From e8237910e89218d86225233493a74e75664da2a6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Wed, 14 Jan 2015 01:39:37 -0200
Subject: [PATCH 01/15] Add a transformer to import the runtime from a file

The `externalRuntime` optional transformer can be used in conjunction
with the `runtime` option to import and use the runtime from a module
instead of polluting the global environment.
---
 lib/6to5/transformation/modules/amd.js               |  2 +-
 lib/6to5/transformation/modules/common.js            | 12 +++++-------
 lib/6to5/transformation/transform.js                 |  1 +
 .../transformers/optional-external-runtime.js        | 11 +++++++++++
 4 files changed, 18 insertions(+), 8 deletions(-)
 create mode 100644 lib/6to5/transformation/transformers/optional-external-runtime.js

diff --git a/lib/6to5/transformation/modules/amd.js b/lib/6to5/transformation/modules/amd.js
index 3940c9d18d..d97ba66118 100644
--- a/lib/6to5/transformation/modules/amd.js
+++ b/lib/6to5/transformation/modules/amd.js
@@ -87,7 +87,7 @@ AMDFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
   var key = t.getSpecifierName(specifier);
   var ref = this._push(node);
 
-  if (t.isImportBatchSpecifier(specifier)) {
+  if (t.isImportBatchSpecifier(specifier) || node._noInteropRequire) {
     // import * as bar from "foo";
   } else if (t.isSpecifierDefault(specifier) && !this.noInteropRequire) {
     // import foo from "foo";
diff --git a/lib/6to5/transformation/modules/common.js b/lib/6to5/transformation/modules/common.js
index 8e6044f2e9..c44f34078f 100644
--- a/lib/6to5/transformation/modules/common.js
+++ b/lib/6to5/transformation/modules/common.js
@@ -26,13 +26,11 @@ CommonJSFormatter.prototype.importSpecifier = function (specifier, node, nodes)
 
   // import foo from "foo";
   if (t.isSpecifierDefault(specifier)) {
-    nodes.push(t.variableDeclaration("var", [
-      t.variableDeclarator(variableName,
-        t.callExpression(this.file.addHelper("interop-require"), [util.template("require", {
-          MODULE_NAME: node.source
-        })])
-      )
-    ]));
+    var ref = util.template("require", {MODULE_NAME: node.source});
+    if (!node._noInteropRequire) {
+      ref = t.callExpression(this.file.addHelper("interop-require"), [ref]);
+    }
+    nodes.push(t.variableDeclaration("var", [t.variableDeclarator(variableName, ref)]));
   } else {
     if (specifier.type === "ImportBatchSpecifier") {
       // import * as bar from "foo";
diff --git a/lib/6to5/transformation/transform.js b/lib/6to5/transformation/transform.js
index 2a5cbb26a2..a1c7a104ac 100644
--- a/lib/6to5/transformation/transform.js
+++ b/lib/6to5/transformation/transform.js
@@ -95,6 +95,7 @@ _.each({
   _moduleFormatter:          require("./transformers/_module-formatter"),
 
   typeofSymbol:              require("./transformers/optional-typeof-symbol"),
+  externalRuntime:           require("./transformers/optional-external-runtime"),
   coreAliasing:              require("./transformers/optional-core-aliasing"),
   undefinedToVoid:           require("./transformers/optional-undefined-to-void"),
 
diff --git a/lib/6to5/transformation/transformers/optional-external-runtime.js b/lib/6to5/transformation/transformers/optional-external-runtime.js
new file mode 100644
index 0000000000..a2f52667cf
--- /dev/null
+++ b/lib/6to5/transformation/transformers/optional-external-runtime.js
@@ -0,0 +1,11 @@
+exports.optional = true;
+
+// In theory, it would be more appropriate to do this in `manipulateOptions`,
+// but we need an identifier for the import and we can't get that before the
+// AST is built.
+exports.ast = {
+  enter: function (ast, file) {
+    file.opts.runtime = file.addImport(file.opts.runtime, "to5Runtime").name;
+    file.dynamicImports[file.dynamicImports.length - 1]._noInteropRequire = true;
+  }
+};

From e9a024e58a14c8fdc452425714c8adec83b01544 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Wed, 14 Jan 2015 02:38:31 -0200
Subject: [PATCH 02/15] Add simple test for externalRuntime transformer

Just import a module namespace and see what happens.
---
 .../transformation/optional-external-runtime/basic/actual.js | 1 +
 .../optional-external-runtime/basic/expected.js              | 5 +++++
 .../transformation/optional-external-runtime/options.json    | 4 ++++
 3 files changed, 10 insertions(+)
 create mode 100644 test/fixtures/transformation/optional-external-runtime/basic/actual.js
 create mode 100644 test/fixtures/transformation/optional-external-runtime/basic/expected.js
 create mode 100644 test/fixtures/transformation/optional-external-runtime/options.json

diff --git a/test/fixtures/transformation/optional-external-runtime/basic/actual.js b/test/fixtures/transformation/optional-external-runtime/basic/actual.js
new file mode 100644
index 0000000000..9e9515cece
--- /dev/null
+++ b/test/fixtures/transformation/optional-external-runtime/basic/actual.js
@@ -0,0 +1 @@
+import * as foo from "someModule";
diff --git a/test/fixtures/transformation/optional-external-runtime/basic/expected.js b/test/fixtures/transformation/optional-external-runtime/basic/expected.js
new file mode 100644
index 0000000000..b10bbe6f09
--- /dev/null
+++ b/test/fixtures/transformation/optional-external-runtime/basic/expected.js
@@ -0,0 +1,5 @@
+"use strict";
+
+var _to5Runtime = require("6to5-runtime");
+
+var foo = _to5Runtime.interopRequireWildcard(require("someModule"));
diff --git a/test/fixtures/transformation/optional-external-runtime/options.json b/test/fixtures/transformation/optional-external-runtime/options.json
new file mode 100644
index 0000000000..44c5164a67
--- /dev/null
+++ b/test/fixtures/transformation/optional-external-runtime/options.json
@@ -0,0 +1,4 @@
+{
+  "runtime": "6to5-runtime",
+  "optional": ["externalRuntime"]
+}

From 84ee0efe32c1ad17b869c2f7a52d451c09734379 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Wed, 14 Jan 2015 12:13:08 -0200
Subject: [PATCH 03/15] Add test for externalRuntime with AMD modules

---
 .../transformation/optional-external-runtime/amd/actual.js  | 1 +
 .../optional-external-runtime/amd/expected.js               | 6 ++++++
 .../optional-external-runtime/amd/options.json              | 3 +++
 .../optional-external-runtime/{basic => commonjs}/actual.js | 0
 .../{basic => commonjs}/expected.js                         | 0
 5 files changed, 10 insertions(+)
 create mode 100644 test/fixtures/transformation/optional-external-runtime/amd/actual.js
 create mode 100644 test/fixtures/transformation/optional-external-runtime/amd/expected.js
 create mode 100644 test/fixtures/transformation/optional-external-runtime/amd/options.json
 rename test/fixtures/transformation/optional-external-runtime/{basic => commonjs}/actual.js (100%)
 rename test/fixtures/transformation/optional-external-runtime/{basic => commonjs}/expected.js (100%)

diff --git a/test/fixtures/transformation/optional-external-runtime/amd/actual.js b/test/fixtures/transformation/optional-external-runtime/amd/actual.js
new file mode 100644
index 0000000000..09493dc9be
--- /dev/null
+++ b/test/fixtures/transformation/optional-external-runtime/amd/actual.js
@@ -0,0 +1 @@
+import foo from "someModule";
diff --git a/test/fixtures/transformation/optional-external-runtime/amd/expected.js b/test/fixtures/transformation/optional-external-runtime/amd/expected.js
new file mode 100644
index 0000000000..20e759af12
--- /dev/null
+++ b/test/fixtures/transformation/optional-external-runtime/amd/expected.js
@@ -0,0 +1,6 @@
+define(["exports", "6to5-runtime", "someModule"], function (exports, _to5Runtime2, _someModule) {
+  "use strict";
+
+  var _to5Runtime = _to5Runtime2;
+  var foo = _to5Runtime.interopRequire(_someModule);
+});
diff --git a/test/fixtures/transformation/optional-external-runtime/amd/options.json b/test/fixtures/transformation/optional-external-runtime/amd/options.json
new file mode 100644
index 0000000000..b76b119f33
--- /dev/null
+++ b/test/fixtures/transformation/optional-external-runtime/amd/options.json
@@ -0,0 +1,3 @@
+{
+  "modules": "amd"
+}
diff --git a/test/fixtures/transformation/optional-external-runtime/basic/actual.js b/test/fixtures/transformation/optional-external-runtime/commonjs/actual.js
similarity index 100%
rename from test/fixtures/transformation/optional-external-runtime/basic/actual.js
rename to test/fixtures/transformation/optional-external-runtime/commonjs/actual.js
diff --git a/test/fixtures/transformation/optional-external-runtime/basic/expected.js b/test/fixtures/transformation/optional-external-runtime/commonjs/expected.js
similarity index 100%
rename from test/fixtures/transformation/optional-external-runtime/basic/expected.js
rename to test/fixtures/transformation/optional-external-runtime/commonjs/expected.js

From e985d8b25de9f3b281a8a700c34c64099acc74b6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Wed, 14 Jan 2015 14:00:33 -0200
Subject: [PATCH 04/15] Don't use interopRequire for dynamic imports

They don't need it at all and this also allows use of `externalRuntime`
without fear of the runtime ending up being loaded after it's used.
---
 lib/6to5/transformation/modules/amd.js                      | 2 +-
 lib/6to5/transformation/modules/common.js                   | 3 ++-
 .../transformers/optional-external-runtime.js               | 1 -
 .../optional-bluebird-coroutines/expression/expected.js     | 6 +-----
 .../optional-bluebird-coroutines/statement/expected.js      | 6 +-----
 .../optional-core-aliasing/aliased-constructors/expected.js | 6 +-----
 .../optional-core-aliasing/es6-destructuring/expected.js    | 6 +-----
 .../optional-core-aliasing/es6-for-of/expected.js           | 6 +-----
 .../optional-core-aliasing/es6-spread/expected.js           | 6 +-----
 .../es7-array-comprehensions/expected.js                    | 6 +-----
 10 files changed, 10 insertions(+), 38 deletions(-)

diff --git a/lib/6to5/transformation/modules/amd.js b/lib/6to5/transformation/modules/amd.js
index d97ba66118..0eb61407b2 100644
--- a/lib/6to5/transformation/modules/amd.js
+++ b/lib/6to5/transformation/modules/amd.js
@@ -87,7 +87,7 @@ AMDFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
   var key = t.getSpecifierName(specifier);
   var ref = this._push(node);
 
-  if (t.isImportBatchSpecifier(specifier) || node._noInteropRequire) {
+  if (t.isImportBatchSpecifier(specifier) || _.contains(this.file.dynamicImports, node)) {
     // import * as bar from "foo";
   } else if (t.isSpecifierDefault(specifier) && !this.noInteropRequire) {
     // import foo from "foo";
diff --git a/lib/6to5/transformation/modules/common.js b/lib/6to5/transformation/modules/common.js
index c44f34078f..950b35790e 100644
--- a/lib/6to5/transformation/modules/common.js
+++ b/lib/6to5/transformation/modules/common.js
@@ -6,6 +6,7 @@ var DefaultFormatter = require("./_default");
 var traverse         = require("../../traverse");
 var util             = require("../../util");
 var t                = require("../../types");
+var _                = require("lodash");
 
 function CommonJSFormatter(file) {
   DefaultFormatter.apply(this, arguments);
@@ -27,7 +28,7 @@ CommonJSFormatter.prototype.importSpecifier = function (specifier, node, nodes)
   // import foo from "foo";
   if (t.isSpecifierDefault(specifier)) {
     var ref = util.template("require", {MODULE_NAME: node.source});
-    if (!node._noInteropRequire) {
+    if (!_.contains(this.file.dynamicImports, node)) {
       ref = t.callExpression(this.file.addHelper("interop-require"), [ref]);
     }
     nodes.push(t.variableDeclaration("var", [t.variableDeclarator(variableName, ref)]));
diff --git a/lib/6to5/transformation/transformers/optional-external-runtime.js b/lib/6to5/transformation/transformers/optional-external-runtime.js
index a2f52667cf..ff39454e4d 100644
--- a/lib/6to5/transformation/transformers/optional-external-runtime.js
+++ b/lib/6to5/transformation/transformers/optional-external-runtime.js
@@ -6,6 +6,5 @@ exports.optional = true;
 exports.ast = {
   enter: function (ast, file) {
     file.opts.runtime = file.addImport(file.opts.runtime, "to5Runtime").name;
-    file.dynamicImports[file.dynamicImports.length - 1]._noInteropRequire = true;
   }
 };
diff --git a/test/fixtures/transformation/optional-bluebird-coroutines/expression/expected.js b/test/fixtures/transformation/optional-bluebird-coroutines/expression/expected.js
index 13943a98de..ed68858b19 100644
--- a/test/fixtures/transformation/optional-bluebird-coroutines/expression/expected.js
+++ b/test/fixtures/transformation/optional-bluebird-coroutines/expression/expected.js
@@ -1,10 +1,6 @@
 "use strict";
 
-var _interopRequire = function (obj) {
-  return obj && (obj["default"] || obj);
-};
-
-var _bluebird = _interopRequire(require("bluebird"));
+var _bluebird = require("bluebird");
 
 var foo = _bluebird.coroutine(function* () {
   var wat = yield bar();
diff --git a/test/fixtures/transformation/optional-bluebird-coroutines/statement/expected.js b/test/fixtures/transformation/optional-bluebird-coroutines/statement/expected.js
index 9b200b29f0..c5dbaaf5d1 100644
--- a/test/fixtures/transformation/optional-bluebird-coroutines/statement/expected.js
+++ b/test/fixtures/transformation/optional-bluebird-coroutines/statement/expected.js
@@ -1,10 +1,6 @@
 "use strict";
 
-var _interopRequire = function (obj) {
-  return obj && (obj["default"] || obj);
-};
-
-var _bluebird = _interopRequire(require("bluebird"));
+var _bluebird = require("bluebird");
 
 var foo = _bluebird.coroutine(function* foo() {
   var wat = yield bar();
diff --git a/test/fixtures/transformation/optional-core-aliasing/aliased-constructors/expected.js b/test/fixtures/transformation/optional-core-aliasing/aliased-constructors/expected.js
index 7c6e3f9ba2..8c6ff60ed1 100644
--- a/test/fixtures/transformation/optional-core-aliasing/aliased-constructors/expected.js
+++ b/test/fixtures/transformation/optional-core-aliasing/aliased-constructors/expected.js
@@ -1,10 +1,6 @@
 "use strict";
 
-var _interopRequire = function (obj) {
-  return obj && (obj["default"] || obj);
-};
-
-var _core = _interopRequire(require("core-js/library"));
+var _core = require("core-js/library");
 
 obj.constructor === Object;
 obj.constructor === _core.Promise;
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js b/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js
index fc43ff5423..15e3ce78b9 100644
--- a/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js
+++ b/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js
@@ -16,11 +16,7 @@ var _slicedToArray = function (arr, i) {
   }
 };
 
-var _interopRequire = function (obj) {
-  return obj && (obj["default"] || obj);
-};
-
-var _core = _interopRequire(require("core-js/library"));
+var _core = require("core-js/library");
 
 var _ref = ["hello", [", ", "junk"], ["world"]];
 
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-for-of/expected.js b/test/fixtures/transformation/optional-core-aliasing/es6-for-of/expected.js
index 3bf1f53a05..2669fd4d0c 100644
--- a/test/fixtures/transformation/optional-core-aliasing/es6-for-of/expected.js
+++ b/test/fixtures/transformation/optional-core-aliasing/es6-for-of/expected.js
@@ -1,10 +1,6 @@
 "use strict";
 
-var _interopRequire = function (obj) {
-  return obj && (obj["default"] || obj);
-};
-
-var _core = _interopRequire(require("core-js/library"));
+var _core = require("core-js/library");
 
 for (var _iterator = _core.$for.getIterator(arr), _step; !(_step = _iterator.next()).done;) {
   var i = _step.value;
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js b/test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js
index 4d00347582..2a41ccd997 100644
--- a/test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js
+++ b/test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js
@@ -4,10 +4,6 @@ var _toArray = function (arr) {
   return Array.isArray(arr) ? arr : _core.Array.from(arr);
 };
 
-var _interopRequire = function (obj) {
-  return obj && (obj["default"] || obj);
-};
-
-var _core = _interopRequire(require("core-js/library"));
+var _core = require("core-js/library");
 
 var lyrics = ["head", "and", "toes"].concat(_toArray(parts));
diff --git a/test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/expected.js b/test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/expected.js
index 01333ca8f9..0bf67a612a 100644
--- a/test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/expected.js
+++ b/test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/expected.js
@@ -1,10 +1,6 @@
 "use strict";
 
-var _interopRequire = function (obj) {
-  return obj && (obj["default"] || obj);
-};
-
-var _core = _interopRequire(require("core-js/library"));
+var _core = require("core-js/library");
 
 var arr = (function () {
   var _arr = [];

From 81bec3e5c4e559cacadbc07dd24aac8d5099caa6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Sat, 17 Jan 2015 22:46:02 -0200
Subject: [PATCH 05/15] Move the _blockHoist transformer after regenerator

Otherwise wrapped generator functions are hoisted to the top of the
scope even if we want something else to come before them.
---
 lib/6to5/transformation/transform.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/lib/6to5/transformation/transform.js b/lib/6to5/transformation/transform.js
index 2a5cbb26a2..74079d5d0b 100644
--- a/lib/6to5/transformation/transform.js
+++ b/lib/6to5/transformation/transform.js
@@ -80,13 +80,12 @@ _.each({
   constants:                 require("./transformers/es6-constants"),
   letScoping:                require("./transformers/es6-let-scoping"),
 
-  _blockHoist:               require("./transformers/_block-hoist"),
-
   generators:                require("./transformers/es6-generators"),
   restParameters:            require("./transformers/es6-rest-parameters"),
 
   protoToAssign:             require("./transformers/optional-proto-to-assign"),
 
+  _blockHoist:               require("./transformers/_block-hoist"),
   _declarations:             require("./transformers/_declarations"),
 
   // wrap up

From d4cc8fefd1c18645c44015b7b6d021aebcc1f37e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Sat, 17 Jan 2015 23:02:20 -0200
Subject: [PATCH 06/15] Add transformer to import regeneratorRuntime from a
 module

Thanks to facebook/regenerator#167 Regenerator's runtime can be now
required as a module (though not in an easily self-containable way).
This transformer, together with `coreAliasing` and `externalRuntime`,
allows users to ditch a runtime dependency on `6to5`/`6to5-core` to
depend directly on `core-js` and `regenerator`.
---
 lib/6to5/transformation/transform.js             |  1 +
 .../optional-external-regenerator-runtime.js     | 16 ++++++++++++++++
 2 files changed, 17 insertions(+)
 create mode 100644 lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js

diff --git a/lib/6to5/transformation/transform.js b/lib/6to5/transformation/transform.js
index 74079d5d0b..9d32b62fa9 100644
--- a/lib/6to5/transformation/transform.js
+++ b/lib/6to5/transformation/transform.js
@@ -95,6 +95,7 @@ _.each({
 
   typeofSymbol:              require("./transformers/optional-typeof-symbol"),
   coreAliasing:              require("./transformers/optional-core-aliasing"),
+  externalRegenerator:       require("./transformers/optional-external-regenerator-runtime"),
   undefinedToVoid:           require("./transformers/optional-undefined-to-void"),
 
   // spec
diff --git a/lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js b/lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js
new file mode 100644
index 0000000000..9294a6c76e
--- /dev/null
+++ b/lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js
@@ -0,0 +1,16 @@
+var t = require("../../types");
+
+exports.optional = true;
+
+exports.ast = {
+  enter: function (ast, file) {
+    file._regeneratorId = file.addImport("regenerator/runtime-module", "regeneratorRuntime");
+  }
+};
+
+exports.MemberExpression = function (node, parent, scope, context, file) {
+  var obj = node.object;
+  var prop = node.property;
+  if (!t.isReferenced(node, parent) || !t.isReferenced(obj, node)) return;
+  if (obj.name === "regeneratorRuntime") return t.memberExpression(file._regeneratorId, prop);
+};

From 7e6da1d368c75fe980bf271feaa90643359e7045 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Sun, 18 Jan 2015 01:41:20 -0200
Subject: [PATCH 07/15] Add tests for the externalRegenerator transformer

---
 .../basic/actual.js                             |  2 ++
 .../basic/expected.js                           | 17 +++++++++++++++++
 .../options.json                                |  3 +++
 3 files changed, 22 insertions(+)
 create mode 100644 test/fixtures/transformation/optional-external-regenerator-runtime/basic/actual.js
 create mode 100644 test/fixtures/transformation/optional-external-regenerator-runtime/basic/expected.js
 create mode 100644 test/fixtures/transformation/optional-external-regenerator-runtime/options.json

diff --git a/test/fixtures/transformation/optional-external-regenerator-runtime/basic/actual.js b/test/fixtures/transformation/optional-external-regenerator-runtime/basic/actual.js
new file mode 100644
index 0000000000..ae6cc4d8c8
--- /dev/null
+++ b/test/fixtures/transformation/optional-external-regenerator-runtime/basic/actual.js
@@ -0,0 +1,2 @@
+void function* () {
+};
diff --git a/test/fixtures/transformation/optional-external-regenerator-runtime/basic/expected.js b/test/fixtures/transformation/optional-external-regenerator-runtime/basic/expected.js
new file mode 100644
index 0000000000..4121cc9700
--- /dev/null
+++ b/test/fixtures/transformation/optional-external-regenerator-runtime/basic/expected.js
@@ -0,0 +1,17 @@
+"use strict";
+
+var _interopRequire = function (obj) {
+  return obj && (obj["default"] || obj);
+};
+
+var _regeneratorRuntime = _interopRequire(require("regenerator/runtime-module"));
+
+void _regeneratorRuntime.mark(function callee$0$0() {
+  return _regeneratorRuntime.wrap(function callee$0$0$(context$1$0) {
+    while (1) switch (context$1$0.prev = context$1$0.next) {
+      case 0:
+      case "end":
+        return context$1$0.stop();
+    }
+  }, callee$0$0, this);
+});
diff --git a/test/fixtures/transformation/optional-external-regenerator-runtime/options.json b/test/fixtures/transformation/optional-external-regenerator-runtime/options.json
new file mode 100644
index 0000000000..40d336b5be
--- /dev/null
+++ b/test/fixtures/transformation/optional-external-regenerator-runtime/options.json
@@ -0,0 +1,3 @@
+{
+  "optional": ["externalRegenerator"]
+}

From 8d288c01ca0dc6ad87643a163d9ec156ebbdd1e0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Sun, 18 Jan 2015 20:39:35 -0200
Subject: [PATCH 08/15] Import ES6 functions and helpers from 6to5-runtime

The new `6to5-runtime` packs core-js, 6to5's helpers and
the Regenerator runtime, and we're moving `coreAliasing`,
`externalRuntime` and `externalRegenerator` to use it
instead of forcing the user to depend on these packages
directly.
---
 .../transformation/transformers/optional-core-aliasing.js     | 2 +-
 .../transformers/optional-external-regenerator-runtime.js     | 2 +-
 .../transformation/transformers/optional-external-runtime.js  | 2 +-
 .../optional-core-aliasing/aliased-constructors/expected.js   | 2 +-
 .../optional-core-aliasing/es6-destructuring/expected.js      | 2 +-
 .../optional-core-aliasing/es6-for-of/expected.js             | 2 +-
 .../optional-core-aliasing/es6-spread/expected.js             | 2 +-
 .../es7-array-comprehensions/expected.js                      | 2 +-
 .../optional-external-regenerator-runtime/basic/expected.js   | 2 +-
 .../transformation/optional-external-runtime/amd/expected.js  | 4 ++--
 .../optional-external-runtime/commonjs/expected.js            | 2 +-
 .../transformation/optional-external-runtime/options.json     | 1 -
 12 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/lib/6to5/transformation/transformers/optional-core-aliasing.js b/lib/6to5/transformation/transformers/optional-core-aliasing.js
index c0db8bd9bd..62613bf198 100644
--- a/lib/6to5/transformation/transformers/optional-core-aliasing.js
+++ b/lib/6to5/transformation/transformers/optional-core-aliasing.js
@@ -23,7 +23,7 @@ exports.optional = true;
 
 exports.ast = {
   enter: function (ast, file) {
-    file._coreId = file.addImport("core-js/library", "core");
+    file._coreId = file.addImport("6to5-runtime/core-js", "core");
   },
 
   exit: function (ast, file) {
diff --git a/lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js b/lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js
index 9294a6c76e..6fee6be612 100644
--- a/lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js
+++ b/lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js
@@ -4,7 +4,7 @@ exports.optional = true;
 
 exports.ast = {
   enter: function (ast, file) {
-    file._regeneratorId = file.addImport("regenerator/runtime-module", "regeneratorRuntime");
+    file._regeneratorId = file.addImport("6to5-runtime/regenerator", "regeneratorRuntime");
   }
 };
 
diff --git a/lib/6to5/transformation/transformers/optional-external-runtime.js b/lib/6to5/transformation/transformers/optional-external-runtime.js
index ff39454e4d..56c14e0fc4 100644
--- a/lib/6to5/transformation/transformers/optional-external-runtime.js
+++ b/lib/6to5/transformation/transformers/optional-external-runtime.js
@@ -5,6 +5,6 @@ exports.optional = true;
 // AST is built.
 exports.ast = {
   enter: function (ast, file) {
-    file.opts.runtime = file.addImport(file.opts.runtime, "to5Runtime").name;
+    file.opts.runtime = file.addImport("6to5-runtime/6to5", "to5Runtime").name;
   }
 };
diff --git a/test/fixtures/transformation/optional-core-aliasing/aliased-constructors/expected.js b/test/fixtures/transformation/optional-core-aliasing/aliased-constructors/expected.js
index 8c6ff60ed1..b517b90ea6 100644
--- a/test/fixtures/transformation/optional-core-aliasing/aliased-constructors/expected.js
+++ b/test/fixtures/transformation/optional-core-aliasing/aliased-constructors/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-var _core = require("core-js/library");
+var _core = require("6to5-runtime/core-js");
 
 obj.constructor === Object;
 obj.constructor === _core.Promise;
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js b/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js
index 15e3ce78b9..7abd2c0cd5 100644
--- a/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js
+++ b/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js
@@ -16,7 +16,7 @@ var _slicedToArray = function (arr, i) {
   }
 };
 
-var _core = require("core-js/library");
+var _core = require("6to5-runtime/core-js");
 
 var _ref = ["hello", [", ", "junk"], ["world"]];
 
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-for-of/expected.js b/test/fixtures/transformation/optional-core-aliasing/es6-for-of/expected.js
index 2669fd4d0c..0fdc4cc4f5 100644
--- a/test/fixtures/transformation/optional-core-aliasing/es6-for-of/expected.js
+++ b/test/fixtures/transformation/optional-core-aliasing/es6-for-of/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-var _core = require("core-js/library");
+var _core = require("6to5-runtime/core-js");
 
 for (var _iterator = _core.$for.getIterator(arr), _step; !(_step = _iterator.next()).done;) {
   var i = _step.value;
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js b/test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js
index 2a41ccd997..d01fa15ace 100644
--- a/test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js
+++ b/test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js
@@ -4,6 +4,6 @@ var _toArray = function (arr) {
   return Array.isArray(arr) ? arr : _core.Array.from(arr);
 };
 
-var _core = require("core-js/library");
+var _core = require("6to5-runtime/core-js");
 
 var lyrics = ["head", "and", "toes"].concat(_toArray(parts));
diff --git a/test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/expected.js b/test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/expected.js
index 0bf67a612a..9ea3b708c6 100644
--- a/test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/expected.js
+++ b/test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-var _core = require("core-js/library");
+var _core = require("6to5-runtime/core-js");
 
 var arr = (function () {
   var _arr = [];
diff --git a/test/fixtures/transformation/optional-external-regenerator-runtime/basic/expected.js b/test/fixtures/transformation/optional-external-regenerator-runtime/basic/expected.js
index 00320c54b6..275ec24ac5 100644
--- a/test/fixtures/transformation/optional-external-regenerator-runtime/basic/expected.js
+++ b/test/fixtures/transformation/optional-external-regenerator-runtime/basic/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-var _regeneratorRuntime = require("regenerator/runtime-module");
+var _regeneratorRuntime = require("6to5-runtime/regenerator");
 
 void _regeneratorRuntime.mark(function callee$0$0() {
   return _regeneratorRuntime.wrap(function callee$0$0$(context$1$0) {
diff --git a/test/fixtures/transformation/optional-external-runtime/amd/expected.js b/test/fixtures/transformation/optional-external-runtime/amd/expected.js
index 20e759af12..6e504dd685 100644
--- a/test/fixtures/transformation/optional-external-runtime/amd/expected.js
+++ b/test/fixtures/transformation/optional-external-runtime/amd/expected.js
@@ -1,6 +1,6 @@
-define(["exports", "6to5-runtime", "someModule"], function (exports, _to5Runtime2, _someModule) {
+define(["exports", "6to5-runtime/6to5", "someModule"], function (exports, _to5Runtime6to5, _someModule) {
   "use strict";
 
-  var _to5Runtime = _to5Runtime2;
+  var _to5Runtime = _to5Runtime6to5;
   var foo = _to5Runtime.interopRequire(_someModule);
 });
diff --git a/test/fixtures/transformation/optional-external-runtime/commonjs/expected.js b/test/fixtures/transformation/optional-external-runtime/commonjs/expected.js
index b10bbe6f09..d660411bc0 100644
--- a/test/fixtures/transformation/optional-external-runtime/commonjs/expected.js
+++ b/test/fixtures/transformation/optional-external-runtime/commonjs/expected.js
@@ -1,5 +1,5 @@
 "use strict";
 
-var _to5Runtime = require("6to5-runtime");
+var _to5Runtime = require("6to5-runtime/6to5");
 
 var foo = _to5Runtime.interopRequireWildcard(require("someModule"));
diff --git a/test/fixtures/transformation/optional-external-runtime/options.json b/test/fixtures/transformation/optional-external-runtime/options.json
index 44c5164a67..5149c1159a 100644
--- a/test/fixtures/transformation/optional-external-runtime/options.json
+++ b/test/fixtures/transformation/optional-external-runtime/options.json
@@ -1,4 +1,3 @@
 {
-  "runtime": "6to5-runtime",
   "optional": ["externalRuntime"]
 }

From c81cc5cda06cc763a4e4cbe7ce702fb3303b5919 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Sun, 18 Jan 2015 21:15:30 -0200
Subject: [PATCH 09/15] Unify coreAliasing, externalRuntime and
 externalRegenerator

Merge all three transformers into the `selfContained` transformer,
as discussed in Gitter.  Name may not be final.
---
 lib/6to5/transformation/transform.js          |  4 +--
 .../optional-external-regenerator-runtime.js  | 16 ----------
 .../transformers/optional-external-runtime.js | 10 -------
 ...aliasing.js => optional-self-contained.js} |  9 ++++++
 .../es6-destructuring/actual.js               |  1 -
 .../es6-destructuring/expected.js             | 30 -------------------
 .../es6-spread/actual.js                      |  1 -
 .../es6-spread/expected.js                    |  9 ------
 .../optional-core-aliasing/options.json       |  4 ---
 .../options.json                              |  3 --
 .../optional-external-runtime/amd/expected.js |  6 ----
 .../optional-external-runtime/options.json    |  3 --
 .../aliased-constructors/actual.js            |  0
 .../aliased-constructors/expected.js          |  4 +++
 .../es6-for-of/actual.js                      |  0
 .../es6-for-of/expected.js                    |  4 +++
 .../es7-array-comprehensions/actual.js        |  0
 .../es7-array-comprehensions/expected.js      |  4 +++
 .../optional-self-contained/options.json      |  4 +++
 .../regenerator-runtime}/actual.js            |  0
 .../regenerator-runtime}/expected.js          |  4 +++
 .../runtime-amd}/actual.js                    |  0
 .../runtime-amd/expected.js                   |  8 +++++
 .../runtime-amd}/options.json                 |  0
 .../runtime-commonjs}/actual.js               |  0
 .../runtime-commonjs}/expected.js             |  4 +++
 26 files changed, 42 insertions(+), 86 deletions(-)
 delete mode 100644 lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js
 delete mode 100644 lib/6to5/transformation/transformers/optional-external-runtime.js
 rename lib/6to5/transformation/transformers/{optional-core-aliasing.js => optional-self-contained.js} (81%)
 delete mode 100644 test/fixtures/transformation/optional-core-aliasing/es6-destructuring/actual.js
 delete mode 100644 test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js
 delete mode 100644 test/fixtures/transformation/optional-core-aliasing/es6-spread/actual.js
 delete mode 100644 test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js
 delete mode 100644 test/fixtures/transformation/optional-core-aliasing/options.json
 delete mode 100644 test/fixtures/transformation/optional-external-regenerator-runtime/options.json
 delete mode 100644 test/fixtures/transformation/optional-external-runtime/amd/expected.js
 delete mode 100644 test/fixtures/transformation/optional-external-runtime/options.json
 rename test/fixtures/transformation/{optional-core-aliasing => optional-self-contained}/aliased-constructors/actual.js (100%)
 rename test/fixtures/transformation/{optional-core-aliasing => optional-self-contained}/aliased-constructors/expected.js (61%)
 rename test/fixtures/transformation/{optional-core-aliasing => optional-self-contained}/es6-for-of/actual.js (100%)
 rename test/fixtures/transformation/{optional-core-aliasing => optional-self-contained}/es6-for-of/expected.js (61%)
 rename test/fixtures/transformation/{optional-core-aliasing => optional-self-contained}/es7-array-comprehensions/actual.js (100%)
 rename test/fixtures/transformation/{optional-core-aliasing => optional-self-contained}/es7-array-comprehensions/expected.js (70%)
 create mode 100644 test/fixtures/transformation/optional-self-contained/options.json
 rename test/fixtures/transformation/{optional-external-regenerator-runtime/basic => optional-self-contained/regenerator-runtime}/actual.js (100%)
 rename test/fixtures/transformation/{optional-external-regenerator-runtime/basic => optional-self-contained/regenerator-runtime}/expected.js (79%)
 rename test/fixtures/transformation/{optional-external-runtime/amd => optional-self-contained/runtime-amd}/actual.js (100%)
 create mode 100644 test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js
 rename test/fixtures/transformation/{optional-external-runtime/amd => optional-self-contained/runtime-amd}/options.json (100%)
 rename test/fixtures/transformation/{optional-external-runtime/commonjs => optional-self-contained/runtime-commonjs}/actual.js (100%)
 rename test/fixtures/transformation/{optional-external-runtime/commonjs => optional-self-contained/runtime-commonjs}/expected.js (54%)

diff --git a/lib/6to5/transformation/transform.js b/lib/6to5/transformation/transform.js
index 4c64371d3a..c90a23290c 100644
--- a/lib/6to5/transformation/transform.js
+++ b/lib/6to5/transformation/transform.js
@@ -94,9 +94,7 @@ _.each({
   _moduleFormatter:          require("./transformers/_module-formatter"),
 
   typeofSymbol:              require("./transformers/optional-typeof-symbol"),
-  externalRuntime:           require("./transformers/optional-external-runtime"),
-  coreAliasing:              require("./transformers/optional-core-aliasing"),
-  externalRegenerator:       require("./transformers/optional-external-regenerator-runtime"),
+  selfContained:             require("./transformers/optional-self-contained"),
   undefinedToVoid:           require("./transformers/optional-undefined-to-void"),
 
   // spec
diff --git a/lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js b/lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js
deleted file mode 100644
index 6fee6be612..0000000000
--- a/lib/6to5/transformation/transformers/optional-external-regenerator-runtime.js
+++ /dev/null
@@ -1,16 +0,0 @@
-var t = require("../../types");
-
-exports.optional = true;
-
-exports.ast = {
-  enter: function (ast, file) {
-    file._regeneratorId = file.addImport("6to5-runtime/regenerator", "regeneratorRuntime");
-  }
-};
-
-exports.MemberExpression = function (node, parent, scope, context, file) {
-  var obj = node.object;
-  var prop = node.property;
-  if (!t.isReferenced(node, parent) || !t.isReferenced(obj, node)) return;
-  if (obj.name === "regeneratorRuntime") return t.memberExpression(file._regeneratorId, prop);
-};
diff --git a/lib/6to5/transformation/transformers/optional-external-runtime.js b/lib/6to5/transformation/transformers/optional-external-runtime.js
deleted file mode 100644
index 56c14e0fc4..0000000000
--- a/lib/6to5/transformation/transformers/optional-external-runtime.js
+++ /dev/null
@@ -1,10 +0,0 @@
-exports.optional = true;
-
-// In theory, it would be more appropriate to do this in `manipulateOptions`,
-// but we need an identifier for the import and we can't get that before the
-// AST is built.
-exports.ast = {
-  enter: function (ast, file) {
-    file.opts.runtime = file.addImport("6to5-runtime/6to5", "to5Runtime").name;
-  }
-};
diff --git a/lib/6to5/transformation/transformers/optional-core-aliasing.js b/lib/6to5/transformation/transformers/optional-self-contained.js
similarity index 81%
rename from lib/6to5/transformation/transformers/optional-core-aliasing.js
rename to lib/6to5/transformation/transformers/optional-self-contained.js
index 62613bf198..7fe1b5b4d9 100644
--- a/lib/6to5/transformation/transformers/optional-core-aliasing.js
+++ b/lib/6to5/transformation/transformers/optional-self-contained.js
@@ -23,7 +23,9 @@ exports.optional = true;
 
 exports.ast = {
   enter: function (ast, file) {
+    file.opts.runtime = file.addImport("6to5-runtime/6to5", "to5Runtime").name;
     file._coreId = file.addImport("6to5-runtime/core-js", "core");
+    file._regeneratorId = file.addImport("6to5-runtime/regenerator", "regeneratorRuntime");
   },
 
   exit: function (ast, file) {
@@ -67,3 +69,10 @@ exports.ast = {
     });
   }
 };
+
+exports.MemberExpression = function (node, parent, scope, context, file) {
+  var obj = node.object;
+  var prop = node.property;
+  if (!t.isReferenced(node, parent) || !t.isReferenced(obj, node)) return;
+  if (obj.name === "regeneratorRuntime") return t.memberExpression(file._regeneratorId, prop);
+};
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/actual.js b/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/actual.js
deleted file mode 100644
index 10aa8799ed..0000000000
--- a/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/actual.js
+++ /dev/null
@@ -1 +0,0 @@
-var [a, [b], [c], d] = ["hello", [", ", "junk"], ["world"]];
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js b/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js
deleted file mode 100644
index 7abd2c0cd5..0000000000
--- a/test/fixtures/transformation/optional-core-aliasing/es6-destructuring/expected.js
+++ /dev/null
@@ -1,30 +0,0 @@
-"use strict";
-
-var _slicedToArray = function (arr, i) {
-  if (Array.isArray(arr)) {
-    return arr;
-  } else {
-    var _arr = [];
-
-    for (var _iterator = _core.$for.getIterator(arr), _step; !(_step = _iterator.next()).done;) {
-      _arr.push(_step.value);
-
-      if (i && _arr.length === i) break;
-    }
-
-    return _arr;
-  }
-};
-
-var _core = require("6to5-runtime/core-js");
-
-var _ref = ["hello", [", ", "junk"], ["world"]];
-
-var a = _ref[0];
-var _ref$1 = _slicedToArray(_ref[1], 1);
-
-var b = _ref$1[0];
-var _ref$2 = _slicedToArray(_ref[2], 1);
-
-var c = _ref$2[0];
-var d = _ref[3];
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-spread/actual.js b/test/fixtures/transformation/optional-core-aliasing/es6-spread/actual.js
deleted file mode 100644
index 5ebb80da66..0000000000
--- a/test/fixtures/transformation/optional-core-aliasing/es6-spread/actual.js
+++ /dev/null
@@ -1 +0,0 @@
-var lyrics = ["head", "and", "toes", ...parts];
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js b/test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js
deleted file mode 100644
index d01fa15ace..0000000000
--- a/test/fixtures/transformation/optional-core-aliasing/es6-spread/expected.js
+++ /dev/null
@@ -1,9 +0,0 @@
-"use strict";
-
-var _toArray = function (arr) {
-  return Array.isArray(arr) ? arr : _core.Array.from(arr);
-};
-
-var _core = require("6to5-runtime/core-js");
-
-var lyrics = ["head", "and", "toes"].concat(_toArray(parts));
diff --git a/test/fixtures/transformation/optional-core-aliasing/options.json b/test/fixtures/transformation/optional-core-aliasing/options.json
deleted file mode 100644
index 371b5f0b20..0000000000
--- a/test/fixtures/transformation/optional-core-aliasing/options.json
+++ /dev/null
@@ -1,4 +0,0 @@
-{
-  "optional": ["coreAliasing"],
-  "experimental": true
-}
diff --git a/test/fixtures/transformation/optional-external-regenerator-runtime/options.json b/test/fixtures/transformation/optional-external-regenerator-runtime/options.json
deleted file mode 100644
index 40d336b5be..0000000000
--- a/test/fixtures/transformation/optional-external-regenerator-runtime/options.json
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-  "optional": ["externalRegenerator"]
-}
diff --git a/test/fixtures/transformation/optional-external-runtime/amd/expected.js b/test/fixtures/transformation/optional-external-runtime/amd/expected.js
deleted file mode 100644
index 6e504dd685..0000000000
--- a/test/fixtures/transformation/optional-external-runtime/amd/expected.js
+++ /dev/null
@@ -1,6 +0,0 @@
-define(["exports", "6to5-runtime/6to5", "someModule"], function (exports, _to5Runtime6to5, _someModule) {
-  "use strict";
-
-  var _to5Runtime = _to5Runtime6to5;
-  var foo = _to5Runtime.interopRequire(_someModule);
-});
diff --git a/test/fixtures/transformation/optional-external-runtime/options.json b/test/fixtures/transformation/optional-external-runtime/options.json
deleted file mode 100644
index 5149c1159a..0000000000
--- a/test/fixtures/transformation/optional-external-runtime/options.json
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-  "optional": ["externalRuntime"]
-}
diff --git a/test/fixtures/transformation/optional-core-aliasing/aliased-constructors/actual.js b/test/fixtures/transformation/optional-self-contained/aliased-constructors/actual.js
similarity index 100%
rename from test/fixtures/transformation/optional-core-aliasing/aliased-constructors/actual.js
rename to test/fixtures/transformation/optional-self-contained/aliased-constructors/actual.js
diff --git a/test/fixtures/transformation/optional-core-aliasing/aliased-constructors/expected.js b/test/fixtures/transformation/optional-self-contained/aliased-constructors/expected.js
similarity index 61%
rename from test/fixtures/transformation/optional-core-aliasing/aliased-constructors/expected.js
rename to test/fixtures/transformation/optional-self-contained/aliased-constructors/expected.js
index b517b90ea6..2b56ea0257 100644
--- a/test/fixtures/transformation/optional-core-aliasing/aliased-constructors/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/aliased-constructors/expected.js
@@ -1,7 +1,11 @@
 "use strict";
 
+var _to5Runtime = require("6to5-runtime/6to5");
+
 var _core = require("6to5-runtime/core-js");
 
+var _regeneratorRuntime = require("6to5-runtime/regenerator");
+
 obj.constructor === Object;
 obj.constructor === _core.Promise;
 
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-for-of/actual.js b/test/fixtures/transformation/optional-self-contained/es6-for-of/actual.js
similarity index 100%
rename from test/fixtures/transformation/optional-core-aliasing/es6-for-of/actual.js
rename to test/fixtures/transformation/optional-self-contained/es6-for-of/actual.js
diff --git a/test/fixtures/transformation/optional-core-aliasing/es6-for-of/expected.js b/test/fixtures/transformation/optional-self-contained/es6-for-of/expected.js
similarity index 61%
rename from test/fixtures/transformation/optional-core-aliasing/es6-for-of/expected.js
rename to test/fixtures/transformation/optional-self-contained/es6-for-of/expected.js
index 0fdc4cc4f5..c520e9da0a 100644
--- a/test/fixtures/transformation/optional-core-aliasing/es6-for-of/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/es6-for-of/expected.js
@@ -1,7 +1,11 @@
 "use strict";
 
+var _to5Runtime = require("6to5-runtime/6to5");
+
 var _core = require("6to5-runtime/core-js");
 
+var _regeneratorRuntime = require("6to5-runtime/regenerator");
+
 for (var _iterator = _core.$for.getIterator(arr), _step; !(_step = _iterator.next()).done;) {
   var i = _step.value;
 }
diff --git a/test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/actual.js b/test/fixtures/transformation/optional-self-contained/es7-array-comprehensions/actual.js
similarity index 100%
rename from test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/actual.js
rename to test/fixtures/transformation/optional-self-contained/es7-array-comprehensions/actual.js
diff --git a/test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/expected.js b/test/fixtures/transformation/optional-self-contained/es7-array-comprehensions/expected.js
similarity index 70%
rename from test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/expected.js
rename to test/fixtures/transformation/optional-self-contained/es7-array-comprehensions/expected.js
index 9ea3b708c6..1a7d5c5482 100644
--- a/test/fixtures/transformation/optional-core-aliasing/es7-array-comprehensions/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/es7-array-comprehensions/expected.js
@@ -1,7 +1,11 @@
 "use strict";
 
+var _to5Runtime = require("6to5-runtime/6to5");
+
 var _core = require("6to5-runtime/core-js");
 
+var _regeneratorRuntime = require("6to5-runtime/regenerator");
+
 var arr = (function () {
   var _arr = [];
 
diff --git a/test/fixtures/transformation/optional-self-contained/options.json b/test/fixtures/transformation/optional-self-contained/options.json
new file mode 100644
index 0000000000..079cf304ad
--- /dev/null
+++ b/test/fixtures/transformation/optional-self-contained/options.json
@@ -0,0 +1,4 @@
+{
+  "optional": ["selfContained"],
+  "experimental": true
+}
diff --git a/test/fixtures/transformation/optional-external-regenerator-runtime/basic/actual.js b/test/fixtures/transformation/optional-self-contained/regenerator-runtime/actual.js
similarity index 100%
rename from test/fixtures/transformation/optional-external-regenerator-runtime/basic/actual.js
rename to test/fixtures/transformation/optional-self-contained/regenerator-runtime/actual.js
diff --git a/test/fixtures/transformation/optional-external-regenerator-runtime/basic/expected.js b/test/fixtures/transformation/optional-self-contained/regenerator-runtime/expected.js
similarity index 79%
rename from test/fixtures/transformation/optional-external-regenerator-runtime/basic/expected.js
rename to test/fixtures/transformation/optional-self-contained/regenerator-runtime/expected.js
index 275ec24ac5..92dc0c8704 100644
--- a/test/fixtures/transformation/optional-external-regenerator-runtime/basic/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/regenerator-runtime/expected.js
@@ -1,5 +1,9 @@
 "use strict";
 
+var _to5Runtime = require("6to5-runtime/6to5");
+
+var _core = require("6to5-runtime/core-js");
+
 var _regeneratorRuntime = require("6to5-runtime/regenerator");
 
 void _regeneratorRuntime.mark(function callee$0$0() {
diff --git a/test/fixtures/transformation/optional-external-runtime/amd/actual.js b/test/fixtures/transformation/optional-self-contained/runtime-amd/actual.js
similarity index 100%
rename from test/fixtures/transformation/optional-external-runtime/amd/actual.js
rename to test/fixtures/transformation/optional-self-contained/runtime-amd/actual.js
diff --git a/test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js b/test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js
new file mode 100644
index 0000000000..17b753e8c5
--- /dev/null
+++ b/test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js
@@ -0,0 +1,8 @@
+define(["exports", "6to5-runtime/6to5", "6to5-runtime/core-js", "6to5-runtime/regenerator", "someModule"], function (exports, _to5Runtime6to5, _to5RuntimeCoreJs, _to5RuntimeRegenerator, _someModule) {
+  "use strict";
+
+  var _to5Runtime = _to5Runtime6to5;
+  var _core = _to5RuntimeCoreJs;
+  var _regeneratorRuntime = _to5RuntimeRegenerator;
+  var foo = _to5Runtime.interopRequire(_someModule);
+});
diff --git a/test/fixtures/transformation/optional-external-runtime/amd/options.json b/test/fixtures/transformation/optional-self-contained/runtime-amd/options.json
similarity index 100%
rename from test/fixtures/transformation/optional-external-runtime/amd/options.json
rename to test/fixtures/transformation/optional-self-contained/runtime-amd/options.json
diff --git a/test/fixtures/transformation/optional-external-runtime/commonjs/actual.js b/test/fixtures/transformation/optional-self-contained/runtime-commonjs/actual.js
similarity index 100%
rename from test/fixtures/transformation/optional-external-runtime/commonjs/actual.js
rename to test/fixtures/transformation/optional-self-contained/runtime-commonjs/actual.js
diff --git a/test/fixtures/transformation/optional-external-runtime/commonjs/expected.js b/test/fixtures/transformation/optional-self-contained/runtime-commonjs/expected.js
similarity index 54%
rename from test/fixtures/transformation/optional-external-runtime/commonjs/expected.js
rename to test/fixtures/transformation/optional-self-contained/runtime-commonjs/expected.js
index d660411bc0..9fd1cd7ec9 100644
--- a/test/fixtures/transformation/optional-external-runtime/commonjs/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/runtime-commonjs/expected.js
@@ -2,4 +2,8 @@
 
 var _to5Runtime = require("6to5-runtime/6to5");
 
+var _core = require("6to5-runtime/core-js");
+
+var _regeneratorRuntime = require("6to5-runtime/regenerator");
+
 var foo = _to5Runtime.interopRequireWildcard(require("someModule"));

From 02019d4d8f728817809d1e51d7889ae11f3e8d2f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Sun, 18 Jan 2015 21:18:25 -0200
Subject: [PATCH 10/15] Drop unnecessary dynamic import redeclaration in AMD

Instead of assigning the import a name and them declaring a new
variabled referencing that name, output the import already with
the destination name, since we know there must be no collisions
because these IDs are also generated.
---
 lib/6to5/transformation/modules/amd.js                      | 6 +++++-
 .../optional-self-contained/runtime-amd/expected.js         | 5 +----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/lib/6to5/transformation/modules/amd.js b/lib/6to5/transformation/modules/amd.js
index 0eb61407b2..6d06ddbe46 100644
--- a/lib/6to5/transformation/modules/amd.js
+++ b/lib/6to5/transformation/modules/amd.js
@@ -87,7 +87,11 @@ AMDFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
   var key = t.getSpecifierName(specifier);
   var ref = this._push(node);
 
-  if (t.isImportBatchSpecifier(specifier) || _.contains(this.file.dynamicImports, node)) {
+  if (_.contains(this.file.dynamicImports, node)) {
+    // Prevent unnecessary renaming of dynamic imports.
+    this.ids[node.source.value] = key;
+    return;
+  } else if (t.isImportBatchSpecifier(specifier)) {
     // import * as bar from "foo";
   } else if (t.isSpecifierDefault(specifier) && !this.noInteropRequire) {
     // import foo from "foo";
diff --git a/test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js b/test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js
index 17b753e8c5..928902ba02 100644
--- a/test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js
@@ -1,8 +1,5 @@
-define(["exports", "6to5-runtime/6to5", "6to5-runtime/core-js", "6to5-runtime/regenerator", "someModule"], function (exports, _to5Runtime6to5, _to5RuntimeCoreJs, _to5RuntimeRegenerator, _someModule) {
+define(["exports", "6to5-runtime/6to5", "6to5-runtime/core-js", "6to5-runtime/regenerator", "someModule"], function (exports, _to5Runtime, _core, _regeneratorRuntime, _someModule) {
   "use strict";
 
-  var _to5Runtime = _to5Runtime6to5;
-  var _core = _to5RuntimeCoreJs;
-  var _regeneratorRuntime = _to5RuntimeRegenerator;
   var foo = _to5Runtime.interopRequire(_someModule);
 });

From e2bf61379f26c809492a96c6ce4455bb1ea1b598 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Sun, 18 Jan 2015 23:10:26 -0200
Subject: [PATCH 11/15] Add full-blown test for the selfContained transformer

---
 .../optional-self-contained/full/actual.js    |  6 +++++
 .../optional-self-contained/full/expected.js  | 27 +++++++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100644 test/fixtures/transformation/optional-self-contained/full/actual.js
 create mode 100644 test/fixtures/transformation/optional-self-contained/full/expected.js

diff --git a/test/fixtures/transformation/optional-self-contained/full/actual.js b/test/fixtures/transformation/optional-self-contained/full/actual.js
new file mode 100644
index 0000000000..3e8b1bcdbc
--- /dev/null
+++ b/test/fixtures/transformation/optional-self-contained/full/actual.js
@@ -0,0 +1,6 @@
+import foo, * as bar from "someModule";
+
+export const myWord = Symbol("abc");
+export function* giveWord () {
+  yield myWord;
+}
diff --git a/test/fixtures/transformation/optional-self-contained/full/expected.js b/test/fixtures/transformation/optional-self-contained/full/expected.js
new file mode 100644
index 0000000000..cbd7e48fbf
--- /dev/null
+++ b/test/fixtures/transformation/optional-self-contained/full/expected.js
@@ -0,0 +1,27 @@
+"use strict";
+
+var _to5Runtime = require("6to5-runtime/6to5");
+
+var _core = require("6to5-runtime/core-js");
+
+var _regeneratorRuntime = require("6to5-runtime/regenerator");
+
+var giveWord = _regeneratorRuntime.mark(function giveWord() {
+  return _regeneratorRuntime.wrap(function giveWord$(context$1$0) {
+    while (1) switch (context$1$0.prev = context$1$0.next) {
+      case 0:
+        context$1$0.next = 2;
+        return myWord;
+      case 2:
+      case "end":
+        return context$1$0.stop();
+    }
+  }, giveWord, this);
+});
+
+exports.giveWord = giveWord;
+var foo = _to5Runtime.interopRequire(require("someModule"));
+
+var bar = _to5Runtime.interopRequireWildcard(require("someModule"));
+
+var myWord = exports.myWord = _core.Symbol("abc");

From 157f5c3304e8b85be8ada99a634393ea22e45045 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Mon, 19 Jan 2015 10:54:33 -0200
Subject: [PATCH 12/15] Remove regenerator edge case from selfContained test

Right now exporting a generator doesn't work because we hoist the
export assignment before the function expression assignment.  This
will be dealt with at another time as it is not specific to this
transformer.
---
 .../transformation/optional-self-contained/full/actual.js       | 2 +-
 .../transformation/optional-self-contained/full/expected.js     | 1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/test/fixtures/transformation/optional-self-contained/full/actual.js b/test/fixtures/transformation/optional-self-contained/full/actual.js
index 3e8b1bcdbc..544c01be3d 100644
--- a/test/fixtures/transformation/optional-self-contained/full/actual.js
+++ b/test/fixtures/transformation/optional-self-contained/full/actual.js
@@ -1,6 +1,6 @@
 import foo, * as bar from "someModule";
 
 export const myWord = Symbol("abc");
-export function* giveWord () {
+function* giveWord () {
   yield myWord;
 }
diff --git a/test/fixtures/transformation/optional-self-contained/full/expected.js b/test/fixtures/transformation/optional-self-contained/full/expected.js
index cbd7e48fbf..5c31f034a6 100644
--- a/test/fixtures/transformation/optional-self-contained/full/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/full/expected.js
@@ -19,7 +19,6 @@ var giveWord = _regeneratorRuntime.mark(function giveWord() {
   }, giveWord, this);
 });
 
-exports.giveWord = giveWord;
 var foo = _to5Runtime.interopRequire(require("someModule"));
 
 var bar = _to5Runtime.interopRequireWildcard(require("someModule"));

From 3f96cf396346390533de4b27c70fe7722f689160 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Mon, 19 Jan 2015 11:55:03 -0200
Subject: [PATCH 13/15] Rename 6to5-runtime's helpers module to 'helpers'

---
 lib/6to5/transformation/transformers/optional-self-contained.js | 2 +-
 .../optional-self-contained/aliased-constructors/expected.js    | 2 +-
 .../optional-self-contained/es6-for-of/expected.js              | 2 +-
 .../es7-array-comprehensions/expected.js                        | 2 +-
 .../transformation/optional-self-contained/full/expected.js     | 2 +-
 .../optional-self-contained/regenerator-runtime/expected.js     | 2 +-
 .../optional-self-contained/runtime-amd/expected.js             | 2 +-
 .../optional-self-contained/runtime-commonjs/expected.js        | 2 +-
 8 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/lib/6to5/transformation/transformers/optional-self-contained.js b/lib/6to5/transformation/transformers/optional-self-contained.js
index 7fe1b5b4d9..0ab0cdbd3a 100644
--- a/lib/6to5/transformation/transformers/optional-self-contained.js
+++ b/lib/6to5/transformation/transformers/optional-self-contained.js
@@ -23,7 +23,7 @@ exports.optional = true;
 
 exports.ast = {
   enter: function (ast, file) {
-    file.opts.runtime = file.addImport("6to5-runtime/6to5", "to5Runtime").name;
+    file.opts.runtime = file.addImport("6to5-runtime/helpers", "to5Runtime").name;
     file._coreId = file.addImport("6to5-runtime/core-js", "core");
     file._regeneratorId = file.addImport("6to5-runtime/regenerator", "regeneratorRuntime");
   },
diff --git a/test/fixtures/transformation/optional-self-contained/aliased-constructors/expected.js b/test/fixtures/transformation/optional-self-contained/aliased-constructors/expected.js
index 2b56ea0257..2242afb8f8 100644
--- a/test/fixtures/transformation/optional-self-contained/aliased-constructors/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/aliased-constructors/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-var _to5Runtime = require("6to5-runtime/6to5");
+var _to5Runtime = require("6to5-runtime/helpers");
 
 var _core = require("6to5-runtime/core-js");
 
diff --git a/test/fixtures/transformation/optional-self-contained/es6-for-of/expected.js b/test/fixtures/transformation/optional-self-contained/es6-for-of/expected.js
index c520e9da0a..4d781e1d60 100644
--- a/test/fixtures/transformation/optional-self-contained/es6-for-of/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/es6-for-of/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-var _to5Runtime = require("6to5-runtime/6to5");
+var _to5Runtime = require("6to5-runtime/helpers");
 
 var _core = require("6to5-runtime/core-js");
 
diff --git a/test/fixtures/transformation/optional-self-contained/es7-array-comprehensions/expected.js b/test/fixtures/transformation/optional-self-contained/es7-array-comprehensions/expected.js
index 1a7d5c5482..374a18cb98 100644
--- a/test/fixtures/transformation/optional-self-contained/es7-array-comprehensions/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/es7-array-comprehensions/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-var _to5Runtime = require("6to5-runtime/6to5");
+var _to5Runtime = require("6to5-runtime/helpers");
 
 var _core = require("6to5-runtime/core-js");
 
diff --git a/test/fixtures/transformation/optional-self-contained/full/expected.js b/test/fixtures/transformation/optional-self-contained/full/expected.js
index 5c31f034a6..8caafa65b9 100644
--- a/test/fixtures/transformation/optional-self-contained/full/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/full/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-var _to5Runtime = require("6to5-runtime/6to5");
+var _to5Runtime = require("6to5-runtime/helpers");
 
 var _core = require("6to5-runtime/core-js");
 
diff --git a/test/fixtures/transformation/optional-self-contained/regenerator-runtime/expected.js b/test/fixtures/transformation/optional-self-contained/regenerator-runtime/expected.js
index 92dc0c8704..e7fa729a14 100644
--- a/test/fixtures/transformation/optional-self-contained/regenerator-runtime/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/regenerator-runtime/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-var _to5Runtime = require("6to5-runtime/6to5");
+var _to5Runtime = require("6to5-runtime/helpers");
 
 var _core = require("6to5-runtime/core-js");
 
diff --git a/test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js b/test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js
index 928902ba02..292e6b96cf 100644
--- a/test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/runtime-amd/expected.js
@@ -1,4 +1,4 @@
-define(["exports", "6to5-runtime/6to5", "6to5-runtime/core-js", "6to5-runtime/regenerator", "someModule"], function (exports, _to5Runtime, _core, _regeneratorRuntime, _someModule) {
+define(["exports", "6to5-runtime/helpers", "6to5-runtime/core-js", "6to5-runtime/regenerator", "someModule"], function (exports, _to5Runtime, _core, _regeneratorRuntime, _someModule) {
   "use strict";
 
   var foo = _to5Runtime.interopRequire(_someModule);
diff --git a/test/fixtures/transformation/optional-self-contained/runtime-commonjs/expected.js b/test/fixtures/transformation/optional-self-contained/runtime-commonjs/expected.js
index 9fd1cd7ec9..d7a8de73f8 100644
--- a/test/fixtures/transformation/optional-self-contained/runtime-commonjs/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/runtime-commonjs/expected.js
@@ -1,6 +1,6 @@
 "use strict";
 
-var _to5Runtime = require("6to5-runtime/6to5");
+var _to5Runtime = require("6to5-runtime/helpers");
 
 var _core = require("6to5-runtime/core-js");
 

From 043bf13d245471d576ec59e69525b43da1ef61d9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Mon, 19 Jan 2015 12:16:25 -0200
Subject: [PATCH 14/15] Revert moving _blockHoist after regenerator

This reverts commits 81bec3e5c4e559cacadbc07dd24aac8d5099caa6 and
157f5c3304e8b85be8ada99a634393ea22e45045.
---
 lib/6to5/transformation/transform.js                           | 3 ++-
 .../transformation/optional-self-contained/full/actual.js      | 2 +-
 .../transformation/optional-self-contained/full/expected.js    | 1 +
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/lib/6to5/transformation/transform.js b/lib/6to5/transformation/transform.js
index c90a23290c..90f615542c 100644
--- a/lib/6to5/transformation/transform.js
+++ b/lib/6to5/transformation/transform.js
@@ -80,12 +80,13 @@ _.each({
   constants:                 require("./transformers/es6-constants"),
   letScoping:                require("./transformers/es6-let-scoping"),
 
+  _blockHoist:               require("./transformers/_block-hoist"),
+
   generators:                require("./transformers/es6-generators"),
   restParameters:            require("./transformers/es6-rest-parameters"),
 
   protoToAssign:             require("./transformers/optional-proto-to-assign"),
 
-  _blockHoist:               require("./transformers/_block-hoist"),
   _declarations:             require("./transformers/_declarations"),
 
   // wrap up
diff --git a/test/fixtures/transformation/optional-self-contained/full/actual.js b/test/fixtures/transformation/optional-self-contained/full/actual.js
index 544c01be3d..3e8b1bcdbc 100644
--- a/test/fixtures/transformation/optional-self-contained/full/actual.js
+++ b/test/fixtures/transformation/optional-self-contained/full/actual.js
@@ -1,6 +1,6 @@
 import foo, * as bar from "someModule";
 
 export const myWord = Symbol("abc");
-function* giveWord () {
+export function* giveWord () {
   yield myWord;
 }
diff --git a/test/fixtures/transformation/optional-self-contained/full/expected.js b/test/fixtures/transformation/optional-self-contained/full/expected.js
index 8caafa65b9..2fe954e8df 100644
--- a/test/fixtures/transformation/optional-self-contained/full/expected.js
+++ b/test/fixtures/transformation/optional-self-contained/full/expected.js
@@ -19,6 +19,7 @@ var giveWord = _regeneratorRuntime.mark(function giveWord() {
   }, giveWord, this);
 });
 
+exports.giveWord = giveWord;
 var foo = _to5Runtime.interopRequire(require("someModule"));
 
 var bar = _to5Runtime.interopRequireWildcard(require("someModule"));

From 9d2e12dfa67121c916a6bc8da897788be3b49242 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Alu=C3=ADsio=20Augusto=20Silva=20Gon=C3=A7alves?=
 <aluisio@aasg.name>
Date: Mon, 19 Jan 2015 12:31:47 -0200
Subject: [PATCH 15/15] Amendments from 6to5/6to5#535 comments

---
 lib/6to5/transformation/modules/common.js                | 4 +++-
 .../transformers/optional-self-contained.js              | 9 ++++-----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/lib/6to5/transformation/modules/common.js b/lib/6to5/transformation/modules/common.js
index 950b35790e..73653c8d04 100644
--- a/lib/6to5/transformation/modules/common.js
+++ b/lib/6to5/transformation/modules/common.js
@@ -27,7 +27,9 @@ CommonJSFormatter.prototype.importSpecifier = function (specifier, node, nodes)
 
   // import foo from "foo";
   if (t.isSpecifierDefault(specifier)) {
-    var ref = util.template("require", {MODULE_NAME: node.source});
+    var ref = util.template("require", {
+      MODULE_NAME: node.source
+    });
     if (!_.contains(this.file.dynamicImports, node)) {
       ref = t.callExpression(this.file.addHelper("interop-require"), [ref]);
     }
diff --git a/lib/6to5/transformation/transformers/optional-self-contained.js b/lib/6to5/transformation/transformers/optional-self-contained.js
index 0ab0cdbd3a..0fd9eac9f3 100644
--- a/lib/6to5/transformation/transformers/optional-self-contained.js
+++ b/lib/6to5/transformation/transformers/optional-self-contained.js
@@ -70,9 +70,8 @@ exports.ast = {
   }
 };
 
-exports.MemberExpression = function (node, parent, scope, context, file) {
-  var obj = node.object;
-  var prop = node.property;
-  if (!t.isReferenced(node, parent) || !t.isReferenced(obj, node)) return;
-  if (obj.name === "regeneratorRuntime") return t.memberExpression(file._regeneratorId, prop);
+exports.Identifier = function (node, parent, scope, context, file) {
+  if (node.name === "regeneratorRuntime" && t.isReferenced(node, parent)) {
+    node.name = file._regeneratorId;
+  }
 };