false) return;
+        if (stopped || result === false) return;
       }
 
       // traverse node

test/fixtures/transformation/es6-modules-amd/exports-default/expected.js

@@ -1,6 +1,7 @@
 define(["exports"], function (exports) {
   "use strict";
 
+  exports["default"] = foo;
   exports["default"] = 42;
   exports["default"] = {};
   exports["default"] = [];
@@ -10,7 +11,6 @@ define(["exports"], function (exports) {
   exports["default"] = function () {};
 
   function foo() {}
-  exports["default"] = foo;
   var Foo = function Foo() {};
 
   exports["default"] = Foo;

test/fixtures/transformation/es6-modules-system/exports-default/expected.js

@@ -1,4 +1,7 @@
 System.register("es6-modules-system/exports-default/expected", [], function (_export) {
+  _export("default", foo);
+
+  function foo() {}
   return {
     setters: [],
     execute: function () {
@@ -16,12 +19,9 @@ System.register("es6-modules-system/exports-default/expected", [], function (_ex
 
       _export("default", function () {});
 
-      function foo() {}
-      _export("default", foo);
-
       var Foo = function Foo() {};
 
       _export("default", Foo);
     }
   };
-});
+});

test/fixtures/transformation/es6-modules-system/exports-variable/expected.js

@@ -1,21 +1,21 @@
 System.register("es6-modules-system/exports-variable/expected", [], function (_export) {
+  _export("foo7", foo7);
+
+  function foo7() {}
   return {
     setters: [],
     execute: function () {
       "use strict";
 
-      _export("foo7", foo7);
-
       var foo = _export("foo", 1);
       var foo2 = _export("foo2", function () {});
       var foo3 = _export("foo3", undefined);
       var foo4 = _export("foo4", 2);
       var foo5 = _export("foo5", undefined);
       var foo6 = _export("foo6", 3);
-      function foo7() {}
       var foo8 = function foo8() {};
 
       _export("foo8", foo8);
     }
   };
-});
+});

test/fixtures/transformation/es6-modules-system/hoist-function-exports/expected.js

@@ -1,4 +1,10 @@
 System.register("es6-modules-system/hoist-function-exports/expected", ["./evens"], function (_export) {
+  _export("nextOdd", nextOdd);
+
+  function nextOdd(n) {
+    return isEven(n) ? n + 1 : n + 2;
+  }
+
   var _evens;
   return {
     setters: [function (m) {
@@ -7,13 +13,7 @@ System.register("es6-modules-system/hoist-function-exports/expected", ["./evens"
     execute: function () {
       "use strict";
 
-      _export("nextOdd", nextOdd);
-
       var isEven = _evens.isEven;
-      function nextOdd(n) {
-        return isEven(n) ? n + 1 : n + 2;
-      }
-
       var isOdd = _export("isOdd", (function (isEven) {
         return function (n) {
           return !isEven(n);
@@ -21,4 +21,4 @@ System.register("es6-modules-system/hoist-function-exports/expected", ["./evens"
       })(isEven));
     }
   };
-});
+});

test/fixtures/transformation/es6-modules-umd/exports-default/expected.js

@@ -7,6 +7,7 @@
 })(function (exports) {
   "use strict";
 
+  exports["default"] = foo;
   exports["default"] = 42;
   exports["default"] = {};
   exports["default"] = [];
@@ -16,7 +17,6 @@
   exports["default"] = function () {};
 
   function foo() {}
-  exports["default"] = foo;
   var Foo = function Foo() {};
 
   exports["default"] = Foo;