From e5ce69d6afe4ef357f0bd59c98612460554f8001 Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Mon, 24 Nov 2014 10:19:06 +1100
Subject: [PATCH] clean up register module formatter and rename it to system

---
 lib/6to5/file.js                              |   5 +-
 lib/6to5/transformation/modules/amd.js        |  29 +---
 lib/6to5/transformation/modules/common.js     |  27 ++++
 .../modules/{register.js => system.js}        | 132 +++++++-----------
 lib/6to5/transformation/transform.js          |   2 +-
 .../exports-default/expected.js               |  32 -----
 .../exports-from/expected.js                  |  31 ----
 .../exports-named/expected.js                 |  24 ----
 .../exports-variable/expected.js              |  35 -----
 .../es6-modules-register/options.json         |   3 -
 .../exports-default/actual.js                 |   0
 .../exports-default/expected.js               |  32 +++++
 .../exports-from/actual.js                    |   0
 .../exports-from/expected.js                  |  31 ++++
 .../exports-named/actual.js                   |   0
 .../exports-named/expected.js                 |  24 ++++
 .../exports-variable/actual.js                |   0
 .../exports-variable/expected.js              |  35 +++++
 .../hoist-function-exports/actual.js          |   0
 .../hoist-function-exports/expected.js        |   6 +-
 .../imports-default/actual.js                 |   0
 .../imports-default/expected.js               |   2 +-
 .../imports-glob/actual.js                    |   0
 .../imports-glob/expected.js                  |   2 +-
 .../imports-mixing/actual.js                  |   0
 .../imports-mixing/expected.js                |   2 +-
 .../imports-named/actual.js                   |   0
 .../imports-named/expected.js                 |   2 +-
 .../imports/actual.js                         |   0
 .../imports/expected.js                       |   2 +-
 .../es6-modules-system/options.json           |   3 +
 .../overview/actual.js                        |   0
 .../overview/expected.js                      |   8 +-
 33 files changed, 221 insertions(+), 248 deletions(-)
 rename lib/6to5/transformation/modules/{register.js => system.js} (60%)
 delete mode 100644 test/fixtures/transformation/es6-modules-register/exports-default/expected.js
 delete mode 100644 test/fixtures/transformation/es6-modules-register/exports-from/expected.js
 delete mode 100644 test/fixtures/transformation/es6-modules-register/exports-named/expected.js
 delete mode 100644 test/fixtures/transformation/es6-modules-register/exports-variable/expected.js
 delete mode 100644 test/fixtures/transformation/es6-modules-register/options.json
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/exports-default/actual.js (100%)
 create mode 100644 test/fixtures/transformation/es6-modules-system/exports-default/expected.js
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/exports-from/actual.js (100%)
 create mode 100644 test/fixtures/transformation/es6-modules-system/exports-from/expected.js
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/exports-named/actual.js (100%)
 create mode 100644 test/fixtures/transformation/es6-modules-system/exports-named/expected.js
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/exports-variable/actual.js (100%)
 create mode 100644 test/fixtures/transformation/es6-modules-system/exports-variable/expected.js
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/hoist-function-exports/actual.js (100%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/hoist-function-exports/expected.js (72%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/imports-default/actual.js (100%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/imports-default/expected.js (76%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/imports-glob/actual.js (100%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/imports-glob/expected.js (73%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/imports-mixing/actual.js (100%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/imports-mixing/expected.js (76%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/imports-named/actual.js (100%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/imports-named/expected.js (82%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/imports/actual.js (100%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/imports/expected.js (87%)
 create mode 100644 test/fixtures/transformation/es6-modules-system/options.json
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/overview/actual.js (100%)
 rename test/fixtures/transformation/{es6-modules-register => es6-modules-system}/overview/expected.js (72%)

diff --git a/lib/6to5/file.js b/lib/6to5/file.js
index 8a6a5a1c97..73c24af8e8 100644
--- a/lib/6to5/file.js
+++ b/lib/6to5/file.js
@@ -10,9 +10,7 @@ var t         = require("./types");
 var _         = require("lodash");
 
 function File(opts) {
-  this.opts            = File.normaliseOptions(opts);
-  this.moduleFormatter = this.getModuleFormatter(this.opts.modules);
-
+  this.opts = File.normaliseOptions(opts);
   this.uids = {};
   this.ast  = {};
 }
@@ -168,6 +166,7 @@ File.prototype.parse = function (code) {
 File.prototype.transform = function (ast) {
   this.ast = ast;
   this.scope = new Scope(ast.program);
+  this.moduleFormatter = this.getModuleFormatter(this.opts.modules);
 
   var self = this;
 
diff --git a/lib/6to5/transformation/modules/amd.js b/lib/6to5/transformation/modules/amd.js
index fba879054a..3a0469cd7e 100644
--- a/lib/6to5/transformation/modules/amd.js
+++ b/lib/6to5/transformation/modules/amd.js
@@ -41,34 +41,11 @@ AMDFormatter.prototype.transform = function (ast) {
 };
 
 AMDFormatter.prototype.getModuleName = function () {
-  var opts = this.file.opts;
-  var filenameRelative = opts.filenameRelative;
-  var moduleName = "";
-
-  if (!opts.amdModuleIds) {
+  if (this.file.opts.amdModuleIds) {
+    return CommonJSFormatter.prototype.getModuleName.apply(this, arguments);
+  } else {
     return null;
   }
-
-  if (opts.moduleRoot) {
-    moduleName = opts.moduleRoot + "/";
-  }
-
-  if (!opts.filenameRelative) {
-    return moduleName + opts.filename.replace(/^\//, "");
-  }
-
-  if (opts.sourceRoot) {
-    // remove sourceRoot from filename
-    var sourceRootRegEx = new RegExp("^" + opts.sourceRoot + "\/?");
-    filenameRelative = filenameRelative.replace(sourceRootRegEx, "");
-  }
-
-  // remove extension
-  filenameRelative = filenameRelative.replace(/\.(.*?)$/, "");
-
-  moduleName += filenameRelative;
-
-  return moduleName;
 };
 
 AMDFormatter.prototype._push = function (node) {
diff --git a/lib/6to5/transformation/modules/common.js b/lib/6to5/transformation/modules/common.js
index 09dbb78816..267c4ca677 100644
--- a/lib/6to5/transformation/modules/common.js
+++ b/lib/6to5/transformation/modules/common.js
@@ -7,6 +7,33 @@ function CommonJSFormatter(file) {
   this.file = file;
 }
 
+CommonJSFormatter.prototype.getModuleName = function () {
+  var opts = this.file.opts;
+  var filenameRelative = opts.filenameRelative;
+  var moduleName = "";
+
+  if (opts.moduleRoot) {
+    moduleName = opts.moduleRoot + "/";
+  }
+
+  if (!opts.filenameRelative) {
+    return moduleName + opts.filename.replace(/^\//, "");
+  }
+
+  if (opts.sourceRoot) {
+    // remove sourceRoot from filename
+    var sourceRootRegEx = new RegExp("^" + opts.sourceRoot + "\/?");
+    filenameRelative = filenameRelative.replace(sourceRootRegEx, "");
+  }
+
+  // remove extension
+  filenameRelative = filenameRelative.replace(/\.(.*?)$/, "");
+
+  moduleName += filenameRelative;
+
+  return moduleName;
+};
+
 CommonJSFormatter.prototype.import = function (node, nodes) {
   // import "foo";
   nodes.push(util.template("require", {
diff --git a/lib/6to5/transformation/modules/register.js b/lib/6to5/transformation/modules/system.js
similarity index 60%
rename from lib/6to5/transformation/modules/register.js
rename to lib/6to5/transformation/modules/system.js
index 15d46abf51..d5b0d53bda 100644
--- a/lib/6to5/transformation/modules/register.js
+++ b/lib/6to5/transformation/modules/system.js
@@ -1,27 +1,24 @@
-module.exports = RegisterFormatter;
+module.exports = SystemFormatter;
 
 var util = require("../../util");
-var t = require("../../types");
-var _ = require("lodash");
+var t    = require("../../types");
+var _    = require("lodash");
 
-var EXPORT_IDENTIFIER = t.identifier("$__export");
-var DEFAULT_IDENTIFIER = t.identifier("default");
 var SETTER_MODULE_NAMESPACE = t.identifier("m");
-var NULL_SETTER = {
-  "type": "Literal",
-  "value": null,
-  "raw": "null"
-};
+var DEFAULT_IDENTIFIER      = t.identifier("default");
+var NULL_SETTER             = t.literal(null);
 
-function RegisterFormatter(file) {
-  this.file = file;
-  this.importedModule = {};
+function SystemFormatter(file) {
   this.exportedStatements = [];
+  this.importedModule     = {};
+
+  this.exportIdentifier   = file.generateUidIdentifier("export");
+  this.file               = file;
 }
 
-RegisterFormatter.prototype.transform = function(ast) {
+SystemFormatter.prototype.transform = function (ast) {
   var program = ast.program;
-  var body = program.body;
+  var body    = program.body;
 
   // extract the module name
   var moduleName = this.file.opts.filename
@@ -44,11 +41,11 @@ RegisterFormatter.prototype.transform = function(ast) {
   var declaredSetters = _(this.importedModule)
     .map()
     .flatten()
-    .pluck("VARIABLE_NAME")
+    .pluck("variableName")
     .pluck("name")
     .uniq()
     .map(t.identifier)
-    .map(function(name) {
+    .map(function (name) {
       return t.variableDeclarator(name);
     })
     .value();
@@ -72,14 +69,13 @@ RegisterFormatter.prototype.transform = function(ast) {
   ]));
   body.push(moduleReturnStatement);
 
-
   // runner
   var runner = util.template("register", {
     MODULE_NAME: t.literal(moduleName),
     MODULE_DEPENDENCIES: t.arrayExpression(dependencies),
     MODULE_BODY: t.functionExpression(
       null,
-      [EXPORT_IDENTIFIER],
+      [this.exportIdentifier],
       t.blockStatement(body)
     )
   });
@@ -88,44 +84,37 @@ RegisterFormatter.prototype.transform = function(ast) {
 };
 
 
-RegisterFormatter.prototype._buildSetters = function() {
+SystemFormatter.prototype._buildSetters = function () {
   // generate setters array expression elements
-  return _(this.importedModule)
-    .map(function(specifications) {
+  return _.map(this.importedModule, function (specs) {
+    if (!specs.length) {
+      return NULL_SETTER;
+    }
 
-      if (!specifications.length) {
-        return NULL_SETTER;
+    var expressionStatements = _.map(specs, function (spec) {
+      var right = SETTER_MODULE_NAMESPACE;
+      if (!spec.isBatch) {
+        right = t.memberExpression(right, spec.key);
       }
 
-      var expressionStatements = _.map(specifications, function(specification) {
-        return t.expressionStatement(
-          t.assignmentExpression(
-            "=",
-            specification.VARIABLE_NAME,
-            specification.IS_BATCH ?
-              SETTER_MODULE_NAMESPACE :
-              t.memberExpression(
-                SETTER_MODULE_NAMESPACE,
-                specification.KEY
-              )
-          )
-        );
-      });
-
-      return t.functionExpression(
-        null, [SETTER_MODULE_NAMESPACE], t.blockStatement(expressionStatements)
+      return t.expressionStatement(
+        t.assignmentExpression("=", spec.variableName, right
+        )
       );
-    }.bind(this))
-    .value();
+    });
+
+    return t.functionExpression(
+      null, [SETTER_MODULE_NAMESPACE], t.blockStatement(expressionStatements)
+    );
+  });
 };
 
-RegisterFormatter.prototype.import = function(node) {
+SystemFormatter.prototype.import = function (node) {
   var MODULE_NAME = node.source.value;
-  this.importedModule[MODULE_NAME] =
-    this.importedModule[MODULE_NAME] || [];
+  this.importedModule[MODULE_NAME] = this.importedModule[MODULE_NAME] || [];
 };
 
-RegisterFormatter.prototype.importSpecifier = function(specifier, node) {
+SystemFormatter.prototype.importSpecifier = function (specifier, node) {
   var variableName = t.getSpecifierName(specifier);
 
   // import foo from "foo";
@@ -135,26 +124,22 @@ RegisterFormatter.prototype.importSpecifier = function(specifier, node) {
 
   var MODULE_NAME = node.source.value;
 
-  this.importedModule[MODULE_NAME] =
-    this.importedModule[MODULE_NAME] || [];
+  this.importedModule[MODULE_NAME] = this.importedModule[MODULE_NAME] || [];
 
-  this.importedModule[MODULE_NAME].push(
-    {
-      VARIABLE_NAME: variableName,
-      KEY: specifier.id,
-      IS_BATCH: specifier.type === "ImportBatchSpecifier"
-    }
-  );
+  this.importedModule[MODULE_NAME].push({
+    variableName: variableName,
+    isBatch:      specifier.type === "ImportBatchSpecifier",
+    key:          specifier.id
+  });
 };
 
-RegisterFormatter.prototype._export = function(name, identifier) {
+SystemFormatter.prototype._export = function (name, identifier) {
   this.exportedStatements.push(t.expressionStatement(
-    t.callExpression(EXPORT_IDENTIFIER, [t.literal(name), identifier])
+    t.callExpression(this.exportIdentifier, [t.literal(name), identifier])
   ));
 };
 
-RegisterFormatter.prototype.export = function(node, nodes) {
-
+SystemFormatter.prototype.export = function (node, nodes) {
   var declar = node.declaration;
   var variableName, identifier;
 
@@ -162,61 +147,48 @@ RegisterFormatter.prototype.export = function(node, nodes) {
     // export default foo
     variableName = DEFAULT_IDENTIFIER.name;
     if (t.isClass(declar) || t.isFunction(declar)) {
-
       if (!declar.id) {
-        declar.id = this.file.generateUidIdentifier("anonymousFct");
+        declar.id = this.file.generateUidIdentifier("anonymous");
       }
 
       nodes.push(t.toStatement(declar));
       declar = declar.id;
-
     }
 
     identifier = declar;
-
   } else if (t.isVariableDeclaration(declar)) {
     // export var foo
     variableName = declar.declarations[0].id.name;
     identifier = declar.declarations[0].id;
 
-    nodes.push((declar));
-
+    nodes.push(declar);
   } else {
     // export function foo () {}
     variableName = declar.id.name;
     identifier = declar.id;
 
     nodes.push(declar);
-
   }
 
   this._export(variableName, identifier);
-
 };
 
-RegisterFormatter.prototype.exportSpecifier = function(specifier, node) {
+SystemFormatter.prototype.exportSpecifier = function (specifier, node) {
   var variableName = t.getSpecifierName(specifier);
 
   if (node.source) {
-
     if (t.isExportBatchSpecifier(specifier)) {
       // export * from "foo";
       var exportIdentifier = t.identifier("exports");
       this.exportedStatements.push(
-        t.variableDeclaration("var",
-          [
-            t.variableDeclarator(
-              exportIdentifier,
-              EXPORT_IDENTIFIER
-            )
-          ]
-        )
+        t.variableDeclaration("var", [
+          t.variableDeclarator(exportIdentifier, this.exportIdentifier)
+        ])
       );
 
       this.exportedStatements.push(util.template("exports-wildcard", {
         OBJECT: t.identifier(node.source.value)
       }, true));
-
     } else {
       // export { foo } from "test";
       this._export(variableName.name, t.memberExpression(
@@ -228,6 +200,4 @@ RegisterFormatter.prototype.exportSpecifier = function(specifier, node) {
     // export { foo };
     this._export(variableName.name, specifier.id);
   }
-
-
 };
diff --git a/lib/6to5/transformation/transform.js b/lib/6to5/transformation/transform.js
index 5de5354ba1..4629a8bb76 100644
--- a/lib/6to5/transformation/transform.js
+++ b/lib/6to5/transformation/transform.js
@@ -20,9 +20,9 @@ transform._ensureTransformerNames = function (type, keys) {
 transform.transformers = {};
 
 transform.moduleFormatters = {
-  register:      require("./modules/register"),
   common:        require("./modules/common"),
   commonInterop: require("./modules/common-interop"),
+  system:        require("./modules/system"),
   ignore:        require("./modules/ignore"),
   amd:           require("./modules/amd"),
   umd:           require("./modules/umd")
diff --git a/test/fixtures/transformation/es6-modules-register/exports-default/expected.js b/test/fixtures/transformation/es6-modules-register/exports-default/expected.js
deleted file mode 100644
index ce80287af0..0000000000
--- a/test/fixtures/transformation/es6-modules-register/exports-default/expected.js
+++ /dev/null
@@ -1,32 +0,0 @@
-System.register("actual", [], function ($__export) {
-  "use strict";
-
-  var __moduleName = "actual";
-
-  function _anonymousFct() {}
-  var _anonymousFct2 = function _anonymousFct2() {};
-
-  function foo() {}
-  var Foo = function Foo() {};
-
-  return {
-    setters: [],
-    execute: function () {
-      $__export("default", 42);
-
-      $__export("default", {});
-
-      $__export("default", []);
-
-      $__export("default", foo);
-
-      $__export("default", _anonymousFct);
-
-      $__export("default", _anonymousFct2);
-
-      $__export("default", foo);
-
-      $__export("default", Foo);
-    }
-  };
-});
diff --git a/test/fixtures/transformation/es6-modules-register/exports-from/expected.js b/test/fixtures/transformation/es6-modules-register/exports-from/expected.js
deleted file mode 100644
index 586a7f067c..0000000000
--- a/test/fixtures/transformation/es6-modules-register/exports-from/expected.js
+++ /dev/null
@@ -1,31 +0,0 @@
-System.register("actual", [], function ($__export) {
-  "use strict";
-
-  var __moduleName = "actual";
-
-  return {
-    setters: [],
-    execute: function () {
-      var exports = $__export;
-      (function (obj) {
-        for (var i in obj) {
-          exports[i] = obj[i];
-        }
-      })(foo);
-
-      $__export("foo", foo.foo);
-
-      $__export("foo", foo.foo);
-
-      $__export("bar", foo.bar);
-
-      $__export("bar", foo.foo);
-
-      $__export("default", foo.foo);
-
-      $__export("default", foo.foo);
-
-      $__export("bar", foo.bar);
-    }
-  };
-});
diff --git a/test/fixtures/transformation/es6-modules-register/exports-named/expected.js b/test/fixtures/transformation/es6-modules-register/exports-named/expected.js
deleted file mode 100644
index ae2884e02c..0000000000
--- a/test/fixtures/transformation/es6-modules-register/exports-named/expected.js
+++ /dev/null
@@ -1,24 +0,0 @@
-System.register("actual", [], function ($__export) {
-  "use strict";
-
-  var __moduleName = "actual";
-
-  return {
-    setters: [],
-    execute: function () {
-      $__export("foo", foo);
-
-      $__export("foo", foo);
-
-      $__export("bar", bar);
-
-      $__export("bar", foo);
-
-      $__export("default", foo);
-
-      $__export("default", foo);
-
-      $__export("bar", bar);
-    }
-  };
-});
diff --git a/test/fixtures/transformation/es6-modules-register/exports-variable/expected.js b/test/fixtures/transformation/es6-modules-register/exports-variable/expected.js
deleted file mode 100644
index 08f8c836c1..0000000000
--- a/test/fixtures/transformation/es6-modules-register/exports-variable/expected.js
+++ /dev/null
@@ -1,35 +0,0 @@
-System.register("actual", [], function ($__export) {
-  "use strict";
-
-  var __moduleName = "actual";
-
-  var foo = 1;
-  var foo2 = function () {};
-  var foo3;
-  var foo4 = 2;
-  var foo5;
-  var foo6 = 3;
-  function foo7() {}
-  var foo8 = function foo8() {};
-
-  return {
-    setters: [],
-    execute: function () {
-      $__export("foo", foo);
-
-      $__export("foo2", foo2);
-
-      $__export("foo3", foo3);
-
-      $__export("foo4", foo4);
-
-      $__export("foo5", foo5);
-
-      $__export("foo6", foo6);
-
-      $__export("foo7", foo7);
-
-      $__export("foo8", foo8);
-    }
-  };
-});
diff --git a/test/fixtures/transformation/es6-modules-register/options.json b/test/fixtures/transformation/es6-modules-register/options.json
deleted file mode 100644
index 110872cbc0..0000000000
--- a/test/fixtures/transformation/es6-modules-register/options.json
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-  "modules": "register"
-}
diff --git a/test/fixtures/transformation/es6-modules-register/exports-default/actual.js b/test/fixtures/transformation/es6-modules-system/exports-default/actual.js
similarity index 100%
rename from test/fixtures/transformation/es6-modules-register/exports-default/actual.js
rename to test/fixtures/transformation/es6-modules-system/exports-default/actual.js
diff --git a/test/fixtures/transformation/es6-modules-system/exports-default/expected.js b/test/fixtures/transformation/es6-modules-system/exports-default/expected.js
new file mode 100644
index 0000000000..1f55b6085a
--- /dev/null
+++ b/test/fixtures/transformation/es6-modules-system/exports-default/expected.js
@@ -0,0 +1,32 @@
+System.register("actual", [], function (_export) {
+  "use strict";
+
+  var __moduleName = "actual";
+
+  function _anonymous() {}
+  var _anonymous2 = function _anonymous2() {};
+
+  function foo() {}
+  var Foo = function Foo() {};
+
+  return {
+    setters: [],
+    execute: function () {
+      _export("default", 42);
+
+      _export("default", {});
+
+      _export("default", []);
+
+      _export("default", foo);
+
+      _export("default", _anonymous);
+
+      _export("default", _anonymous2);
+
+      _export("default", foo);
+
+      _export("default", Foo);
+    }
+  };
+});
diff --git a/test/fixtures/transformation/es6-modules-register/exports-from/actual.js b/test/fixtures/transformation/es6-modules-system/exports-from/actual.js
similarity index 100%
rename from test/fixtures/transformation/es6-modules-register/exports-from/actual.js
rename to test/fixtures/transformation/es6-modules-system/exports-from/actual.js
diff --git a/test/fixtures/transformation/es6-modules-system/exports-from/expected.js b/test/fixtures/transformation/es6-modules-system/exports-from/expected.js
new file mode 100644
index 0000000000..7cc20911b1
--- /dev/null
+++ b/test/fixtures/transformation/es6-modules-system/exports-from/expected.js
@@ -0,0 +1,31 @@
+System.register("actual", [], function (_export) {
+  "use strict";
+
+  var __moduleName = "actual";
+
+  return {
+    setters: [],
+    execute: function () {
+      var exports = _export;
+      (function (obj) {
+        for (var i in obj) {
+          exports[i] = obj[i];
+        }
+      })(foo);
+
+      _export("foo", foo.foo);
+
+      _export("foo", foo.foo);
+
+      _export("bar", foo.bar);
+
+      _export("bar", foo.foo);
+
+      _export("default", foo.foo);
+
+      _export("default", foo.foo);
+
+      _export("bar", foo.bar);
+    }
+  };
+});
diff --git a/test/fixtures/transformation/es6-modules-register/exports-named/actual.js b/test/fixtures/transformation/es6-modules-system/exports-named/actual.js
similarity index 100%
rename from test/fixtures/transformation/es6-modules-register/exports-named/actual.js
rename to test/fixtures/transformation/es6-modules-system/exports-named/actual.js
diff --git a/test/fixtures/transformation/es6-modules-system/exports-named/expected.js b/test/fixtures/transformation/es6-modules-system/exports-named/expected.js
new file mode 100644
index 0000000000..716fd14641
--- /dev/null
+++ b/test/fixtures/transformation/es6-modules-system/exports-named/expected.js
@@ -0,0 +1,24 @@
+System.register("actual", [], function (_export) {
+  "use strict";
+
+  var __moduleName = "actual";
+
+  return {
+    setters: [],
+    execute: function () {
+      _export("foo", foo);
+
+      _export("foo", foo);
+
+      _export("bar", bar);
+
+      _export("bar", foo);
+
+      _export("default", foo);
+
+      _export("default", foo);
+
+      _export("bar", bar);
+    }
+  };
+});
diff --git a/test/fixtures/transformation/es6-modules-register/exports-variable/actual.js b/test/fixtures/transformation/es6-modules-system/exports-variable/actual.js
similarity index 100%
rename from test/fixtures/transformation/es6-modules-register/exports-variable/actual.js
rename to test/fixtures/transformation/es6-modules-system/exports-variable/actual.js
diff --git a/test/fixtures/transformation/es6-modules-system/exports-variable/expected.js b/test/fixtures/transformation/es6-modules-system/exports-variable/expected.js
new file mode 100644
index 0000000000..1b1b09af2c
--- /dev/null
+++ b/test/fixtures/transformation/es6-modules-system/exports-variable/expected.js
@@ -0,0 +1,35 @@
+System.register("actual", [], function (_export) {
+  "use strict";
+
+  var __moduleName = "actual";
+
+  var foo = 1;
+  var foo2 = function () {};
+  var foo3;
+  var foo4 = 2;
+  var foo5;
+  var foo6 = 3;
+  function foo7() {}
+  var foo8 = function foo8() {};
+
+  return {
+    setters: [],
+    execute: function () {
+      _export("foo", foo);
+
+      _export("foo2", foo2);
+
+      _export("foo3", foo3);
+
+      _export("foo4", foo4);
+
+      _export("foo5", foo5);
+
+      _export("foo6", foo6);
+
+      _export("foo7", foo7);
+
+      _export("foo8", foo8);
+    }
+  };
+});
diff --git a/test/fixtures/transformation/es6-modules-register/hoist-function-exports/actual.js b/test/fixtures/transformation/es6-modules-system/hoist-function-exports/actual.js
similarity index 100%
rename from test/fixtures/transformation/es6-modules-register/hoist-function-exports/actual.js
rename to test/fixtures/transformation/es6-modules-system/hoist-function-exports/actual.js
diff --git a/test/fixtures/transformation/es6-modules-register/hoist-function-exports/expected.js b/test/fixtures/transformation/es6-modules-system/hoist-function-exports/expected.js
similarity index 72%
rename from test/fixtures/transformation/es6-modules-register/hoist-function-exports/expected.js
rename to test/fixtures/transformation/es6-modules-system/hoist-function-exports/expected.js
index d142facb26..4477ef9b78 100644
--- a/test/fixtures/transformation/es6-modules-register/hoist-function-exports/expected.js
+++ b/test/fixtures/transformation/es6-modules-system/hoist-function-exports/expected.js
@@ -1,4 +1,4 @@
-System.register("actual", ["./evens"], function ($__export) {
+System.register("actual", ["./evens"], function (_export) {
   "use strict";
 
   var __moduleName = "actual";
@@ -17,9 +17,9 @@ System.register("actual", ["./evens"], function ($__export) {
       isEven = m.isEven;
     }],
     execute: function () {
-      $__export("nextOdd", nextOdd);
+      _export("nextOdd", nextOdd);
 
-      $__export("isOdd", isOdd);
+      _export("isOdd", isOdd);
     }
   };
 });
diff --git a/test/fixtures/transformation/es6-modules-register/imports-default/actual.js b/test/fixtures/transformation/es6-modules-system/imports-default/actual.js
similarity index 100%
rename from test/fixtures/transformation/es6-modules-register/imports-default/actual.js
rename to test/fixtures/transformation/es6-modules-system/imports-default/actual.js
diff --git a/test/fixtures/transformation/es6-modules-register/imports-default/expected.js b/test/fixtures/transformation/es6-modules-system/imports-default/expected.js
similarity index 76%
rename from test/fixtures/transformation/es6-modules-register/imports-default/expected.js
rename to test/fixtures/transformation/es6-modules-system/imports-default/expected.js
index ecc5b0b8b6..c2bd28f729 100644
--- a/test/fixtures/transformation/es6-modules-register/imports-default/expected.js
+++ b/test/fixtures/transformation/es6-modules-system/imports-default/expected.js
@@ -1,4 +1,4 @@
-System.register("actual", ["foo"], function ($__export) {
+System.register("actual", ["foo"], function (_export) {
   "use strict";
 
   var __moduleName = "actual";
diff --git a/test/fixtures/transformation/es6-modules-register/imports-glob/actual.js b/test/fixtures/transformation/es6-modules-system/imports-glob/actual.js
similarity index 100%
rename from test/fixtures/transformation/es6-modules-register/imports-glob/actual.js
rename to test/fixtures/transformation/es6-modules-system/imports-glob/actual.js
diff --git a/test/fixtures/transformation/es6-modules-register/imports-glob/expected.js b/test/fixtures/transformation/es6-modules-system/imports-glob/expected.js
similarity index 73%
rename from test/fixtures/transformation/es6-modules-register/imports-glob/expected.js
rename to test/fixtures/transformation/es6-modules-system/imports-glob/expected.js
index 73c8fbde65..cb6d64cc04 100644
--- a/test/fixtures/transformation/es6-modules-register/imports-glob/expected.js
+++ b/test/fixtures/transformation/es6-modules-system/imports-glob/expected.js
@@ -1,4 +1,4 @@
-System.register("actual", ["foo"], function ($__export) {
+System.register("actual", ["foo"], function (_export) {
   "use strict";
 
   var __moduleName = "actual";
diff --git a/test/fixtures/transformation/es6-modules-register/imports-mixing/actual.js b/test/fixtures/transformation/es6-modules-system/imports-mixing/actual.js
similarity index 100%
rename from test/fixtures/transformation/es6-modules-register/imports-mixing/actual.js
rename to test/fixtures/transformation/es6-modules-system/imports-mixing/actual.js
diff --git a/test/fixtures/transformation/es6-modules-register/imports-mixing/expected.js b/test/fixtures/transformation/es6-modules-system/imports-mixing/expected.js
similarity index 76%
rename from test/fixtures/transformation/es6-modules-register/imports-mixing/expected.js
rename to test/fixtures/transformation/es6-modules-system/imports-mixing/expected.js
index 9891592b72..77c3348166 100644
--- a/test/fixtures/transformation/es6-modules-register/imports-mixing/expected.js
+++ b/test/fixtures/transformation/es6-modules-system/imports-mixing/expected.js
@@ -1,4 +1,4 @@
-System.register("actual", ["foo"], function ($__export) {
+System.register("actual", ["foo"], function (_export) {
   "use strict";
 
   var __moduleName = "actual";
diff --git a/test/fixtures/transformation/es6-modules-register/imports-named/actual.js b/test/fixtures/transformation/es6-modules-system/imports-named/actual.js
similarity index 100%
rename from test/fixtures/transformation/es6-modules-register/imports-named/actual.js
rename to test/fixtures/transformation/es6-modules-system/imports-named/actual.js
diff --git a/test/fixtures/transformation/es6-modules-register/imports-named/expected.js b/test/fixtures/transformation/es6-modules-system/imports-named/expected.js
similarity index 82%
rename from test/fixtures/transformation/es6-modules-register/imports-named/expected.js
rename to test/fixtures/transformation/es6-modules-system/imports-named/expected.js
index ddfb20d79a..1610dafb58 100644
--- a/test/fixtures/transformation/es6-modules-register/imports-named/expected.js
+++ b/test/fixtures/transformation/es6-modules-system/imports-named/expected.js
@@ -1,4 +1,4 @@
-System.register("actual", ["foo"], function ($__export) {
+System.register("actual", ["foo"], function (_export) {
   "use strict";
 
   var __moduleName = "actual";
diff --git a/test/fixtures/transformation/es6-modules-register/imports/actual.js b/test/fixtures/transformation/es6-modules-system/imports/actual.js
similarity index 100%
rename from test/fixtures/transformation/es6-modules-register/imports/actual.js
rename to test/fixtures/transformation/es6-modules-system/imports/actual.js
diff --git a/test/fixtures/transformation/es6-modules-register/imports/expected.js b/test/fixtures/transformation/es6-modules-system/imports/expected.js
similarity index 87%
rename from test/fixtures/transformation/es6-modules-register/imports/expected.js
rename to test/fixtures/transformation/es6-modules-system/imports/expected.js
index 75c627ec56..809982b1c2 100644
--- a/test/fixtures/transformation/es6-modules-register/imports/expected.js
+++ b/test/fixtures/transformation/es6-modules-system/imports/expected.js
@@ -1,4 +1,4 @@
-System.register("actual", ["foo", "foo-bar", "./directory/foo-bar"], function ($__export) {
+System.register("actual", ["foo", "foo-bar", "./directory/foo-bar"], function (_export) {
   "use strict";
 
   var __moduleName = "actual";
diff --git a/test/fixtures/transformation/es6-modules-system/options.json b/test/fixtures/transformation/es6-modules-system/options.json
new file mode 100644
index 0000000000..ee42d8e1c8
--- /dev/null
+++ b/test/fixtures/transformation/es6-modules-system/options.json
@@ -0,0 +1,3 @@
+{
+  "modules": "system"
+}
diff --git a/test/fixtures/transformation/es6-modules-register/overview/actual.js b/test/fixtures/transformation/es6-modules-system/overview/actual.js
similarity index 100%
rename from test/fixtures/transformation/es6-modules-register/overview/actual.js
rename to test/fixtures/transformation/es6-modules-system/overview/actual.js
diff --git a/test/fixtures/transformation/es6-modules-register/overview/expected.js b/test/fixtures/transformation/es6-modules-system/overview/expected.js
similarity index 72%
rename from test/fixtures/transformation/es6-modules-register/overview/expected.js
rename to test/fixtures/transformation/es6-modules-system/overview/expected.js
index 75802c2a5c..84c358d6d6 100644
--- a/test/fixtures/transformation/es6-modules-register/overview/expected.js
+++ b/test/fixtures/transformation/es6-modules-system/overview/expected.js
@@ -1,4 +1,4 @@
-System.register("actual", ["foo", "foo-bar", "./directory/foo-bar"], function ($__export) {
+System.register("actual", ["foo", "foo-bar", "./directory/foo-bar"], function (_export) {
   "use strict";
 
   var __moduleName = "actual";
@@ -14,11 +14,11 @@ System.register("actual", ["foo", "foo-bar", "./directory/foo-bar"], function ($
       bar = m.foo;
     }, null, null],
     execute: function () {
-      $__export("test", test);
+      _export("test", test);
 
-      $__export("test", test);
+      _export("test", test);
 
-      $__export("default", test);
+      _export("default", test);
     }
   };
 });