v3.3.2

CHANGELOG.md

@@ -11,6 +11,18 @@
 
 _Note: Gaps between patch versions are faulty/broken releases._
 
+## 3.3.1
+
+ * **Bug Fix**
+  * Block hoist assignment pattern destructuring.
+
+## 3.3.0
+
+ * **Bug Fix**
+  * Do all transforms before the regenerator transform is ran.
+ * **New Feature**
+  * Added back the 2.x optional runtime.
+
 ## 3.2.1
 
  * **Bug Fix**

Makefile

@@ -21,6 +21,9 @@ build:
 	node $(BROWSERIFY_CMD) lib/6to5/browser.js -s to5 >dist/6to5.js
 	node $(UGLIFY_CMD) dist/6to5.js >dist/6to5.min.js
 
+	node bin/6to5-runtime >dist/runtime.js
+	node $(UGLIFY_CMD) dist/runtime.js >dist/runtime.min.js
+
 	rm -rf templates.json
 
 clean:
@@ -77,6 +80,7 @@ publish:
 	make build
 	cp dist/6to5.min.js browser.js
 	cp dist/polyfill.min.js browser-polyfill.js
+	cp dist/runtime.min.js runtime.js
 
 	node tools/cache-templates
 	test -f templates.json

bin/6to5-runtime

@@ -0,0 +1,4 @@
+#!/usr/bin/env node
+
+var runtime = require("../lib/6to5/build-runtime");
+console.log(runtime());

bin/6to5/index.js

@@ -11,6 +11,7 @@ commander.option("-t, --source-maps-inline", "Append sourceMappingURL comment to
 commander.option("-s, --source-maps", "Save source map alongside the compiled code");
 commander.option("-f, --filename [filename]", "Filename to use when reading from stdin - this will be used in source-maps, errors etc [stdin]", "stdin");
 commander.option("-w, --watch", "Recompile files on changes");
+commander.option("-r, --runtime", "Replace 6to5 declarations with references to a runtime");
 commander.option("-e, --experimental", "Enable experimental support for proposed ES7 features");
 commander.option("-p, --playground", "Enable playground support");
 
@@ -108,6 +109,7 @@ exports.opts = {
   sourceMap:              commander.sourceMaps || commander.sourceMapsInline,
   optional:               commander.optional,
   comments:               !commander.removeComments,
+  runtime:                commander.runtime,
   modules:                commander.modules,
   loose:                  commander.loose
 };

lib/6to5/build-helpers.js

@@ -0,0 +1,13 @@
+var File = require("./file");
+var util = require("./util");
+var each = require("lodash/collection/each");
+var t    = require("./types");
+
+module.exports = function (body, namespace) {
+  each(File.helpers, function (name) {
+    var key = t.identifier(t.toIdentifier(name));
+    body.push(t.expressionStatement(
+      t.assignmentExpression("=", t.memberExpression(namespace, key), util.template(name))
+    ));
+  });
+};

lib/6to5/build-runtime.js

@@ -0,0 +1,25 @@
+"use strict";
+
+var buildHelpers = require("./build-helpers");
+var generator    = require("./generation");
+var util         = require("./util");
+var t            = require("./types");
+
+module.exports = function () {
+  var namespace = t.identifier("to5Runtime");
+
+  var body      = [];
+  var container = t.functionExpression(null, [t.identifier("global")], t.blockStatement(body));
+  var tree      = t.program([t.expressionStatement(t.callExpression(container, [util.template("self-global")]))]);
+
+  body.push(t.variableDeclaration("var", [
+    t.variableDeclarator(
+      namespace,
+      t.assignmentExpression("=", t.memberExpression(t.identifier("global"), namespace), t.objectExpression([]))
+    )
+  ]));
+
+  buildHelpers(body, namespace);
+
+  return generator(tree).code;
+};

lib/6to5/detection/index.js

@@ -1,9 +1,7 @@
 module.exports = detect;
 
-//var useragent = require("useragent");
-var traverse  = require("../traverse");
-
 var SYNTAX_KEYS = require("./syntax-keys");
+var traverse    = require("../traverse");
 var visitors    = traverse.explode(require("./visitors"));
 
 function detect(ast) {

lib/6to5/file.js

@@ -24,7 +24,7 @@ function File(opts) {
   this.data             = {};
 
   this.lastStatements   = [];
-  this.opts             = File.normaliseOptions(opts);
+  this.opts             = this.normaliseOptions(opts);
   this.ast              = {};
 
   this.buildTransformers();
@@ -76,6 +76,7 @@ File.validOptions = [
   "playground",
   "experimental",
   "resolveModuleSource",
+  "runtime",
 
   // these are used by plugins
   "ignore",
@@ -84,7 +85,7 @@ File.validOptions = [
   "accept"
 ];
 
-File.normaliseOptions = function (opts) {
+File.prototype.normaliseOptions = function (opts) {
   opts = clone(opts);
 
   for (var key in opts) {
@@ -108,6 +109,7 @@ File.normaliseOptions = function (opts) {
     comments:               true,
     filename:               "unknown",
     modules:                "common",
+    runtime:                false,
     loose:                  [],
     code:                   true,
     ast:                    true
@@ -146,6 +148,10 @@ File.normaliseOptions = function (opts) {
     opts.experimental = true;
   }
 
+  if (opts.runtime) {
+    this.set("runtimeIdentifier", t.identifier("to5Runtime"));
+  }
+
   opts.blacklist = transform._ensureTransformerNames("blacklist", opts.blacklist);
   opts.whitelist = transform._ensureTransformerNames("whitelist", opts.whitelist);
   opts.optional = transform._ensureTransformerNames("optional", opts.optional);

lib/6to5/generation/index.js

@@ -40,9 +40,11 @@ each(Buffer.prototype, function (fn, key) {
 });
 
 CodeGenerator.normaliseOptions = function (code, opts) {
-  var indent = detectIndent(code);
-  var style  = indent.indent;
-  if (!style || style === " ") style = "  ";
+  var style = "  ";
+  if (code) {
+    var indent = detectIndent(code).indent;
+    if (indent && indent !== " ") style = indent;
+  }
 
   return merge({
     parentheses: true,

lib/6to5/helpers/levenshtein.js

@@ -0,0 +1,38 @@
+// taken from stackoverflow, it's crap i know.
+
+module.exports = function (a, b) {
+  if (a.length === 0) return b.length;
+  if (b.length === 0) return a.length;
+
+  var matrix = [];
+
+  // increment along the first column of each row
+  var i;
+  for (i = 0; i <= b.length; i++) {
+    matrix[i] = [i];
+  }
+
+  // increment each column in the first row
+  var j;
+  for (j = 0; j <= a.length; j++) {
+    matrix[0][j] = j;
+  }
+
+  // Fill in the rest of the matrix
+  for (i = 1; i <= b.length; i++) {
+    for (j = 1; j <= a.length; j++) {
+      if (b.charAt(i - 1) == a.charAt(j - 1)) {
+        matrix[i][j] = matrix[i - 1][j - 1];
+      } else {
+        matrix[i][j] = Math.min(
+          matrix[i - 1][j - 1] + 1, // substitution
+          Math.min(
+            matrix[i][j - 1] + 1, // insertion
+            matrix[i - 1][j] + 1) // deletion
+          );
+      }
+    }
+  }
+
+  return matrix[b.length][a.length];
+};

lib/6to5/index.js

@@ -7,6 +7,8 @@ var isFunction = require("lodash/lang/isFunction");
 
 exports.version = require("../../package").version;
 
+exports.runtime = require("./build-runtime");
+
 exports.types = require("./types");
 
 exports.register = function (opts) {

lib/6to5/transformation/helpers/react.js

@@ -0,0 +1,22 @@
+var t = require("../../types");
+
+var isCreateClassCallExpression = t.buildMatchMemberExpression("React.createClass");
+
+exports.isCreateClass = function (node) {
+  if (!node || !t.isCallExpression(node)) return false;
+
+  // not React.createClass call member object
+  if (!isCreateClassCallExpression(node.callee)) return false;
+
+  // no call arguments
+  var args = node.arguments;
+  if (args.length !== 1) return false;
+
+  // first node arg is not an object
+  var first = args[0];
+  if (!t.isObjectExpression(first)) return false;
+
+  return true;
+};
+
+exports.isReactComponent = t.buildMatchMemberExpression("React.Component");

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

@@ -3,9 +3,9 @@
 module.exports = CommonJSFormatter;
 
 var DefaultFormatter = require("./_default");
+var contains         = require("lodash/collection/contains");
 var util             = require("../../util");
 var t                = require("../../types");
-var contains         = require("lodash/collection/contains");
 
 function CommonJSFormatter() {
   DefaultFormatter.apply(this, arguments);

lib/6to5/transformation/transformer-pass.js

@@ -41,6 +41,8 @@ TransformerPass.prototype.canRun = function () {
 
   if (transformer.experimental && !opts.experimental) return false;
 
+  if (transformer.playground && !opts.playground) return false;
+
   return true;
 };
 

lib/6to5/transformation/transformer.js

@@ -17,6 +17,7 @@ var each            = require("lodash/collection/each");
 function Transformer(key, transformer, opts) {
   this.manipulateOptions = transformer.manipulateOptions;
   this.experimental      = !!transformer.experimental;
+  this.playground        = !!transformer.playground;
   this.secondPass        = !!transformer.secondPass;
   this.optional          = !!transformer.optional;
   this.handlers          = this.normalise(transformer);

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

@@ -31,7 +31,7 @@ var visitor = {
 
 exports.Scope = function (node, parent, scope, context, file) {
   traverse(node, visitor, scope, {
-    constants: scope.getAllOfKind("const"),
+    constants: scope.getAllDeclarationsOfKind("const"),
     file:      file
   });
 };

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

@@ -46,9 +46,11 @@ var push = function (opts, nodes, elem, parentId) {
 var pushAssignmentPattern = function (opts, nodes, pattern, parentId) {
   var tempParentId = opts.scope.generateUidBasedOnNode(parentId, opts.file);
 
-  nodes.push(t.variableDeclaration("var", [
+  var declar = t.variableDeclaration("var", [
     t.variableDeclarator(tempParentId, parentId)
-  ]));
+  ]);
+  declar._blockHoist = opts.blockHoist;
+  nodes.push(declar);
 
   nodes.push(buildVariableAssign(
     opts,

lib/6to5/transformation/transformers/es6/parameters.rest.js

@@ -58,15 +58,15 @@ exports.Function = function (node, parent, scope) {
     node.body.body.unshift(restDeclar);
   }
 
-  node.body.body.unshift(
-    util.template("rest", {
-      ARGUMENTS: argsId,
-      ARRAY_KEY: arrKey,
-      ARRAY_LEN: arrLen,
-      START: start,
-      ARRAY: rest,
-      KEY: key,
-      LEN: len,
-    })
-  );
+  var loop = util.template("rest", {
+    ARGUMENTS: argsId,
+    ARRAY_KEY: arrKey,
+    ARRAY_LEN: arrLen,
+    START: start,
+    ARRAY: rest,
+    KEY: key,
+    LEN: len,
+  });
+  loop._blockHoist = node.params.length + 1;
+  node.body.body.unshift(loop);
 };

lib/6to5/transformation/transformers/index.js

@@ -12,6 +12,7 @@ module.exports = {
   "playground.objectGetterMemoization":    require("./playground/object-getter-memoization"),
 
   react:                                   require("./other/react"),
+  "optimisation.react":                    require("./optimisation/react"),
 
   _modules:                                require("./internal/modules"),
 
@@ -52,14 +53,13 @@ module.exports = {
   // needs to be after `es6.blockScoping` due to needing `letReferences` set on blocks
   "es6.blockScopingTDZ":                   require("./es6/block-scoping-tdz"),
 
-  // needs to be after block scoping since regenerator doesn't support it
-  regenerator:                             require("./other/regenerator"),
-
   "es6.parameters.default":                require("./es6/parameters.default"),
   "es6.parameters.rest":                   require("./es6/parameters.rest"),
 
   "es6.destructuring":                     require("./es6/destructuring"),
 
+  regenerator:                             require("./other/regenerator"),
+
   // needs to be after `regenerator` due to needing `regeneratorRuntime` references
   // needs to be after `es6.forOf` due to needing `Symbol.iterator` references
   // needs to be before `es6.modules` due to dynamic imports

lib/6to5/transformation/transformers/optimisation/react/base.js

@@ -0,0 +1,55 @@
+module.exports = BaseOptimiser;
+
+var object = require("../../../../helpers/object");
+
+/**
+ * Description
+ *
+ * @param {Node} node
+ */
+
+function BaseOptimiser(node) {
+  this.methods = object();
+  this.types   = object();
+
+  this.node  = node;
+}
+
+/**
+ * Description
+ */
+
+BaseOptimiser.prototype.run = function () {
+  this.getMethods();
+  this.getTypes();
+};
+
+/**
+ * Add an `ObjectExpression` `node` that contains `propTypes`.
+ *
+ * Search it and match it against the types that we can optimise
+ * and register it for consumption later.
+ *
+ * @param {Node} node
+ */
+
+BaseOptimiser.prototype.addPropTypes = function (node) {
+  var props = node.properties;
+
+  for (var i = 0; i < props.length; i++) {
+    this.addPropType(props[i]);
+  }
+};
+
+/**
+ * Register a `Property` node as a prop type.
+ *
+ * We'll try and resolve it to a known type if we can and normalise
+ * it for consumption later.
+ *
+ * @param {Node} prop
+ */
+
+BaseOptimiser.prototype.addPropType = function () {
+
+};

lib/6to5/transformation/transformers/optimisation/react/create-class.js

@@ -0,0 +1,51 @@
+module.exports = CreateClassOptimiser;
+
+var BaseOptimiser = require("./base");
+var util          = require("../../../../util");
+var t             = require("../../../../types");
+
+function CreateClassOptimiser() {
+  BaseOptimiser.apply(this, arguments);
+}
+
+util.inherits(CreateClassOptimiser, BaseOptimiser);
+
+/**
+ * Get all function expressions.
+ */
+
+CreateClassOptimiser.prototype.getMethods = function () {
+  var props = this.node.properties;
+
+  for (var i = 0; i < props.length; i++) {
+    var prop = props[i];
+
+    // irrelevant
+    if (!t.isFunctionExpression(prop.value)) continue;
+
+    // deopt
+    if (prop.computed) continue;
+
+    this.methods[prop.key.name] = prop;
+  }
+};
+
+/**
+ * Find a `propTypes` property.
+ */
+
+CreateClassOptimiser.prototype.getTypes = function () {
+  var props = this.node.properties;
+
+  for (var i = 0; i < props.length; i++) {
+    var prop = props[i];
+    var key  = t.toComputedKey(prop, prop.key);
+
+    if (t.isLiteral(key, { value: "propTypes" }) && t.isObjectExpression(prop.value)) {
+      this.addPropTypes(prop.value);
+      return;
+    }
+  }
+
+  // not found
+};

lib/6to5/transformation/transformers/optimisation/react/index.js

@@ -0,0 +1,17 @@
+var CreateClassOptimiser = require("./create-class");
+var NativeClassOptimiser = require("./native-class");
+var react                = require("../../../helpers/react");
+
+exports.optional = true;
+
+exports.CallExpression = function (node) {
+  if (react.isCreateClass(node)) {
+    new CreateClassOptimiser(node.arguments[0]).run();
+  }
+};
+
+exports.CallExpression = function (node) {
+  if (react.isReactComponent(node.superClass)) {
+    new NativeClassOptimiser(node).run();
+  }
+};

lib/6to5/transformation/transformers/optimisation/react/native-class.js

@@ -0,0 +1,42 @@
+module.exports = NativeClassOptimiser;
+
+var BaseOptimiser = require("./base");
+var util          = require("../../../../util");
+var t             = require("../../../../types");
+
+function NativeClassOptimiser() {
+  BaseOptimiser.apply(this, arguments);
+}
+
+util.inherits(NativeClassOptimiser, BaseOptimiser);
+
+/**
+ * Get all instance methods.
+ */
+
+NativeClassOptimiser.prototype.getMethods = function () {
+  var body = this.node.body;
+
+  for (var i = 0; i < body.length; i++) {
+    var node = body[i];
+
+    // PrivateDeclaration etc
+    if (!t.isMethodDefinition(node)) continue;
+
+    // deopt
+    if (node.computed) continue;
+
+    // irrelevant
+    if (node.static) continue;
+
+    this.methods[node.key.name] = node;
+  }
+};
+
+/**
+ * Description
+ */
+
+NativeClassOptimiser.prototype.getTypes = function () {
+
+};

lib/6to5/transformation/transformers/other/react.js

@@ -6,6 +6,7 @@
 // jsx
 
 var esutils = require("esutils");
+var react   = require("../../helpers/react");
 var t       = require("../../../types");
 
 exports.JSXIdentifier = function (node, parent) {
@@ -197,33 +198,8 @@ var cleanJSXElementLiteralChild = function (child, args) {
 
 // display names
 
-var isCreateClass = function (call) {
-  if (!call || !t.isCallExpression(call)) return false;
-
-  var callee = call.callee;
-  if (!t.isMemberExpression(callee)) return false;
-
-  // not React call member object
-  var obj = callee.object;
-  if (!t.isIdentifier(obj, { name: "React" })) return false;
-
-  // not createClass call member property
-  var prop = callee.property;
-  if (!t.isIdentifier(prop, { name: "createClass" })) return false;
-
-  // no call arguments
-  var args = call.arguments;
-  if (args.length !== 1) return false;
-
-  // first call arg is not an object
-  var first = args[0];
-  if (!t.isObjectExpression(first)) return;
-
-  return true;
-};
-
 var addDisplayName = function (id, call) {
-  if (!isCreateClass(call)) return;
+  if (!react.isCreateClass(call)) return;
 
   var props = call.arguments[0].properties;
   var safe = true;

lib/6to5/transformation/transformers/playground/mallet-operator.js

@@ -1,7 +1,9 @@
 "use strict";
 
 var build = require("../../helpers/build-conditional-assignment-operator-transformer");
-var t      = require("../../../types");
+var t     = require("../../../types");
+
+exports.playground = true;
 
 build(exports, {
   is: function (node, file) {

lib/6to5/transformation/transformers/playground/memoization-operator.js

@@ -3,6 +3,8 @@
 var build = require("../../helpers/build-conditional-assignment-operator-transformer");
 var t     = require("../../../types");
 
+exports.playground = true;
+
 build(exports, {
   is: function (node) {
     var is = t.isAssignmentExpression(node) && node.operator === "?=";

lib/6to5/transformation/transformers/playground/method-binding.js

@@ -2,6 +2,8 @@
 
 var t = require("../../../types");
 
+exports.playground = true;
+
 exports.BindMemberExpression = function (node, parent, scope) {
   var object = node.object;
   var prop   = node.property;

lib/6to5/transformation/transformers/playground/object-getter-memoization.js

@@ -3,6 +3,8 @@
 var traverse = require("../../../traverse");
 var t        = require("../../../types");
 
+exports.playground = true;
+
 var visitor = {
   enter: function (node, parent, scope, context, state) {
     if (t.isFunction(node)) return;

lib/6to5/transformation/transformers/validation/undeclared-variable-check.js

@@ -1,9 +1,38 @@
 "use strict";
 
+var levenshtein = require("../../../helpers/levenshtein");
+var t           = require("../../../types");
+
 exports.optional = true;
 
 exports.Identifier = function (node, parent, scope, context, file) {
-  if (!scope.has(node.name, true)) {
-    throw file.errorWithNode(node, "Reference to undeclared variable", ReferenceError);
+  if (!t.isReferenced(node, parent)) return;
+  if (scope.has(node.name, true)) return;
+
+  var msg = "Reference to undeclared variable";
+
+  // get the closest declaration to offer as a suggestion
+  // the variable name may have just been mistyped
+
+  var declarations = scope.getAllDeclarations();
+
+  var closest;
+  var shortest = -1;
+
+  for (var name in declarations) {
+    var distance = levenshtein(node.name, name);
+    if (distance <= 0 || distance > 3) continue;
+    if (distance <= shortest) continue;
+
+    closest = name;
+    shortest = distance;
   }
+
+  if (closest) {
+    msg += " - Did you mean " + closest + "?";
+  }
+
+  //
+
+  throw file.errorWithNode(node, msg, ReferenceError);
 };

lib/6to5/traverse/scope.js

@@ -326,12 +326,31 @@ Scope.prototype.getFunctionParent = function () {
 };
 
 /**
- * Walks the scope tree and gathers all declarations of `kind`.
+ * Walks the scope tree and gathers **all** declarations.
  *
  * @returns {Object}
  */
 
-Scope.prototype.getAllOfKind = function (kind) {
+Scope.prototype.getAllDeclarations = function () {
+  var ids = object();
+
+  var scope = this;
+  do {
+    defaults(ids, scope.declarations);
+    scope = scope.parent;
+  } while (scope);
+
+  return ids;
+};
+
+/**
+ * Walks the scope tree and gathers all declarations of `kind`.
+ *
+ * @param {String} kind
+ * @returns {Object}
+ */
+
+Scope.prototype.getAllDeclarationsOfKind = function (kind) {
   var ids = object();
 
   var scope = this;

lib/6to5/types/index.js

@@ -399,6 +399,60 @@ t.ensureBlock = function (node, key) {
   node[key] = t.toBlock(node[key], node);
 };
 
+/**
+ * Build a function that when called will return whether or not the
+ * input `node` `MemberExpression` matches the input `match`.
+ *
+ * For example, given the match `React.createClass` it would match the
+ * parsed nodes of `React.createClass` and `React["createClass"]`.
+ *
+ * @param {String} match Dot delimetered string
+ * @returns {Function}
+ */
+
+t.buildMatchMemberExpression = function (match) {
+  var parts = match.split(".");
+
+  return function (member) {
+    // not a member expression
+    if (!t.isMemberExpression(member)) return false;
+
+    var search = [member];
+    var i = 0;
+
+    while (search.length) {
+      var node = search.shift();
+
+      if (t.isIdentifier(node)) {
+        // this part doesn't match
+        if (parts[i] !== node.name) return false;
+      } else if (t.isLiteral(node)) {
+        // this part doesn't match
+        if (parts[i] !== node.value) return false;
+      } else if (t.isMemberExpression(node)) {
+        if (node.computed && !t.isLiteral(node.property)) {
+          // we can't deal with this
+          return false;
+        } else {
+          search.push(node.object);
+          search.push(node.property);
+          continue;
+        }
+      } else {
+        // we can't deal with this
+        return false;
+      }
+
+      // too many parts
+      if (++i > parts.length) {
+        return false;
+      }
+    }
+
+    return true;
+  };
+};
+
 /**
  * Description
  *

package.json

@@ -1,7 +1,7 @@
 {
   "name": "6to5",
   "description": "Turn ES6 code into readable vanilla ES5 with source maps",
-  "version": "3.2.1",
+  "version": "3.3.2",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://6to5.org/",
   "repository": "6to5/6to5",
@@ -9,7 +9,8 @@
   "main": "lib/6to5/index.js",
   "bin": {
     "6to5": "./bin/6to5/index.js",
-    "6to5-node": "./bin/6to5-node"
+    "6to5-node": "./bin/6to5-node",
+    "6to5-runtime": "./bin/6to5-runtime"
   },
   "browser": {
     "./lib/6to5/index.js": "./lib/6to5/browser.js",
@@ -48,7 +49,7 @@
     "lodash": "3.0.0",
     "output-file-sync": "1.1.0",
     "private": "0.1.6",
-    "regenerator-6to5": "0.8.9-7",
+    "regenerator-6to5": "0.8.9-8",
     "regexpu": "1.1.0",
     "roadrunner": "1.0.4",
     "source-map": "0.1.43",

packages/6to5-runtime/package.json

@@ -1,7 +1,7 @@
 {
   "name": "6to5-runtime",
   "description": "6to5 selfContained runtime",
-  "version": "3.2.0",
+  "version": "3.3.1",
   "repository": "6to5/6to5",
   "author": "Sebastian McKenzie <sebmck@gmail.com>"
 }

packages/build-runtime.js

@@ -1,11 +1,10 @@
 "use strict";
 
-var transform = require("../lib/6to5/transformation");
-var File      = require("../lib/6to5/file");
-var util      = require("../lib/6to5/util");
-var fs        = require("fs");
-var t         = require("../lib/6to5/types");
-var _         = require("lodash");
+var buildHelpers = require("../lib/6to5/build-helpers");
+var transform    = require("../lib/6to5/transformation");
+var fs           = require("fs");
+var t            = require("../lib/6to5/types");
+var _            = require("lodash");
 
 var relative = function (filename) {
   return __dirname + "/6to5-runtime/" + filename;
@@ -31,23 +30,18 @@ var updatePackage = function () {
   writeFile("package.json", JSON.stringify(pkg, null, 2));
 };
 
-var buildHelpers = function () {
+var buildHelpers2 = function () {
   var body = [];
   var tree = t.program(body);
 
-  _.each(File.helpers, function (name) {
-    var key = t.identifier(t.toIdentifier(name));
-    body.push(t.expressionStatement(
-      t.assignmentExpression("=", t.memberExpression(t.identifier("exports"), key), util.template(name))
-    ));
-  });
+  buildHelpers(body, t.identifier("exports"));
 
   return transform.fromAst(tree, null, {
     optional: ["selfContained"]
   }).code;
 };
 
-writeFile("helpers.js", buildHelpers());
+writeFile("helpers.js", buildHelpers2());
 writeFile("core-js.js", readFile("core-js/library"));
 writeFile("regenerator/index.js", readFile("regenerator-6to5/runtime-module"));
 writeFile("regenerator/runtime.js", readFile("regenerator-6to5/runtime"));

test/fixtures/transformation/regenerator/destructuring-parameters/exec.js

@@ -0,0 +1,5 @@
+function* foo({ bar }) {
+  return bar;
+}
+
+assert(foo({ bar: "bar" }).next().value, "bar");

test/fixtures/transformation/regenerator/destructuring/exec.js

@@ -1,5 +1,13 @@
-function* foo({ bar }) {
+function* foo() {
+  var { bar } = { bar: "bar" };
   return bar;
 }
 
-assert(foo({ bar: "bar" }).next().value, "bar");
+assert.equal(foo().next().value, "bar");
+
+function* foo2({ bar = 0 }) {
+  return bar;
+}
+
+assert.equal(foo2({ bar: undefined }).next().value, 0);
+assert.equal(foo2({ bar: 3 }).next().value, 3);