v1.12.2

.gitignore

@@ -6,7 +6,7 @@ test/tmp
 /templates.json
 /tests.json
 /browser.js
-/polyfill.js
+/browser-polyfill.js
 /runtime.js
 coverage
 dist

.travis.yml

@@ -9,3 +9,11 @@ branches:
 
 before_script: "npm install -g codeclimate-test-reporter"
 script: "make test-travis"
+
+notifications:
+  webhooks:
+    urls:
+      - https://webhooks.gitter.im/e/acf1870e9d223c65e8d5
+    on_success: always
+    on_failure: always
+    on_start: false

CHANGELOG.md

@@ -0,0 +1,28 @@
+# 1.12.2
+
+ * Upgrade `matcha` to `0.6.0` and `browserify` to `6.3.2`.
+ * Add own `trimRight` helper instead of relying on the string instance method.
+ * Support JSX spreads that aren't the first.
+
+# 1.12.1
+
+ * Fix `this` and `arguments` mapping in the `_aliasFunctions` transformer.
+
+# 1.12.0
+
+ * Combine `jsx` and `react` transformers to `react`.
+ * Update `react` syntax output to React v0.12.
+
+# 1.11.15
+
+ * Fix JSX literal whitespace generation.
+
+# 1.11.14
+
+ * Avoid using a switch for let-scoping continue and break statements and use an if statement instead.
+ * Remove excess whitespace and newlines from JSX literals.
+
+# 1.11.13
+
+ * Update regenerator-6to5
+ * Add support for most escodegen formatting options

FEATURES.md

@@ -6,6 +6,16 @@
 [for (i of [1, 2, 3]) i * i]; // [1, 4, 9]
 ```
 
+## Async functions
+
+```javascript
+async function chainAnimationsAsync(elem, animations) {
+  for (var anim of animations) {
+    await anim(elem);
+  }
+}
+```
+
 ## Arrow functions
 
 ```javascript

Makefile

@@ -6,7 +6,7 @@ MOCHA_CMD = node_modules/mocha/bin/_mocha
 
 export NODE_ENV = test
 
-.PHONY: clean test test-cov test-travis test-browser publish bench build
+.PHONY: clean test test-cov test-clean lint test-travis test-spec test-browser publish bench build
 
 clean:
 	rm -rf coverage templates.json test/tmp dist
@@ -15,16 +15,26 @@ bench:
 	npm install es6-transpiler traceur esnext es6now jstransform
 	node node_modules/matcha/bin/_matcha
 
-test:
+lint:
 	$(JSHINT_CMD) lib bin benchmark/index.js
+
+test-clean:
+	rm -rf test/tmp
+
+test:
+	make lint
 	$(MOCHA_CMD)
+	make test-clean
 
 test-cov:
 	rm -rf coverage
 	node $(ISTANBUL_CMD) $(MOCHA_CMD) --
 
-test-travis:
+test-spec:
 	node $(ISTANBUL_CMD) $(MOCHA_CMD) -- --reporter spec
+
+test-travis:
+	make test-spec
 	if test -n "$$CODECLIMATE_REPO_TOKEN"; then codeclimate < coverage/lcov.info; fi
 
 test-browser:
@@ -60,7 +70,7 @@ publish:
 
 	make build
 	cp dist/6to5.min.js browser.js
-	cp dist/polyfill.min.js polyfill.js
+	cp dist/polyfill.min.js browser-polyfill.js
 	cp dist/runtime.min.js runtime.js
 
 	node bin/cache-templates
@@ -72,4 +82,4 @@ publish:
 
 	git push --follow-tags
 
-	rm -rf templates.json browser.js runtime.js polyfill.js
+	rm -rf templates.json browser.js runtime.js browser-polyfill.js

README.md

@@ -7,6 +7,10 @@
     <img alt="Travis Status" src="http://img.shields.io/travis/6to5/6to5.svg?branch=master&amp;style=flat&amp;label=travis">
   </a>
 
+  <a href="https://ci.appveyor.com/project/sebmck/6to5">
+    <img alt="Appveyor Status" src="http://img.shields.io/appveyor/ci/sebmck/6to5.svg?style=flat&amp;label=appveyor">
+  </a>
+
   <a href="https://codeclimate.com/github/6to5/6to5">
     <img alt="Code Climate Score" src="http://img.shields.io/codeclimate/github/6to5/6to5.svg?style=flat">
   </a>
@@ -45,11 +49,13 @@ It's as easy as:
 - [Caveats](#caveats)
 - [Polyfill](#polyfill)
 - [Optional runtime](#optional-runtime)
+- [React/JSX](#reactjsx)
 - [Differences](#differences)
 
 ## [Features](FEATURES.md)
 
  - [Array comprehension](FEATURES.md#array-comprehension)
+ - [Async functions](FEATURES.md#async-functions) via [regenerator](https://github.com/facebook/regenerator)
  - [Arrow functions](FEATURES.md#arrow-functions)
  - [Classes](FEATURES.md#classes)
  - [Computed property names](FEATURES.md#computed-property-names)
@@ -80,7 +86,10 @@ It's as easy as:
  - [Gulp](https://github.com/sindresorhus/gulp-6to5)
  - [Grunt](https://github.com/sindresorhus/grunt-6to5)
  - [Jade](https://github.com/Apoxx/jade-6to5)
+ - [Jest](https://github.com/6to5/6to5-jest)
  - [Karma](https://github.com/shuhei/karma-6to5-preprocessor)
+ - [Mocha](https://github.com/6to5/6to5-mocha)
+ - [Rails](https://github.com/6to5/6to5-rails)
  - [webpack](https://github.com/Couto/6to5-loader)
 
 ### CLI
@@ -342,8 +351,8 @@ require("6to5/polyfill");
 
 ### Browser
 
-Available from the `polyfill.js` file within the 6to5 directory of an npm
-release.
+Available from the `browser-polyfill.js` file within the 6to5 directory of an
+npm release.
 
 ## Optional runtime
 
@@ -397,6 +406,14 @@ require("6to5").runtime("myCustomNamespace");
 See [Options - runtime](#options) for documentation on changing the reference in
 generated code.
 
+## React/JSX
+
+6to5 has built-in support for React v0.12. Tags are automatically transformed to
+their equivalent `React.createElement(...)` and `displayName` is automatically
+inferred and added to all `React.createClass` calls.
+
+To disable this behaviour add `react` to your blacklist.
+
 ## Differences
 
 ### Philosophy

appveyor.yml

@@ -0,0 +1,17 @@
+environment:
+  matrix:
+    - nodejs_version: "0.10"
+    - nodejs_version: "0.11"
+
+install:
+ - "npm install"
+ - "cinst make"
+
+test_script:
+ - "node --version"
+ - "npm --version"
+ - "make test-spec"
+
+build: "off"
+
+version: "{build}"

bin/6to5/util.js

@@ -6,7 +6,9 @@ var fs      = require("fs");
 var _       = require("lodash");
 
 exports.readdirFilter = function (filename) {
-  return readdir(filename).filter(util.canCompile);
+  return readdir(filename).filter(function (filename) {
+    return util.canCompile(filename);
+  });
 };
 
 exports.transform = function (filename, code, opts) {

lib/6to5/file.js

@@ -11,7 +11,7 @@ var _         = require("lodash");
 
 function File(opts) {
   this.opts            = File.normaliseOptions(opts);
-  this.moduleFormatter = this.getModuleFormatter(opts.modules);
+  this.moduleFormatter = this.getModuleFormatter(this.opts.modules);
 
   this.declarations = {};
   this.uids         = {};
@@ -21,7 +21,7 @@ function File(opts) {
 File.declarations = ["extends", "class-props", "slice"];
 
 File.normaliseOptions = function (opts) {
-  opts = opts || {};
+  opts = _.cloneDeep(opts || {});
 
   _.defaults(opts, {
     whitespace: true,
@@ -33,6 +33,9 @@ File.normaliseOptions = function (opts) {
     runtime:    false
   });
 
+  // normalise windows path separators to unix
+  opts.filename = opts.filename.replace(/\\/g, "/");
+
   _.defaults(opts, {
     sourceFileName: opts.filename,
     sourceMapName:  opts.filename
@@ -110,6 +113,8 @@ File.prototype.errorWithNode = function (node, msg, Error) {
 };
 
 File.prototype.parse = function (code) {
+  code = (code || "") + "";
+
   var self = this;
 
   this.code = code;
@@ -141,7 +146,7 @@ File.prototype.generate = function () {
 
   if (this.shebang) {
     // add back shebang
-    result.code = this.shebang + result.code;
+    result.code = this.shebang + "\n" + result.code;
   }
 
   if (opts.sourceMap === "inline") {

lib/6to5/generation/buffer.js

@@ -0,0 +1,123 @@
+module.exports = Buffer;
+
+var util = require("../util");
+var _    = require("lodash");
+
+function Buffer(position, format) {
+  this.position = position;
+  this._indent  = format.indent.base;
+  this.format   = format;
+  this.buf      = "";
+}
+
+Buffer.prototype.get = function () {
+  return util.trimRight(this.buf);
+};
+
+Buffer.prototype.getIndent = function () {
+  if (this.format.compact) {
+    return "";
+  } else {
+    return util.repeat(this._indent, this.format.indent.style);
+  }
+};
+
+Buffer.prototype.indentSize = function () {
+  return this.getIndent().length;
+};
+
+Buffer.prototype.indent = function () {
+  this._indent++;
+};
+
+Buffer.prototype.dedent = function () {
+  this._indent--;
+};
+
+Buffer.prototype.semicolon = function () {
+  if (this.format.semicolons) this.push(";");
+};
+
+Buffer.prototype.ensureSemicolon = function () {
+  if (!this.isLast(";")) this.semicolon();
+};
+
+Buffer.prototype.rightBrace = function () {
+  this.newline(true);
+  this.push("}");
+};
+
+Buffer.prototype.keyword = function (name) {
+  this.push(name);
+  this.push(" ");
+};
+
+Buffer.prototype.space = function () {
+  if (this.buf && !this.isLast([" ", "\n"])) {
+    this.push(" ");
+  }
+};
+
+Buffer.prototype.removeLast = function (cha) {
+  if (!this.isLast(cha)) return;
+
+  this.buf = this.buf.slice(0, -1);
+  this.position.unshift(cha);
+};
+
+Buffer.prototype.newline = function (i, removeLast) {
+  if (!this.buf) return;
+  if (this.format.compact) return;
+  if (this.endsWith("{\n")) return;
+
+  if (_.isBoolean(i)) {
+    removeLast = i;
+    i = null;
+  }
+
+  if (_.isNumber(i)) {
+    var self = this;
+    _.times(i, function () {
+      self.newline(null, removeLast);
+    });
+    return;
+  }
+
+  if (removeLast && this.isLast("\n")) this.removeLast("\n");
+
+  this.removeLast(" ");
+  this.buf = this.buf.replace(/\n(\s+)$/, "\n");
+  this._push("\n");
+};
+
+Buffer.prototype.push = function (str, noIndent) {
+  if (this._indent && !noIndent && str !== "\n") {
+    // we have an indent level and we aren't pushing a newline
+    var indent = this.getIndent();
+
+    // replace all newlines with newlines with the indentation
+    str = str.replace(/\n/g, "\n" + indent);
+
+    // we've got a newline before us so prepend on the indentation
+    if (this.isLast("\n")) str = indent + str;
+  }
+
+  this._push(str);
+};
+
+Buffer.prototype._push = function (str) {
+  this.position.push(str);
+  this.buf += str;
+};
+
+Buffer.prototype.endsWith = function (str) {
+  return this.buf.slice(-str.length) === str;
+};
+
+Buffer.prototype.isLast = function (cha, trimRight) {
+  var buf = this.buf;
+  if (trimRight) buf = util.trimRight(buf);
+
+  var chars = [].concat(cha);
+  return _.contains(chars, _.last(buf));
+};

lib/6to5/generation/generator.js

@@ -8,6 +8,7 @@ module.exports.CodeGenerator = CodeGenerator;
 var Whitespace = require("./whitespace");
 var SourceMap  = require("./source-map");
 var Position   = require("./position");
+var Buffer     = require("./buffer");
 var util       = require("../util");
 var n          = require("./node");
 var t          = require("../types");
@@ -16,29 +17,41 @@ var _          = require("lodash");
 function CodeGenerator(ast, opts, code) {
   opts = opts || {};
 
-  this.style = {
-    semicolons: true,
-    comments: true,
-    compact: false,
-    indent: {
-      char: " ",
-      width: 2
-    }
-  };
-
   this.comments = ast.comments || [];
   this.tokens   = ast.tokens || [];
-  this.opts     = opts;
+  this.format   = CodeGenerator.normaliseOptions(opts);
   this.ast      = ast;
-  this.buf      = "";
-
-  this._indent = 0;
 
   this.whitespace = new Whitespace(this.tokens, this.comments);
   this.position   = new Position;
   this.map        = new SourceMap(this.position, opts, code);
+  this.buffer     = new Buffer(this.position, this.format);
 }
 
+_.each(Buffer.prototype, function (fn, key) {
+  CodeGenerator.prototype[key] = function () {
+    return fn.apply(this.buffer, arguments);
+  };
+});
+
+CodeGenerator.normaliseOptions = function (opts) {
+  opts = opts.format || {};
+
+  opts = _.merge({
+    parentheses: true,
+    semicolons: true,
+    comments: true,
+    compact: false,
+    indent: {
+      adjustMultilineComment: true,
+      style: "  ",
+      base: 0
+    }
+  }, opts);
+
+  return opts;
+};
+
 CodeGenerator.generators = {
   arrayComprehensions: require("./generators/array-comprehensions"),
   templateLiterals:    require("./generators/template-literals"),
@@ -56,125 +69,15 @@ _.each(CodeGenerator.generators, function (generator) {
   _.extend(CodeGenerator.prototype, generator);
 });
 
-CodeGenerator.prototype.newline = function (i, removeLast) {
-  if (!this.buf) return;
-  if (this.style.compact) return;
-  if (this.endsWith("{\n")) return;
-
-  if (_.isBoolean(i)) {
-    removeLast = i;
-    i = null;
-  }
-
-  if (_.isNumber(i)) {
-    var self = this;
-    _.times(i, function () {
-      self.newline(null, removeLast);
-    });
-    return;
-  }
-
-  if (removeLast && this.isLast("\n")) this.removeLast("\n");
-
-  this.removeLast(" ");
-  this.buf = this.buf.replace(/\n(\s+)$/, "\n");
-  this._push("\n");
-};
-
-CodeGenerator.prototype.removeLast = function (cha) {
-  if (!this.isLast(cha)) return;
-
-  this.buf = this.buf.slice(0, -1);
-  this.position.unshift(cha);
-};
-
-CodeGenerator.prototype.semicolon = function () {
-  if (this.style.semicolons) this.push(";");
-};
-
-CodeGenerator.prototype.ensureSemicolon = function () {
-  if (!this.isLast(";")) this.semicolon();
-};
-
-CodeGenerator.prototype.rightBrace = function () {
-  this.newline(true);
-  this.push("}");
-};
-
-CodeGenerator.prototype.keyword = function (name) {
-  this.push(name);
-  this.push(" ");
-};
-
-CodeGenerator.prototype.space = function () {
-  if (this.buf && !this.isLast([" ", "\n"])) {
-    this.push(" ");
-  }
-};
-
-CodeGenerator.prototype.push = function (str, noIndent) {
-  if (this._indent && !noIndent && str !== "\n") {
-    // we have an indent level and we aren't pushing a newline
-    var indent = this.getIndent();
-
-    // replace all newlines with newlines with the indentation
-    str = str.replace(/\n/g, "\n" + indent);
-
-    // we've got a newline before us so prepend on the indentation
-    if (this.isLast("\n")) str = indent + str;
-  }
-
-  this._push(str);
-};
-
-CodeGenerator.prototype._push = function (str) {
-  this.position.push(str);
-  this.buf += str;
-};
-
-CodeGenerator.prototype.endsWith = function (str) {
-  return this.buf.slice(-str.length) === str;
-};
-
-CodeGenerator.prototype.isLast = function (cha, trimRight) {
-  var buf = this.buf;
-  if (trimRight) buf = buf.trimRight();
-
-  var chars = [].concat(cha);
-  return _.contains(chars, _.last(buf));
-};
-
-CodeGenerator.prototype.getIndent = function () {
-  if (this.style.compact) {
-    return "";
-  } else {
-    return util.repeat(this.indentSize(), this.style.indent.char);
-  }
-};
-
-CodeGenerator.prototype.indentSize = function () {
-  return this._indent * this.style.indent.width;
-};
-
-CodeGenerator.prototype.indent = function () {
-  this._indent++;
-};
-
-CodeGenerator.prototype.dedent = function () {
-  this._indent--;
-};
-
 CodeGenerator.prototype.generate = function () {
   var ast = this.ast;
 
   this.print(ast);
 
-  this.buf = this.buf.trimRight();
-
   return {
     map:  this.map.get(),
     ast:  ast,
-    code: this.buf
+    code: this.buffer.get()
   };
 };
 
@@ -353,8 +256,8 @@ CodeGenerator.prototype._getComments = function (key, node) {
 };
 
 CodeGenerator.prototype._printComments = function (comments) {
-  if (this.style.compact) return;
-  if (!this.style.comments) return;
+  if (this.format.compact) return;
+  if (!this.format.comments) return;
   if (!comments || !comments.length) return;
 
   var self = this;
@@ -373,14 +276,16 @@ CodeGenerator.prototype._printComments = function (comments) {
 
     //
 
-    var offset = comment.loc.start.column;
-    if (offset) {
-      var newlineRegex = new RegExp("\\n\\s{1," + offset + "}", "g");
-      val = val.replace(newlineRegex, "\n");
-    }
+    if (comment.type === "Block" && self.format.indent.adjustMultilineComment) {
+      var offset = comment.loc.start.column;
+      if (offset) {
+        var newlineRegex = new RegExp("\\n\\s{1," + offset + "}", "g");
+        val = val.replace(newlineRegex, "\n");
+      }
 
-    var indent = Math.max(self.indentSize(), column);
-    val = val.replace(/\n/g, "\n" + util.repeat(indent));
+      var indent = Math.max(self.indentSize(), column);
+      val = val.replace(/\n/g, "\n" + util.repeat(indent));
+    }
 
     if (column === 0) {
       val = self.getIndent() + val;

lib/6to5/generation/generators/expressions.js

@@ -44,9 +44,11 @@ exports.ConditionalExpression = function (node, print) {
 exports.NewExpression = function (node, print) {
   this.push("new ");
   print(node.callee);
-  this.push("(");
-  print.join(node.arguments, { separator: ", " });
-  this.push(")");
+  if (node.arguments.length || this.format.parentheses) {
+    this.push("(");
+    print.join(node.arguments, { separator: ", " });
+    this.push(")");
+  }
 };
 
 exports.SequenceExpression = function (node, print) {
@@ -64,15 +66,20 @@ exports.CallExpression = function (node, print) {
   this.push(")");
 };
 
-exports.YieldExpression = function (node, print) {
-  this.push("yield");
-  if (node.delegate) this.push("*");
-  if (node.argument) {
-    this.space();
-    print(node.argument);
-  }
+var buildYieldAwait = function (keyword) {
+  return function (node, print) {
+    this.push(keyword);
+    if (node.delegate) this.push("*");
+    if (node.argument) {
+      this.space();
+      print(node.argument);
+    }
+  };
 };
 
+exports.YieldExpression = buildYieldAwait("yield");
+exports.AwaitExpression = buildYieldAwait("await");
+
 exports.EmptyStatement = function () {
   this.semicolon();
 };

lib/6to5/generation/generators/jsx.js

@@ -46,15 +46,11 @@ exports.XJSElement = function (node, print) {
 
   this.indent();
   _.each(node.children, function (child) {
-    if (t.isLiteral(child) && typeof child.value === "string") {
-      if (/\S/.test(child.value)) {
-        return self.push(child.value.replace(/^\s+|\s+$/g, ""));
-      } else if (/\n/.test(child.value)) {
-        return self.newline();
-      }
+    if (t.isLiteral(child)) {
+      self.push(child.value);
+    } else {
+      print(child);
     }
-
-    print(child);
   });
   this.dedent();
 

lib/6to5/generation/node.js

@@ -1,290 +0,0 @@
-module.exports = Node;
-
-var t = require("../types");
-var _ = require("lodash");
-
-function Node(node, parent) {
-  this.parent = parent;
-  this.node   = node;
-}
-
-//
-
-Node.whitespace = {
-  FunctionExpression: 1,
-  FunctionStatement: 1,
-  ClassExpression: 1,
-  ClassStatement: 1,
-  ForOfStatement: 1,
-  ForInStatement: 1,
-  ForStatement: 1,
-  SwitchStatement: 1,
-  IfStatement: { before: 1 },
-  //Property: { before: 1 },
-  Literal: { after: 1 }
-};
-
-_.each(Node.whitespace, function (amounts, type) {
-  if (_.isNumber(amounts)) amounts = { after: amounts, before: amounts };
-  Node.whitespace[type] = amounts;
-});
-
-//
-
-Node.PRECEDENCE = {};
-
-_.each([
-  ["||"],
-  ["&&"],
-  ["|"],
-  ["^"],
-  ["&"],
-  ["==", "===", "!=", "!=="],
-  ["<", ">", "<=", ">=", "in", "instanceof"],
-  [">>", "<<", ">>>"],
-  ["+", "-"],
-  ["*", "/", "%"]
-], function (tier, i) {
-  _.each(tier, function (op) {
-    Node.PRECEDENCE[op] = i;
-  });
-});
-
-//
-
-Node.prototype.isUserWhitespacable = function () {
-  //var parent = this.parent;
-  var node = this.node;
-
-  if (t.isUserWhitespacable(node)) {
-    return true;
-  }
-
-  //if (t.isArrayExpression(parent)) {
-  //  return true;
-  //}
-
-  return false;
-};
-
-Node.prototype.needsWhitespace = function (type) {
-  var parent = this.parent;
-  var node   = this.node;
-  if (!node) return 0;
-
-  if (t.isExpressionStatement(node)) {
-    node = node.expression;
-  }
-
-  if (type === "before") {
-    if (t.isProperty(node) && parent.properties[0] === node) {
-      return 1;
-    }
-  }
-
-  if (type === "after") {
-    if (t.isCallExpression(node)) {
-      return 1;
-    }
-
-    var exprs = [];
-
-    if (t.isVariableDeclaration(node)) {
-      exprs = _.map(node.declarations, "init");
-    }
-
-    if (t.isArrayExpression(node)) {
-      exprs = node.elements;
-    }
-
-    if (t.isObjectExpression(node)) {
-      exprs = node.properties;
-    }
-
-    var lines = 0;
-
-    _.each(exprs, function (expr) {
-      lines = Node.needsWhitespace(expr, node, type);
-      if (lines) return false;
-    });
-
-    if (lines) return lines;
-  }
-
-  if (t.isCallExpression(node) && t.isFunction(node.callee)) {
-    return 1;
-  }
-
-  var opts = Node.whitespace[node.type];
-  return (opts && opts[type]) || 0;
-};
-
-Node.prototype.needsWhitespaceBefore = function () {
-  return this.needsWhitespace("before");
-};
-
-Node.prototype.needsWhitespaceAfter = function () {
-  return this.needsWhitespace("after");
-};
-
-Node.prototype.needsParens = function () {
-  var parent = this.parent;
-  var node = this.node;
-
-  if (!parent) return false;
-
-  //
-  if (t.isUnaryLike(node)) {
-    return t.isMemberExpression(parent) && parent.object === node;
-  }
-
-  if (t.isBinary(node)) {
-    //
-    if (t.isCallExpression(parent) && parent.callee === node) {
-      return true;
-    }
-
-    //
-    if (t.isUnaryLike(parent)) {
-      return true;
-    }
-
-    //
-    if (t.isMemberExpression(parent) && parent.object === node) {
-      return true;
-    }
-
-    if (t.isBinary(parent)) {
-      var parentOp  = parent.operator;
-      var parentPos = Node.PRECEDENCE[parentOp];
-
-      var nodeOp = node.operator;
-      var nodePos = Node.PRECEDENCE[nodeOp];
-
-      if (parentPos > nodePos) {
-        return true;
-      }
-
-      if (parentPos === nodePos && parent.right === node) {
-        return true;
-      }
-    }
-  }
-
-  if (t.isBinaryExpression(node) && node.operator === "in") {
-    // var i = (1 in []);
-    if (t.isVariableDeclarator(parent)) {
-      return true;
-    }
-
-    // for ((1 in []);;);
-    if (t.isFor(parent)) {
-      return true;
-    }
-  }
-
-  // (class {});
-  if (t.isClassExpression(node) && t.isExpressionStatement(parent)) {
-    return true;
-  }
-
-  if (t.isSequenceExpression(node)) {
-    if (t.isForStatement(parent)) {
-      // Although parentheses wouldn't hurt around sequence
-      // expressions in the head of for loops, traditional style
-      // dictates that e.g. i++, j++ should not be wrapped with
-      // parentheses.
-      return false;
-    }
-
-    if (t.isExpressionStatement(parent) && parent.expression === node) {
-      return false;
-    }
-
-    // Otherwise err on the side of overparenthesization, adding
-    // explicit exceptions above if this proves overzealous.
-    return true;
-  }
-
-  //
-  if (t.isYieldExpression(node)) {
-    return t.isBinary(parent) ||
-           t.isUnaryLike(parent) ||
-           t.isCallExpression(parent) ||
-           t.isMemberExpression(parent) ||
-           t.isNewExpression(parent) ||
-           t.isConditionalExpression(parent) ||
-           t.isYieldExpression(parent);
-  }
-
-  if (t.isNewExpression(parent) && parent.callee === node) {
-    return t.isCallExpression(node) || _.some(node, function (val) {
-      return t.isCallExpression(val);
-    });
-  }
-
-  // (1).valueOf()
-  if (t.isLiteral(node) && _.isNumber(node.value) && t.isMemberExpression(parent) && parent.object === node) {
-    return true;
-  }
-
-  if (t.isAssignmentExpression(node) || t.isConditionalExpression(node)) {
-    //
-    if (t.isUnaryLike(parent)) {
-      return true;
-    }
-
-    //
-    if (t.isBinary(parent)) {
-      return true;
-    }
-
-    //
-    if (t.isCallExpression(parent) && parent.callee === node) {
-      return true;
-    }
-
-    //
-    if (t.isConditionalExpression(parent) && parent.test === node) {
-      return true;
-    }
-
-    //
-    if (t.isMemberExpression(parent) && parent.object === node) {
-      return true;
-    }
-  }
-
-  if (t.isFunctionExpression(node)) {
-    // function () {};
-    if (t.isExpressionStatement(parent)) {
-      return true;
-    }
-
-    // (function test() {}).name;
-    if (t.isMemberExpression(parent) && parent.object === node) {
-      return true;
-    }
-
-    // (function () {})();
-    if (t.isCallExpression(parent) && parent.callee === node) {
-      return true;
-    }
-  }
-
-  // ({ x, y }) = { x: 5, y: 6 };
-  if (t.isObjectPattern(node) && t.isAssignmentExpression(parent) && parent.left == node) {
-    return true;
-  }
-
-  return false;
-};
-
-_.each(Node.prototype, function (fn, key) {
-  Node[key] = function (node, parent) {
-    var n = new Node(node, parent);
-
-    var args = _.toArray(arguments).slice(2);
-    return n[key].apply(n, args);
-  };
-});

lib/6to5/generation/node/index.js

@@ -0,0 +1,90 @@
+module.exports = Node;
+
+var whitespace = require("./whitespace");
+var parens     = require("./parentheses");
+var t           = require("../../types");
+var _           = require("lodash");
+
+var find = function (obj, node, parent) {
+  var result;
+
+  _.each(obj, function (fn, type) {
+    if (t["is" + type](node)) {
+      result = fn(node, parent);
+      if (result != null) return false;
+    }
+  });
+
+  return result;
+};
+
+function Node(node, parent) {
+  this.parent = parent;
+  this.node   = node;
+}
+
+Node.prototype.isUserWhitespacable = function () {
+  //var parent = this.parent;
+  var node = this.node;
+
+  if (t.isUserWhitespacable(node)) {
+    return true;
+  }
+
+  //if (t.isArrayExpression(parent)) {
+  //  return true;
+  //}
+
+  return false;
+};
+
+Node.prototype.needsWhitespace = function (type) {
+  var parent = this.parent;
+  var node   = this.node;
+  if (!node) return 0;
+
+  if (t.isExpressionStatement(node)) {
+    node = node.expression;
+  }
+
+  var lines = find(whitespace[type].nodes, node, parent);
+  if (lines) return lines;
+
+  _.each(find(whitespace[type].list, node, parent), function (expr) {
+    lines = Node.needsWhitespace(expr, node, type);
+    if (lines) return false;
+  });
+  return lines || 0;
+};
+
+Node.prototype.needsWhitespaceBefore = function () {
+  return this.needsWhitespace("before");
+};
+
+Node.prototype.needsWhitespaceAfter = function () {
+  return this.needsWhitespace("after");
+};
+
+Node.prototype.needsParens = function () {
+  var parent = this.parent;
+  var node   = this.node;
+
+  if (!parent) return false;
+
+  if (t.isNewExpression(parent) && parent.callee === node) {
+    return t.isCallExpression(node) || _.some(node, function (val) {
+      return t.isCallExpression(val);
+    });
+  }
+
+  return find(parens, node, parent);
+};
+
+_.each(Node.prototype, function (fn, key) {
+  Node[key] = function (node, parent) {
+    var n = new Node(node, parent);
+
+    var args = _.toArray(arguments).slice(2);
+    return n[key].apply(n, args);
+  };
+});

lib/6to5/generation/node/parentheses.js

@@ -0,0 +1,150 @@
+var t = require("../../types");
+var _ = require("lodash");
+
+var PRECEDENCE = {};
+
+_.each([
+  ["||"],
+  ["&&"],
+  ["|"],
+  ["^"],
+  ["&"],
+  ["==", "===", "!=", "!=="],
+  ["<", ">", "<=", ">=", "in", "instanceof"],
+  [">>", "<<", ">>>"],
+  ["+", "-"],
+  ["*", "/", "%"]
+], function (tier, i) {
+  _.each(tier, function (op) {
+    PRECEDENCE[op] = i;
+  });
+});
+
+exports.Binary = function (node, parent) {
+  if (t.isCallExpression(parent) && parent.callee === node) {
+    return true;
+  }
+
+  if (t.isUnaryLike(parent)) {
+    return true;
+  }
+
+  if (t.isMemberExpression(parent) && parent.object === node) {
+    return true;
+  }
+
+  if (t.isBinary(parent)) {
+    var parentOp  = parent.operator;
+    var parentPos = PRECEDENCE[parentOp];
+
+    var nodeOp = node.operator;
+    var nodePos = PRECEDENCE[nodeOp];
+
+    if (parentPos > nodePos) {
+      return true;
+    }
+
+    if (parentPos === nodePos && parent.right === node) {
+      return true;
+    }
+  }
+};
+
+exports.BinaryExpression = function (node, parent) {
+  if (node.operator === "in") {
+    // var i = (1 in []);
+    if (t.isVariableDeclarator(parent)) {
+      return true;
+    }
+
+    // for ((1 in []);;);
+    if (t.isFor(parent)) {
+      return true;
+    }
+  }
+};
+
+exports.SequenceExpression = function (node, parent) {
+  if (t.isForStatement(parent)) {
+    // Although parentheses wouldn't hurt around sequence
+    // expressions in the head of for loops, traditional style
+    // dictates that e.g. i++, j++ should not be wrapped with
+    // parentheses.
+    return false;
+  }
+
+  if (t.isExpressionStatement(parent) && parent.expression === node) {
+    return false;
+  }
+
+  // Otherwise err on the side of overparenthesization, adding
+  // explicit exceptions above if this proves overzealous.
+  return true;
+};
+
+exports.YieldExpression = function (node, parent) {
+  return t.isBinary(parent) ||
+         t.isUnaryLike(parent) ||
+         t.isCallExpression(parent) ||
+         t.isMemberExpression(parent) ||
+         t.isNewExpression(parent) ||
+         t.isConditionalExpression(parent) ||
+         t.isYieldExpression(parent);
+};
+
+exports.Literal = function (node, parent) {
+  // (1).valueOf()
+  if (_.isNumber(node.value) && t.isMemberExpression(parent) && parent.object === node) {
+    return true;
+  }
+};
+
+exports.ClassExpression = function (node, parent) {
+  return t.isExpressionStatement(parent);
+};
+
+exports.UnaryLike = function (node, parent) {
+  return t.isMemberExpression(parent) && parent.object === node;
+};
+
+exports.FunctionExpression = function (node, parent) {
+  // function () {};
+  if (t.isExpressionStatement(parent)) {
+    return true;
+  }
+
+  // (function test() {}).name;
+  if (t.isMemberExpression(parent) && parent.object === node) {
+    return true;
+  }
+
+  // (function () {})();
+  if (t.isCallExpression(parent) && parent.callee === node) {
+    return true;
+  }
+};
+
+exports.AssignmentExpression =
+exports.ConditionalExpression = function (node, parent) {
+  if (t.isUnaryLike(parent)) {
+    return true;
+  }
+
+  if (t.isBinary(parent)) {
+    return true;
+  }
+
+  if (t.isCallExpression(parent) && parent.callee === node) {
+    return true;
+  }
+
+  if (t.isConditionalExpression(parent) && parent.test === node) {
+    return true;
+  }
+
+  if (t.isMemberExpression(parent) && parent.object === node) {
+    return true;
+  }
+
+  return false;
+};

lib/6to5/generation/node/whitespace.js

@@ -0,0 +1,60 @@
+var _ = require("lodash");
+var t = require("../../types");
+
+exports.before = {
+  nodes: {
+    Property: function (node, parent) {
+      if (parent.properties[0] === node) {
+        return 1;
+      }
+    },
+
+    SwitchCase: function (node, parent) {
+      if (parent.cases[0] === node) {
+        return 1;
+      }
+    },
+
+    CallExpression: function (node) {
+      if (t.isFunction(node.callee)) {
+        return 1;
+      }
+    }
+  }
+};
+
+exports.after = {
+  nodes: {},
+
+  list: {
+    VariableDeclaration: function (node) {
+      return _.map(node.declarations, "init");
+    },
+
+    ArrayExpression: function (node) {
+      return node.elements;
+    },
+
+    ObjectExpression: function (node) {
+      return node.properties;
+    }
+  }
+};
+
+_.each({
+  Function: 1,
+  Class: 1,
+  For: 1,
+  SwitchStatement: 1,
+  IfStatement: { before: 1 },
+  CallExpression: { after: 1 },
+  Literal: { after: 1 }
+}, function (amounts, type) {
+  if (_.isNumber(amounts)) amounts = { after: amounts, before: amounts };
+
+  _.each(amounts, function (amount, key) {
+    exports[key].nodes[type] = function () {
+      return amount;
+    };
+  });
+});

lib/6to5/index.js

@@ -1,4 +1,5 @@
 var transform = require("./transformation/transform");
+var util      = require("./util");
 var fs        = require("fs");
 var _         = require("lodash");
 
@@ -14,6 +15,8 @@ exports.polyfill = function () {
   require("./polyfill");
 };
 
+exports.canCompile = util.canCompile;
+
 exports.transform = transform;
 
 exports.transformFile = function (filename, opts, callback) {

lib/6to5/runtime.js

@@ -11,16 +11,7 @@ module.exports = function (namespace) {
   var container = t.functionExpression(null, [], t.blockStatement(body));
   var tree      = t.program([t.expressionStatement(t.callExpression(container, []))]);
 
-  body.push(t.variableDeclaration("var", [
-    t.variableDeclarator(t.identifier("self"), t.conditionalExpression(
-      t.binaryExpression("===",
-        t.unaryExpression("typeof", t.identifier("global"), true),
-        t.literal("undefined")
-      ),
-      t.identifier("window"),
-      t.identifier("global"))
-    )
-  ]));
+  body.push(util.template("self-global", true));
 
   body.push(t.variableDeclaration("var", [
     t.variableDeclarator(

lib/6to5/templates/let-scoping-return.js

@@ -0,0 +1 @@
+if (typeof RETURN === "object") return RETURN.v;

lib/6to5/templates/self-global.js

@@ -0,0 +1 @@
+var self = typeof global === "undefined" ? window : global;

lib/6to5/transformation/transform.js

@@ -5,9 +5,6 @@ var File        = require("../file");
 var _           = require("lodash");
 
 function transform(code, opts) {
-  opts = opts || {};
-  code = (code || "") + "";
-
   var file = new File(opts);
   return file.parse(code);
 }
@@ -20,7 +17,16 @@ transform._ensureTransformerNames = function (type, keys) {
   });
 };
 
-transform.transformers = {
+transform.transformers = {};
+
+transform.moduleFormatters = {
+  common: require("./modules/common"),
+  ignore: require("./modules/ignore"),
+  amd:    require("./modules/amd"),
+  umd:    require("./modules/umd")
+};
+
+_.each({
   modules:                  require("./transformers/modules"),
   propertyNameShorthand:    require("./transformers/property-name-shorthand"),
   constants:                require("./transformers/constants"),
@@ -40,28 +46,17 @@ transform.transformers = {
   letScoping:               require("./transformers/let-scoping"),
   forOf:                    require("./transformers/for-of"),
   unicodeRegex:             require("./transformers/unicode-regex"),
-  generators:               require("./transformers/generators"),
-  numericLiterals:          require("./transformers/numeric-literals"),
 
   react:                    require("./transformers/react"),
-  jsx:                      require("./transformers/jsx"),
 
   _aliasFunctions:          require("./transformers/_alias-functions"),
   _blockHoist:              require("./transformers/_block-hoist"),
   _declarations:            require("./transformers/_declarations"),
 
+  generators:               require("./transformers/generators"),
   useStrict:                require("./transformers/use-strict"),
 
   _moduleFormatter:         require("./transformers/_module-formatter")
-};
-
-transform.moduleFormatters = {
-  common: require("./modules/common"),
-  ignore: require("./modules/ignore"),
-  amd:    require("./modules/amd"),
-  umd:    require("./modules/umd")
-};
-
-_.each(transform.transformers, function (transformer, key) {
+}, function (transformer, key) {
   transform.transformers[key] = new Transformer(key, transformer);
 });

lib/6to5/transformation/transformers/_alias-functions.js

@@ -14,10 +14,9 @@ var go = function (getBody, node, file, scope) {
   };
 
   // traverse the function and find all alias functions so we can alias
-  // arguments and this if necessary
+  // `arguments` and `this` if necessary
   traverse(node, function (node) {
-    var _aliasFunction = node._aliasFunction;
-    if (!_aliasFunction) {
+    if (!node._aliasFunction) {
       if (t.isFunction(node)) {
         // stop traversal of this node as it'll be hit again by this transformer
         return false;
@@ -26,12 +25,10 @@ var go = function (getBody, node, file, scope) {
       }
     }
 
-    // traverse all child nodes of this function and find arguments and this
+    // traverse all child nodes of this function and find `arguments` and `this`
     traverse(node, function (node, parent) {
-      if (_aliasFunction === "arrows") {
-        if (t.isFunction(node) && node._aliasFunction !== "arrows") {
-          return false;
-        }
+      if (t.isFunction(node) && !node._aliasFunction) {
+        return false;
       }
 
       if (node._ignoreAliasFunctions) return;

lib/6to5/transformation/transformers/_property-literals.js

@@ -1,10 +1,11 @@
 var esutils = require("esutils");
 var t       = require("../../types");
+var _       = require("lodash");
 
 exports.Property = function (node) {
   // ignore key literals that are valid identifiers
   var key = node.key;
-  if (t.isLiteral(key) && esutils.keyword.isIdentifierName(key.value)) {
+  if (t.isLiteral(key) && _.isString(key.value) && esutils.keyword.isIdentifierName(key.value)) {
     key.type = "Identifier";
     key.name = key.value;
     delete key.value;

lib/6to5/transformation/transformers/array-comprehension.js

@@ -1,5 +1,6 @@
 var util = require("../../util");
 var t    = require("../../types");
+var _    = require("lodash");
 
 var singleArrayExpression = function (node) {
   var block = node.blocks[0];
@@ -13,7 +14,13 @@ var singleArrayExpression = function (node) {
     ARRAY:     block.right,
     KEY:       block.left
   });
-  result._aliasFunction = true;
+
+  _.each([result.callee.object, result], function (call) {
+    if (t.isCallExpression(call)) {
+      call.arguments[0]._aliasFunction = true;
+    }
+  });
+
   return result;
 };
 
@@ -23,7 +30,7 @@ var multiple = function (node, file) {
   var container = util.template("array-comprehension-container", {
     KEY: uid
   });
-  container._aliasFunction = true;
+  container.callee.expression._aliasFunction = true;
 
   var block = container.callee.expression.body;
   var body  = block.body;

lib/6to5/transformation/transformers/arrow-functions.js

@@ -3,7 +3,7 @@ var t = require("../../types");
 exports.ArrowFunctionExpression = function (node) {
   t.ensureBlock(node);
 
-  node._aliasFunction = "arrows";
+  node._aliasFunction = true;
   node.expression = false;
   node.type = "FunctionExpression";
 

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

@@ -5,12 +5,12 @@ var _        = require("lodash");
 
 exports.ClassDeclaration = function (node, parent, file, scope) {
   return t.variableDeclaration("var", [
-    t.variableDeclarator(node.id, buildClass(node, file, scope))
+    t.variableDeclarator(node.id, new Class(node, file, scope).run())
   ]);
 };
 
 exports.ClassExpression = function (node, parent, file, scope) {
-  return buildClass(node, file, scope);
+  return new Class(node, file, scope).run();
 };
 
 var getMemberExpressionObject = function (node) {
@@ -20,31 +20,59 @@ var getMemberExpressionObject = function (node) {
   return node;
 };
 
-var buildClass = function (node, file, scope) {
-  var superName = node.superClass;
-  var className = node.id || t.identifier(file.generateUid("class", scope));
+/**
+ * Description
+ *
+ * @param {Node} node
+ * @param {File} file
+ * @param {Scope} scope
+ */
 
-  var superClassArgument = node.superClass;
-  var superClassCallee   = node.superClass;
+function Class(node, file, scope) {
+  this.scope = scope;
+  this.node  = node;
+  this.file  = file;
+
+  this.instanceMutatorMap = {};
+  this.staticMutatorMap   = {};
+  this.hasConstructor     = false;
+  this.className          = node.id || t.identifier(file.generateUid("class", scope));
+  this.superName          = node.superClass;
+}
+
+/**
+ * Description
+ *
+ * @returns {Array}
+ */
+
+Class.prototype.run = function () {
+  var superClassArgument = this.superName;
+  var superClassCallee   = this.superName;
+  var superName          = this.superName;
+  var className          = this.className;
+  var file               = this.file;
 
   if (superName) {
     if (t.isMemberExpression(superName)) {
       superClassArgument = superClassCallee = getMemberExpressionObject(superName);
     } else if (!t.isIdentifier(superName)) {
       superClassArgument = superName;
-      superClassCallee   = superName = t.identifier(file.generateUid("ref", scope));
+      superClassCallee   = superName = t.identifier(file.generateUid("ref", this.scope));
     }
   }
 
+  this.superName = superName;
+
   var container = util.template("class", {
     CLASS_NAME: className
   });
 
   var block       = container.callee.expression.body;
-  var body        = block.body;
-  var constructor = body[0].declarations[0].init;
+  var body        = this.body = block.body;
+  var constructor = this.constructor = body[0].declarations[0].init;
 
-  if (node.id) constructor.id = className;
+  if (this.node.id) constructor.id = className;
 
   var returnStatement = body.pop();
 
@@ -55,14 +83,7 @@ var buildClass = function (node, file, scope) {
     container.callee.expression.params.push(superClassCallee);
   }
 
-  buildClassBody({
-    file:        file,
-    body:        body,
-    node:        node,
-    className:   className,
-    superName:   superName,
-    constructor: constructor,
-  });
+  this.buildBody();
 
   if (body.length === 1) {
     // only a constructor so no need for a closure container
@@ -73,49 +94,29 @@ var buildClass = function (node, file, scope) {
   }
 };
 
-var buildClassBody = function (opts) {
-  var file        = opts.file;
-  var body        = opts.body;
-  var node        = opts.node;
-  var constructor = opts.constructor;
-  var className   = opts.className;
-  var superName   = opts.superName;
+/**
+ * Description
+ */
 
-  var instanceMutatorMap = {};
-  var staticMutatorMap   = {};
-  var hasConstructor     = false;
-
-  var classBody = node.body.body;
+Class.prototype.buildBody = function () {
+  var constructor = this.constructor;
+  var className   = this.className;
+  var superName   = this.superName;
+  var classBody   = this.node.body.body;
+  var body        = this.body;
+  var self        = this;
 
   _.each(classBody, function (node) {
-    var methodName = node.key;
-    var method     = node.value;
-
-    replaceInstanceSuperReferences(superName, node);
+    self.replaceInstanceSuperReferences(node);
 
     if (node.key.name === "constructor") {
-      if (node.kind === "") {
-        hasConstructor = true;
-        addConstructor(constructor, method);
-      } else {
-        throw file.errorWithNode(node, "illegal kind for constructor method");
-      }
+      self.pushConstructor(node);
     } else {
-      var mutatorMap = instanceMutatorMap;
-      if (node.static) mutatorMap = staticMutatorMap;
-
-      var kind = node.kind;
-
-      if (kind === "") {
-        kind = "value";
-        util.pushMutatorMap(mutatorMap, methodName, "writable", t.identifier("true"));
-      }
-
-      util.pushMutatorMap(mutatorMap, methodName, kind, node);
+      self.pushMethod(node);
     }
   });
 
-  if (!hasConstructor && superName) {
+  if (!this.hasConstructor && superName) {
     constructor.body.body.push(util.template("class-super-constructor-call", {
       SUPER_NAME: superName
     }, true));
@@ -124,16 +125,16 @@ var buildClassBody = function (opts) {
   var instanceProps;
   var staticProps;
 
-  if (!_.isEmpty(instanceMutatorMap)) {
+  if (!_.isEmpty(this.instanceMutatorMap)) {
     var protoId = util.template("prototype-identifier", {
       CLASS_NAME: className
     });
 
-    instanceProps = util.buildDefineProperties(instanceMutatorMap, protoId);
+    instanceProps = util.buildDefineProperties(this.instanceMutatorMap, protoId);
   }
 
-  if (!_.isEmpty(staticMutatorMap)) {
-    staticProps = util.buildDefineProperties(staticMutatorMap, className);
+  if (!_.isEmpty(this.staticMutatorMap)) {
+    staticProps = util.buildDefineProperties(this.staticMutatorMap, className);
   }
 
   if (instanceProps || staticProps) {
@@ -143,17 +144,50 @@ var buildClassBody = function (opts) {
     if (instanceProps) args.push(instanceProps);
 
     body.push(t.expressionStatement(
-      t.callExpression(file.addDeclaration("class-props"), args)
+      t.callExpression(this.file.addDeclaration("class-props"), args)
     ));
   }
 };
 
-var superIdentifier = function (superName, methodNode, node, parent) {
-  var methodName = methodNode.key;
+/**
+ * Push a method to it's respective mutatorMap.
+ *
+ * @param {Node} node MethodDefinition
+ */
 
-  if (parent.property === node) {
+Class.prototype.pushMethod = function (node) {
+  var methodName = node.key;
+
+  var mutatorMap = this.instanceMutatorMap;
+  if (node.static) mutatorMap = this.staticMutatorMap;
+
+  var kind = node.kind;
+
+  if (kind === "") {
+    kind = "value";
+    util.pushMutatorMap(mutatorMap, methodName, "writable", t.identifier("true"));
+  }
+
+  util.pushMutatorMap(mutatorMap, methodName, kind, node);
+};
+
+/**
+ * Given a `methodNode`, produce a `MemberExpression` super class reference.
+ *
+ * @param {Node} methodNode MethodDefinition
+ * @param {Node} node Identifier
+ * @param {Node} parent
+ *
+ * @returns {Node}
+ */
+
+Class.prototype.superIdentifier = function (methodNode, id, parent) {
+  var methodName = methodNode.key;
+  var superName  = this.superName || t.identifier("Function");
+
+  if (parent.property === id) {
     return;
-  } else if (t.isCallExpression(parent, { callee: node })) {
+  } else if (t.isCallExpression(parent, { callee: id })) {
     // super(); -> ClassName.prototype.MethodName.call(this);
     parent.arguments.unshift(t.thisExpression());
 
@@ -161,15 +195,15 @@ var superIdentifier = function (superName, methodNode, node, parent) {
       // constructor() { super(); }
       return t.memberExpression(superName, t.identifier("call"));
     } else {
-      node = superName;
+      id = superName;
 
       // foo() { super(); }
       if (!methodNode.static) {
-        node = t.memberExpression(node, t.identifier("prototype"));
+        id = t.memberExpression(id, t.identifier("prototype"));
       }
 
-      node = t.memberExpression(node, methodName, methodNode.computed);
-      return t.memberExpression(node, t.identifier("call"));
+      id = t.memberExpression(id, methodName, methodNode.computed);
+      return t.memberExpression(id, t.identifier("call"));
     }
   } else if (t.isMemberExpression(parent) && !methodNode.static) {
     // super.test -> ClassName.prototype.test
@@ -179,31 +213,50 @@ var superIdentifier = function (superName, methodNode, node, parent) {
   }
 };
 
-var replaceInstanceSuperReferences = function (superName, methodNode) {
-  var method = methodNode.value;
+/**
+ * Replace all `super` references with a reference to our `superClass`.
+ *
+ * @param {Node} methodNode MethodDefinition
+ */
 
-  superName = superName || t.identifier("Function");
+Class.prototype.replaceInstanceSuperReferences = function (methodNode) {
+  var method = methodNode.value;
+  var self = this;
 
   traverse(method, function (node, parent) {
     if (t.isIdentifier(node, { name: "super" })) {
-      return superIdentifier(superName, methodNode, node, parent);
+      return self.superIdentifier(methodNode, node, parent);
     } else if (t.isCallExpression(node)) {
       var callee = node.callee;
       if (!t.isMemberExpression(callee)) return;
       if (callee.object.name !== "super") return;
 
-      //  super.test(); -> ClassName.prototype.MethodName.call(this);
-      callee.property.name = callee.property.name + ".call";
+      // super.test(); -> ClassName.prototype.MethodName.call(this);
+      callee.property = t.memberExpression(callee.property, t.identifier("call"));
       node.arguments.unshift(t.thisExpression());
     }
   });
 };
 
-var addConstructor = function (construct, method) {
-  construct.defaults = method.defaults;
-  construct.params   = method.params;
-  construct.body     = method.body;
-  construct.rest     = method.rest;
+/**
+ * Replace the constructor body of our class.
+ *
+ * @param {Node} method MethodDefinition
+ */
 
-  t.inherits(construct, method);
+Class.prototype.pushConstructor = function (method) {
+  if (method.kind !== "") {
+    throw this.file.errorWithNode(method, "illegal kind for constructor method");
+  }
+
+  var construct = this.constructor;
+  var fn        = method.value;
+
+  this.hasConstructor = true;
+  t.inherits(construct, fn);
+
+  construct.defaults = fn.defaults;
+  construct.params   = fn.params;
+  construct.body     = fn.body;
+  construct.rest     = fn.rest;
 };

lib/6to5/transformation/transformers/computed-property-names.js

@@ -29,7 +29,7 @@ exports.ObjectExpression = function (node, parent, file) {
   var containerCallee = container.callee.expression;
   var containerBody = containerCallee.body.body;
 
-  containerCallee._aliasFunction = "arrows";
+  containerCallee._aliasFunction = true;
 
   _.each(computed, function (prop) {
     containerBody.unshift(

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

@@ -17,10 +17,14 @@ exports.ForStatement = function (node, parent, file) {
     });
   };
 
+  var getIds = function (node) {
+    return t.getIds(node, false, ["MemberExpression"]);
+  };
+
   _.each(node.body, function (child) {
     if (child && t.isVariableDeclaration(child, { kind: "const" })) {
       _.each(child.declarations, function (declar) {
-        _.each(t.getIds(declar), function (name) {
+        _.each(getIds(declar), function (name) {
           check(declar, [name]);
           constants.push(name);
         });
@@ -39,7 +43,7 @@ exports.ForStatement = function (node, parent, file) {
     if (child._ignoreConstant) return;
 
     if (t.isVariableDeclarator(child) || t.isDeclaration(child) || t.isAssignmentExpression(child)) {
-      check(child, t.getIds(child));
+      check(child, getIds(child));
     }
   });
 };

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

@@ -11,21 +11,7 @@ var buildVariableAssign = function (kind, id, init) {
   }
 };
 
-var normalise = function (node) {
-  if (t.isParenthesizedExpression(node)) {
-    return node.expression;
-  } else {
-    return node;
-  }
-};
-
-var isPattern = function (node) {
-  return t.isPattern(normalise(node));
-};
-
 var push = function (kind, nodes, elem, parentId) {
-  elem = normalise(elem);
-
   if (t.isObjectPattern(elem)) {
     pushObjectPattern(kind, nodes, elem, parentId);
   } else if (t.isArrayPattern(elem)) {
@@ -42,7 +28,7 @@ var pushObjectPattern = function (kind, nodes, pattern, parentId) {
     var pattern2   = prop.value;
     var patternId2 = t.memberExpression(parentId, prop.key);
 
-    if (isPattern(pattern2)) {
+    if (t.isPattern(pattern2)) {
       push(kind, nodes, pattern2, patternId2);
     } else {
       nodes.push(buildVariableAssign(kind, pattern2, patternId2));
@@ -94,7 +80,7 @@ exports.ForOfStatement = function (node, parent, file, scope) {
   if (!t.isVariableDeclaration(declar)) return;
 
   var pattern = declar.declarations[0].id;
-  if (!isPattern(pattern)) return;
+  if (!t.isPattern(pattern)) return;
 
   var key = t.identifier(file.generateUid("ref", scope));
   node.left = t.variableDeclaration(declar.kind, [
@@ -117,7 +103,7 @@ exports.Function = function (node, parent, file, scope) {
   var hasDestructuring = false;
 
   node.params = node.params.map(function (pattern) {
-    if (!isPattern(pattern)) return pattern;
+    if (!t.isPattern(pattern)) return pattern;
 
     hasDestructuring = true;
     var parentId = t.identifier(file.generateUid("ref", scope));
@@ -146,7 +132,7 @@ exports.ExpressionStatement = function (node, parent, file, scope) {
   var expr = node.expression;
   if (expr.type !== "AssignmentExpression") return;
 
-  if (!isPattern(expr.left)) return;
+  if (!t.isPattern(expr.left)) return;
 
   var nodes = [];
 
@@ -167,7 +153,7 @@ exports.VariableDeclaration = function (node, parent, file, scope) {
 
   var hasPattern = false;
   _.each(node.declarations, function (declar) {
-    if (isPattern(declar.id)) {
+    if (t.isPattern(declar.id)) {
       hasPattern = true;
       return false;
     }

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

@@ -1,89 +0,0 @@
-// Based upon the excellent jsx-transpiler by Ingvar Stepanyan (RReverser)
-// https://github.com/RReverser/jsx-transpiler
-
-var esutils = require("esutils");
-var t       = require("../../types");
-var _       = require("lodash");
-
-var JSX_ANNOTATION_REGEX = /^\*\s*@jsx\s+([^\s]+)/;
-
-exports.Program = function (node, parent, file) {
-  var jsx = "React.DOM";
-
-  // looking for namespace annotation
-  _.each(node.leadingComments, function (comment) {
-    var matches = JSX_ANNOTATION_REGEX.exec(comment.value);
-    if (matches) jsx = matches[1];
-  });
-
-  // prebuilding AST node
-  file.jsx = jsx.split(".").map(t.identifier).reduce(function (object, property) {
-    return t.memberExpression(object, property);
-  });
-};
-
-exports.XJSIdentifier = function (node) {
-  if (esutils.keyword.isIdentifierName(node.name)) {
-    node.type = "Identifier";
-  } else {
-    return t.literal(node.name);
-  }
-};
-
-exports.XJSNamespacedName = function () {
-  throw new Error("Namespace tags are not supported. ReactJSX is not XML.");
-};
-
-exports.XJSMemberExpression = {
-  exit: function (node) {
-    node.computed = t.isLiteral(node.property);
-    node.type = "MemberExpression";
-  }
-};
-
-exports.XJSExpressionContainer = function (node) {
-  return node.expression;
-};
-
-exports.XJSAttribute = {
-  exit: function (node) {
-    var value = node.value || t.literal(true);
-    return t.property("init", node.name, value);
-  }
-};
-
-exports.XJSOpeningElement = {
-  exit: function (node, parent, file) {
-    var tagExpr = node.name;
-
-    if (t.isIdentifier(tagExpr)) {
-      var tagName = tagExpr.name;
-
-      if (/[a-z]/.exec(tagName[0]) || _.contains(tagName, "-")) {
-        tagExpr = t.memberExpression(file.jsx, tagExpr);
-      }
-    }
-
-    var props = node.attributes;
-    if (props.length) {
-      props = t.objectExpression(props);
-    } else {
-      props = t.literal(null);
-    }
-
-    return t.callExpression(tagExpr, [props]);
-  }
-};
-
-exports.XJSElement = {
-  exit: function (node) {
-    var callExpr = node.openingElement;
-    var children = node.children;
-
-    _.each(children, function (child) {
-      callExpr.arguments.push(child);
-    });
-
-    return t.inherits(callExpr, node);
-  }
-};

lib/6to5/transformation/transformers/let-scoping.js

@@ -1,4 +1,5 @@
 var traverse = require("../../traverse");
+var util     = require("../../util");
 var t        = require("../../types");
 var _        = require("lodash");
 
@@ -16,6 +17,12 @@ var isVar = function (node) {
   return t.isVariableDeclaration(node, { kind: "var" }) && !isLet(node);
 };
 
+var standardiseLets = function (declars) {
+  _.each(declars, function (declar) {
+    delete declar._let;
+  });
+};
+
 exports.VariableDeclaration = function (node) {
   isLet(node);
 };
@@ -32,7 +39,8 @@ exports.For = function (node, parent, file, scope) {
     node.label = parent.label;
   }
 
-  run(node, node.body, parent, file, scope);
+  var letScoping = new LetScoping(node, node.body, parent, file, scope);
+  letScoping.run();
 
   if (node.label && !t.isLabeledStatement(parent)) {
     // we've been given a label so let's wrap ourselves
@@ -42,12 +50,98 @@ exports.For = function (node, parent, file, scope) {
 
 exports.BlockStatement = function (block, parent, file, scope) {
   if (!t.isFor(parent)) {
-    run(false, block, parent, file, scope);
+    var letScoping = new LetScoping(false, block, parent, file, scope);
+    letScoping.run();
   }
 };
 
-var noClosure = function (letDeclars, block, replacements) {
-  standardiseLets(letDeclars);
+/**
+ * Description
+ *
+ * @param {Boolean|Node} forParent
+ * @param {Node} block
+ * @param {Node} parent
+ * @param {File} file
+ * @param {Scope} scope
+ */
+
+function LetScoping(forParent, block, parent, file, scope) {
+  this.forParent = forParent;
+  this.parent    = parent;
+  this.scope     = scope;
+  this.block     = block;
+  this.file      = file;
+
+  this.letReferences = {};
+  this.body          = [];
+  this.info          = this.getInfo();
+}
+
+/**
+ * Start the ball rolling.
+ */
+
+LetScoping.prototype.run = function () {
+  var block = this.block;
+
+  if (block._letDone) return;
+  block._letDone = true;
+
+  // this is a block within a `Function` so we can safely leave it be
+  if (t.isFunction(this.parent)) return;
+
+  // this block has no let references so let's clean up
+  if (!this.info.keys.length) return this.noClosure();
+
+  // returns whether or not there are any outside let references within any
+  // functions
+  var referencesInClosure = this.getLetReferences();
+
+  // no need for a closure so let's clean up
+  if (!referencesInClosure) return this.noClosure();
+
+  // if we're inside of a for loop then we search to see if there are any
+  // `break`s, `continue`s, `return`s etc
+  this.has = this.checkFor();
+
+  // hoist var references to retain scope
+  this.hoistVarDeclarations();
+
+  // set let references to plain var references
+  standardiseLets(this.info.declarators);
+
+  // turn letReferences into an array
+  var letReferences = _.values(this.letReferences);
+
+  // build the closure that we're going to wrap the block with
+  var fn = t.functionExpression(null, letReferences, t.blockStatement(block.body));
+  fn._aliasFunction = true;
+
+  // replace the current block body with the one we're going to build
+  block.body = this.body;
+
+  // change upper scope references with their uid if they have one
+  var params = this.getParams(letReferences);
+
+  // build a call and a unique id that we can assign the return value to
+  var call = t.callExpression(fn, params);
+  var ret  = t.identifier(this.file.generateUid("ret", this.scope));
+
+  this.build(ret, call);
+};
+
+/**
+ * There are no let references accessed within a closure so we can just traverse
+ * through this block and replace all references that exist in a high scope to
+ * their uids.
+ */
+
+LetScoping.prototype.noClosure = function () {
+  var replacements = this.info.duplicates;
+  var declarators  = this.info.declarators;
+  var block        = this.block;
+
+  standardiseLets(declarators);
 
   if (_.isEmpty(replacements)) return;
 
@@ -58,13 +152,17 @@ var noClosure = function (letDeclars, block, replacements) {
   });
 };
 
-var standardiseLets = function (declars) {
-  _.each(declars, function (declar) {
-    delete declar._let;
-  });
-};
+/**
+ * Description
+ *
+ * @returns {Object}
+ */
+
+LetScoping.prototype.getInfo = function () {
+  var block = this.block;
+  var scope = this.scope;
+  var file  = this.file;
 
-var getInfo = function (block, file, scope) {
   var opts = {
     // array of `Identifier` names of let variables that appear lexically out of
     // this scope but should be accessible - eg. `ForOfStatement`.left
@@ -110,15 +208,23 @@ var getInfo = function (block, file, scope) {
   return opts;
 };
 
-var checkFor = function (forParent, block) {
+/**
+ * If we're inside of a `For*Statement` then traverse it and check if it has one
+ * of the following node types `ReturnStatement`, `BreakStatement`,
+ * `ContinueStatement` and replace it with a return value we can track later on.
+ *
+ * @returns {Object}
+ */
+
+LetScoping.prototype.checkFor = function () {
   var has = {
     hasContinue: false,
     hasReturn:   false,
     hasBreak:    false,
   };
 
-  if (forParent) {
-    traverse(block, function (node) {
+  if (this.forParent) {
+    traverse(this.block, function (node) {
       var replace;
 
       if (t.isFunction(node) || t.isFor(node)) {
@@ -132,7 +238,7 @@ var checkFor = function (forParent, block) {
       } else if (t.isReturnStatement(node)) {
         has.hasReturn = true;
         replace = t.returnStatement(t.objectExpression([
-          t.property("init", t.identifier("v"), node.argument)
+          t.property("init", t.identifier("v"), node.argument || t.identifier("undefined"))
         ]));
       }
 
@@ -143,38 +249,59 @@ var checkFor = function (forParent, block) {
   return has;
 };
 
-var hoistVarDeclarations = function (block, pushDeclar) {
-  traverse(block, function (node) {
+/**
+ * Hoist all var declarations in this block to before it so they retain scope
+ * once we wrap everything is in a closure.
+ */
+
+LetScoping.prototype.hoistVarDeclarations = function () {
+  var self = this;
+  traverse(this.block, function (node) {
     if (t.isForStatement(node)) {
       if (isVar(node.init)) {
-        node.init = t.sequenceExpression(pushDeclar(node.init));
+        node.init = t.sequenceExpression(self.pushDeclar(node.init));
       }
     } else if (t.isFor(node)) {
       if (isVar(node.left)) {
         node.left = node.left.declarations[0].id;
       }
     } else if (isVar(node)) {
-      return pushDeclar(node).map(t.expressionStatement);
+      return self.pushDeclar(node).map(t.expressionStatement);
     } else if (t.isFunction(node)) {
       return false;
     }
   });
 };
 
-var getParams = function (info, letReferences) {
-  var params = _.cloneDeep(letReferences);
+/**
+ * Build up a parameter list that we'll call our closure wrapper with, replacing
+ * all duplicate ids with their uid.
+ *
+ * @param {Array} params
+ * @returns {Array}
+ */
+
+LetScoping.prototype.getParams = function (params) {
+  var info = this.info;
+  params = _.cloneDeep(params);
   _.each(params, function (param) {
     param.name = info.duplicates[param.name] || param.name;
   });
   return params;
 };
 
-var getLetReferences = function (block, info, letReferences) {
+/**
+ * Get all let references within this block. Stopping whenever we reach another
+ * block.
+ */
+
+LetScoping.prototype.getLetReferences = function () {
   var closurify = false;
+  var self = this;
 
   // traverse through this block, stopping on functions and checking if they
   // contain any outside let references
-  traverse(block, function (node, parent, scope) {
+  traverse(this.block, function (node, parent, scope) {
     if (t.isFunction(node)) {
       traverse(node, function (node, parent) {
         // not an identifier so we have no use
@@ -190,10 +317,10 @@ var getLetReferences = function (block, info, letReferences) {
         closurify = true;
 
         // this key doesn't appear just outside our scope
-        if (!_.contains(info.outsideKeys, node.name)) return;
+        if (!_.contains(self.info.outsideKeys, node.name)) return;
 
         // push this badboy
-        letReferences[node.name] = node;
+        self.letReferences[node.name] = node;
       });
 
       return false;
@@ -205,121 +332,100 @@ var getLetReferences = function (block, info, letReferences) {
   return closurify;
 };
 
-var buildPushDeclar = function (body) {
-  return function (node) {
-    body.push(t.variableDeclaration(node.kind, node.declarations.map(function (declar) {
-      return t.variableDeclarator(declar.id);
-    })));
+/**
+ * Turn a `VariableDeclaration` into an array of `AssignmentExpressions` with
+ * their declarations hoisted to before the closure wrapper.
+ *
+ * @param {Node} node VariableDeclaration
+ * @returns {Array}
+ */
 
-    var replace = [];
+LetScoping.prototype.buildPushDeclar = function (node) {
+  this.body.push(t.variableDeclaration(node.kind, node.declarations.map(function (declar) {
+    return t.variableDeclarator(declar.id);
+  })));
 
-    _.each(node.declarations, function (declar) {
-      if (!declar.init) return;
+  var replace = [];
 
-      var expr = t.assignmentExpression("=", declar.id, declar.init);
-      replace.push(t.inherits(expr, declar));
-    });
+  _.each(node.declarations, function (declar) {
+    if (!declar.init) return;
 
-    return replace;
-  };
+    var expr = t.assignmentExpression("=", declar.id, declar.init);
+    replace.push(t.inherits(expr, declar));
+  });
+
+  return replace;
 };
 
-var run = function (forParent, block, parent, file, scope) {
-  if (block._letDone) return;
-  block._letDone = true;
-
-  var info = getInfo(block, file, scope);
-  var declarators = info.declarators;
-  var letKeys = info.keys;
-
-  // this is a block within a `Function` so we can safely leave it be
-  if (t.isFunction(parent)) return;
-
-  // this block has no let references so let's clean up
-  if (!letKeys.length) return noClosure(declarators, block, info.duplicates);
-
-  // outside let references that we need to wrap
-  var letReferences = {};
-
-  // returns whether or not there are any outside let references within any
-  // functions
-  var closurify = getLetReferences(block, info, letReferences);
-
-  letReferences = _.values(letReferences);
-
-  // no need for a closure so let's clean up
-  if (!closurify) return noClosure(declarators, block, info.duplicates);
-
-  // if we're inside of a for loop then we search to see if there are any
-  // `break`s, `continue`s, `return`s etc
-  var has = checkFor(forParent, block);
-
-  var body = [];
-
-  // hoist a `VariableDeclaration` and add `AssignmentExpression`s in it's place
-  var pushDeclar = buildPushDeclar(body);
-
-  // hoist var references to retain scope
-  hoistVarDeclarations(block, pushDeclar);
-
-  // set let references to plain var references
-  standardiseLets(declarators);
-
-  // build the closure that we're going to wrap the block with
-  var fn = t.functionExpression(null, letReferences, t.blockStatement(block.body));
-  fn._aliasFunction = true;
-
-  // replace the current block body with the one we've built
-  block.body = body;
-
-  // change duplicate let references to their uid if they have one
-  var params = getParams(info, letReferences);
-
-  var call = t.callExpression(fn, params);
-  var ret  = t.identifier(file.generateUid("ret", scope));
+/**
+ * Push the closure to the body.
+ *
+ * @param {Node} ret Identifier
+ * @param {Node} call CallExpression
+ */
 
+LetScoping.prototype.build = function (ret, call) {
+  var has = this.has;
   if (has.hasReturn || has.hasBreak || has.hasContinue) {
-    body.push(t.variableDeclaration("var", [
-      t.variableDeclarator(ret, call)
-    ]));
+    this.buildHas(ret, call);
+  } else {
+    this.body.push(t.expressionStatement(call));
+  }
+};
 
-    var retCheck;
+/**
+ * Description
+ *
+ * @param {Node} ret Identifier
+ * @param {Node} call CallExpression
+ */
 
-    if (has.hasReturn) {
-      // typeof ret === "object"
-      retCheck = t.ifStatement(
-        t.binaryExpression("===", t.unaryExpression("typeof", ret, true), t.literal("object")),
-        t.returnStatement(t.memberExpression(ret, t.identifier("v")))
-      );
+LetScoping.prototype.buildHas = function (ret, call) {
+  var body = this.body;
 
-      // there's no `break` or `continue` so we can just push in the `if`
-      if (!has.hasBreak && !has.hasContinue) {
-        body.push(retCheck);
-      }
+  body.push(t.variableDeclaration("var", [
+    t.variableDeclarator(ret, call)
+  ]));
+
+  var forParent = this.forParent;
+  var retCheck;
+  var has = this.has;
+  var cases = [];
+
+  if (has.hasReturn) {
+    // typeof ret === "object"
+    retCheck = util.template("let-scoping-return", {
+      RETURN: ret
+    });
+  }
+
+  if (has.hasBreak || has.hasContinue) {
+    // ensure that the parent has a label as we're building a switch and we
+    // need to be able to access it
+    var label = forParent.label = forParent.label || t.identifier(this.file.generateUid("loop", this.scope));
+
+    if (has.hasBreak) {
+      cases.push(t.switchCase(t.literal("break"), [t.breakStatement(label)]));
     }
 
-    if (has.hasBreak || has.hasContinue) {
-      // ensure that the parent has a label as we're building a switch and we
-      // need to be able to access it
-      var label = forParent.label = forParent.label || t.identifier(file.generateUid("loop", scope));
+    if (has.hasContinue) {
+      cases.push(t.switchCase(t.literal("continue"), [t.continueStatement(label)]));
+    }
 
-      var cases = [];
-
-      if (has.hasBreak) {
-        cases.push(t.switchCase(t.literal("break"), [t.breakStatement(label)]));
-      }
-
-      if (has.hasContinue) {
-        cases.push(t.switchCase(t.literal("continue"), [t.continueStatement(label)]));
-      }
-
-      if (has.hasReturn) {
-        cases.push(t.switchCase(null, [retCheck]));
-      }
+    if (has.hasReturn) {
+      cases.push(t.switchCase(null, [retCheck]));
+    }
 
+    if (cases.length === 1) {
+      var single = cases[0];
+      body.push(t.ifStatement(
+        t.binaryExpression("===", ret, single.test),
+        single.consequent[0]
+      ));
+    } else {
       body.push(t.switchStatement(ret, cases));
     }
   } else {
-    body.push(t.expressionStatement(call));
+    if (has.hasReturn) body.push(retCheck);
   }
 };

lib/6to5/transformation/transformers/numeric-literals.js

@@ -1,6 +0,0 @@
-var _ = require("lodash");
-
-exports.Literal = function (node) {
-  // TODO: remove this when the new code generator is released
-  if (_.isNumber(node.value)) delete node.raw;
-};

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

@@ -1,5 +1,124 @@
-var t = require("../../types");
-var _ = require("lodash");
+// Based upon the excellent jsx-transpiler by Ingvar Stepanyan (RReverser)
+// https://github.com/RReverser/jsx-transpiler
+
+// jsx
+
+var esutils = require("esutils");
+var t       = require("../../types");
+var _       = require("lodash");
+
+exports.XJSIdentifier = function (node) {
+  if (esutils.keyword.isIdentifierName(node.name)) {
+    node.type = "Identifier";
+  } else {
+    return t.literal(node.name);
+  }
+};
+
+exports.XJSNamespacedName = function (node, parent, file) {
+  throw file.errorWithNode(node, "Namespace tags are not supported. ReactJSX is not XML.");
+};
+
+exports.XJSMemberExpression = {
+  exit: function (node) {
+    node.computed = t.isLiteral(node.property);
+    node.type = "MemberExpression";
+  }
+};
+
+exports.XJSExpressionContainer = function (node) {
+  return node.expression;
+};
+
+exports.XJSAttribute = {
+  exit: function (node) {
+    var value = node.value || t.literal(true);
+    return t.property("init", node.name, value);
+  }
+};
+
+exports.XJSOpeningElement = {
+  exit: function (node) {
+    var tagExpr = node.name;
+    var args = [];
+
+    var tagName;
+    if (t.isIdentifier(tagExpr)) {
+      tagName = tagExpr.name;
+    } else if (t.isLiteral(tagExpr)) {
+      tagName = tagExpr.value;
+    }
+
+    if (tagName && (/[a-z]/.exec(tagName[0]) || _.contains(tagName, "-"))) {
+      args.push(t.literal(tagName));
+    } else {
+      args.push(tagExpr);
+    }
+
+    var props = node.attributes;
+    if (props.length) {
+      var _props = [];
+      var objs = [];
+
+      var pushProps = function () {
+        if (!_props.length) return;
+
+        objs.push(t.objectExpression(_props));
+        _props = [];
+      };
+
+      while (props.length) {
+        var prop = props.shift();
+        if (t.isXJSSpreadAttribute(prop)) {
+          pushProps();
+          objs.push(prop.argument);
+        } else {
+          _props.push(prop);
+        }
+      }
+
+      pushProps();
+
+      if (objs.length === 1) {
+        props = objs[0];
+      } else {
+        if (!t.isObjectExpression(objs[0])) {
+          objs.unshift(t.objectExpression([]));
+        }
+
+        props = t.callExpression(
+          t.memberExpression(t.identifier("React"), t.identifier("__spread")),
+          objs
+        );
+      }
+    } else {
+      props = t.literal(null);
+    }
+
+    args.push(props);
+
+    tagExpr = t.memberExpression(t.identifier("React"), t.identifier("createElement"));
+    return t.callExpression(tagExpr, args);
+  }
+};
+
+exports.XJSElement = {
+  exit: function (node) {
+    var callExpr = node.openingElement;
+
+    var childrenToRender = node.children.filter(function(child) {
+      return !(t.isLiteral(child) && _.isString(child.value) && child.value.match(/^[ \t]*[\r\n][ \t\r\n]*$/));
+    });
+
+    _.each(childrenToRender, function (child) {
+      callExpr.arguments.push(child);
+    });
+
+    return t.inherits(callExpr, node);
+  }
+};
+
+// display names
 
 var addDisplayName = function (id, call) {
   if (!call || !t.isCallExpression(call)) return;

lib/6to5/traverse/index.js

@@ -40,8 +40,6 @@ function traverse(parent, callbacks, opts) {
       // type is blacklisted
       if (_.contains(blacklistTypes, node.type)) return;
 
-      var result;
-
       // replace node
       var maybeReplace = function (result) {
         if (result === false) return;
@@ -54,12 +52,11 @@ function traverse(parent, callbacks, opts) {
 
       // enter
       if (callbacks.enter) {
-        result = callbacks.enter(node, parent, opts2.scope);
+        var result = callbacks.enter(node, parent, opts2.scope);
+        maybeReplace(result);
 
         // stop iteration
         if (result === false) return;
-
-        maybeReplace(result);
       }
 
       // traverse node
@@ -114,25 +111,18 @@ traverse.hasType = function (tree, type, blacklistTypes) {
 
   var has = false;
 
-  if (_.isArray(tree)) {
-    // array of nodes, find the first
-    return tree.some(function (node) {
-      return traverse.hasType(node, type, blacklistTypes);
-    });
-  } else {
-    // the node we're searching in is blacklisted
-    if (_.contains(blacklistTypes, tree.type)) return false;
+  // the node we're searching in is blacklisted
+  if (_.contains(blacklistTypes, tree.type)) return false;
 
-    // the type we're looking for is the same as the passed node
-    if (tree.type === type) return true;
+  // the type we're looking for is the same as the passed node
+  if (tree.type === type) return true;
 
-    traverse(tree, function (node) {
-      if (node.type === type) {
-        has = true;
-        return false;
-      }
-    }, { blacklist: blacklistTypes });
-  }
+  traverse(tree, function (node) {
+    if (node.type === type) {
+      has = true;
+      return false;
+    }
+  }, { blacklist: blacklistTypes });
 
   return has;
 };

lib/6to5/types/index.js

@@ -156,37 +156,26 @@ t.toBlock = function (node, parent) {
   return t.blockStatement(node);
 };
 
-t.getIds = function (node, map) {
+t.getIds = function (node, map, ignoreTypes) {
+  ignoreTypes = ignoreTypes || [];
+
   var search = [node];
   var ids    = {};
 
   while (search.length) {
     var id = search.shift();
+    if (!id) continue;
+    if (_.contains(ignoreTypes, id.type)) continue;
+
+    var nodeKey = t.getIds.nodes[id.type];
+    var arrKey  = t.getIds.arrays[id.type];
 
     if (t.isIdentifier(id)) {
       ids[id.name] = id;
-    } else if (t.isArrayPattern(id)) {
-      _.each(id.elements, function (elem) {
-        search.push(elem);
-      });
-    } else if (t.isAssignmentExpression(id)) {
-      search.push(id.left);
-    } else if (t.isObjectPattern(id)) {
-      _.each(id.properties, function (prop) {
-        search.push(prop.value);
-      });
-    } else if (t.isVariableDeclaration(id)) {
-      search = search.concat(id.declarations);
-    } else if (t.isImportSpecifier(id) || t.isExportSpecifier(id) || t.isVariableDeclarator(id) || t.isFunctionDeclaration(id) || t.isClassDeclaration(id)) {
-      search.push(id.id);
-    } else if (t.isSpreadElement(id)) {
-      search.push(id.argument);
-    } else if (t.isExportDeclaration(id) || t.isImportDeclaration(id)) {
-      search = search.concat(id.specifiers);
-    } else if (t.isMemberExpression(id)) {
-      search.push(id.object);
-    } else if (t.isParenthesizedExpression(id)) {
-      search.push(id.expression);
+    } else if (nodeKey) {
+      if (id[nodeKey]) search.push(id[nodeKey]);
+    } else if (arrKey) {
+      search = search.concat(id[arrKey] || []);
     }
   }
 
@@ -194,11 +183,34 @@ t.getIds = function (node, map) {
   return ids;
 };
 
+t.getIds.nodes = {
+  AssignmentExpression: "left",
+  ImportSpecifier: "id",
+  ExportSpecifier: "id",
+  VariableDeclarator: "id",
+  FunctionDeclaration: "id",
+  ClassDeclaration: "id",
+  ParenthesizedExpression: "expression",
+  MemeberExpression: "object",
+  SpreadElement: "argument",
+  Property: "value"
+};
+
+t.getIds.arrays = {
+  ExportDeclaration: "specifiers",
+  ImportDeclaration: "specifiers",
+  VariableDeclaration: "declarations",
+  ArrayPattern: "elements",
+  ObjectPattern: "properties"
+};
+
 t.inherits = function (child, parent) {
-  child.loc   = parent.loc;
-  child.end   = parent.end;
-  child.range = parent.range;
-  child.start = parent.start;
+  child.loc              = parent.loc;
+  child.end              = parent.end;
+  child.range            = parent.range;
+  child.start            = parent.start;
+  child.leadingComments  = parent.leadingComments;
+  child.trailingComments = parent.trailingComments;
   return child;
 };
 

lib/6to5/types/visitor-keys.json

@@ -3,6 +3,7 @@
   "ArrayPattern":             ["elements"],
   "ArrowFunctionExpression":  ["params", "defaults", "rest", "body"],
   "AssignmentExpression":     ["left", "right"],
+  "AwaitExpression":          ["argument"],
   "BinaryExpression":         ["left", "right"],
   "BlockStatement":           ["body"],
   "BreakStatement":           ["label"],
@@ -70,6 +71,6 @@
   "XJSMemberExpression":      ["object", "property"],
   "XJSNamespacedName":        ["namespace", "name"],
   "XJSOpeningElement":        ["name", "attributes"],
-  "XJSSpreadAttribute":       [],
+  "XJSSpreadAttribute":       ["argument"],
   "YieldExpression":          ["argument"]
 }

lib/6to5/util.js

@@ -11,6 +11,12 @@ var _          = require("lodash");
 
 exports.inherits = util.inherits;
 
+exports.canCompile = function (filename, altExts) {
+  var exts = altExts || [".js", ".jsx", ".es6"];
+  var ext = path.extname(filename);
+  return _.contains(exts, ext);
+};
+
 exports.resolve = function (loc) {
   try {
     return require.resolve(loc);
@@ -19,6 +25,10 @@ exports.resolve = function (loc) {
   }
 };
 
+exports.trimRight = function (str) {
+  return str.replace(/[\n\s]+$/g, "");
+};
+
 exports.list = function (val) {
   return val ? val.split(",") : [];
 };
@@ -46,11 +56,6 @@ exports.isAbsolute = function (loc) {
   return false;
 };
 
-exports.canCompile = function (filename) {
-  var ext = path.extname(filename);
-  return _.contains([".js", ".es6"], ext);
-};
-
 exports.sourceMapToComment = function (map) {
   var json = JSON.stringify(map);
   var base64 = new Buffer(json).toString("base64");
@@ -111,6 +116,11 @@ exports.template = function (name, nodes, keepExpression) {
   var template = exports.templates[name];
   if (!template) throw new ReferenceError("unknown template " + name);
 
+  if (nodes === true) {
+    keepExpression = true;
+    nodes = null;
+  }
+
   template = _.cloneDeep(template);
 
   var inherits = false;
@@ -192,13 +202,14 @@ exports.parse = function (opts, code, callback) {
     var tokens   = [];
 
     var ast = acorn.parse(code, {
-      preserveParens: true,
-      ecmaVersion:    Infinity,
-      strictMode:     true,
-      onComment:      comments,
-      locations:      true,
-      onToken:        tokens,
-      ranges:         true
+      allowReturnOutsideFunction: true,
+      preserveParens:             true,
+      ecmaVersion:                Infinity,
+      strictMode:                 true,
+      onComment:                  comments,
+      locations:                  true,
+      onToken:                    tokens,
+      ranges:                     true
     });
 
     estraverse.attachComments(ast, comments, tokens);

package.json

@@ -1,7 +1,7 @@
 {
   "name": "6to5",
   "description": "Turn ES6 code into readable vanilla ES5 with source maps",
-  "version": "1.11.2",
+  "version": "1.12.2",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://github.com/6to5/6to5",
   "repository": {
@@ -44,19 +44,19 @@
     "es6-symbol": "0.1.1",
     "regexpu": "0.3.0",
     "source-map": "0.1.40",
-    "regenerator-6to5": "https://github.com/6to5/regenerator-6to5/archive/b7bc53e1a655879974aad53a8ceb93a70efaa08d.tar.gz",
+    "regenerator-6to5": "https://github.com/6to5/regenerator-6to5/archive/62d1bfcb331dcf0bbcdbbee8043da0c6408f09cf.tar.gz",
     "chokidar": "0.10.5",
     "source-map-support": "0.2.8",
     "esutils": "1.1.4",
-    "acorn-6to5": "https://github.com/6to5/acorn-6to5/archive/f5110383517eef0bea78c2da2a1fb01fbed74e4e.tar.gz",
+    "acorn-6to5": "https://github.com/6to5/acorn-6to5/archive/0384a0d51f630f66ed591769c1765581a17d2124.tar.gz",
     "estraverse": "^1.7.0"
   },
   "devDependencies": {
     "istanbul": "0.3.2",
-    "matcha": "0.5.0",
+    "matcha": "0.6.0",
     "mocha": "2.0.1",
     "uglify-js": "2.4.15",
-    "browserify": "6.2.0",
+    "browserify": "6.3.2",
     "rimraf": "2.2.8",
     "jshint": "2.5.10",
     "chai": "^1.9.2"

polyfill.js

@@ -0,0 +1 @@
+module.exports = require("./lib/6to5/polyfill");

test/_helper.js

@@ -5,9 +5,11 @@ var humanise = function (val) {
   return val.replace(/-/g, " ");
 };
 
-var readFile = function (filename) {
+var readFile = exports.readFile = function (filename) {
   if (fs.existsSync(filename)) {
-    return fs.readFileSync(filename, "utf8").trim();
+    var file = fs.readFileSync(filename, "utf8").trim();
+    file = file.replace(/\r\n/g, "\n");
+    return file;
   } else {
     return "";
   }

test/bin.js

@@ -1,4 +1,5 @@
 var readdir = require("fs-readdir-recursive");
+var helper  = require("./_helper");
 var assert  = require("assert");
 var rimraf  = require("rimraf");
 var mkdirp  = require("mkdirp");
@@ -11,15 +12,11 @@ var _       = require("lodash");
 var fixtureLoc = __dirname + "/fixtures/bin";
 var tmpLoc = __dirname + "/tmp";
 
-var readFile = function (filename) {
-  return fs.readFileSync(filename, "utf8").trim();
-};
-
 var readDir = function (loc) {
   var files = {};
   if (fs.existsSync(loc)) {
     _.each(readdir(loc), function (filename) {
-      var contents = readFile(loc + "/" + filename);
+      var contents = helper.readFile(loc + "/" + filename);
       files[filename] = contents;
     });
   }
@@ -51,6 +48,7 @@ var assertTest = function (stdout, stderr, opts) {
 
   var expectStdout = opts.stdout.trim();
   stdout = stdout.trim();
+  stdout = stdout.replace(/\\/g, "/");
 
   if (opts.stdout) {
     if (opts.stdoutContains) {
@@ -63,7 +61,7 @@ var assertTest = function (stdout, stderr, opts) {
   }
 
   _.each(opts.outFiles, function (expect, filename) {
-    var actual = readFile(filename);
+    var actual = helper.readFile(filename);
     chai.expect(actual).to.equal(expect, "out-file " + filename);
   });
 };
@@ -138,7 +136,7 @@ _.each(fs.readdirSync(fixtureLoc), function (binName) {
       _.each(["stdout", "stdin", "stderr"], function (key) {
         var loc = testLoc + "/" + key + ".txt";
         if (fs.existsSync(loc)) {
-          opts[key] = readFile(loc);
+          opts[key] = helper.readFile(loc);
         } else {
           opts[key] = opts[key] || "";
         }
@@ -151,7 +149,3 @@ _.each(fs.readdirSync(fixtureLoc), function (binName) {
     });
   });
 });
-
-after(function () {
-  rimraf.sync(tmpLoc);
-});

test/fixtures/generation/harmony-edgecase/one-assignment-property/actual.js

@@ -1,5 +0,0 @@
-({ t: t }) = obj;
-({
-  t: { C: C }
-}) = obj;
-({ a, b, c }) = obj;

test/fixtures/generation/harmony-edgecase/one-assignment-property/expected.js

@@ -1,5 +0,0 @@
-({ t: t }) = obj;
-({
-  t: { C: C }
-}) = obj;
-({ a, b, c }) = obj;

test/fixtures/transformation/destructuring/assignment/actual.js

@@ -1,2 +1 @@
 [a, b] = f();
-({ x }) = e();

test/fixtures/transformation/destructuring/assignment/expected.js

@@ -4,6 +4,3 @@ var _ref = f();
 
 a = _ref[0];
 b = _ref[1];
-var _ref2 = e();
-
-x = _ref2.x;

test/fixtures/transformation/jsx/annotation/actual.js

@@ -1,3 +0,0 @@
-/** @jsx CUSTOM_DOM */
-
-<a></a>

test/fixtures/transformation/jsx/annotation/expected.js

@@ -1,5 +0,0 @@
-/** @jsx CUSTOM_DOM */
-
-"use strict";
-
-CUSTOM_DOM.a(null);

test/fixtures/transformation/jsx/empty/actual.js

@@ -1 +0,0 @@
-<X>{}</X>

test/fixtures/transformation/jsx/empty/expected.js

@@ -1,3 +0,0 @@
-"use strict";
-
-X(null, null);

test/fixtures/transformation/jsx/everything/actual.js

@@ -1,2 +0,0 @@
-<X data-prop={x ? <Y prop={2} /> : <Z>
-</Z>}></X>

test/fixtures/transformation/jsx/everything/expected.js

@@ -1,7 +0,0 @@
-"use strict";
-
-X({
-  "data-prop": x ? Y({
-    prop: 2
-  }) : Z(null, "\n")
-});

test/fixtures/transformation/jsx/expressions/actual.js

@@ -1,5 +0,0 @@
-(<X>{a}</X>);
-
-(<X>{a} {b}</X>);
-
-(<X prop={a} yes></X>);

test/fixtures/transformation/jsx/expressions/expected.js

@@ -1,10 +0,0 @@
-"use strict";
-
-(X(null, a));
-
-(X(null, a, " ", b));
-
-(X({
-  prop: a,
-  yes: true
-}));

test/fixtures/transformation/jsx/known-tags/actual.js

@@ -1 +0,0 @@
-<a></a>

test/fixtures/transformation/jsx/known-tags/expected.js

@@ -1,3 +0,0 @@
-"use strict";
-
-React.DOM.a(null);

test/fixtures/transformation/jsx/member-expression/actual.js

@@ -1 +0,0 @@
-<Test.X></Test.X>

test/fixtures/transformation/jsx/member-expression/expected.js

@@ -1,3 +0,0 @@
-"use strict";
-
-Test.X(null);

test/fixtures/transformation/jsx/no-xml-namespaces/actual.js

@@ -1 +0,0 @@
-<Test:X></Test:X>

test/fixtures/transformation/jsx/self-closing-tags/actual.js

@@ -1,3 +0,0 @@
-(<X />);
-
-(<X prop="1" />);

test/fixtures/transformation/jsx/self-closing-tags/expected.js

@@ -1,7 +0,0 @@
-"use strict";
-
-(X(null));
-
-(X({
-  prop: "1"
-}));

test/fixtures/transformation/jsx/simple-tags/actual.js

@@ -1 +0,0 @@
-<X></X>

test/fixtures/transformation/jsx/simple-tags/expected.js

@@ -1,3 +0,0 @@
-"use strict";
-
-X(null);

test/fixtures/transformation/jsx/tags-with-children/actual.js

@@ -1,3 +0,0 @@
-(<X prop="2"><Y /></X>);
-
-(<X prop="2"><Y /><Z /></X>);

test/fixtures/transformation/jsx/tags-with-children/expected.js

@@ -1,9 +0,0 @@
-"use strict";
-
-(X({
-  prop: "2"
-}, Y(null)));
-
-(X({
-  prop: "2"
-}, Y(null), Z(null)));

test/fixtures/transformation/jsx/tags-with-literals/actual.js

@@ -1,13 +0,0 @@
-(<X>   </X>);
-
-(<X>
-</X>);
-
-(<X>
-  string
-</X>);
-
-(<X>
-  string
-  string
-  </X>);

test/fixtures/transformation/jsx/tags-with-literals/expected.js

@@ -1,9 +0,0 @@
-"use strict";
-
-(X(null, "   "));
-
-(X(null, "\n"));
-
-(X(null, "\n  string\n"));
-
-(X(null, "\n  string\n  string\n  "));

test/fixtures/transformation/let-scoping/for-break-continue-return/actual.js

@@ -0,0 +1,10 @@
+for (let i in nums) {
+  fns.push(function () { return i; });
+  if (i === 1) {
+    continue;
+  } else if (i === 2) {
+    break;
+  } else if (i === 3) {
+    return i;
+  }
+}

test/fixtures/transformation/let-scoping/for-break-continue-return/expected.js

@@ -0,0 +1,24 @@
+"use strict";
+
+_loop: for (var i in nums) {
+  var _ret = (function (i) {
+    fns.push(function () {
+      return i;
+    });
+    if (i === 1) {
+      return "continue";
+    } else if (i === 2) {
+      return "break";
+    } else if (i === 3) {
+      return {
+        v: i
+      };
+    }
+  })(i);
+
+  switch (_ret) {
+    case "break": break _loop;
+    case "continue": continue _loop;
+    default: if (typeof _ret === "object") return _ret.v;
+  }
+}

test/fixtures/transformation/let-scoping/for-break/actual.js

@@ -0,0 +1,4 @@
+for (let i in nums) {
+  fns.push(function () { return i; });
+  break;
+}

test/fixtures/transformation/let-scoping/for-break/expected.js

@@ -0,0 +1,12 @@
+"use strict";
+
+_loop: for (var i in nums) {
+  var _ret = (function (i) {
+    fns.push(function () {
+      return i;
+    });
+    return "break";
+  })(i);
+
+  if (_ret === "break") break _loop;
+}

test/fixtures/transformation/let-scoping/for-continue/actual.js

@@ -0,0 +1,4 @@
+for (let i in nums) {
+  fns.push(function () { return i; });
+  continue;
+}

test/fixtures/transformation/let-scoping/for-continue/expected.js

@@ -0,0 +1,12 @@
+"use strict";
+
+_loop: for (var i in nums) {
+  var _ret = (function (i) {
+    fns.push(function () {
+      return i;
+    });
+    return "continue";
+  })(i);
+
+  if (_ret === "continue") continue _loop;
+}

test/fixtures/transformation/let-scoping/for-return-undefined/actual.js

@@ -0,0 +1,4 @@
+for (let i in nums) {
+  fns.push(function () { return i; });
+  return;
+}

test/fixtures/transformation/let-scoping/for-return-undefined/expected.js

@@ -0,0 +1,14 @@
+"use strict";
+
+for (var i in nums) {
+  var _ret = (function (i) {
+    fns.push(function () {
+      return i;
+    });
+    return {
+      v: undefined
+    };
+  })(i);
+
+  if (typeof _ret === "object") return _ret.v;
+}

test/fixtures/transformation/let-scoping/for-return/actual.js

@@ -0,0 +1,4 @@
+for (let i in nums) {
+  fns.push(function () { return i; });
+  return i;
+}

test/fixtures/transformation/let-scoping/for-return/expected.js

@@ -0,0 +1,14 @@
+"use strict";
+
+for (var i in nums) {
+  var _ret = (function (i) {
+    fns.push(function () {
+      return i;
+    });
+    return {
+      v: i
+    };
+  })(i);
+
+  if (typeof _ret === "object") return _ret.v;
+}

test/fixtures/transformation/let-scoping/function/actual.js

@@ -0,0 +1,3 @@
+function test() {
+  let foo = "bar";
+}

test/fixtures/transformation/let-scoping/function/expected.js

@@ -0,0 +1,5 @@
+"use strict";
+
+function test() {
+  var foo = "bar";
+}

test/fixtures/transformation/let-scoping/program/actual.js

@@ -0,0 +1 @@
+let test = "foo";

test/fixtures/transformation/let-scoping/program/expected.js

@@ -0,0 +1,3 @@
+"use strict";
+
+var test = "foo";

test/fixtures/transformation/misc/custom-runtime/actual.js

@@ -0,0 +1,3 @@
+function foo(...test) {
+
+}

test/fixtures/transformation/misc/custom-runtime/expected.js

@@ -0,0 +1,5 @@
+"use strict";
+
+function foo() {
+  var test = customNamespace.slice.call(arguments);
+}

test/fixtures/transformation/misc/custom-runtime/options.json

@@ -0,0 +1,3 @@
+{
+  "runtime": "customNamespace"
+}

test/fixtures/transformation/misc/property-literals/actual.js

@@ -0,0 +1,3 @@
+var obj = {
+  "foobar": "lol"
+};

test/fixtures/transformation/misc/property-literals/expected.js

@@ -0,0 +1,5 @@
+"use strict";
+
+var obj = {
+  foobar: "lol"
+};

test/fixtures/transformation/misc/runtime/actual.js

@@ -0,0 +1,3 @@
+function foo(...test) {
+
+}

test/fixtures/transformation/misc/runtime/expected.js

@@ -0,0 +1,5 @@
+"use strict";
+
+function foo() {
+  var test = to5Runtime.slice.call(arguments);
+}

test/fixtures/transformation/misc/runtime/options.json

@@ -0,0 +1,3 @@
+{
+  "runtime": true
+}

test/fixtures/transformation/misc/shebang/actual.js

@@ -0,0 +1,3 @@
+#!/usr/bin/env node
+
+foobar();

test/fixtures/transformation/misc/shebang/expected.js

@@ -0,0 +1,4 @@
+#!/usr/bin/env node
+"use strict";
+
+foobar();

test/fixtures/transformation/react/.should-not-strip-nbsp-even-coupled-with-other-whitespace/actual.js

@@ -0,0 +1 @@
+<div>&nbsp; </div>;

test/fixtures/transformation/react/.should-not-strip-nbsp-even-coupled-with-other-whitespace/expected.js

@@ -0,0 +1 @@
+React.createElement("div", null, "\u00A0 ");

test/fixtures/transformation/react/.should-not-strip-tags-with-a-single-child-of-nbsp/actual.js

@@ -0,0 +1 @@
+<div>&nbsp;</div>;

test/fixtures/transformation/react/.should-not-strip-tags-with-a-single-child-of-nbsp/expected.js

@@ -0,0 +1 @@
+React.createElement("div", null, "\u00A0");

test/fixtures/transformation/react/.should-properly-handle-comments-adjacent-to-children/actual.js

@@ -0,0 +1,13 @@
+var x = (
+  <div>
+    {/* A comment at the beginning */}
+    {/* A second comment at the beginning */}
+    <span>
+      {/* A nested comment */}
+    </span>
+    {/* A sandwiched comment */}
+    <br />
+    {/* A comment at the end */}
+    {/* A second comment at the end */}
+  </div>
+);

test/fixtures/transformation/react/.should-properly-handle-comments-adjacent-to-children/expected.js

@@ -0,0 +1,11 @@
+var x = (React.createElement("div", null,
+  /* A comment at the beginning */
+  /* A second comment at the beginning */
+  React.createElement("span", null
+    /* A nested comment */
+  ),
+  /* A sandwiched comment */
+  React.createElement("br", null)
+  /* A comment at the end */
+  /* A second comment at the end */
+));

test/fixtures/transformation/react/.should-properly-handle-comments-between-props/actual.js

@@ -0,0 +1,10 @@
+var x = (
+  <div
+    /* a multi-line
+       comment */
+    attr1="foo">
+    <span // a double-slash comment
+      attr2="bar"
+    />
+  </div>
+);

test/fixtures/transformation/react/.should-properly-handle-comments-between-props/expected.js

@@ -0,0 +1,8 @@
+var x = (React.createElement("div", {
+  /* a multi-line
+     comment */
+  attr1: "foo"},
+  React.createElement("span", {// a double-slash comment
+    attr2: "bar"}
+  )
+));

test/fixtures/transformation/react/adds-appropriate-newlines-when-using-spread-attribute/actual.js

@@ -0,0 +1,3 @@
+<Component
+  {...this.props}
+  sound="moo" />