v3.3.9

First pass at converting identifiers/words from en-au -> en-us

.gitmodules

@@ -7,3 +7,6 @@
 [submodule "vendor/test262"]
 	path = vendor/test262
 	url = https://github.com/tc39/test262
+[submodule "vendor/compat-table"]
+	path = vendor/compat-table
+	url = https://github.com/kangax/compat-table

.istanbul.yml

@@ -0,0 +1,2 @@
+instrumentation:
+  root: lib

.jscsrc

@@ -14,7 +14,6 @@
   },
   "disallowSpacesInsideArrayBrackets": true,
   "disallowSpacesInsideParentheses": true,
-  "disallowQuotedKeysInObjects": true,
   "disallowSpaceAfterObjectKeys": true,
   "disallowSpaceAfterPrefixUnaryOperators": true,
   "disallowSpaceBeforePostfixUnaryOperators": true,
@@ -33,10 +32,8 @@
   "requireCommaBeforeLineBreak": true,
   "requireSpaceBeforeBinaryOperators": true,
   "requireSpaceAfterBinaryOperators": true,
-  "requireCamelCaseOrUpperCaseIdentifiers": true,
   "requireLineFeedAtFileEnd": true,
   "requireCapitalizedConstructors": true,
-  "requireDotNotation": true,
   "requireSpacesInForStatement": true,
   "requireCurlyBraces": [
     "do"
@@ -52,7 +49,8 @@
     "return",
     "try",
     "catch",
-    "typeof"
+    "typeof",
+    "function"
   ],
   "validateLineBreaks": "LF",
   "validateQuoteMarks": "\"",

CHANGELOG.md

@@ -11,6 +11,73 @@
 
 _Note: Gaps between patch versions are faulty/broken releases._
 
+## 3.3.8
+
+ * **Bug Fix**
+  * Fix super inside of functions.
+  * Fix super constructor inheritance.
+
+## 3.3.7
+
+ * **Bug Fix**
+  * Add `--use-strict` to valid node flags in `6to5-node`.
+  * Fix booleans not being properly stripped from the arguments in `6to5-node`.
+  * Force `.js` extension when writing files to directories with `6to5`.
+
+## 3.3.5
+
+ * **Bug Fix**
+  * Fix block scoping inside of while loops.
+  * Make module name regex more conservative. Thanks [@johlrich](https://github.com/johlrich)!
+  * Fix block scoping of constants.
+  * Fix istanbul interop.
+  * Make JSX transforming more inline with the official transformer with spaces after non-empty last lines.
+ * **Polish**
+  * Make it illegal to export a property called `__esModule`.
+
+## 3.3.4
+
+ * **Polish**
+  * Add istanbul `require` interop.
+ * **Bug Fix**
+  * Fix incorrect source map column tracking in specific scenarios.
+
+## 3.3.3
+
+ * **Polish**
+  * Remap top level `this` to `undefined` instead of throwing an error.
+ * **Bug Fix**
+  * Run `selfContained` transformer over the regenerator runtime when building `6to5-runtime`.
+  * Fix `t.isReferenced` not properly allowing `value` nodes.
+
+## 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**
+  * Fix block scoping transformer rewriting breaks and continues to inner labels.
+
+## 3.2.0
+
+ * **Bug Fix**
+  * Fixed scope tracking for default parameters IIFE.
+  * Fixed block scoped functions.
+  * Improved `bin/6to5` path resolution.
+ * **New Feature**
+  * You can now trigger super setters in classes. Thanks [@kruppel](https://github.com/kruppel)!
+  * Add `resolveSourceMap` option.
+  * Better support and output for block scoping loops with labels.
+
 ## 3.1.1
 
  * **Polish**
@@ -290,8 +357,8 @@ _Note: Gaps between patch versions are faulty/broken releases._
  * **Polish**
   * Rest parameters now allocate the array before populating.
  * **Internal**
-  * `for...in` loops have been changed to optimised `for` loops - better performance and no enumeration of protoype keys.
-  * Parts of the code generator have now been optimised thanks to [gaearon](https://github.com/gaearon).
+  * `for...in` loops have been changed to optimized `for` loops - better performance and no enumeration of protoype keys.
+  * Parts of the code generator have now been optimized thanks to [gaearon](https://github.com/gaearon).
 
 ## 2.12.3
 
@@ -314,7 +381,7 @@ _Note: Gaps between patch versions are faulty/broken releases._
  * **Bug Fix**
   * Support non-string JSX literals.
  * **New Feature**
-  * Loose mode for some transformers that enables non-spec behaviour.
+  * Loose mode for some transformers that enables non-spec behavior.
  * **Internal**
   * Uglify `--mangle sort` has been added to the build script, cutting minified scripts in half.
 
@@ -752,7 +819,7 @@ _Note: Gaps between patch versions are faulty/broken releases._
 
 ## 1.13.2
 
- * Optimise `Array.from` usage by adding a helper method.
+ * Optimize `Array.from` usage by adding a helper method.
  * Upgrade `acorn-6to5`.
 
 ## 1.13.1

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
@@ -110,3 +114,4 @@ bootstrap:
 	npm install
 	git submodule update --init
 	cd vendor/regenerator; npm install
+	cd vendor/compat-table; npm install object-assign

NOTES.md

@@ -1,3 +1,3 @@
 # Notes
 
- * Wildcard exports/imports wont normalise if `export default` is a non-object. See [#224](https://github.com/6to5/6to5/issues/224).
+ * Wildcard exports/imports wont normalize if `export default` is a non-object. See [#224](https://github.com/6to5/6to5/issues/224).

bin/6to5-minify

@@ -0,0 +1,7 @@
+#!/usr/bin/env node
+
+var opts = require("./6to5").opts;
+opts.optional = (opts.optional || []).concat("minification");
+opts.format = {
+  compact: true
+};

bin/6to5-node

@@ -5,7 +5,7 @@
  * when found, before invoking the "real" _6to5-node(1) executable.
  */
 
-var args  = ["--harmony", __dirname + "/_6to5-node"];
+var args  = [__dirname + "/_6to5-node"];
 
 process.argv.slice(2).forEach(function(arg){
   var flag = arg.split("=")[0];
@@ -35,6 +35,7 @@ process.argv.slice(2).forEach(function(arg){
     case "--prof":
     case "--throw-deprecation":
     case "--trace-deprecation":
+    case "--use-strict":
       args.unshift(arg);
       break;
 

bin/6to5-runtime

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

bin/6to5/dir.js

@@ -11,6 +11,9 @@ module.exports = function (commander, filenames, opts) {
   }
 
   var write = function (src, relative) {
+    // remove extension and then append back on .js
+    relative = relative.replace(/\.(\w*?)$/, "") + ".js";
+
     var dest = path.join(commander.outDir, relative);
 
     var data = util.compile(src, { sourceMapName: dest });
@@ -53,10 +56,7 @@ module.exports = function (commander, filenames, opts) {
 
       _.each(["add", "change"], function (type) {
         watcher.on(type, function (filename) {
-          // chop off the dirname plus the path separator
-          var relative = filename.slice(dirname.length + 1);
-
-          console.log(type, filename);
+          var relative = path.relative(dirname, filename) || filename;
           write(filename, relative);
         });
       });

bin/6to5/index.js

@@ -1,7 +1,7 @@
 #!/usr/bin/env node
 
 var commander = require("commander");
-var transform = require("../../lib/6to5/transformation/transform");
+var transform = require("../../lib/6to5/transformation");
 var util      = require("../../lib/6to5/util");
 var fs        = require("fs");
 var each      = require("lodash/collection/each");
@@ -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");
 
@@ -108,16 +109,22 @@ exports.opts = {
   sourceMap:              commander.sourceMaps || commander.sourceMapsInline,
   optional:               commander.optional,
   comments:               !commander.removeComments,
+  runtime:                commander.runtime,
   modules:                commander.modules,
   loose:                  commander.loose
 };
 
-var fn;
+setTimeout(function () {
+  // this is just a hack to give `6to5-minify` and other files including this
+  // time to modify `exports.opts`
 
-if (commander.outDir) {
-  fn = require("./dir");
-} else {
-  fn = require("./file");
-}
+  var fn;
 
-fn(commander, filenames, exports.opts);
+  if (commander.outDir) {
+    fn = require("./dir");
+  } else {
+    fn = require("./file");
+  }
+
+  fn(commander, filenames, exports.opts);
+}, 0);

bin/_6to5-node

@@ -72,7 +72,8 @@ if (program.eval || program.print) {
       }
 
       if (arg[0] === "-") {
-        if (program[arg.slice(2)]) {
+        var parsedArg = program[arg.slice(2)];
+        if (parsedArg && parsedArg !== true) {
           ignoreNext = true;
         }
       } else {

lib/6to5/browser.js

@@ -1,6 +1,6 @@
 "use strict";
 
-var transform = module.exports = require("./transformation/transform");
+var transform = module.exports = require("./transformation");
 
 transform.version = require("../../package").version;
 

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

@@ -1,7 +1,29 @@
-//exports.canRun = function (ast, userAgent) {
+module.exports = detect;
 
-//};
+var SYNTAX_KEYS = require("./syntax-keys");
+var traverse    = require("../traverse");
+var visitors    = traverse.explode(require("./visitors"));
 
-//exports.whoCanRun = function (ast, userAgent) {
+function detect(ast) {
+  var stats = {
+    syntax: {},
+    builtins: {}
+  };
 
-//};
+  var detectedSyntax = function (name) {
+    stats.syntax[name] = true;
+  };
+
+  traverse(ast, {
+    enter: function (node, parent) {
+      if (SYNTAX_KEYS[node.type]) {
+        detectedSyntax(SYNTAX_KEYS[node.type]);
+      }
+
+      var visitor = visitors[node.type];
+      if (visitor) visitor(node, parent, detectedSyntax);
+    }
+  });
+
+  return stats;
+}

lib/6to5/detection/syntax-keys.json

@@ -0,0 +1,84 @@
+{
+  "ArrowFunctionExpression":   "es6.arrowFunctions",
+
+  "AwaitExpression":           "es7.asyncFunctions",
+
+  "ClassBody":                 "es6.classes",
+  "ClassDeclaration":          "es6.classes",
+  "ClassExpression":           "es6.classes",
+  "MethodDefinition":          "es6.classes",
+
+  "ComprehensionBlock":        "es7.comprehensions",
+  "ComprehensionExpression":   "es7.comprehensions",
+
+  "ForOfStatement":            "es6.forOf",
+
+  "ExportBatchSpecifier":      "es6.modules",
+  "ExportDeclaration":         "es6.modules",
+  "ExportSpecifier":           "es6.modules",
+  "ImportBatchSpecifier":      "es6.modules",
+  "ImportDeclaration":         "es6.modules",
+  "ImportSpecifier":           "es6.modules",
+
+  "ArrayPattern":              "es6.destructuring",
+  "AssignmentPattern":         "es6.destructuring",
+  "ObjectPattern":             "es6.destructuring",
+
+  "RestElement":               "es6.parameters.rest",
+
+  "SpreadElement":             "es6.spread",
+
+  "SpreadProperty":            "es7.objectSpread",
+
+  "TaggedTemplateExpression":  "es6.templateLiterals",
+  "TemplateElement":           "es6.templateLiterals",
+  "TemplateLiteral":           "es6.templateLiterals",
+
+  "VirtualPropertyExpression": "es7.abstractReferences",
+  "PrivateDeclaration":        "es7.abstractReferences",
+
+  "YieldExpression":           "es6.generators",
+
+  "AnyTypeAnnotation":           "flow",
+  "ArrayTypeAnnotation":         "flow",
+  "BooleanTypeAnnotation":       "flow",
+  "ClassProperty":               "flow",
+  "DeclareClass":                "flow",
+  "DeclareFunction":             "flow",
+  "DeclareModule":               "flow",
+  "DeclareVariable":             "flow",
+  "FunctionTypeAnnotation":      "flow",
+  "FunctionTypeParam":           "flow",
+  "GenericTypeAnnotation":       "flow",
+  "InterfaceExtends":            "flow",
+  "InterfaceDeclaration":        "flow",
+  "IntersectionTypeAnnotation":  "flow",
+  "NullableTypeAnnotation":      "flow",
+  "NumberTypeAnnotation":        "flow",
+  "StringLiteralTypeAnnotation": "flow",
+  "StringTypeAnnotation":        "flow",
+  "TupleTypeAnnotation":         "flow",
+  "TypeofTypeAnnotation":        "flow",
+  "TypeAlias":                   "flow",
+  "TypeAnnotation":              "flow",
+  "TypeParameterDeclaration":    "flow",
+  "TypeParameterInstantiation":  "flow",
+  "ObjectTypeAnnotation":        "flow",
+  "ObjectTypeCallProperty":      "flow",
+  "ObjectTypeIndexer":           "flow",
+  "ObjectTypeProperty":          "flow",
+  "QualifiedTypeIdentifier":     "flow",
+  "UnionTypeAnnotation":         "flow",
+  "VoidTypeAnnotation":          "flow",
+
+  "JSXAttribute":              "jsx",
+  "JSXClosingElement":         "jsx",
+  "JSXElement":                "jsx",
+  "JSXEmptyExpression":        "jsx",
+  "JSXExpressionContainer":    "jsx",
+  "JSXIdentifier":             "jsx",
+  "JSXMemberExpression":       "jsx",
+  "JSXNamespacedName":         "jsx",
+  "JSXOpeningElement":         "jsx",
+  "JSXSpreadAttribute":        "jsx"
+}

lib/6to5/detection/visitors.js

@@ -0,0 +1,54 @@
+var t = require("../types");
+var _ = require("lodash");
+
+exports.AssignmentExpression = function (node, parent, detected) {
+  if (node.operator === "**=") {
+    detected("es6.exponentation");
+  }
+};
+
+exports.BinaryExpression = function (node, parent, detected) {
+  if (node.operator === "**") {
+    detected("es6.exponentation");
+  }
+};
+
+exports.VariableDeclaration = function (node, parent, detected) {
+  if (node.kind === "let" || node.kind === "const") {
+    detected("es6.blockScoping");
+  }
+
+  if (node.kind === "const") {
+    detected("es6.constants");
+  }
+};
+
+exports.Property = function (node, parent, detected) {
+  if (node.shorthand || node.method) {
+    detected("es6.properties.shorthand");
+  }
+
+  if (node.kind === "set" || node.kind === "get") {
+    detected("es5.properties.mutators");
+  }
+
+  if (node.computed) {
+    detected("es6.properties.computed");
+  }
+};
+
+exports.AssignmentPattern = function (node, parent, detected) {
+  if (t.isFunction(parent) && _.contains(parent.params, node)) {
+    detected("es6.parameters.default");
+  }
+};
+
+exports.Function = function (node, parent, detected) {
+  if (node.generator) {
+    detected("es6.generators");
+  }
+
+  if (node.async) {
+    detected("es7.asyncFunctions");
+  }
+};

lib/6to5/file.js

@@ -4,16 +4,17 @@ module.exports = File;
 
 var SHEBANG_REGEX = /^\#\!.*/;
 
-var transform  = require("./transformation/transform");
-var generate   = require("./generation/generator");
+var isFunction = require("lodash/lang/isFunction");
+var transform  = require("./transformation");
+var generate   = require("./generation");
+var defaults   = require("lodash/object/defaults");
+var contains   = require("lodash/collection/contains");
 var clone      = require("./helpers/clone");
 var Scope      = require("./traverse/scope");
 var util       = require("./util");
-var t          = require("./types");
-var contains   = require("lodash/collection/contains");
+var path       = require("path");
 var each       = require("lodash/collection/each");
-var defaults   = require("lodash/object/defaults");
-var isFunction = require("lodash/lang/isFunction");
+var t          = require("./types");
 
 function File(opts) {
   this.dynamicImportIds = {};
@@ -24,7 +25,7 @@ function File(opts) {
   this.data             = {};
 
   this.lastStatements   = [];
-  this.opts             = File.normaliseOptions(opts);
+  this.opts             = this.normalizeOptions(opts);
   this.ast              = {};
 
   this.buildTransformers();
@@ -49,7 +50,9 @@ File.helpers = [
   "interop-require-wildcard",
   "typeof",
   "extends",
-  "get"
+  "get",
+  "set",
+  "class-call-check"
 ];
 
 File.validOptions = [
@@ -74,14 +77,17 @@ File.validOptions = [
   "format",
   "playground",
   "experimental",
+  "resolveModuleSource",
+  "runtime",
 
   // these are used by plugins
   "ignore",
   "only",
-  "extensions"
+  "extensions",
+  "accept"
 ];
 
-File.normaliseOptions = function (opts) {
+File.prototype.normalizeOptions = function (opts) {
   opts = clone(opts);
 
   for (var key in opts) {
@@ -92,6 +98,7 @@ File.normaliseOptions = function (opts) {
 
   defaults(opts, {
     keepModuleIdExtensions: false,
+    resolveModuleSource:    null,
     experimental:           false,
     reactCompat:            false,
     playground:             false,
@@ -104,14 +111,17 @@ File.normaliseOptions = function (opts) {
     comments:               true,
     filename:               "unknown",
     modules:                "common",
+    runtime:                false,
     loose:                  [],
     code:                   true,
     ast:                    true
   });
 
-  // normalise windows path separators to unix
+  // normalize windows path separators to unix
   opts.filename = opts.filename.replace(/\\/g, "/");
 
+  opts.basename = path.basename(opts.filename, path.extname(opts.filename));
+
   opts.blacklist = util.arrayify(opts.blacklist);
   opts.whitelist = util.arrayify(opts.whitelist);
   opts.optional  = util.arrayify(opts.optional);
@@ -142,6 +152,10 @@ 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);
@@ -332,7 +346,11 @@ File.prototype.transform = function (ast) {
   this.ast = ast;
   this.lastStatements = t.getLastStatements(ast.program);
   this.scope = new Scope(ast.program, ast, null, this);
-  this.moduleFormatter = this.getModuleFormatter(this.opts.modules);
+
+  var modFormatter = this.moduleFormatter = this.getModuleFormatter(this.opts.modules);
+  if (modFormatter.init && this.transformers["es6.modules"].canRun()) {
+    modFormatter.init();
+  }
 
   var astRun = function (key) {
     each(self.transformerStack, function (pass) {
@@ -388,14 +406,14 @@ File.prototype.generateUid = function (name, scope) {
   do {
     uid = this._generateUid(name, i);
     i++;
-  } while (scope.has(uid));
+  } while (scope.hasReference(uid));
   return uid;
 };
 
 File.prototype.generateUidIdentifier = function (name, scope) {
   scope = scope || this.scope;
   var id = t.identifier(this.generateUid(name, scope));
-  scope.add(id);
+  scope.addDeclarationToFunctionScope("var", id);
   return id;
 };
 

lib/6to5/generation/buffer.js

@@ -19,7 +19,7 @@ Buffer.prototype.get = function () {
 };
 
 Buffer.prototype.getIndent = function () {
-  if (this.format.compact) {
+  if (this.format.compact || this.format.concise) {
     return "";
   } else {
     return util.repeat(this._indent, this.format.indent.style);
@@ -53,10 +53,12 @@ Buffer.prototype.rightBrace = function () {
 
 Buffer.prototype.keyword = function (name) {
   this.push(name);
-  this.push(" ");
+  this.space();
 };
 
 Buffer.prototype.space = function () {
+  if (this.format.compact) return;
+
   if (this.buf && !this.isLast([" ", "\n"])) {
     this.push(" ");
   }
@@ -70,7 +72,7 @@ Buffer.prototype.removeLast = function (cha) {
 };
 
 Buffer.prototype.newline = function (i, removeLast) {
-  if (this.format.compact) {
+  if (this.format.compact || this.format.concise) {
     this.space();
     return;
   }

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

@@ -17,7 +17,7 @@ exports.UnaryExpression = function (node, print) {
   }
 
   this.push(node.operator);
-  if (hasSpace) this.space();
+  if (hasSpace) this.push(" ");
   print(node.argument);
 };
 
@@ -33,9 +33,13 @@ exports.UpdateExpression = function (node, print) {
 
 exports.ConditionalExpression = function (node, print) {
   print(node.test);
-  this.push(" ? ");
+  this.space();
+  this.push("?");
+  this.space();
   print(node.consequent);
-  this.push(" : ");
+  this.space();
+  this.push(":");
+  this.space();
   print(node.alternate);
 };
 
@@ -44,13 +48,13 @@ exports.NewExpression = function (node, print) {
   print(node.callee);
   if (node.arguments.length || this.format.parentheses) {
     this.push("(");
-    print.join(node.arguments, { separator: ", " });
+    print.list(node.arguments);
     this.push(")");
   }
 };
 
 exports.SequenceExpression = function (node, print) {
-  print.join(node.expressions, { separator: ", " });
+  print.list(node.expressions);
 };
 
 exports.ThisExpression = function () {
@@ -72,9 +76,7 @@ exports.CallExpression = function (node, print) {
     separator += " ";
   }
 
-  print.join(node.arguments, {
-    separator: separator
-  });
+  print.list(node.arguments, { separator: separator });
 
   if (node._prettyCall) {
     this.newline();
@@ -115,10 +117,11 @@ exports.BinaryExpression =
 exports.LogicalExpression =
 exports.AssignmentPattern =
 exports.AssignmentExpression = function (node, print) {
+  // todo: add cases where the spaces can be dropped when in compact mode
   print(node.left);
-  this.space();
+  this.push(" ");
   this.push(node.operator);
-  this.space();
+  this.push(" ");
   print(node.right);
 };
 

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

@@ -4,11 +4,7 @@ var t = require("../../types");
 
 exports._params = function (node, print) {
   this.push("(");
-
-  print.join(node.params, {
-    separator: ", "
-  });
-
+  print.list(node.params);
   this.push(")");
 };
 
@@ -45,11 +41,14 @@ exports.FunctionExpression = function (node, print) {
   if (node.async) this.push("async ");
   this.push("function");
   if (node.generator) this.push("*");
-  this.push(" ");
+
   if (node.id) {
-    this.space();
+    this.push(" ");
     print(node.id);
+  } else {
+    this.space();
   }
+
   this._params(node, print);
   this.space();
   print(node.body);

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

@@ -23,6 +23,11 @@ exports.IfStatement = function (node, print) {
   if (node.alternate) {
     if (this.isLast("}")) this.push(" ");
     this.keyword("else");
+
+    if (this.format.format && !t.isBlockStatement(node.alternate)) {
+      this.push(" ");
+    }
+
     print.indentOnComments(node.alternate);
   }
 };
@@ -190,7 +195,7 @@ exports.VariableDeclaration = function (node, print, parent) {
     sep += " ";
   }
 
-  print.join(node.declarations, { separator: sep });
+  print.list(node.declarations, { separator: sep });
 
   if (!t.isFor(parent)) {
     this.semicolon();

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

@@ -27,7 +27,7 @@ exports.ObjectPattern = function (node, print) {
     this.push("{");
     this.space();
 
-    print.join(props, { separator: ", ", indent: true });
+    print.list(props, { indent: true });
 
     this.space();
     this.push("}");
@@ -49,7 +49,8 @@ exports.Property = function (node, print) {
       if (node.shorthand) return;
     }
 
-    this.push(": ");
+    this.push(":");
+    this.space();
     print(node.value);
   }
 };
@@ -71,7 +72,7 @@ exports.ArrayPattern = function (node, print) {
       // both (all) of the holes.
       self.push(",");
     } else {
-      if (i > 0) self.push(" ");
+      if (i > 0 && !self.format.compact) self.push(" ");
       print(elem);
       if (i < len - 1) self.push(",");
     }

lib/6to5/generation/index.js

@@ -24,7 +24,7 @@ function CodeGenerator(ast, opts, code) {
 
   this.comments = ast.comments || [];
   this.tokens   = ast.tokens || [];
-  this.format   = CodeGenerator.normaliseOptions(code, opts);
+  this.format   = CodeGenerator.normalizeOptions(code, opts);
   this.ast      = ast;
 
   this.whitespace = new Whitespace(this.tokens, this.comments);
@@ -39,15 +39,18 @@ each(Buffer.prototype, function (fn, key) {
   };
 });
 
-CodeGenerator.normaliseOptions = function (code, opts) {
-  var indent = detectIndent(code);
-  var style  = indent.indent;
-  if (!style || style === " ") style = "  ";
+CodeGenerator.normalizeOptions = function (code, opts) {
+  var style = "  ";
+  if (code) {
+    var indent = detectIndent(code).indent;
+    if (indent && indent !== " ") style = indent;
+  }
 
   return merge({
     parentheses: true,
     comments: opts.comments == null || opts.comments,
     compact: false,
+    concise: false,
     indent: {
       adjustMultilineComment: true,
       style: style,
@@ -109,6 +112,16 @@ CodeGenerator.prototype.buildPrint = function (parent) {
     return self.printJoin(print, nodes, opts);
   };
 
+  print.list = function (items, opts) {
+    opts = opts || {};
+
+    var sep = opts.separator || ", ";
+    if (self.format.compact) sep = ",";
+    opts.separator = sep;
+
+    print.join(items, opts);
+  };
+
   print.block = function (node) {
     return self.printBlock(print, node);
   };
@@ -127,9 +140,9 @@ CodeGenerator.prototype.print = function (node, parent, opts) {
     node._compact = true;
   }
 
-  var oldCompact = this.format.compact;
+  var oldConcise = this.format.concise;
   if (node._compact) {
-    this.format.compact = true;
+    this.format.concise = true;
   }
 
   var self = this;
@@ -177,7 +190,7 @@ CodeGenerator.prototype.print = function (node, parent, opts) {
     newline(true);
 
     if (opts.before) opts.before();
-    this.map.mark(node, "start");
+    this.map.mark(node);
 
     this[node.type](node, this.buildPrint(node), parent);
 
@@ -187,7 +200,6 @@ CodeGenerator.prototype.print = function (node, parent, opts) {
     }
     if (needsParens) this.push(")");
 
-    this.map.mark(node, "end");
     if (opts.after) opts.after();
 
     newline(false);
@@ -197,7 +209,7 @@ CodeGenerator.prototype.print = function (node, parent, opts) {
     throw new ReferenceError("unknown node of type " + JSON.stringify(node.type) + " with constructor " + JSON.stringify(node && node.constructor.name));
   }
 
-  this.format.compact = oldCompact;
+  this.format.concise = oldConcise;
 };
 
 CodeGenerator.prototype.printJoin = function (print, nodes, opts) {

lib/6to5/generation/source-map.js

@@ -30,7 +30,7 @@ SourceMap.prototype.get = function () {
   }
 };
 
-SourceMap.prototype.mark = function (node, type) {
+SourceMap.prototype.mark = function (node) {
   var loc = node.loc;
   if (!loc) return; // no location info
 
@@ -46,9 +46,7 @@ SourceMap.prototype.mark = function (node, type) {
     column: position.column
   };
 
-  var original = loc[type];
-
-  if (generated.line === original.line && generated.column === original.column) return; // nothing to map
+  var original = loc.start;
 
   map.addMapping({
     source: this.opts.sourceFileName,

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

@@ -1,12 +1,14 @@
 "use strict";
 
-var transform  = require("./transformation/transform");
+var transform  = require("./transformation");
 var util       = require("./util");
 var fs         = require("fs");
 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/register.js

@@ -34,20 +34,14 @@ var cache = registerCache.get();
 var transformOpts = {};
 var ignoreRegex   = /node_modules/;
 var onlyRegex;
-var whitelist     = [];
 var exts          = {};
 var maps          = {};
-var old           = require.extensions[".js"];
 
 var mtime = function (filename) {
   return +fs.statSync(filename).mtime;
 };
 
-var loader = function (m, filename) {
-  if ((ignoreRegex && ignoreRegex.test(filename)) || (onlyRegex && !onlyRegex.test(filename))) {
-    return old.apply(this, arguments);
-  }
-
+var compile = function (filename) {
   var result;
 
   if (cache) {
@@ -57,11 +51,12 @@ var loader = function (m, filename) {
     }
   }
 
-  result = result || to5.transformFileSync(filename, extend({
-    whitelist: whitelist,
-    sourceMap: true,
-    ast:       false
-  }, transformOpts));
+  if (!result) {
+    result = to5.transformFileSync(filename, extend({
+      sourceMap: true,
+      ast:       false
+    }, transformOpts));
+  }
 
   if (cache) {
     result.mtime = mtime(filename);
@@ -70,7 +65,54 @@ var loader = function (m, filename) {
 
   maps[filename] = result.map;
 
-  m._compile(result.code, filename);
+  return result.code;
+};
+
+var shouldIgnore = function (filename) {
+  return (ignoreRegex && ignoreRegex.test(filename)) || (onlyRegex && !onlyRegex.test(filename));
+};
+
+var istanbulMonkey = {};
+
+if (process.env.running_under_istanbul) { // jshint ignore:line
+  // we need to monkey patch fs.readFileSync so we can hook into
+  // what istanbul gets, it's extremely dirty but it's the only way
+  var _readFileSync = fs.readFileSync;
+
+  fs.readFileSync = function (filename) {
+    if (istanbulMonkey[filename]) {
+      delete istanbulMonkey[filename];
+      var code = compile(filename);
+      istanbulMonkey[filename] = true;
+      return code;
+    } else {
+      return _readFileSync.apply(this, arguments);
+    }
+  };
+}
+
+var istanbulLoader = function (m, filename, old) {
+  istanbulMonkey[filename] = true;
+  old(m, filename);
+};
+
+var normalLoader = function (m, filename) {
+  m._compile(compile(filename), filename);
+};
+
+var registerExtension = function (ext) {
+  var old = require.extensions[ext];
+
+  var loader = normalLoader;
+  if (process.env.running_under_istanbul) loader = istanbulLoader; // jshint ignore:line
+
+  require.extensions[ext] = function (m, filename) {
+    if (shouldIgnore(filename)) {
+      old(m, filename);
+    } else {
+      loader(m, filename, old);
+    }
+  };
 };
 
 var hookExtensions = function (_exts) {
@@ -82,14 +124,14 @@ var hookExtensions = function (_exts) {
 
   each(_exts, function (ext) {
     exts[ext] = require.extensions[ext];
-    require.extensions[ext] = loader;
+    registerExtension(ext);
   });
 };
 
 hookExtensions(util.canCompile.EXTENSIONS);
 
 module.exports = function (opts) {
-  // normalise options
+  // normalize options
   opts = opts || {};
 
   if (opts.only != null) onlyRegex = util.regexify(opts.only);

lib/6to5/transformation/helpers/define-map.js

@@ -0,0 +1,73 @@
+var cloneDeep = require("lodash/lang/cloneDeep");
+var traverse  = require("../../traverse");
+var clone      = require("lodash/lang/clone");
+var each      = require("lodash/collection/each");
+var has       = require("lodash/object/has");
+var t         = require("../../types");
+
+exports.push = function (mutatorMap, key, kind, computed, value) {
+  var alias;
+
+  if (t.isIdentifier(key)) {
+    alias = key.name;
+    if (computed) alias = "computed:" + alias;
+  } else if (t.isLiteral(key)) {
+    alias = String(key.value);
+  } else {
+    alias = JSON.stringify(traverse.removeProperties(cloneDeep(key)));
+  }
+
+  var map;
+  if (has(mutatorMap, alias)) {
+    map = mutatorMap[alias];
+  } else {
+    map = {};
+  }
+  mutatorMap[alias] = map;
+
+  map._key = key;
+  if (computed) {
+    map._computed = true;
+  }
+
+  map[kind] = value;
+};
+
+exports.build = function (mutatorMap) {
+  var objExpr = t.objectExpression([]);
+
+  each(mutatorMap, function (map) {
+    var mapNode = t.objectExpression([]);
+
+    var propNode = t.property("init", map._key, mapNode, map._computed);
+
+    if (!map.get && !map.set) {
+      map.writable = t.literal(true);
+    }
+
+    if (map.enumerable === false) {
+      delete map.enumerable;
+    } else {
+      map.enumerable = t.literal(true);
+    }
+
+    map.configurable = t.literal(true);
+
+    each(map, function (node, key) {
+      if (key[0] === "_") return;
+
+      node = clone(node);
+      var inheritNode = node;
+      if (t.isMethodDefinition(node)) node = node.value;
+
+      var prop = t.property("init", t.identifier(key), node);
+      t.inheritsComments(prop, inheritNode);
+      t.removeComments(inheritNode);
+      mapNode.properties.push(prop);
+    });
+
+    objExpr.properties.push(propNode);
+  });
+
+  return objExpr;
+};

lib/6to5/transformation/helpers/explode-assignable-expression.js

@@ -5,7 +5,7 @@ var t = require("../../types");
 var getObjRef = function (node, nodes, file, scope) {
   var ref;
   if (t.isIdentifier(node)) {
-    if (scope.has(node.name, true)) {
+    if (scope.hasBinding(node.name)) {
       // this variable is declared in scope so we can be 100% sure
       // that evaluating it multiple times wont trigger a getter
       // or something else
@@ -18,7 +18,7 @@ var getObjRef = function (node, nodes, file, scope) {
   } else if (t.isMemberExpression(node)) {
     ref = node.object;
 
-    if (t.isIdentifier(ref) && scope.has(ref.name)) {
+    if (t.isIdentifier(ref) && scope.hasReference(ref.name)) {
       // the object reference that we need to save is locally declared
       // so as per the previous comment we can be 100% sure evaluating
       // it multiple times will be safe

lib/6to5/transformation/helpers/name-method.js

@@ -14,7 +14,7 @@ var visitor = {
 
     // check that we don't have a local variable declared as that removes the need
     // for the wrapper
-    var localDeclar = scope.get(state.id, true);
+    var localDeclar = scope.getBinding(state.id);
     if (localDeclar !== state.outerDeclar) return;
 
     state.selfReference = true;
@@ -32,7 +32,7 @@ exports.property = function (node, file, scope) {
   var state = {
     id: id,
     selfReference: false,
-    outerDeclar: scope.get(id, true),
+    outerDeclar: scope.getBinding(id),
   };
 
   traverse(node, visitor, scope, state);

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/helpers/replace-supers.js

@@ -21,6 +21,36 @@ function ReplaceSupers(opts) {
   this.file                  = opts.file;
 }
 
+/**
+ * Sets a super class value of the named property.
+ *
+ * @example
+ *
+ *   _set(Object.getPrototypeOf(CLASS.prototype), "METHOD", "VALUE", this)
+ *
+ * @param {Node} property
+ * @param {boolean} isStatic
+ * @param {boolean} isComputed
+ *
+ * @returns {Node}
+ */
+ReplaceSupers.prototype.setSuperProperty = function (property, value, isStatic, isComputed, thisExpression) {
+  return t.callExpression(
+    this.file.addHelper("set"),
+    [
+      t.callExpression(
+        t.memberExpression(t.identifier("Object"), t.identifier("getPrototypeOf")),
+        [
+          isStatic ? this.className : t.memberExpression(this.className, t.identifier("prototype"))
+        ]
+      ),
+      isComputed ? property : t.literal(property.name),
+      value,
+      thisExpression
+    ]
+  );
+};
+
 /**
  * Gets a node representing the super class value of the named property.
  *
@@ -120,7 +150,7 @@ var visitor = {
       // top level so `this` is the instance
       t.thisExpression :
       // not in the top level so we need to create a reference
-      self.getThisReference;
+      self.getThisReference.bind(self);
 
     var callback = self.specHandle;
     if (self.isLoose) callback = self.looseHandle;
@@ -191,6 +221,7 @@ ReplaceSupers.prototype.specHandle = function (getThisReference, node, parent) {
   var property;
   var computed;
   var args;
+  var thisReference;
 
   if (t.isIdentifier(node, { name: "super" })) {
     if (!(t.isMemberExpression(parent) && !parent.computed && parent.property === node)) {
@@ -226,11 +257,18 @@ ReplaceSupers.prototype.specHandle = function (getThisReference, node, parent) {
     // super.name; -> _get(Object.getPrototypeOf(ClassName.prototype), "name", this);
     property = node.property;
     computed = node.computed;
+  } else if (t.isAssignmentExpression(node)) {
+    if (!t.isIdentifier(node.left.object, { name: "super" })) return;
+    if (methodNode.kind !== "set") return;
+
+    thisReference = getThisReference();
+    // super.name = "val"; -> _set(Object.getPrototypeOf(ClassName.prototype), "name", this);
+    return this.setSuperProperty(node.left.property, node.right, methodNode.static, node.left.computed, thisReference);
   }
 
   if (!property) return;
 
-  var thisReference = getThisReference();
+  thisReference = getThisReference();
   var superProperty = this.superProperty(property, methodNode.static, computed, thisReference);
   if (args) {
     if (args.length === 1 && t.isSpreadElement(args[0])) {

lib/6to5/transformation/index.js

@@ -14,7 +14,7 @@ function transform(code, opts) {
 }
 
 transform.fromAst = function (ast, code, opts) {
-  ast = util.normaliseAst(ast);
+  ast = util.normalizeAst(ast);
 
   var file = new File(opts);
   file.addCode(code);

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

@@ -45,7 +45,7 @@ var exportsVisitor = {
       formatter.hasLocalImports = true;
 
       if (declar && t.isStatement(declar)) {
-        extend(formatter.localExports, t.getIds(declar, true));
+        extend(formatter.localExports, t.getBindingIdentifiers(declar));
       }
 
       if (!node.default) {
@@ -67,7 +67,7 @@ var importsVisitor = {
   enter: function (node, parent, scope, context, formatter) {
     if (t.isImportDeclaration(node)) {
       formatter.hasLocalImports = true;
-      extend(formatter.localImports, t.getIds(node, true));
+      extend(formatter.localImports, t.getBindingIdentifiers(node));
       formatter.bumpImportOccurences(node);
     }
   }
@@ -147,7 +147,7 @@ DefaultFormatter.prototype.remapExportAssignment = function (node) {
 DefaultFormatter.prototype.isLocalReference = function (node, scope) {
   var localExports = this.localExports;
   var name = node.name;
-  return t.isIdentifier(node) && localExports[name] && localExports[name] === scope.get(name, true);
+  return t.isIdentifier(node) && localExports[name] && localExports[name] === scope.getBinding(name);
 };
 
 DefaultFormatter.prototype.getModuleName = function () {
@@ -171,12 +171,12 @@ DefaultFormatter.prototype.getModuleName = function () {
 
   if (!opts.keepModuleIdExtensions) {
     // remove extension
-    filenameRelative = filenameRelative.replace(/\.(.*?)$/, "");
+    filenameRelative = filenameRelative.replace(/\.(\w*?)$/, "");
   }
 
   moduleName += filenameRelative;
 
-  // normalise path separators
+  // normalize path separators
   moduleName = moduleName.replace(/\\/g, "/");
 
   return moduleName;
@@ -212,6 +212,12 @@ DefaultFormatter.prototype.getExternalReference = function (node, nodes) {
   }
 };
 
+DefaultFormatter.prototype.checkExportIdentifier = function (node) {
+  if (t.isIdentifier(node, { name: "__esModule" })) {
+    throw this.file.errorWithNode(node, "Illegal export __esModule - this is used internally for CommonJS interop");
+  }
+};
+
 DefaultFormatter.prototype.exportSpecifier = function (specifier, node, nodes) {
   var inherits = false;
   if (node.specifiers.length === 1) inherits = node;
@@ -224,7 +230,7 @@ DefaultFormatter.prototype.exportSpecifier = function (specifier, node, nodes) {
       nodes.push(this.buildExportsWildcard(ref, node));
     } else {
       if (t.isSpecifierDefault(specifier) && !this.noInteropRequire) {
-        // importing a default so we need to normalise it
+        // importing a default so we need to normalize it
         ref = t.callExpression(this.file.addHelper("interop-require"), [ref]);
       } else {
         ref = t.memberExpression(ref, t.getSpecifierId(specifier));
@@ -251,6 +257,7 @@ DefaultFormatter.prototype.buildExportsWildcard = function (objectIdentifier) {
 };
 
 DefaultFormatter.prototype.buildExportsAssignment = function (id, init) {
+  this.checkExportIdentifier(id);
   return util.template("exports-assign", {
     VALUE: init,
     KEY:   id

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

@@ -15,6 +15,8 @@ function AMDFormatter() {
 
 util.inherits(AMDFormatter, DefaultFormatter);
 
+AMDFormatter.prototype.init = CommonFormatter.prototype.init;
+
 AMDFormatter.prototype.buildDependencyLiterals = function () {
   var names = [];
   for (var name in this.ids) {

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

@@ -3,20 +3,22 @@
 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(file) {
+function CommonJSFormatter() {
   DefaultFormatter.apply(this, arguments);
-
-  if (this.hasNonDefaultExports) {
-    file.ast.program.body.push(util.template("exports-module-declaration", true));
-  }
 }
 
 util.inherits(CommonJSFormatter, DefaultFormatter);
 
+CommonJSFormatter.prototype.init = function () {
+  if (this.hasNonDefaultExports) {
+    this.file.ast.program.body.push(util.template("exports-module-declaration", true));
+  }
+};
+
 CommonJSFormatter.prototype.importSpecifier = function (specifier, node, nodes) {
   var variableName = t.getSpecifierName(specifier);
 

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

@@ -21,6 +21,8 @@ function SystemFormatter(file) {
 
 util.inherits(SystemFormatter, AMDFormatter);
 
+SystemFormatter.prototype.init = function () {};
+
 SystemFormatter.prototype._addImportSource = function (node, exportNode) {
   node._importSource = exportNode.source && exportNode.source.value;
   return node;

lib/6to5/transformation/templates/class-call-check.js

@@ -0,0 +1,5 @@
+(function (instance, Constructor) {
+  if (!(instance instanceof Constructor)) {
+    throw new TypeError("Cannot call a class as a function");
+  }
+});

lib/6to5/transformation/templates/set.js

@@ -0,0 +1,24 @@
+(function set(object, property, value, receiver) {
+  var desc = Object.getOwnPropertyDescriptor(object, property);
+
+  if (desc === undefined) {
+    var parent = Object.getPrototypeOf(object);
+
+    if (parent === null) {
+      return;
+    } else {
+      return set(parent, property, value, receiver);
+    }
+  } else if ("value" in desc && desc.writable) {
+    desc.value = value;
+    return;
+  } else {
+    var setter = desc.set;
+
+    if (setter === undefined) {
+      return;
+    }
+
+    return setter.call(receiver, value);
+  }
+});

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

@@ -3,8 +3,8 @@
 module.exports = Transformer;
 
 var TransformerPass = require("./transformer-pass");
-var t               = require("../types");
 var isFunction      = require("lodash/lang/isFunction");
+var traverse        = require("../traverse");
 var isObject        = require("lodash/lang/isObject");
 var each            = require("lodash/collection/each");
 
@@ -17,20 +17,23 @@ 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);
+  this.handlers          = this.normalize(transformer);
   this.opts              = opts || {};
   this.key               = key;
 }
 
-Transformer.prototype.normalise = function (transformer) {
+Transformer.prototype.normalize = function (transformer) {
   var self = this;
 
   if (isFunction(transformer)) {
     transformer = { ast: transformer };
   }
 
+  traverse.explode(transformer);
+
   each(transformer, function (fns, type) {
     // hidden property
     if (type[0] === "_") {
@@ -46,13 +49,6 @@ Transformer.prototype.normalise = function (transformer) {
     if (!fns.exit) fns.exit = function () { };
 
     transformer[type] = fns;
-
-    var aliases = t.FLIPPED_ALIAS_KEYS[type];
-    if (aliases) {
-      each(aliases, function (alias) {
-        transformer[alias] = fns;
-      });
-    }
   });
 
   return transformer;

lib/6to5/transformation/transformers/es5/properties.mutators.js

@@ -1,7 +1,7 @@
 "use strict";
 
-var util = require("../../../util");
-var t    = require("../../../types");
+var defineMap = require("../../helpers/define-map");
+var t         = require("../../../types");
 
 exports.ObjectExpression = function (node) {
   var mutatorMap = {};
@@ -10,7 +10,7 @@ exports.ObjectExpression = function (node) {
   node.properties = node.properties.filter(function (prop) {
     if (prop.kind === "get" || prop.kind === "set") {
       hasAny = true;
-      util.pushMutatorMap(mutatorMap, prop.key, prop.kind, prop.computed, prop.value);
+      defineMap.push(mutatorMap, prop.key, prop.kind, prop.computed, prop.value);
       return false;
     } else {
       return true;
@@ -21,6 +21,6 @@ exports.ObjectExpression = function (node) {
 
   return t.callExpression(
     t.memberExpression(t.identifier("Object"), t.identifier("defineProperties")),
-    [node, util.buildDefineProperties(mutatorMap)]
+    [node, defineMap.build(mutatorMap)]
   );
 };

lib/6to5/transformation/transformers/es6/block-scoping-tdz.js

@@ -11,7 +11,7 @@ var visitor = {
     if (!declared) return;
 
     // declared node is different in this scope
-    if (scope.get(node.name, true) !== declared) return;
+    if (scope.getBinding(node.name) !== declared) return;
 
     var declaredLoc  = declared.loc;
     var referenceLoc = node.loc;

lib/6to5/transformation/transformers/es6/block-scoping.js

@@ -29,7 +29,7 @@ var isVar = function (node, parent) {
   return t.isVariableDeclaration(node, { kind: "var" }) && !isLet(node, parent);
 };
 
-var standardiseLets = function (declars) {
+var standardizeLets = function (declars) {
   for (var i = 0; i < declars.length; i++) {
     delete declars[i]._let;
   }
@@ -45,26 +45,15 @@ exports.Loop = function (node, parent, scope, context, file) {
     t.ensureBlock(node);
     node.body._letDeclarators = [init];
   }
-
-  if (t.isLabeledStatement(parent)) {
-    // set label so `run` has access to it
-    node.label = parent.label;
-  }
-
-  var letScoping = new LetScoping(node, node.body, parent, scope, file);
-  letScoping.run();
-
-  if (node.label && !t.isLabeledStatement(parent)) {
-    // we've been given a label so let's wrap ourselves
-    return t.labeledStatement(node.label, node);
-  }
+  var blockScoping = new BlockScoping(node, node.body, parent, scope, file);
+  blockScoping.run();
 };
 
 exports.Program =
 exports.BlockStatement = function (block, parent, scope, context, file) {
   if (!t.isLoop(parent)) {
-    var letScoping = new LetScoping(false, block, parent, scope, file);
-    letScoping.run();
+    var blockScoping = new BlockScoping(false, block, parent, scope, file);
+    blockScoping.run();
   }
 };
 
@@ -78,7 +67,7 @@ exports.BlockStatement = function (block, parent, scope, context, file) {
  * @param {File} file
  */
 
-function LetScoping(loopParent, block, parent, scope, file) {
+function BlockScoping(loopParent, block, parent, scope, file) {
   this.loopParent = loopParent;
   this.parent     = parent;
   this.scope      = scope;
@@ -95,7 +84,7 @@ function LetScoping(loopParent, block, parent, scope, file) {
  * Start the ball rolling.
  */
 
-LetScoping.prototype.run = function () {
+BlockScoping.prototype.run = function () {
   var block = this.block;
   if (block._letDone) return;
   block._letDone = true;
@@ -121,11 +110,11 @@ function replace(node, parent, scope, context, remaps) {
   var remap = remaps[node.name];
   if (!remap) return;
 
-  var own = scope.get(node.name, true);
-  if (own === remap.node) {
+  var ownBinding = scope.getBinding(node.name);
+  if (ownBinding === remap.binding) {
     node.name = remap.uid;
   } else {
-    // scope already has it's own declaration that doesn't
+    // scope already has it's own binding that doesn't
     // match the one we have a stored replacement for
     if (context) context.skip();
   }
@@ -144,7 +133,7 @@ function traverseReplace(node, parent, scope, remaps) {
  * Description
  */
 
-LetScoping.prototype.remap = function () {
+BlockScoping.prototype.remap = function () {
   var hasRemaps = false;
   var letRefs   = this.letReferences;
   var scope     = this.scope;
@@ -160,13 +149,13 @@ LetScoping.prototype.remap = function () {
     // this is the defining identifier of a declaration
     var ref = letRefs[key];
 
-    if (scope.parentHas(key)) {
+    if (scope.parentHasReference(key)) {
       var uid = scope.generateUidIdentifier(ref.name).name;
       ref.name = uid;
 
       hasRemaps = true;
       remaps[key] = remaps[uid] = {
-        node: ref,
+        binding: ref,
         uid: uid
       };
     }
@@ -190,7 +179,7 @@ LetScoping.prototype.remap = function () {
  * Description
  */
 
-LetScoping.prototype.needsClosure = function () {
+BlockScoping.prototype.needsClosure = function () {
   var block = this.block;
 
   // if we're inside of a for loop then we search to see if there are any
@@ -238,7 +227,7 @@ var letReferenceFunctionVisitor = {
 
     // this scope has a variable with the same name so it couldn't belong
     // to our let scope
-    if (scope.hasOwn(node.name, true)) return;
+    if (scope.hasOwnBinding(node.name)) return;
 
     // not a part of our scope
     if (!state.letReferences[node.name]) return;
@@ -260,7 +249,7 @@ var letReferenceBlockVisitor = {
  * Description
  */
 
-LetScoping.prototype.getLetReferences = function () {
+BlockScoping.prototype.getLetReferences = function () {
   var block = this.block;
 
   var declarators = block._letDeclarators || [];
@@ -269,7 +258,7 @@ LetScoping.prototype.getLetReferences = function () {
   //
   for (var i = 0; i < declarators.length; i++) {
     declar = declarators[i];
-    extend(this.outsideLetReferences, t.getIds(declar, true));
+    extend(this.outsideLetReferences, t.getBindingIdentifiers(declar));
   }
 
   //
@@ -285,7 +274,7 @@ LetScoping.prototype.getLetReferences = function () {
   //
   for (i = 0; i < declarators.length; i++) {
     declar = declarators[i];
-    var keys = t.getIds(declar, true);
+    var keys = t.getBindingIdentifiers(declar);
     extend(this.letReferences, keys);
     this.hasLetReferences = true;
   }
@@ -294,7 +283,7 @@ LetScoping.prototype.getLetReferences = function () {
   if (!this.hasLetReferences) return;
 
   // set let references to plain var references
-  standardiseLets(declarators);
+  standardizeLets(declarators);
 
   var state = {
     letReferences: this.letReferences,
@@ -308,34 +297,71 @@ LetScoping.prototype.getLetReferences = function () {
   return state.closurify;
 };
 
+var loopNodeTo = function (node) {
+  if (t.isBreakStatement(node)) {
+    return "break";
+  } else if (t.isContinueStatement(node)) {
+    return "continue";
+  }
+};
+
 var loopVisitor = {
   enter: function (node, parent, scope, context, state) {
     var replace;
 
+    if (t.isLoop(node)) {
+      state.ignoreLabeless = true;
+      traverse(node, loopVisitor, scope, state);
+      state.ignoreLabeless = false;
+    }
+
     if (t.isFunction(node) || t.isLoop(node)) {
       return context.skip();
     }
 
-    if (node && !node.label && state.isLoop) {
-      if (t.isBreakStatement(node)) {
-        if (t.isSwitchCase(parent)) return;
+    var loopText = loopNodeTo(node);
 
-        state.hasBreak = true;
-        replace = t.returnStatement(t.literal("break"));
-      } else if (t.isContinueStatement(node)) {
-        state.hasContinue = true;
-        replace = t.returnStatement(t.literal("continue"));
+    if (loopText) {
+      if (node.label) {
+        // we shouldn't be transforming this because it exists somewhere inside
+        if (state.innerLabels.indexOf(node.label.name) >= 0) {
+          return;
+        }
+
+        loopText = loopText + "|" + node.label.name;
+      } else {
+        // we shouldn't be transforming these statements because
+        // they don't refer to the actual loop we're scopifying
+        if (state.ignoreLabeless) return;
+
+        // break statements mean something different in this context
+        if (t.isBreakStatement(node) && t.isSwitchCase(parent)) return;
       }
+
+      state.hasBreakContinue = true;
+      state.map[loopText] = node;
+      replace = t.literal(loopText);
     }
 
     if (t.isReturnStatement(node)) {
       state.hasReturn = true;
-      replace = t.returnStatement(t.objectExpression([
+      replace = t.objectExpression([
         t.property("init", t.identifier("v"), node.argument || t.identifier("undefined"))
-      ]));
+      ]);
     }
 
-    if (replace) return t.inherits(replace, node);
+    if (replace) {
+      replace = t.returnStatement(replace);
+      return t.inherits(replace, node);
+    }
+  }
+};
+
+var loopLabelVisitor = {
+  enter: function (node, parent, scope, context, state) {
+    if (t.isLabeledStatement(node)) {
+      state.innerLabels.push(node.label.name);
+    }
   }
 };
 
@@ -348,15 +374,19 @@ var loopVisitor = {
  * @returns {Object}
  */
 
-LetScoping.prototype.checkLoop = function () {
+BlockScoping.prototype.checkLoop = function () {
   var state = {
-    hasContinue: false,
-    hasReturn:   false,
-    hasBreak:    false,
-    isLoop:      !!this.loopParent
+    hasBreakContinue: false,
+    ignoreLabeless:   false,
+    innerLabels:      [],
+    hasReturn:        false,
+    isLoop:           !!this.loopParent,
+    map:              {}
   };
 
+  traverse(this.block, loopLabelVisitor, this.scope, state);
   traverse(this.block, loopVisitor, this.scope, state);
+
   return state;
 };
 
@@ -383,7 +413,7 @@ var hoistVarDeclarationsVisitor = {
  * once we wrap everything in a closure.
  */
 
-LetScoping.prototype.hoistVarDeclarations = function () {
+BlockScoping.prototype.hoistVarDeclarations = function () {
   traverse(this.block, hoistVarDeclarationsVisitor, this.scope, this);
 };
 
@@ -395,7 +425,7 @@ LetScoping.prototype.hoistVarDeclarations = function () {
  * @returns {Array}
  */
 
-LetScoping.prototype.pushDeclar = function (node) {
+BlockScoping.prototype.pushDeclar = function (node) {
   this.body.push(t.variableDeclaration(node.kind, node.declarations.map(function (declar) {
     return t.variableDeclarator(declar.id);
   })));
@@ -420,9 +450,9 @@ LetScoping.prototype.pushDeclar = function (node) {
  * @param {Node} call CallExpression
  */
 
-LetScoping.prototype.build = function (ret, call) {
+BlockScoping.prototype.build = function (ret, call) {
   var has = this.has;
-  if (has.hasReturn || has.hasBreak || has.hasContinue) {
+  if (has.hasReturn || has.hasBreakContinue) {
     this.buildHas(ret, call);
   } else {
     this.body.push(t.expressionStatement(call));
@@ -436,7 +466,7 @@ LetScoping.prototype.build = function (ret, call) {
  * @param {Node} call CallExpression
  */
 
-LetScoping.prototype.buildHas = function (ret, call) {
+BlockScoping.prototype.buildHas = function (ret, call) {
   var body = this.body;
 
   body.push(t.variableDeclaration("var", [
@@ -455,22 +485,14 @@ LetScoping.prototype.buildHas = function (ret, call) {
     });
   }
 
-  if (has.hasBreak || has.hasContinue) {
+  if (has.hasBreakContinue) {
     if (!loopParent) {
       throw new Error("Has no loop parent but we're trying to reassign breaks " +
                       "and continues, something is going wrong here.");
     }
 
-    // ensure that the parent has a label as we're building a switch and we
-    // need to be able to access it
-    var label = loopParent.label = loopParent.label || this.scope.generateUidIdentifier("loop");
-
-    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)]));
+    for (var key in has.map) {
+      cases.push(t.switchCase(t.literal(key), [has.map[key]]));
     }
 
     if (has.hasReturn) {

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

@@ -2,6 +2,7 @@
 
 var ReplaceSupers = require("../../helpers/replace-supers");
 var nameMethod    = require("../../helpers/name-method");
+var defineMap     = require("../../helpers/define-map");
 var util          = require("../../../util");
 var t             = require("../../../types");
 
@@ -66,12 +67,19 @@ Class.prototype.run = function () {
 
   var body = this.body = [];
 
+  var constructorBody = t.blockStatement([
+    t.expressionStatement(t.callExpression(file.addHelper("class-call-check"), [
+      t.thisExpression(),
+      className
+    ]))
+  ]);
   var constructor;
+
   if (this.node.id) {
-    constructor = t.functionDeclaration(className, [], t.blockStatement([]));
+    constructor = t.functionDeclaration(className, [], constructorBody);
     body.push(constructor);
   } else {
-    constructor = t.functionExpression(null, [], t.blockStatement([]));
+    constructor = t.functionExpression(null, [], constructorBody);
     body.push(t.variableDeclaration("var", [
       t.variableDeclarator(className, constructor)
     ]));
@@ -160,10 +168,9 @@ Class.prototype.buildBody = function () {
 
   // we have no constructor, we have a super, and the super doesn't appear to be falsy
   if (!this.hasConstructor && superName && !t.isFalsyExpression(superName)) {
-    var defaultConstructorTemplate = "class-super-constructor-call";
-    if (this.isLoose) defaultConstructorTemplate += "-loose";
-
-    constructor.body.body.push(util.template(defaultConstructorTemplate, {
+    var helperName = "class-super-constructor-call";
+    if (this.isLoose) helperName += "-loose";
+    constructor.body.body.push(util.template(helperName, {
       CLASS_NAME: className,
       SUPER_NAME: this.superName
     }, true));
@@ -173,11 +180,11 @@ Class.prototype.buildBody = function () {
   var staticProps;
 
   if (this.hasInstanceMutators) {
-    instanceProps = util.buildDefineProperties(this.instanceMutatorMap);
+    instanceProps = defineMap.build(this.instanceMutatorMap);
   }
 
   if (this.hasStaticMutators) {
-    staticProps = util.buildDefineProperties(this.staticMutatorMap);
+    staticProps = defineMap.build(this.staticMutatorMap);
   }
 
   if (instanceProps || staticProps) {
@@ -230,8 +237,8 @@ Class.prototype.pushMethod = function (node) {
     this.hasInstanceMutators = true;
   }
 
-  util.pushMutatorMap(mutatorMap, methodName, kind, node.computed, node);
-  util.pushMutatorMap(mutatorMap, methodName, "enumerable", node.computed, false);
+  defineMap.push(mutatorMap, methodName, kind, node.computed, node);
+  defineMap.push(mutatorMap, methodName, "enumerable", node.computed, false);
 };
 
 /**
@@ -255,5 +262,5 @@ Class.prototype.pushConstructor = function (method) {
 
   construct._ignoreUserWhitespace = true;
   construct.params                = fn.params;
-  construct.body                  = fn.body;
+  construct.body.body             = construct.body.body.concat(fn.body.body);
 };

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

@@ -5,8 +5,8 @@ var t        = require("../../../types");
 
 var visitor = {
   enter: function (node, parent, scope, context, state) {
-    if (t.isDeclaration(node) || t.isAssignmentExpression(node)) {
-      var ids = t.getIds(node, true);
+    if (t.isAssignmentExpression(node) || t.isUpdateExpression(node)) {
+      var ids = t.getBindingIdentifiers(node);
 
       for (var key in ids) {
         var id = ids[key];
@@ -21,6 +21,9 @@ var visitor = {
         // constant so we can just ignore it
         if (id === constant) continue;
 
+        var localBinding = scope.getBinding(key);
+        if (localBinding !== constant) continue;
+
         throw state.file.errorWithNode(id, key + " is read-only");
       }
     } else if (t.isScope(node)) {
@@ -31,7 +34,7 @@ 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/modules.js

@@ -26,7 +26,7 @@ exports.ExportDeclaration = function (node, parent, scope, context, file) {
   var i;
 
   if (node.declaration) {
-    // make sure variable exports have an initialiser
+    // make sure variable exports have an initializer
     // this is done here to avoid duplicating it in the module formatters
     if (t.isVariableDeclaration(node.declaration)) {
       var declar = node.declaration.declarations[0];

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

@@ -13,7 +13,7 @@ var hasDefaults = function (node) {
 
 var iifeVisitor = {
   enter: function (node, parent, scope, context, state) {
-    if (t.isReferencedIdentifier(node, parent) && scope.hasOwn(node.name)) {
+    if (t.isReferencedIdentifier(node, parent) && state.scope.hasOwnReference(node.name)) {
       state.iife = true;
       context.stop();
     }
@@ -48,7 +48,7 @@ exports.Function = function (node, parent, scope) {
     node.params[i] = scope.generateUidIdentifier("x");
 
     if (!state.iife) {
-      if (t.isIdentifier(right) && scope.hasOwn(right.name)) {
+      if (t.isIdentifier(right) && scope.hasOwnReference(right.name)) {
         state.iife = true;
       } else {
         traverse(right, iifeVisitor, scope, state);

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/es6/properties.computed.js

@@ -58,7 +58,7 @@ var spec = function (node, body, objId, initProps, file) {
   var props = node.properties;
   var prop, key;
 
-  // normalise key
+  // normalize key
 
   for (var i = 0; i < props.length; i++) {
     prop = props[i];

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

@@ -13,7 +13,7 @@ module.exports = {
 
   react:                                   require("./other/react"),
 
-  _modulesSplit:                           require("./internal/modules-split"),
+  _modules:                                require("./internal/modules"),
 
   // needs to be before `regenerator` due to generator comprehensions
   // needs to be before `_aliasFunction`
@@ -52,14 +52,13 @@ 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
@@ -81,5 +80,10 @@ module.exports = {
   "spec.undefinedToVoid":                  require("./spec/undefined-to-void"),
 
   "minification.propertyLiterals":         require("./minification/property-literals"),
-  "minification.memberExpressionLiterals": require("./minification/member-expression-literals")
+  "minification.memberExpressionLiterals": require("./minification/member-expression-literals"),
+
+  "minification.removeDebugger":           require("./minification/remove-debugger"),
+  "minification.removeConsoleCalls":       require("./minification/remove-console-calls"),
+  "minification.deadCodeElimination":      require("./minification/dead-code-elimination"),
+  "minification.renameLocalVariables":     require("./minification/rename-local-variables")
 };

lib/6to5/transformation/transformers/internal/modules.js

@@ -8,7 +8,18 @@
 
 var t = require("../../../types");
 
+var resolveModuleSource = function (node, parent, scope, context, file) {
+  var resolveModuleSource = file.opts.resolveModuleSource;
+  if (node.source && resolveModuleSource) {
+    node.source.value = resolveModuleSource(node.source.value);
+  }
+};
+
+exports.ImportDeclaration = resolveModuleSource;
+
 exports.ExportDeclaration = function (node, parent, scope) {
+  resolveModuleSource.apply(null, arguments);
+
   var declar = node.declaration;
 
   if (node.default) {

lib/6to5/transformation/transformers/minification/dead-code-elimination.js

@@ -0,0 +1,77 @@
+var t = require("../../../types");
+
+exports.optional = true;
+
+exports.ExpressionStatement = function (node, parent, scope, context) {
+  // remove consequenceless expressions such as local variables and literals
+  //
+  //   var foo = true; foo; -> var foo = true;
+  //   "foo"; ->
+  //
+
+  var expr = node.expression;
+  if (t.isLiteral(expr) || (t.isIdentifier(node) && t.hasBinding(node.name))) {
+    context.remove();
+  }
+};
+
+exports.IfStatement = {
+  exit: function (node, parent, scope, context) {
+    // todo: in scenarios where we can just return the consequent or
+    // alternate we should drop the block statement if it contains no
+    // block scoped variables
+
+    var consequent = node.consequent;
+    var alternate  = node.alternate;
+    var test       = node.test;
+
+    // we can check if a test will be truthy 100% and if so we can inline
+    // the consequent and completely ignore the alternate
+    //
+    //   if (true) { foo; } -> { foo; }
+    //   if ("foo") { foo; } -> { foo; }
+    //
+
+    if (t.isLiteral(test) && test.value) {
+      return alternate;
+    }
+
+    // we can check if a test will be falsy 100% and if so we can inline
+    // the alternate if there is one and completely remove the consequent
+    //
+    //   if ("") { bar; } else { foo; } -> { foo; }
+    //   if ("") { bar; } ->
+    //
+
+    if (t.isFalsyExpression(test)) {
+      if (alternate) {
+        return alternate;
+      } else {
+        return context.remove();
+      }
+    }
+
+    // remove alternate blocks that are empty
+    //
+    //   if (foo) { foo; } else {} -> if (foo) { foo; }
+    //
+
+    if (t.isBlockStatement(alternate) && !alternate.body.length) {
+      alternate = node.alternate = null;
+    }
+
+    // turn alternate blocks into a consequent and flip the test if the
+    // consequent block is empty
+    //
+    //   if (foo) {} else { bar; }
+    //   if (!foo) { bar; }
+    //
+
+    if (t.blockStatement(consequent) && !consequent.body.length &&
+        t.isBlockStatement(alternate) && alternate.body.length) {
+      node.consequent = node.alternate;
+      node.alternate  = null;
+      node.test       = t.unaryExpression("!", test, true);
+    }
+  }
+};

lib/6to5/transformation/transformers/minification/remove-console-calls.js

@@ -0,0 +1,13 @@
+"use strict";
+
+var t = require("../../../types");
+
+var isConsole = t.buildMatchMemberExpression("console", true);
+
+exports.optional = true;
+
+exports.CallExpression = function (node, parent, scope, context) {
+  if (isConsole(node.callee)) {
+    context.remove();
+  }
+};

lib/6to5/transformation/transformers/minification/remove-debugger.js

@@ -0,0 +1,9 @@
+var t = require("../../../types");
+
+exports.optional = true;
+
+exports.ExpressionStatement = function (node, parent, scope, context) {
+  if (t.isIdentifier(node.expression, { name: "debugger" })) {
+    context.remove();
+  }
+};

lib/6to5/transformation/transformers/minification/rename-local-variables.js

@@ -0,0 +1,10 @@
+//var t = require("../../../types");
+
+exports.optional = true;
+
+exports.Scope = function () {
+  // todo: get all binding identifiers, generate compact names
+  // that wont collide and then call the remap identifier helper
+  // this transformer **has** to be ran last as it will absolutley
+  // destroy the scope tree
+};

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) {
@@ -170,11 +171,21 @@ exports.JSXElement = {
 var cleanJSXElementLiteralChild = function (child, args) {
   var lines = child.value.split(/\r\n|\n|\r/);
 
-  for (var i = 0; i < lines.length; i++) {
+  var lastNonEmptyLine = 0;
+  var i;
+
+  for (i = 0; i < lines.length; i++) {
+    if (lines[i].match(/[^ \t]/)) {
+      lastNonEmptyLine = i;
+    }
+  }
+
+  for (i = 0; i < lines.length; i++) {
     var line = lines[i];
 
     var isFirstLine = i === 0;
     var isLastLine = i === lines.length - 1;
+    var isLastNonEmptyLine = i === lastNonEmptyLine;
 
     // replace rendered whitespace tabs with spaces
     var trimmedLine = line.replace(/\t/g, " ");
@@ -190,6 +201,10 @@ var cleanJSXElementLiteralChild = function (child, args) {
     }
 
     if (trimmedLine) {
+      if (!isLastNonEmptyLine) {
+        trimmedLine += " ";
+      }
+
       args.push(t.literal(trimmedLine));
     }
   }
@@ -197,34 +212,7 @@ 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;
-
   var props = call.arguments[0].properties;
   var safe = true;
 
@@ -241,6 +229,12 @@ var addDisplayName = function (id, call) {
   }
 };
 
+exports.ExportDeclaration = function (node, parent, scope, context, file) {
+  if (node.default && react.isCreateClass(node.declaration)) {
+    addDisplayName(file.opts.basename, node.declaration);
+  }
+};
+
 exports.AssignmentExpression =
 exports.Property =
 exports.VariableDeclarator = function (node) {
@@ -261,7 +255,7 @@ exports.VariableDeclarator = function (node) {
     left = left.property;
   }
 
-  if (t.isIdentifier(left)) {
+  if (t.isIdentifier(left) && react.isCreateClass(right)) {
     addDisplayName(left.name, right);
   }
 };

lib/6to5/transformation/transformers/other/self-contained.js

@@ -35,7 +35,7 @@ var astVisitor = {
         context.skip();
         return t.prependToMemberExpression(node, file.get("coreIdentifier"));
       }
-    } else if (t.isReferencedIdentifier(node, parent) && !t.isMemberExpression(parent) && contains(ALIASABLE_CONSTRUCTORS, node.name) && !scope.get(node.name, true)) {
+    } else if (t.isReferencedIdentifier(node, parent) && !t.isMemberExpression(parent) && contains(ALIASABLE_CONSTRUCTORS, node.name) && !scope.getBinding(node.name)) {
       // Symbol() -> _core.Symbol(); new Promise -> new _core.Promise
       return t.memberExpression(file.get("coreIdentifier"), node);
     } else if (t.isCallExpression(node)) {

lib/6to5/transformation/transformers/other/use-strict.js

@@ -16,6 +16,6 @@ exports.FunctionExpression = function (node, parent, scope, context) {
   context.skip();
 };
 
-exports.ThisExpression = function (node, parent, scope, context, file) {
-  throw file.errorWithNode(node, "Top level `this` is not allowed", ReferenceError);
+exports.ThisExpression = function () {
+  return t.identifier("undefined");
 };

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/spec/block-scoped-functions.js

@@ -3,13 +3,13 @@
 var t = require("../../../types");
 
 exports.BlockStatement = function (node, parent) {
-  if (t.isFunction(parent) || t.isExportDeclaration(parent)) {
+  if ((t.isFunction(parent) && parent.body === node) || t.isExportDeclaration(parent)) {
     return;
   }
 
   for (var i = 0; i < node.body.length; i++) {
     var func = node.body[i];
-    if (!t.isFunctionDeclaration(i)) continue;
+    if (!t.isFunctionDeclaration(func)) continue;
 
     var declar = t.variableDeclaration("let", [
       t.variableDeclarator(func.id, t.toExpression(func))
@@ -21,6 +21,6 @@ exports.BlockStatement = function (node, parent) {
     // todo: name this
     func.id = null;
 
-    func.body[i] = declar;
+    node.body[i] = declar;
   }
 };

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.hasBinding(node.name)) 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 bindings = scope.getAllBindings();
+
+  var closest;
+  var shortest = -1;
+
+  for (var name in bindings) {
+    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/global-keys.json

@@ -1,64 +0,0 @@
-[
-  "Set",
-  "Map",
-  "WeakMap",
-  "WeakSet",
-  "Proxy",
-  "Promise",
-  "Reflect",
-  "Symbol",
-  "System",
-  "__filename",
-  "__dirname",
-  "GLOBAL",
-  "global",
-  "module",
-  "require",
-  "Buffer",
-  "console",
-  "exports",
-  "process",
-  "setTimeout",
-  "clearTimeout",
-  "setInterval",
-  "clearInterval",
-  "setImmediate",
-  "clearImmediate",
-  "Array",
-  "Boolean",
-  "Date",
-  "decodeURI",
-  "decodeURIComponent",
-  "encodeURI",
-  "encodeURIComponent",
-  "Error",
-  "eval",
-  "EvalError",
-  "Function",
-  "hasOwnProperty",
-  "isFinite",
-  "isNaN",
-  "JSON",
-  "Map",
-  "Math",
-  "Number",
-  "Object",
-  "Proxy",
-  "Promise",
-  "parseInt",
-  "parseFloat",
-  "RangeError",
-  "ReferenceError",
-  "RegExp",
-  "Set",
-  "String",
-  "SyntaxError",
-  "TypeError",
-  "URIError",
-  "WeakMap",
-  "WeakSet",
-  "arguments",
-  "NaN",
-  "window",
-  "self"
-]

lib/6to5/traverse/index.js

@@ -41,6 +41,13 @@ TraversalContext.prototype.reset = function () {
   this.shouldStop   = false;
 };
 
+TraversalContext.prototype.maybeRemove = function (obj, key) {
+  if (this.shouldRemove) {
+    obj[key] = null;
+    this.shouldFlatten = true;
+  }
+};
+
 function replaceNode(obj, key, node, result) {
   var isArray = Array.isArray(result);
 
@@ -76,10 +83,7 @@ TraversalContext.prototype.enterNode = function (obj, key, node, enter, parent,
     }
   }
 
-  if (this.shouldRemove) {
-    obj[key] = null;
-    this.shouldFlatten = true;
-  }
+  this.maybeRemove(obj, key);
 
   return node;
 };
@@ -97,6 +101,8 @@ TraversalContext.prototype.exitNode = function (obj, key, node, exit, parent, sc
     }
   }
 
+  this.maybeRemove(obj, key);
+
   return node;
 };
 
@@ -237,6 +243,20 @@ traverse.removeProperties = function (tree) {
   return tree;
 };
 
+traverse.explode = function (obj) {
+  for (var type in obj) {
+    var fns = obj[type];
+
+    var aliases = t.FLIPPED_ALIAS_KEYS[type];
+    if (aliases) {
+      for (var i = 0; i < aliases.length; i++) {
+        obj[aliases[i]] = fns;
+      }
+    }
+  }
+  return obj;
+};
+
 function hasBlacklistedType(node, parent, scope, context, state) {
   if (node.type === state.type) {
     state.has = true;

lib/6to5/traverse/scope.js

@@ -2,18 +2,19 @@
 
 module.exports = Scope;
 
+var contains = require("lodash/collection/contains");
 var traverse = require("./index");
+var defaults = require("lodash/object/defaults");
+var globals  = require("globals");
+var flatten  = require("lodash/array/flatten");
+var extend   = require("lodash/object/extend");
 var object   = require("../helpers/object");
-var t        = require("../types");
 var each     = require("lodash/collection/each");
 var has      = require("lodash/object/has");
-var contains = require("lodash/collection/contains");
-var defaults = require("lodash/object/defaults");
-
-var FOR_KEYS = ["left", "init"];
+var t        = require("../types");
 
 /**
- * This searches the current "scope" and collects all references/declarations
+ * This searches the current "scope" and collects all references/bindings
  * within.
  *
  * @param {Node} block
@@ -29,29 +30,10 @@ function Scope(block, parentBlock, parent, file) {
   this.parentBlock = parentBlock;
   this.block       = block;
 
-  var info = this.getInfo();
-  this.references = info.references;
-  this.declarations = info.declarations;
-  this.declarationKinds = info.declarationKinds;
+  this.crawl();
 }
 
-Scope.defaultDeclarations = require("./global-keys");
-
-Scope.prototype._add = function (node, references, throwOnDuplicate) {
-  if (!node) return;
-
-  var ids = t.getIds(node, true);
-
-  for (var key in ids) {
-    var id = ids[key];
-
-    if (throwOnDuplicate && references[key]) {
-      throw this.file.errorWithNode(id, "Duplicate declaration", TypeError);
-    }
-
-    references[key] = id;
-  }
-};
+Scope.defaultDeclarations = flatten([globals.builtin, globals.browser, globals.node].map(Object.keys));
 
 /**
  * Description
@@ -128,7 +110,7 @@ Scope.prototype.generateUidBasedOnNode = function (parent) {
  */
 
 Scope.prototype.generateTempBasedOnNode = function (node) {
-  if (t.isIdentifier(node) && this.has(node.name, true)) {
+  if (t.isIdentifier(node) && this.hasBinding(node.name)) {
     return null;
   }
 
@@ -140,12 +122,91 @@ Scope.prototype.generateTempBasedOnNode = function (node) {
   return id;
 };
 
+Scope.prototype.checkBlockScopedCollisions = function (key, id) {
+  if (this.declarationKinds["let"][key] || this.declarationKinds["const"][key]) {
+    throw this.file.errorWithNode(id, "Duplicate declaration " + key, TypeError);
+  }
+};
+
+Scope.prototype.inferType = function (node) {
+  var target;
+
+  if (t.isVariableDeclarator(node)) {
+    target = node.init;
+  }
+
+  if (t.isLiteral(target) || t.isArrayExpression(target) || t.isObjectExpression(target)) {
+    // todo: possibly call some helper that will resolve these to a type annotation
+  }
+
+  if (t.isCallExpression(target)) {
+    // todo: need to resolve this to a return type
+  }
+
+  if (t.isMemberExpression(target)) {
+    // todo: crawl this and find the correct type, bail on anything that we cannot
+    // possibly be 100% confident on
+  }
+
+  if (t.isIdentifier(target)) {
+    return this.getType(target.name);
+  }
+};
+
+Scope.prototype.registerType = function (key, id, node) {
+  var type;
+
+  if (id.typeAnnotation) {
+    type = id.typeAnnotation;
+  }
+
+  if (!type) {
+    type = this.inferType(node);
+  }
+
+  if (type) {
+    if (t.isTypeAnnotation(type)) type = type.typeAnnotation;
+    this.types[key] = type;
+  }
+};
+
+Scope.prototype.register = function (node, reference, kind) {
+  if (t.isVariableDeclaration(node)) {
+    return this.registerVariableDeclaration(node);
+  }
+
+  var ids = t.getBindingIdentifiers(node);
+
+  extend(this.references, ids);
+
+  if (reference) return;
+
+  for (var key in ids) {
+    var id = ids[key];
+
+    this.checkBlockScopedCollisions(key, id);
+
+    this.registerType(key, id, node);
+    this.bindings[key] = id;
+  }
+
+  var kinds = this.declarationKinds[kind];
+  if (kinds) extend(kinds, ids);
+};
+
+Scope.prototype.registerVariableDeclaration = function (declar) {
+  var declars = declar.declarations;
+  for (var i = 0; i < declars.length; i++) {
+    this.register(declars[i], false, declar.kind);
+  }
+};
+
 var functionVariableVisitor = {
   enter: function (node, parent, scope, context, state) {
     if (t.isFor(node)) {
-      each(FOR_KEYS, function (key) {
+      each(t.FOR_INIT_KEYS, function (key) {
         var declar = node[key];
-        if (t.isVar(declar)) state.add(declar);
+        if (t.isVar(declar)) state.scope.register(declar);
       });
     }
 
@@ -156,64 +217,76 @@ var functionVariableVisitor = {
     // function identifier doesn't belong to this scope
     if (state.blockId && node === state.blockId) return;
 
+    // delegate block scope handling to the `blockVariableVisitor`
+    if (t.isBlockScoped(node)) return;
+
+    // this will be hit again once we traverse into it after this iteration
+    if (t.isExportDeclaration(node) && t.isDeclaration(node.declaration)) return;
+
     // we've ran into a declaration!
-    // we'll let the BlockStatement scope deal with `let` declarations unless
-    if (t.isDeclaration(node) && !t.isBlockScoped(node)) {
-      state.add(node);
-    }
+    if (t.isDeclaration(node)) state.scope.register(node);
   }
 };
 
 var programReferenceVisitor = {
-  enter: function (node, parent, scope, context, add) {
-    if (t.isReferencedIdentifier(node, parent) && !scope.has(node.name)) {
-      add(node, true);
+  enter: function (node, parent, scope, context, state) {
+    if (t.isReferencedIdentifier(node, parent) && !scope.hasReference(node.name)) {
+      state.register(node, true);
     }
   }
 };
 
 var blockVariableVisitor = {
-  enter: function (node, parent, scope, context, add) {
+  enter: function (node, parent, scope, context, state) {
     if (t.isBlockScoped(node)) {
-      add(node, false, t.isLet(node));
+      state.register(node);
     } else if (t.isScope(node)) {
       context.skip();
     }
   }
 };
 
-Scope.prototype.getInfo = function () {
+Scope.prototype.crawl = function () {
   var parent = this.parent;
   var block  = this.block;
-  var self   = this;
-  if (block._scopeInfo) return block._scopeInfo;
+  var i;
 
-  var info = block._scopeInfo = {};
-  var references = info.references = object();
-  var declarations = info.declarations = object();
-  var declarationKinds = info.declarationKinds = {};
+  //
 
-  var add = function (node, reference, throwOnDuplicate) {
-    self._add(node, references);
+  var info = block._scopeInfo;
+  if (info) {
+    extend(this, info);
+    return;
+  }
 
-    if (!reference) {
-      self._add(node, declarations, throwOnDuplicate);
-      self._add(node, declarationKinds[node.kind] = declarationKinds[node.kind] || object());
-    }
+  info = block._scopeInfo = {
+    declarationKinds: {
+      "const": object(),
+      "var":   object(),
+      "let":   object()
+    },
+
+    references: object(),
+    bindings:   object(),
+    types:      object(),
   };
 
-  if (parent && t.isBlockStatement(block) && t.isFor(parent.block, { body: block })) {
-    // delegate block let declarations to the parent loop
-    return info;
+  extend(this, info);
+
+  //
+
+  if (parent && t.isBlockStatement(block) && t.isLoop(parent.block, { body: block })) {
+    // delegate let bindings to the parent loop
+    return;
   }
 
   // ForStatement - left, init
 
-  if (t.isFor(block)) {
-    each(FOR_KEYS, function (key) {
-      var node = block[key];
-      if (t.isBlockScoped(node)) add(node, false, true);
-    });
+  if (t.isLoop(block)) {
+    for (i = 0; i < t.FOR_INIT_KEYS.length; i++) {
+      var node = block[t.FOR_INIT_KEYS[i]];
+      if (t.isBlockScoped(node)) this.register(node, false, true);
+    }
 
     if (t.isBlockStatement(block.body)) {
       block = block.body;
@@ -223,19 +296,27 @@ Scope.prototype.getInfo = function () {
   // Program, BlockStatement - let variables
 
   if (t.isBlockStatement(block) || t.isProgram(block)) {
-    traverse(block, blockVariableVisitor, this, add);
+    traverse(block, blockVariableVisitor, this, this);
   }
 
   // CatchClause - param
 
   if (t.isCatchClause(block)) {
-    add(block.param);
+    this.register(block.param);
   }
 
   // ComprehensionExpression - blocks
 
   if (t.isComprehensionExpression(block)) {
-    add(block);
+    this.register(block);
+  }
+
+  // Function - params, rest
+
+  if (t.isFunction(block)) {
+    for (i = 0; i < block.params.length; i++) {
+      this.register(block.params[i]);
+    }
   }
 
   // Program, Function - var variables
@@ -243,7 +324,7 @@ Scope.prototype.getInfo = function () {
   if (t.isProgram(block) || t.isFunction(block)) {
     traverse(block, functionVariableVisitor, this, {
       blockId: block.id,
-      add:     add
+      scope:   this
     });
   }
 
@@ -251,25 +332,15 @@ Scope.prototype.getInfo = function () {
     if (!t.isProperty(this.parentBlock, { method: true })) {
       // SpiderMonkey AST doesn't use MethodDefinition here when it probably
       // should since they should be semantically the same?
-      add(block.id);
+      this.register(block.id);
     }
   }
 
   // Program
 
   if (t.isProgram(block)) {
-    traverse(block, programReferenceVisitor, this, add);
+    traverse(block, programReferenceVisitor, this, this);
   }
-
-  // Function - params, rest
-
-  if (t.isFunction(block)) {
-    each(block.params, function (param) {
-      add(param);
-    });
-  }
-
-  return info;
 };
 
 /**
@@ -302,12 +373,20 @@ Scope.prototype.push = function (opts) {
  * Walk up the scope tree until we hit a `Function` and then
  * push our `node` to it's references.
  *
+ * @param {String} kind
  * @param {Object} node
  */
 
-Scope.prototype.add = function (node) {
+Scope.prototype.addDeclarationToFunctionScope = function (kind, node) {
   var scope = this.getFunctionParent();
-  scope._add(node, scope.references);
+  var ids   = t.getBindingIdentifiers(node);
+
+  extend(scope.bindings, ids);
+  extend(scope.references, ids);
+
+  // this ignores the duplicate declaration logic specified in `getInfo`
+  // but it doesn't really matter
+  extend(scope.declarationKinds[kind], ids);
 };
 
 /**
@@ -324,12 +403,31 @@ Scope.prototype.getFunctionParent = function () {
 };
 
 /**
- * Walks the scope tree and gathers all declarations of `kind`.
+ * Walks the scope tree and gathers **all** bindings.
  *
  * @returns {Object}
  */
 
-Scope.prototype.getAllOfKind = function (kind) {
+Scope.prototype.getAllBindings = function () {
+  var ids = object();
+
+  var scope = this;
+  do {
+    defaults(ids, scope.bindings);
+    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;
@@ -341,74 +439,56 @@ Scope.prototype.getAllOfKind = function (kind) {
   return ids;
 };
 
-/**
- * Description
- *
- * @param {String} [id]
- * @param {Boolean} [decl]
- */
+//
 
-Scope.prototype.get = function (id, decl) {
-  return id && (this.getOwn(id, decl) || this.parentGet(id, decl));
+Scope.prototype.get = function (id, type) {
+  return id && (this.getOwn(id, type) || this.parentGet(id, type));
 };
 
-/**
- * Description
- *
- * @param {String} [id]
- * @param {Boolean} [decl]
- */
-
-Scope.prototype.getOwn = function (id, decl) {
-  var refs = this.references;
-  if (decl) refs = this.declarations;
-  return has(refs, id) && refs[id];
+Scope.prototype.getOwn = function (id, type) {
+  var refs = {
+    reference: this.references,
+    binding:   this.bindings,
+    type:      this.types
+  }[type];
+  return refs && has(refs, id) && refs[id];
 };
 
-/**
- * Description
- *
- * @param {String} [id]
- * @param {Boolean} [decl]
- */
-
-Scope.prototype.parentGet = function (id, decl) {
-  return this.parent && this.parent.get(id, decl);
+Scope.prototype.parentGet = function (id, type) {
+  return this.parent && this.parent.get(id, type);
 };
 
-/**
- * Description
- *
- * @param {String} [id]
- * @param {Boolean} [decl]
- * @returns {Boolean}
- */
-
-Scope.prototype.has = function (id, decl) {
-  return (id && (this.hasOwn(id, decl) || this.parentHas(id, decl))) ||
-         contains(Scope.defaultDeclarations, id);
+Scope.prototype.has = function (id, type) {
+  if (!id) return false;
+  if (this.hasOwn(id, type)) return true;
+  if (this.parentHas(id, type)) return true;
+  if (contains(Scope.defaultDeclarations, id)) return true;
+  return false;
 };
 
-/**
- * Description
- *
- * @param {String} [id]
- * @param {Boolean} [decl]
- * @returns {Boolean}
- */
-
-Scope.prototype.hasOwn = function (id, decl) {
-  return !!this.getOwn(id, decl);
+Scope.prototype.hasOwn = function (id, type) {
+  return !!this.getOwn(id, type);
 };
 
-/**
- * Description
- *
- * @param {String} [id]
- * @param {Boolean} [decl]
- * @returns {Boolean}
- */
-
-Scope.prototype.parentHas = function (id, decl) {
-  return this.parent && this.parent.has(id, decl);
+Scope.prototype.parentHas = function (id, type) {
+  return this.parent && this.parent.has(id, type);
 };
+
+each({
+  reference: "Reference",
+  binding: "Binding",
+  type: "Type"
+}, function (title, type) {
+  each([
+    "get",
+    "has",
+    "getOwn",
+    "hasOwn",
+    "parentGet",
+    "parentHas",
+  ], function (methodName) {
+    Scope.prototype[methodName + title] = function (id) {
+      return this[methodName](id, type);
+    };
+  });
+});

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

@@ -3,13 +3,13 @@
   "BreakStatement":      ["Statement"],
   "ContinueStatement":   ["Statement"],
   "DebuggerStatement":   ["Statement"],
-  "DoWhileStatement":    ["Statement", "Loop", "While"],
+  "DoWhileStatement":    ["Statement", "Loop", "While", "Scope"],
   "IfStatement":         ["Statement"],
   "ReturnStatement":     ["Statement"],
   "SwitchStatement":     ["Statement"],
   "ThrowStatement":      ["Statement"],
   "TryStatement":        ["Statement"],
-  "WhileStatement":      ["Statement", "Loop", "While"],
+  "WhileStatement":      ["Statement", "Loop", "While", "Scope"],
   "WithStatement":       ["Statement"],
   "EmptyStatement":      ["Statement"],
   "LabeledStatement":    ["Statement"],

lib/6to5/types/index.js

@@ -8,15 +8,10 @@ var each             = require("lodash/collection/each");
 var uniq             = require("lodash/array/uniq");
 var compact          = require("lodash/array/compact");
 var defaults         = require("lodash/object/defaults");
-var keys             = require("lodash/object/keys");
 var isString         = require("lodash/lang/isString");
 
 var t = exports;
 
-t.NATIVE_TYPE_NAMES = ["Array", "Object", "Number", "Boolean", "Date", "Array", "String"];
-
-//
-
 /**
  * Registers `is[Type]` and `assert[Type]` generated functions for a given `type`.
  * Pass `skipAliasCheck` to force it to directly compare `node.type` with `type`.
@@ -39,12 +34,11 @@ function registerType(type, skipAliasCheck) {
 }
 
 t.STATEMENT_OR_BLOCK_KEYS = ["consequent", "body"];
-
-//
+t.NATIVE_TYPE_NAMES       = ["Array", "Object", "Number", "Boolean", "Date", "Array", "String"];
+t.FOR_INIT_KEYS           = ["left", "init"];
 
 t.VISITOR_KEYS = require("./visitor-keys");
-
-t.ALIAS_KEYS = require("./alias-keys");
+t.ALIAS_KEYS   = require("./alias-keys");
 
 t.FLIPPED_ALIAS_KEYS = {};
 
@@ -66,6 +60,7 @@ each(t.FLIPPED_ALIAS_KEYS, function (types, type) {
 
 /**
  * Returns whether `node` is of given `type`.
+ *
  * For better performance, use this instead of `is[Type]` when `type` is unknown.
  * Optionally, pass `skipAliasCheck` to directly compare `node.type` with `type`.
  *
@@ -132,9 +127,7 @@ t.toComputedKey = function (node, key) {
 };
 
 /*
- * Shallowly checks to see if the passed `node` will evaluate to a
- * falsy. This is if `node` is a `Literal` and `value` is falsy or
- * `node` is an `Identifier` with a name of `undefiend`.
+ * Shallowly checks to see if the passed `node` is falsy.
  *
  * @param {Object} node
  * @returns {Boolean}
@@ -156,6 +149,9 @@ t.isFalsyExpression = function (node) {
  * declarations hoisted to the top of the current scope.
  *
  * Expression statements are just resolved to their standard expression.
+ *
+ * @param {Array} nodes
+ * @param {Scope} scope
  */
 
 t.toSequenceExpression = function (nodes, scope) {
@@ -185,17 +181,23 @@ t.toSequenceExpression = function (nodes, scope) {
   }
 };
 
-//
+/*
+ * Description
+ *
+ * @param {Object} actual
+ * @param {Object} expected
+ * @returns {Boolean}
+ */
 
 t.shallowEqual = function (actual, expected) {
   var keys = Object.keys(expected);
-  var key;
 
   for (var i = 0; i < keys.length; i++) {
-    key = keys[i];
+    var key = keys[i];
 
-    if (actual[key] !== expected[key])
+    if (actual[key] !== expected[key]) {
       return false;
+    }
   }
 
   return true;
@@ -253,8 +255,9 @@ t.isReferenced = function (node, parent) {
   }
 
   // yes: { [NODE]: "" }
-  if (t.isProperty(parent)) {
-    return parent.key === node && parent.computed;
+  // no: { NODE: "" }
+  if (t.isProperty(parent) && parent.key === node) {
+    return parent.computed;
   }
 
   // no: var NODE = init;
@@ -330,7 +333,7 @@ t.isReferenced = function (node, parent) {
 };
 
 /**
- * Description
+ * Check if the input `node` is an `Identifier` and `isReferenced`.
  *
  * @param {Object} node
  * @param {Object} parent
@@ -342,7 +345,8 @@ t.isReferencedIdentifier = function (node, parent) {
 };
 
 /**
- * Description
+ * Check if the input `name` is a valid identifier name
+ * and isn't a reserved word.
  *
  * @param {String} name
  * @returns {Boolean}
@@ -394,6 +398,65 @@ 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
+ * @param {Boolean} [allowPartial] Allow a partial match
+ * @returns {Function}
+ */
+
+t.buildMatchMemberExpression = function (match, allowPartial) {
+  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) {
+        if (allowPartial) {
+          return true;
+        } else {
+          return false;
+        }
+      }
+    }
+
+    return true;
+  };
+};
+
 /**
  * Description
  *
@@ -495,19 +558,14 @@ t.toBlock = function (node, parent) {
 };
 
 /**
- * Return a list of identifiers that will be assigned
- * as a result of runtime evaluation.
- *
- * If an identifier is passed as `node` instead of a
- * declaration then it's assumed to be an assignable.
+ * Return a list of binding identifiers associated with
+ * the input `node`.
  *
  * @param {Object} node
- * @param {Boolean} [map]
- * @param {Array} [ignoreTypes]
  * @returns {Array|Object}
  */
 
-t.getIds = function (node, map, ignoreTypes) {
+t.getBindingIdentifiers = function (node) {
   var search = [].concat(node);
   var ids    = object();
 
@@ -515,13 +573,7 @@ t.getIds = function (node, map, ignoreTypes) {
     var id = search.shift();
     if (!id) continue;
 
-    // blacklist types
-    if (ignoreTypes && ignoreTypes.indexOf(id.type) >= 0) continue;
-
-    var nodeKeys = t.getIds.nodes[id.type];
-    var arrKeys  = t.getIds.arrays[id.type];
-
-    var i, key;
+    var keys = t.getBindingIdentifiers.keys[id.type];
 
     if (t.isIdentifier(id)) {
       ids[id.name] = id;
@@ -529,27 +581,18 @@ t.getIds = function (node, map, ignoreTypes) {
       if (t.isDeclaration(node.declaration)) {
         search.push(node.declaration);
       }
-    } else if (nodeKeys) {
-      for (i = 0; i < nodeKeys.length; i++) {
-        key = nodeKeys[i];
-        if (id[key]) {
-          search.push(id[key]);
-          break;
-        }
-      }
-    } else if (arrKeys) {
-      for (i = 0; i < arrKeys.length; i++) {
-        key = arrKeys[i];
+    } else if (keys) {
+      for (var i = 0; i < keys.length; i++) {
+        var key = keys[i];
         search = search.concat(id[key] || []);
       }
     }
   }
 
-  if (!map) ids = keys(ids);
   return ids;
 };
 
-t.getIds.nodes = {
+t.getBindingIdentifiers.keys = {
   AssignmentExpression: ["left"],
   ImportBatchSpecifier: ["name"],
   ImportSpecifier: ["name", "id"],
@@ -560,12 +603,10 @@ t.getIds.nodes = {
   MemeberExpression: ["object"],
   SpreadElement: ["argument"],
   RestElement: ["argument"],
+  UpdateExpression: ["argument"],
   Property: ["value"],
   ComprehensionBlock: ["left"],
-  AssignmentPattern: ["left"]
-};
-
-t.getIds.arrays = {
+  AssignmentPattern: ["left"],
   PrivateDeclaration: ["declarations"],
   ComprehensionExpression: ["blocks"],
   ImportDeclaration: ["specifiers"],
@@ -593,7 +634,7 @@ t.isLet = function (node) {
  */
 
 t.isBlockScoped = function (node) {
-  return t.isFunctionDeclaration(node) || t.isLet(node);
+  return t.isFunctionDeclaration(node) || t.isClassDeclaration(node) || t.isLet(node);
 };
 
 /**

lib/6to5/util.js

@@ -16,7 +16,6 @@ var isNumber   = require("lodash/lang/isNumber");
 var isString   = require("lodash/lang/isString");
 var isRegExp   = require("lodash/lang/isRegExp");
 var isEmpty    = require("lodash/lang/isEmpty");
-var clone      = require("lodash/lang/clone");
 var cloneDeep  = require("lodash/lang/cloneDeep");
 var has        = require("lodash/object/has");
 var contains   = require("lodash/collection/contains");
@@ -81,73 +80,6 @@ exports.sourceMapToComment = function (map) {
   return "//# sourceMappingURL=data:application/json;base64," + base64;
 };
 
-exports.pushMutatorMap = function (mutatorMap, key, kind, computed, value) {
-  var alias;
-
-  if (t.isIdentifier(key)) {
-    alias = key.name;
-    if (computed) alias = "computed:" + alias;
-  } else if (t.isLiteral(key)) {
-    alias = String(key.value);
-  } else {
-    alias = JSON.stringify(traverse.removeProperties(cloneDeep(key)));
-  }
-
-  var map;
-  if (has(mutatorMap, alias)) {
-    map = mutatorMap[alias];
-  } else {
-    map = {};
-  }
-  mutatorMap[alias] = map;
-
-  map._key = key;
-  if (computed) {
-    map._computed = true;
-  }
-
-  map[kind] = value;
-};
-
-exports.buildDefineProperties = function (mutatorMap) {
-  var objExpr = t.objectExpression([]);
-
-  each(mutatorMap, function (map) {
-    var mapNode = t.objectExpression([]);
-
-    var propNode = t.property("init", map._key, mapNode, map._computed);
-
-    if (!map.get && !map.set) {
-      map.writable = t.literal(true);
-    }
-
-    if (map.enumerable === false) {
-      delete map.enumerable;
-    } else {
-      map.enumerable = t.literal(true);
-    }
-
-    map.configurable = t.literal(true);
-
-    each(map, function (node, key) {
-      if (key[0] === "_") return;
-
-      node = clone(node);
-      var inheritNode = node;
-      if (t.isMethodDefinition(node)) node = node.value;
-
-      var prop = t.property("init", t.identifier(key), node);
-      t.inheritsComments(prop, inheritNode);
-      t.removeComments(inheritNode);
-      mapNode.properties.push(prop);
-    });
-
-    objExpr.properties.push(propNode);
-  });
-
-  return objExpr;
-};
-
 var templateVisitor = {
   enter: function (node, parent, scope, context, nodes) {
     if (t.isIdentifier(node) && has(nodes, node.name)) {
@@ -191,7 +123,7 @@ exports.repeat = function (width, cha) {
   return result;
 };
 
-exports.normaliseAst = function (ast, comments, tokens) {
+exports.normalizeAst = function (ast, comments, tokens) {
   if (ast && ast.type === "Program") {
     return t.file(ast, comments || [], tokens || []);
   } else {
@@ -218,7 +150,7 @@ exports.parse = function (opts, code, callback) {
 
     estraverse.attachComments(ast, comments, tokens);
 
-    ast = exports.normaliseAst(ast, comments, tokens);
+    ast = exports.normalizeAst(ast, comments, tokens);
 
     if (callback) {
       return callback(ast);

package.json

@@ -1,7 +1,7 @@
 {
   "name": "6to5",
   "description": "Turn ES6 code into readable vanilla ES5 with source maps",
-  "version": "3.1.1",
+  "version": "3.3.9",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://6to5.org/",
   "repository": "6to5/6to5",
@@ -9,7 +9,9 @@
   "main": "lib/6to5/index.js",
   "bin": {
     "6to5": "./bin/6to5/index.js",
-    "6to5-node": "./bin/6to5-node"
+    "6to5-minify": "./bin/6to5-minify",
+    "6to5-node": "./bin/6to5-node",
+    "6to5-runtime": "./bin/6to5-runtime"
   },
   "browser": {
     "./lib/6to5/index.js": "./lib/6to5/browser.js",
@@ -42,13 +44,13 @@
     "detect-indent": "3.0.0",
     "estraverse": "1.9.1",
     "esutils": "1.1.6",
-    "esvalid": "1.1.0",
     "fs-readdir-recursive": "0.1.0",
+    "globals": "^5.1.0",
     "js-tokenizer": "1.3.3",
     "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",
@@ -59,6 +61,7 @@
   "devDependencies": {
     "browserify": "8.1.1",
     "chai": "1.10.0",
+    "esvalid": "1.1.0",
     "istanbul": "0.3.5",
     "jscs": "1.10.0",
     "jshint": "2.6.0",

packages/6to5-runtime/package.json

@@ -1,7 +1,7 @@
 {
   "name": "6to5-runtime",
   "description": "6to5 selfContained runtime",
-  "version": "3.1.0",
+  "version": "3.3.7",
   "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/transform");
-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;
@@ -31,24 +30,25 @@ var updatePackage = function () {
   writeFile("package.json", JSON.stringify(pkg, null, 2));
 };
 
-var buildHelpers = function () {
+var selfContainify = function (code) {
+  return transform(code, {
+    optional: ["selfContained"]
+  }).code;
+};
+
+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"));
+writeFile("regenerator/runtime.js", selfContainify(readFile("regenerator-6to5/runtime")));
 updatePackage();

test/_helper.js

@@ -1,8 +1,9 @@
+var util = require("../lib/6to5/util");
 var path = require("path");
 var fs   = require("fs");
 var _    = require("lodash");
 
-var humanise = function (val, noext) {
+var humanize = function (val, noext) {
   if (noext) val = path.basename(val, path.extname(val));
   return val.replace(/-/g, " ");
 };
@@ -17,6 +18,13 @@ var readFile = exports.readFile = function (filename) {
   }
 };
 
+exports.assertVendor = function (name) {
+  if (!fs.existsSync(__dirname + "/../vendor/" + name)) {
+    console.error("No vendor/" + name + " - run `make bootstrap`");
+    process.exit(1);
+  }
+};
+
 exports.get = function (entryName, entryLoc) {
   if (exports.cache[entryName]) return exports.cache[entryName];
 
@@ -29,13 +37,13 @@ exports.get = function (entryName, entryLoc) {
     var suite = {
       options: {},
       tests: [],
-      title: humanise(suiteName),
+      title: humanize(suiteName),
       filename: entryLoc + "/" + suiteName
     };
     suites.push(suite);
 
-    var suiteOptsLoc = suite.filename + "/options.json";
-    if (fs.existsSync(suiteOptsLoc)) suite.options = require(suiteOptsLoc);
+    var suiteOptsLoc = util.resolve(suite.filename + "/options");
+    if (suiteOptsLoc) suite.options = require(suiteOptsLoc);
 
     if (fs.statSync(suite.filename).isFile()) {
       push(suiteName, suite.filename);
@@ -71,11 +79,11 @@ exports.get = function (entryName, entryLoc) {
         sourceMapName:    expectLocAlias
       }, _.cloneDeep(suite.options));
 
-      var taskOptsLoc = taskDir + "/options.json";
-      if (fs.existsSync(taskOptsLoc)) _.merge(taskOpts, require(taskOptsLoc));
+      var taskOptsLoc = util.resolve(taskDir + "/options");
+      if (taskOptsLoc) _.merge(taskOpts, require(taskOptsLoc));
 
       var test = {
-        title: humanise(taskName, true),
+        title: humanize(taskName, true),
         disabled: taskName[0] === ".",
         options: taskOpts,
         exec: {

test/_transformation-helper.js

@@ -1,5 +1,5 @@
 var genHelpers = require("./_generator-helpers");
-var transform  = require("../lib/6to5/transformation/transform");
+var transform  = require("../lib/6to5/transformation");
 var sourceMap  = require("source-map");
 var codeFrame  = require("../lib/6to5/helpers/code-frame");
 var esvalid    = require("esvalid");
@@ -114,10 +114,10 @@ var run = function (task, done) {
     var consumer = new sourceMap.SourceMapConsumer(result.map);
 
     _.each(task.sourceMappings, function (mapping, i) {
-      var expect = mapping.original;
+      var actual = mapping.original;
 
-      var actual = consumer.originalPositionFor(mapping.generated);
-      chai.expect({ line: actual.line, column: actual.column }).to.deep.equal(expect);
+      var expect = consumer.originalPositionFor(mapping.generated);
+      chai.expect({ line: expect.line, column: expect.column }).to.deep.equal(actual);
     });
   }
 };
@@ -125,12 +125,14 @@ var run = function (task, done) {
 module.exports = function (suiteOpts, taskOpts, dynamicOpts) {
   taskOpts = taskOpts || {};
 
-  require("../register")(taskOpts);
-
   _.each(helper.get(suiteOpts.name, suiteOpts.loc), function (testSuite) {
     if (_.contains(suiteOpts.ignoreSuites, testSuite.title)) return;
 
     suite(suiteOpts.name + "/" + testSuite.title, function () {
+      setup(function () {
+        require("../register")(taskOpts);
+      });
+
       _.each(testSuite.tests, function (task) {
         if (_.contains(suiteOpts.ignoreTasks, task.title) || _.contains(suiteOpts.ignoreTasks, testSuite.title + "/" + task.title)) return;
 

test/api.js

@@ -1,4 +1,4 @@
-var transform = require("../lib/6to5/transformation/transform");
+var transform = require("../lib/6to5/transformation");
 var assert    = require("assert");
 var File      = require("../lib/6to5/file");
 

test/detection.js

@@ -0,0 +1,140 @@
+var detect = require("../lib/6to5/detection");
+var assert = require("assert");
+var util   = require("../lib/6to5/util");
+
+suite("detection", function () {
+  var checkSyntax = function (code, name) {
+    var ast = util.parse({
+      experimental: true
+    }, code);
+
+    assert.ok(detect(ast).syntax[name]);
+  };
+
+  test("es5.properties.mutators", function () {
+    checkSyntax("var obj = { get foo() {} };", "es5.properties.mutators");
+    checkSyntax("var obj = { set foo() {} };", "es5.properties.mutators");
+  });
+
+  test("es6.exponentation", function () {
+    checkSyntax("x ** 2;", "es6.exponentation");
+    checkSyntax("x **= 2;", "es6.exponentation");
+  });
+
+  test("es6.blockScoping", function () {
+    checkSyntax("let foo;", "es6.blockScoping");
+    checkSyntax("let foo = bar;", "es6.blockScoping");
+    checkSyntax("const foo = bar;", "es6.blockScoping");
+  });
+
+  test("es6.constants", function () {
+    checkSyntax("const foo = bar;", "es6.constants");
+  });
+
+  test("es6.properties.shorthand", function () {
+    checkSyntax("var obj = { foo };", "es6.properties.shorthand");
+    checkSyntax("var obj = { foo };", "es6.properties.shorthand");
+  });
+
+  test("es6.properties.computed", function () {
+    checkSyntax("var obj = { [foo]: bar };", "es6.properties.computed");
+    checkSyntax("var obj = { ['foo']: bar };", "es6.properties.computed");
+  });
+
+  test("es6.parameters.default", function () {
+    checkSyntax("var obj = (foo = bar) => {};", "es6.parameters.default");
+    checkSyntax("var obj = function (foo = bar) {};", "es6.parameters.default");
+    checkSyntax("function foo(foo = bar) {}", "es6.parameters.default");
+  });
+
+  test("es6.arrowFunctions", function () {
+    checkSyntax("var foo = x => x;", "es6.arrowFunctions");
+    checkSyntax("var foo = x => { return x * x };", "es6.arrowFunctions");
+    checkSyntax("var foo = (x) => x;", "es6.arrowFunctions");
+    checkSyntax("var foo = (a, b) => { return a * b };", "es6.arrowFunctions");
+  });
+
+  test("es6.classes", function () {
+    checkSyntax("class Foo {}", "es6.classes");
+    checkSyntax("var Foo = class {};", "es6.classes");
+  });
+
+  test("es6.forOf", function () {
+    checkSyntax("for (var val of foo);", "es6.forOf");
+    checkSyntax("for (val of foo);", "es6.forOf");
+  });
+
+  test("es6.modules", function () {
+    checkSyntax("import 'foo';", "es6.modules");
+    checkSyntax("import foo from 'foo';", "es6.modules");
+    checkSyntax("import * as foo from 'foo';", "es6.modules");
+    checkSyntax("import { foo } from 'foo';", "es6.modules");
+    checkSyntax("export { foo } from 'foo';", "es6.modules");
+    checkSyntax("export var foo = 5;", "es6.modules");
+    checkSyntax("export class Foo {}", "es6.modules");
+    checkSyntax("export function foo() {}", "es6.modules");
+    checkSyntax("export default class Foo {}", "es6.modules");
+    checkSyntax("export default function foo() {}", "es6.modules");
+  });
+
+  test("es6.destructuring", function () {
+    checkSyntax("[a, b] = [];", "es6.destructuring");
+    checkSyntax("var [a, b] = [];", "es6.destructuring");
+    checkSyntax("({ a, b }) = {};", "es6.destructuring");
+    checkSyntax("var { a, b } = {};", "es6.destructuring");
+    checkSyntax("function foo(foo = bar) {}", "es6.destructuring");
+  });
+
+  test("es6.parameters.rest", function () {
+    checkSyntax("function foo(...items) {}", "es6.parameters.rest");
+    checkSyntax("var foo = (...items) => {}", "es6.parameters.rest");
+  });
+
+  test("es6.spread", function () {
+    checkSyntax("new Foo(...items);", "es6.spread");
+    checkSyntax("foo(...items);", "es6.spread");
+    checkSyntax("[...items];", "es6.spread");
+  });
+
+  test("es6.templateLiterals", function () {
+    checkSyntax("`foobar`;", "es6.templateLiterals");
+    checkSyntax("foobar`foobar`;", "es6.templateLiterals");
+  });
+
+  test("es6.generators", function () {
+    checkSyntax("function* foo() {}", "es6.generators");
+    checkSyntax("var foo = function* () {};", "es6.generators");
+  });
+
+  test("es7.asyncFunctions", function () {
+    checkSyntax("async function foo() {}", "es7.asyncFunctions");
+    checkSyntax("var foo = async function() {};", "es7.asyncFunctions");
+    checkSyntax("var foo = async () => {};", "es7.asyncFunctions");
+  });
+
+  test("es7.comprehensions", function () {
+    checkSyntax("[for (i of test) i]", "es7.comprehensions");
+    checkSyntax("(for (i of test) i)", "es7.comprehensions");
+  });
+
+  test("es7.objectSpread", function () {
+    checkSyntax("var foo = { ...bar };", "es7.objectSpread");
+  });
+
+  test("es7.abstractReferences", function () {
+    checkSyntax("class Foo { private A; }", "es7.abstractReferences");
+    checkSyntax("foo::bar();", "es7.abstractReferences");
+    checkSyntax("delete foo::bar;", "es7.abstractReferences");
+    checkSyntax("foo::bar;", "es7.abstractReferences");
+    checkSyntax("foo::bar = baz;", "es7.abstractReferences");
+  });
+
+  test("flow", function () {
+
+  });
+
+  test("jsx", function () {
+    checkSyntax("<div />", "jsx");
+    checkSyntax("<Element />", "jsx");
+  });
+});

test/fixtures/bin/6to5/dir --out-dir --source-maps-inline/out-files/lib/bar/bar.js

@@ -1,4 +1,8 @@
 "use strict";
 
-var Test = function Test() {};
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNyYy9iYXIvYmFyLmpzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7O0lBQU0sSUFBSSxZQUFKLElBQUkiLCJmaWxlIjoic3JjL2Jhci9iYXIuanMiLCJzb3VyY2VzQ29udGVudCI6WyJjbGFzcyBUZXN0IHtcblxufSJdfQ==
+var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
+var Test = function Test() {
+  _classCallCheck(this, Test);
+};
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNyYy9iYXIvYmFyLmpzIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7Ozs7SUFBTSxnQkFBQTt3QkFBQSIsImZpbGUiOiJzcmMvYmFyL2Jhci5qcyIsInNvdXJjZXNDb250ZW50IjpbImNsYXNzIFRlc3Qge1xuXG59Il19

test/fixtures/bin/6to5/dir --out-dir --source-maps-inline/out-files/lib/foo.js

@@ -3,4 +3,4 @@
 arr.map(function (x) {
   return x * MULTIPLIER;
 });
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNyYy9mb28uanMiXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6Ijs7QUFBQSxHQUFHLENBQUMsR0FBRyxDQUFDLFVBQUEsQ0FBQztTQUFJLENBQUMsR0FBRyxVQUFVO0NBQUEsQ0FBQyxDQUFDIiwiZmlsZSI6InNyYy9mb28uanMiLCJzb3VyY2VzQ29udGVudCI6WyJhcnIubWFwKHggPT4geCAqIE1VTFRJUExJRVIpOyJdfQ==
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNyYy9mb28uanMiXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6Ijs7QUFBQSxJQUFJLElBQUksVUFBQTtTQUFLLElBQUkiLCJmaWxlIjoic3JjL2Zvby5qcyIsInNvdXJjZXNDb250ZW50IjpbImFyci5tYXAoeCA9PiB4ICogTVVMVElQTElFUik7Il19

test/fixtures/bin/6to5/dir --out-dir --source-maps/out-files/lib/bar/bar.js

@@ -1,4 +1,8 @@
 "use strict";
 
-var Test = function Test() {};
+var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
+var Test = function Test() {
+  _classCallCheck(this, Test);
+};
 //# sourceMappingURL=bar.js.map

test/fixtures/bin/6to5/dir --out-dir --source-maps/out-files/lib/bar/bar.js.map

@@ -1 +1 @@
-{"version":3,"sources":["src/bar/bar.js"],"names":[],"mappings":";;IAAM,IAAI,YAAJ,IAAI","file":"src/bar/bar.js","sourcesContent":["class Test {\n\n}"]}
+{"version":3,"sources":["src/bar/bar.js"],"names":[],"mappings":";;;;IAAM,gBAAA;wBAAA","file":"src/bar/bar.js","sourcesContent":["class Test {\n\n}"]}

test/fixtures/bin/6to5/dir --out-dir --source-maps/out-files/lib/foo.js.map

@@ -1 +1 @@
-{"version":3,"sources":["src/foo.js"],"names":[],"mappings":";;AAAA,GAAG,CAAC,GAAG,CAAC,UAAA,CAAC;SAAI,CAAC,GAAG,UAAU;CAAA,CAAC,CAAC","file":"src/foo.js","sourcesContent":["arr.map(x => x * MULTIPLIER);"]}
+{"version":3,"sources":["src/foo.js"],"names":[],"mappings":";;AAAA,IAAI,IAAI,UAAA;SAAK,IAAI","file":"src/foo.js","sourcesContent":["arr.map(x => x * MULTIPLIER);"]}

test/fixtures/bin/6to5/dir --out-dir/out-files/lib/bar/bar.js

@@ -1,3 +1,7 @@
 "use strict";
 
-var Test = function Test() {};
+var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
+var Test = function Test() {
+  _classCallCheck(this, Test);
+};

test/fixtures/bin/6to5/filename --out-file --source-maps-inline/out-files/script2.js

@@ -4,4 +4,4 @@ arr.map(function (x) {
   return x * MULTIPLIER;
 });
 
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNjcmlwdC5qcyJdLCJuYW1lcyI6W10sIm1hcHBpbmdzIjoiOztBQUFBLEdBQUcsQ0FBQyxHQUFHLENBQUMsVUFBQSxDQUFDO1NBQUksQ0FBQyxHQUFHLFVBQVU7Q0FBQSxDQUFDLENBQUMiLCJmaWxlIjoic2NyaXB0Mi5qcyIsInNvdXJjZXNDb250ZW50IjpbImFyci5tYXAoeCA9PiB4ICogTVVMVElQTElFUik7Il19
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNjcmlwdC5qcyJdLCJuYW1lcyI6W10sIm1hcHBpbmdzIjoiOztBQUFBLElBQUksSUFBSSxVQUFBO1NBQUssSUFBSSIsImZpbGUiOiJzY3JpcHQyLmpzIiwic291cmNlc0NvbnRlbnQiOlsiYXJyLm1hcCh4ID0+IHggKiBNVUxUSVBMSUVSKTsiXX0=

test/fixtures/bin/6to5/filenames --out-file --source-maps-inline/out-files/script3.js

@@ -1,11 +1,14 @@
 "use strict";
 
-var Test = function Test() {};
+var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
+var Test = function Test() {
+  _classCallCheck(this, Test);
+};
 "use strict";
 
 arr.map(function (x) {
   return x * MULTIPLIER;
 });
 
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNjcmlwdC5qcyIsInNjcmlwdDIuanMiXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6Ijs7SUFBTSxJQUFJLFlBQUosSUFBSTs7OztBQ0FWLEdBQUcsQ0FBQyxHQUFHLENBQUMsVUFBQSxDQUFDO1NBQUksQ0FBQyxHQUFHLFVBQVU7Q0FBQSxDQUFDLENBQUMiLCJmaWxlIjoic2NyaXB0My5qcyIsInNvdXJjZXNDb250ZW50IjpbImNsYXNzIFRlc3Qge1xuXG59IiwiYXJyLm1hcCh4ID0+IHggKiBNVUxUSVBMSUVSKTsiXX0=
-
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInNjcmlwdC5qcyIsInNjcmlwdDIuanMiXSwibmFtZXMiOltdLCJtYXBwaW5ncyI6Ijs7OztJQUFNLGdCQUFBO3dCQUFBOzs7OztBQ0FOLElBQUksSUFBSSxVQUFBO1NBQUssSUFBSSIsImZpbGUiOiJzY3JpcHQzLmpzIiwic291cmNlc0NvbnRlbnQiOlsiY2xhc3MgVGVzdCB7XG5cbn0iLCJhcnIubWFwKHggPT4geCAqIE1VTFRJUExJRVIpOyJdfQ==

test/fixtures/bin/6to5/filenames --out-file --source-maps/out-files/script3.js

@@ -1,6 +1,10 @@
 "use strict";
 
-var Test = function Test() {};
+var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
+var Test = function Test() {
+  _classCallCheck(this, Test);
+};
 "use strict";
 
 arr.map(function (x) {

test/fixtures/bin/6to5/filenames --out-file --source-maps/out-files/script3.js.map

@@ -1 +1 @@
-{"version":3,"sources":["script.js","script2.js"],"names":[],"mappings":";;IAAM,IAAI,YAAJ,IAAI;;;;ACAV,GAAG,CAAC,GAAG,CAAC,UAAA,CAAC;SAAI,CAAC,GAAG,UAAU;CAAA,CAAC,CAAC","file":"script3.js","sourcesContent":["class Test {\n\n}","arr.map(x => x * MULTIPLIER);"]}
+{"version":3,"sources":["script.js","script2.js"],"names":[],"mappings":";;;;IAAM,gBAAA;wBAAA;;;;;ACAN,IAAI,IAAI,UAAA;SAAK,IAAI","file":"script3.js","sourcesContent":["class Test {\n\n}","arr.map(x => x * MULTIPLIER);"]}

test/fixtures/bin/6to5/filenames --out-file/out-files/script3.js

@@ -1,6 +1,10 @@
 "use strict";
 
-var Test = function Test() {};
+var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
+var Test = function Test() {
+  _classCallCheck(this, Test);
+};
 "use strict";
 
 arr.map(function (x) {

test/fixtures/bin/6to5/stdin --out-file --source-maps/out-files/test.js.map

@@ -1 +1 @@
-{"version":3,"sources":["stdin"],"names":[],"mappings":";;AAAA,GAAG,CAAC,GAAG,CAAC,UAAA,CAAC;SAAI,CAAC,GAAG,CAAC;CAAA,CAAC,CAAC","file":"test.js","sourcesContent":["arr.map(x => x * x);"]}
+{"version":3,"sources":["stdin"],"names":[],"mappings":";;AAAA,IAAI,IAAI,UAAA;SAAK,IAAI","file":"test.js","sourcesContent":["arr.map(x => x * x);"]}

test/fixtures/bin/6to5/stdin --source-maps-inline/stdout.txt

@@ -4,4 +4,4 @@ arr.map(function (x) {
   return x * x;
 });
 
-//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7O0FBQUEsR0FBRyxDQUFDLEdBQUcsQ0FBQyxVQUFBLENBQUM7U0FBSSxDQUFDLEdBQUcsQ0FBQztDQUFBLENBQUMsQ0FBQyIsImZpbGUiOiJzdGRvdXQiLCJzb3VyY2VzQ29udGVudCI6WyJhcnIubWFwKHggPT4geCAqIHgpOyJdfQ==
+//# sourceMappingURL=data:application/json;base64,eyJ2ZXJzaW9uIjozLCJzb3VyY2VzIjpbInN0ZGluIl0sIm5hbWVzIjpbXSwibWFwcGluZ3MiOiI7O0FBQUEsSUFBSSxJQUFJLFVBQUE7U0FBSyxJQUFJIiwiZmlsZSI6InN0ZG91dCIsInNvdXJjZXNDb250ZW50IjpbImFyci5tYXAoeCA9PiB4ICogeCk7Il19

test/fixtures/esnext/es6-classes/getter-setter-super.js

@@ -2,6 +2,14 @@ class Base {
   get sound() {
     return 'I am a ' + this.type + '.';
   }
+
+  get name() {
+    return this._name;
+  }
+
+  set name(val) {
+    this._name = val;
+  }
 }
 
 class Animal extends Base {}
@@ -12,6 +20,18 @@ class Cat extends Animal {
   get sound() {
     return super.sound + ' MEOW!';
   }
+
+  get name() {
+    return super.name;
+  }
+
+  set name(val) {
+    super.name = val + ' Cat';
+  }
 }
 
-assert.equal(new Cat().sound, 'I am a cat. MEOW!');
+var cat = new Cat();
+
+assert.equal(cat.sound, 'I am a cat. MEOW!');
+cat.name = 'Nyan';
+assert.equal(cat.name, 'Nyan Cat');

test/fixtures/transformation/api/blacklist/expected.js

@@ -1,5 +1,9 @@
 "use strict";
 
+var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
 var Test = function Test() {
+  _classCallCheck(this, Test);
+
   arr.map(x => x * x);
-};
+};

test/fixtures/transformation/api/resolve-module-source/actual.js

@@ -0,0 +1,3 @@
+export { foo } from "foo-export-named";
+import foo from "foo-import-default";
+import "foo-import-bare";

test/fixtures/transformation/api/resolve-module-source/expected.js

@@ -0,0 +1,5 @@
+"use strict";
+
+export { foo } from "resolved/foo-export-named";
+import foo from "resolved/foo-import-default";
+import "resolved/foo-import-bare";

test/fixtures/transformation/api/resolve-module-source/options.js

@@ -0,0 +1,5 @@
+exports.blacklist = ["es6.modules"];
+
+exports.resolveModuleSource = function (originalSource) {
+  return "resolved/" + originalSource;
+};

test/fixtures/transformation/async-to-generator/async/expected.js

@@ -4,8 +4,12 @@ var _asyncToGenerator = function (fn) { return function () { var gen = fn.apply(
 
 var _prototypeProperties = function (child, staticProps, instanceProps) { if (staticProps) Object.defineProperties(child, staticProps); if (instanceProps) Object.defineProperties(child.prototype, instanceProps); };
 
+var _classCallCheck = function (instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } };
+
 var Foo = (function () {
-  function Foo() {}
+  function Foo() {
+    _classCallCheck(this, Foo);
+  }
 
   _prototypeProperties(Foo, null, {
     foo: {