v1.14.2

Remove --no-timeouts flag.

CHANGELOG.md

@@ -1,3 +1,20 @@
+# 1.14.2
+
+ * Fix `commonInterop` default export handling.
+ * Fix keyworded property key identifiers being turned into computed property key literals.
+
+# 1.14.1
+
+ * Inherit comments from `ClassDeclaration`.
+
+# 1.14.0
+
+ * Add [playground](https://6to5.github.io/playground.html).
+
+# 1.13.13
+
+ * Fix `--debug` in `bin/6to5-node`. Thanks [@timoxley](https://github.com/timoxley).
+
 # 1.13.12
 
  * Ignore `XJSEmptyExpression`s in `react` transformer output.

CONTRIBUTING.md

@@ -9,7 +9,6 @@
    * CamelCase all class names
    * camelBack all variable names
  * **Spacing**
-   * 80 character line max
    * Spaces after all keywords
    * Spaces before all left curly braces
  * **Comments**

bin/6to5-node

@@ -14,13 +14,11 @@ process.argv.slice(2).forEach(function(arg){
   switch (flag) {
     case "-d":
       args.unshift("--debug");
-      args.push("--no-timeouts");
       break;
     case "debug":
     case "--debug":
     case "--debug-brk":
       args.unshift(arg);
-      args.push("--no-timeouts");
       break;
     case "-gc":
     case "--expose-gc":

bin/6to5/index.js

@@ -12,6 +12,7 @@ commander.option("-f, --filename [filename]", "Filename to use when reading from
 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");
 
 commander.option("-m, --modules [modules]", "Module formatter type to use [common]", "common");
 commander.option("-w, --whitelist [whitelist]", "Whitelist of transformers to ONLY use", util.list);
@@ -90,6 +91,7 @@ exports.opts = {
   sourceMapName: commander.outFile,
   amdModuleIds:  commander.amdModuleIds,
   experimental:  commander.experimental,
+  playground:    commander.playground,
   blacklist:     commander.blacklist,
   whitelist:     commander.whitelist,
   sourceMap:     commander.sourceMaps || commander.sourceMapsInline,

bin/_6to5-node

@@ -13,6 +13,7 @@ commander.option("-p, --print", "Evaluate script and print result");
 commander.option("-i, --ignore [regex]", "Ignore all files that match this regex when using the require hook");
 commander.option("-x, --extensions [extensions]", "List of extensions to hook into [.es6,.js]");
 commander.option("-r, --experimental", "Enable experimental support for proposed ES7 features");
+commander.option("-g, --playground", "Enable playground support");
 
 var pkg = require("../package.json");
 commander.version(pkg.version);

doc/playground.md

@@ -0,0 +1,65 @@
+# Playground
+
+Playground is a proving ground for **possible** ES7 proposals.
+
+**NOTE: These features are in no way endorsed by Ecma International and are not a part of ES6. They might become a part of ECMAScript in the future.**
+
+## Usage
+
+    $ 6to5 --playground
+
+```javascript
+to5.transform("code", { playground: true });
+```
+
+**NOTE:** Enabling `playground` also enables [experimental support](usage.md#experimental).
+
+## Features
+
+ * [Memoization operator](#memoization-operator)
+ * [Method binding](#method-binding)
+
+### Memoization assignment operator
+
+```javascript
+var obj = {};
+obj.x ?= 2;
+obj.x; // 2
+
+obj = { x: 1 };
+obj.x ?= 2;
+obj.x; // 1
+
+obj = { x: undefined }
+obj.x ?= 2;
+obj.x; // undefined
+```
+
+```javascript
+var obj = {};
+obj.x ?= 2;
+```
+
+equivalent to:
+
+```javascript
+var obj = {};
+if (!Object.prototype.hasOwnProperty.call(obj, "x")) obj.x = 2;
+```
+
+### Method binding expression
+
+```javascript
+var fn = obj:method;
+var fn = obj:method("foob");
+```
+
+equivalent to:
+
+```javascript
+var fn = obj.method.bind(obj);
+var fn = obj.method.bind(obj, "foob");
+```
+
+**NOTE:** Method binding can **only** be used as an **expression** and not as
+statement.

lib/6to5/file.js

@@ -22,8 +22,9 @@ File.declarations = [
   "tagged-template-literal",
   "interop-require",
   "to-array",
-  "arguments-to-array",
-  "object-spread"
+  "object-spread",
+  "has-own",
+  "slice"
 ];
 
 File.normaliseOptions = function (opts) {
@@ -31,6 +32,7 @@ File.normaliseOptions = function (opts) {
 
   _.defaults(opts, {
     experimental: false,
+    playground:   false,
     whitespace:   true,
     blacklist:    [],
     whitelist:    [],
@@ -69,6 +71,10 @@ File.normaliseOptions = function (opts) {
     opts.runtime = "to5Runtime";
   }
 
+  if (opts.playground) {
+    opts.experimental = true;
+  }
+
   transform._ensureTransformerNames("blacklist", opts.blacklist);
   transform._ensureTransformerNames("whitelist", opts.whitelist);
 
@@ -78,14 +84,11 @@ File.normaliseOptions = function (opts) {
 File.prototype.toArray = function (node) {
   if (t.isArrayExpression(node)) {
     return node;
+  } else if (t.isIdentifier(node) && node.name === "arguments") {
+    return t.callExpression(t.memberExpression(this.addDeclaration("slice"), t.identifier("call")), [node]);
+  } else {
+    return t.callExpression(this.addDeclaration("to-array"), [node]);
   }
-
-  var templateName = "to-array";
-  if (t.isIdentifier(node) && node.name === "arguments") {
-    templateName = "arguments-to-array";
-  }
-
-  return t.callExpression(this.addDeclaration(templateName), [node]);
 };
 
 File.prototype.getModuleFormatter = function (type) {
@@ -135,7 +138,11 @@ File.prototype.addDeclaration = function (name) {
   }
 
   var uid = this.generateUidIdentifier(name);
-  this.scope.push(name, uid, ref);
+  this.scope.push({
+    key: name,
+    id: uid,
+    init: ref
+  });
   return uid;
 };
 

lib/6to5/generation/generator.js

@@ -53,6 +53,7 @@ CodeGenerator.generators = {
   comprehensions:   require("./generators/comprehensions"),
   expressions:      require("./generators/expressions"),
   statements:       require("./generators/statements"),
+  playground:       require("./generators/playground"),
   classes:          require("./generators/classes"),
   methods:          require("./generators/methods"),
   modules:          require("./generators/modules"),

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

@@ -0,0 +1,7 @@
+var _ = require("lodash");
+
+_.each(["BindMemberExpression"], function (type) {
+  exports[type] = function () {
+    throw new ReferenceError("Trying to render non-standard playground node " + JSON.stringify(type));
+  };
+});

lib/6to5/patch.js

@@ -30,6 +30,14 @@ def("VirtualPropertyExpression")
   .field("object", def("Expression"))
   .field("property", or(def("Identifier"), def("Expression")));
 
+// Playground
+def("BindMemberExpression")
+  .bases("Expression")
+  .build("object", "property", "arguments")
+  .field("object", def("Expression"))
+  .field("property", or(def("Identifier"), def("Expression")))
+  .field("arguments", [def("Expression")]);
+
 types.finalize();
 
 var estraverse = require("estraverse");

lib/6to5/templates/arguments-to-array.js

@@ -1,7 +0,0 @@
-(function (args) {
-  var target = new Array(args.length);
-  for (var i = 0; i< args.length; i++) {
-    target[i] = args[i];
-  }
-  return target;
-})

lib/6to5/templates/has-own.js

@@ -0,0 +1 @@
+Object.prototype.hasOwnProperty;

lib/6to5/templates/slice.js

@@ -0,0 +1 @@
+Array.prototype.slice;

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

@@ -3,10 +3,16 @@ module.exports = CommonJSInteropFormatter;
 var CommonJSFormatter = require("./common");
 var util              = require("../../util");
 var t                 = require("../../types");
+var _                 = require("lodash");
 
-function CommonJSInteropFormatter() {
-  this.has = false;
+function CommonJSInteropFormatter(file) {
   CommonJSFormatter.apply(this, arguments);
+
+  var has = false;
+  _.each(file.ast.program.body, function (node) {
+    if (t.isExportDeclaration(node) && !node.default) has = true;
+  });
+  this.has = has;
 }
 
 util.inherits(CommonJSInteropFormatter, CommonJSFormatter);
@@ -40,14 +46,11 @@ CommonJSInteropFormatter.prototype.export = function (node, nodes) {
     // hoist to the top if this default is a function
     nodes.push(this._hoistExport(declar, assign));
     return;
-  } else {
-    this.has = true;
   }
 
   CommonJSFormatter.prototype.export.apply(this, arguments);
 };
 
 CommonJSInteropFormatter.prototype.exportSpecifier = function () {
-  this.has = true;
   CommonJSFormatter.prototype.exportSpecifier.apply(this, arguments);
 };

lib/6to5/transformation/transform.js

@@ -36,7 +36,6 @@ _.each({
   arrowFunctions:            require("./transformers/es6-arrow-functions"),
   classes:                   require("./transformers/es6-classes"),
 
-  _propertyLiterals:         require("./transformers/_property-literals"),
   computedPropertyNames:     require("./transformers/es6-computed-property-names"),
 
   objectSpread:              require("./transformers/es7-object-spread"),
@@ -57,13 +56,18 @@ _.each({
 
   generators:                require("./transformers/es6-generators"),
 
+  // plyground
+  methodBinding:             require("./transformers/playground-method-binding"),
+  memoizationOperator:       require("./transformers/playground-memoization-operator"),
+
   _blockHoist:               require("./transformers/_block-hoist"),
   _declarations:             require("./transformers/_declarations"),
   _aliasFunctions:           require("./transformers/_alias-functions"),
 
   useStrict:                 require("./transformers/use-strict"),
 
-  _memberExpressionKeywords: require("./transformers/_member-expression-keywords"),
+  _propertyLiterals:         require("./transformers/_property-literals"),
+  _memberExpressioLiterals:  require("./transformers/_member-expression-literals"),
   _moduleFormatter:          require("./transformers/_module-formatter")
 }, function (transformer, key) {
   transform.transformers[key] = new Transformer(key, transformer);

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

@@ -3,9 +3,21 @@ var _ = require("lodash");
 
 exports.BlockStatement =
 exports.Program = function (node) {
+  var kinds = {};
+
   _.each(node._declarations, function (declar) {
-    node.body.unshift(t.variableDeclaration("var", [
-      t.variableDeclarator(declar.id, declar.init)
-    ]));
+    var kind = declar.kind || "var";
+    var declarNode = t.variableDeclarator(declar.id, declar.init);
+
+    if (!declar.init) {
+      kinds[kind] = kinds[kind] || [];
+      kinds[kind].push(declarNode);
+    } else {
+      node.body.unshift(t.variableDeclaration(kind, [declarNode]));
+    }
+  });
+
+  _.each(kinds, function (declars, kind) {
+    node.body.unshift(t.variableDeclaration(kind, declars));
   });
 };

lib/6to5/transformation/transformers/_member-expression-keywords.js

@@ -1,10 +0,0 @@
-var esutils = require("esutils");
-var t = require("../../types");
-
-exports.MemberExpression = function (node) {
-  var prop = node.property;
-  if (t.isIdentifier(prop) && esutils.keyword.isKeywordES6(prop.name, true)) {
-    node.property = t.literal(prop.name);
-    node.computed = true;
-  }
-};

lib/6to5/transformation/transformers/_member-expression-literals.js

@@ -0,0 +1,14 @@
+var esutils = require("esutils");
+var t       = require("../../types");
+
+exports.MemberExpression = function (node) {
+  var prop = node.property;
+  if (node.computed && t.isLiteral(prop) && t.isValidIdentifier(prop.value)) {
+    // computed literal that is a valid identifier
+    node.property = t.identifier(prop.value);
+    node.computed = false;
+  } else if (!node.computed && t.isIdentifier(prop) && esutils.keyword.isKeywordES6(prop.name, true)) {
+    node.property = t.literal(prop.name);
+    node.computed = true;
+  }
+};

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

@@ -1,15 +1,14 @@
 var esutils = require("esutils");
 var t       = require("../../types");
-var _       = require("lodash");
 
 exports.Property = function (node) {
-  // ignore key literals that are valid identifiers
   var key = node.key;
-  if (t.isLiteral(key) && _.isString(key.value) && esutils.keyword.isIdentifierName(key.value)) {
-    key.type = "Identifier";
-    key.name = key.value;
-    delete key.value;
-
+  if (t.isLiteral(key) && t.isValidIdentifier(key.value)) {
+    // property key is a literal but a valid identifier
+    node.key = t.identifier(key.value);
     node.computed = false;
+  } else if (!node.computed && t.isIdentifier(key) && esutils.keyword.isKeywordES6(key.name, true)) {
+    // property key is a keyword
+    node.key = t.literal(key.name);
   }
 };

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

@@ -4,9 +4,13 @@ var t        = require("../../types");
 var _        = require("lodash");
 
 exports.ClassDeclaration = function (node, parent, file, scope) {
-  return t.variableDeclaration("let", [
-    t.variableDeclarator(node.id, new Class(node, file, scope).run())
+  var built = new Class(node, file, scope).run();
+
+  var declar = t.variableDeclaration("let", [
+    t.variableDeclarator(node.id, built)
   ]);
+  t.inheritsComments(declar, node);
+  return declar;
 };
 
 exports.ClassExpression = function (node, parent, file, scope) {

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

@@ -3,11 +3,14 @@
 var t = require("../../types");
 var _ = require("lodash");
 
-var buildVariableAssign = function (kind, id, init) {
-  if (kind === false) {
+var buildVariableAssign = function (opts, id, init) {
+  var op = opts.operator;
+  if (t.isMemberExpression(id)) op = "=";
+
+  if (op) {
     return t.expressionStatement(t.assignmentExpression("=", id, init));
   } else {
-    return t.variableDeclaration(kind, [
+    return t.variableDeclaration(opts.kind, [
       t.variableDeclarator(id, init)
     ]);
   }
@@ -18,10 +21,8 @@ var push = function (opts, nodes, elem, parentId) {
     pushObjectPattern(opts, nodes, elem, parentId);
   } else if (t.isArrayPattern(elem)) {
     pushArrayPattern(opts, nodes, elem, parentId);
-  } else if (t.isMemberExpression(elem)) {
-    nodes.push(buildVariableAssign(false, elem, parentId));
   } else {
-    nodes.push(buildVariableAssign(opts.kind, elem, parentId));
+    nodes.push(buildVariableAssign(opts, elem, parentId));
   }
 };
 
@@ -43,7 +44,7 @@ var pushObjectPattern = function (opts, nodes, pattern, parentId) {
         keys = t.arrayExpression(keys);
 
         var value = t.callExpression(opts.file.addDeclaration("object-spread"), [parentId, keys]);
-        nodes.push(buildVariableAssign(opts.kind, prop.argument, value));
+        nodes.push(buildVariableAssign(opts, prop.argument, value));
     } else {
       var pattern2   = prop.value;
       var patternId2 = t.memberExpression(parentId, prop.key, prop.computed);
@@ -51,7 +52,7 @@ var pushObjectPattern = function (opts, nodes, pattern, parentId) {
       if (t.isPattern(pattern2)) {
         push(opts, nodes, pattern2, patternId2);
       } else {
-        nodes.push(buildVariableAssign(opts.kind, pattern2, patternId2));
+        nodes.push(buildVariableAssign(opts, pattern2, patternId2));
       }
     }
   });
@@ -177,7 +178,7 @@ exports.ExpressionStatement = function (node, parent, file, scope) {
   ]));
 
   push({
-    kind: false,
+    operator: expr.operator,
     file: file,
     scope: scope
   }, nodes, expr.left, ref);
@@ -190,33 +191,24 @@ exports.AssignmentExpression = function (node, parent, file, scope) {
   if (!t.isPattern(node.left)) return;
 
   var tempName = file.generateUid("temp", scope);
-  var temp = t.identifier(tempName);
-  scope.push(tempName, temp);
-
-  var nodes = [];
-  nodes.push(t.assignmentExpression("=", temp, node.right));
-
-  push({
-    kind: false,
-    file: file,
-    scope: scope
-  }, nodes, node.left, temp);
-
-  nodes.push(temp);
-
-  nodes = nodes.map(function (node) {
-    if (t.isExpressionStatement(node)) {
-      return node.expression;
-    } else if (t.isVariableDeclaration(node)) {
-      var declar = node.declarations[0];
-      scope.push(declar.id.name, declar.id);
-      return t.assignmentExpression("=", declar.id, declar.init);
-    } else {
-      return node;
-    }
+  var ref = t.identifier(tempName);
+  scope.push({
+    key: tempName,
+    id: ref
   });
 
-  return t.sequenceExpression(nodes);
+  var nodes = [];
+  nodes.push(t.assignmentExpression("=", ref, node.right));
+
+  push({
+    operator: node.operator,
+    file: file,
+    scope: scope
+  }, nodes, node.left, ref);
+
+  nodes.push(ref);
+
+  return t.toSequenceExpression(nodes, scope);
 };
 
 exports.VariableDeclaration = function (node, parent, file, scope) {
@@ -236,17 +228,18 @@ exports.VariableDeclaration = function (node, parent, file, scope) {
   _.each(node.declarations, function (declar) {
     var patternId = declar.init;
     var pattern   = declar.id;
+    var opts = {
+      kind:    node.kind,
+      nodes:   nodes,
+      pattern: pattern,
+      id:      patternId,
+      file:    file,
+      scope:   scope
+    };
     if (t.isPattern(pattern) && patternId) {
-      pushPattern({
-        kind:    node.kind,
-        nodes:   nodes,
-        pattern: pattern,
-        id:      patternId,
-        file:    file,
-        scope:   scope
-      });
+      pushPattern(opts);
     } else {
-      nodes.push(buildVariableAssign(node.kind, declar.id, declar.init));
+      nodes.push(buildVariableAssign(opts, declar.id, declar.init));
     }
   });
 
@@ -268,4 +261,3 @@ exports.VariableDeclaration = function (node, parent, file, scope) {
 
   return nodes;
 };
-

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

@@ -8,13 +8,10 @@ exports.Function = function (node, parent, file) {
 
   t.ensureBlock(node);
 
-  var call = t.callExpression(
-    file.addDeclaration("arguments-to-array"),
-    [t.identifier("arguments")]
-  );
+  var call = file.toArray(t.identifier("arguments"));
 
   if (node.params.length) {
-    call = t.callExpression(t.memberExpression(call, t.identifier("slice")), [t.literal(node.params.length)]);
+    call.arguments.push(t.literal(node.params.length));
   }
 
   call._ignoreAliasFunctions = true;

lib/6to5/transformation/transformers/es7-abstract-references.js

@@ -32,7 +32,10 @@ exports.AssignmentExpression = function (node, parent, file, scope) {
     if (t.isDynamic(value)) {
       var tempName = file.generateUid("temp");
       temp = value = t.identifier(tempName);
-      scope.push(tempName, temp);
+      scope.push({
+        key: tempName,
+        id: temp
+      });
     }
   }
 
@@ -74,7 +77,10 @@ exports.CallExpression = function (node, parent, file, scope) {
     // we need to save `callee.object` so we can call it again
     var tempName = file.generateUid("temp");
     temp = t.identifier(tempName);
-    scope.push(tempName, temp);
+    scope.push({
+      key: tempName,
+      id: temp
+    });
   }
 
   var call = util.template("abstract-expression-call", {

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

@@ -0,0 +1,90 @@
+var t = require("../../types");
+
+var isMemo = function (node) {
+  var is = t.isAssignmentExpression(node) && node.operator === "?=";
+  if (is) t.assertMemberExpression(node.left);
+  return is;
+};
+
+var getPropRef = function (nodes, prop, file, scope) {
+  if (t.isIdentifier(prop)) {
+    return t.literal(prop.name);
+  } else {
+    var temp = file.generateUidIdentifier("propKey", scope);
+    nodes.push(t.variableDeclaration("var", [
+      t.variableDeclarator(temp, prop)
+    ]));
+    return temp;
+  }
+};
+
+var getObjRef = function (nodes, obj, file, scope) {
+  if (t.isDynamic(obj)) {
+    var temp = file.generateUidIdentifier("obj", scope);
+    nodes.push(t.variableDeclaration("var", [
+      t.variableDeclarator(temp, obj)
+    ]));
+    return temp;
+  } else {
+    return obj;
+  }
+};
+
+var buildHasOwn = function (obj, prop, file) {
+  return t.unaryExpression(
+    "!",
+    t.callExpression(
+      t.memberExpression(file.addDeclaration("has-own"), t.identifier("call")),
+      [obj, prop]
+    ),
+    true
+  );
+};
+
+var buildAbsoluteRef = function (left, obj, prop) {
+  var computed = left.computed || t.isLiteral(prop);
+  return t.memberExpression(obj, prop, computed);
+};
+
+var buildAssignment = function (expr, obj, prop) {
+  return t.assignmentExpression("=", buildAbsoluteRef(expr.left, obj, prop), expr.right);
+};
+
+exports.ExpressionStatement = function (node, parent, file, scope) {
+  var expr = node.expression;
+  if (!isMemo(expr)) return;
+
+  var nodes = [];
+
+  var left = expr.left;
+  var obj  = getObjRef(nodes, left.object, file, scope);
+  var prop = getPropRef(nodes, left.property, file, scope);
+
+  nodes.push(t.ifStatement(
+    buildHasOwn(obj, prop, file),
+    t.expressionStatement(buildAssignment(expr, obj, prop))
+  ));
+
+  return nodes;
+};
+
+exports.AssignmentExpression = function (node, parent, file, scope) {
+  if (t.isExpressionStatement(parent)) return;
+  if (!isMemo(node)) return;
+
+  var nodes = [];
+
+  var left = node.left;
+  var obj  = getObjRef(nodes, left.object, file, scope);
+  var prop = getPropRef(nodes, left.property, file, scope);
+
+  nodes.push(t.logicalExpression(
+    "&&",
+    buildHasOwn(obj, prop, file),
+    buildAssignment(node, obj, prop)
+  ));
+
+  nodes.push(buildAbsoluteRef(left, obj, prop));
+
+  return t.toSequenceExpression(nodes, scope);
+};

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

@@ -0,0 +1,30 @@
+var t = require("../../types");
+
+exports.BindMemberExpression = function (node, parent, file, scope) {
+  var object = node.object;
+  var prop   = node.property;
+
+  var temp;
+  if (t.isDynamic(object)) {
+    var tempName = file.generateUid("temp", scope);
+    temp =  object = t.identifier(tempName);
+    scope.push({
+      key: tempName,
+      id: temp
+    });
+  }
+
+  var call = t.callExpression(
+    t.memberExpression(t.memberExpression(object, prop), t.identifier("bind")),
+    [object].concat(node.arguments)
+  );
+
+  if (temp) {
+    return t.sequenceExpression([
+      t.assignmentExpression("=", temp, node.object),
+      call
+    ]);
+  } else {
+    return call;
+  }
+};

lib/6to5/traverse/scope.js

@@ -101,7 +101,7 @@ Scope.prototype.getReferences = function () {
   return references;
 };
 
-Scope.prototype.push = function (name, id, init) {
+Scope.prototype.push = function (opts) {
   var block = this.block;
 
   if (t.isFor(block) || t.isCatchClause(block) || t.isFunction(block)) {
@@ -111,9 +111,10 @@ Scope.prototype.push = function (name, id, init) {
 
   if (t.isBlockStatement(block) || t.isProgram(block)) {
     block._declarations = block._declarations || {};
-    block._declarations[name] = {
-      id: id,
-      init: init
+    block._declarations[opts.key] = {
+      kind: opts.kind,
+      id: opts.id,
+      init: opts.init
     };
   } else {
     throw new TypeError("cannot add a declaration here in node type " + block.type);

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

@@ -11,6 +11,7 @@
   "Identifier":              ["name"],
   "IfStatement":             ["test", "consequent", "alternate"],
   "Literal":                 ["value"],
+  "LogicalExpression":       ["operator", "left", "right"],
   "MemberExpression":        ["object", "property", "computed"],
   "NewExpression":           ["callee", "arguments"],
   "ObjectExpression":        ["properties"],

lib/6to5/types/index.js

@@ -1,4 +1,5 @@
-var _ = require("lodash");
+var esutils = require("esutils");
+var _       = require("lodash");
 
 var t = exports;
 
@@ -71,6 +72,31 @@ addAssert("Expression", t.isExpression);
 
 //
 
+t.toSequenceExpression = function (nodes, scope) {
+  var exprs = [];
+
+  _.each(nodes, function (node) {
+    if (t.isExpression(node)) {
+      exprs.push(node);
+    } if (t.isExpressionStatement(node)) {
+      exprs.push(node.expression);
+    } else if (t.isVariableDeclaration(node)) {
+      _.each(node.declarations, function (declar) {
+        scope.push({
+          kind: node.kind,
+          key: declar.id.name,
+          id: declar.id
+        });
+        exprs.push(t.assignmentExpression("=", declar.id, declar.init));
+      });
+    }
+  });
+
+  return t.sequenceExpression(exprs);
+};
+
+//
+
 t.shallowEqual = function (actual, expected) {
   var same = true;
 
@@ -88,7 +114,9 @@ t.shallowEqual = function (actual, expected) {
 //
 
 t.isDynamic = function (node) {
-  if (t.isIdentifier(node) || t.isLiteral(node) || t.isThisExpression(node)) {
+  if (t.isParenthesizedExpression(node)) {
+    return t.isDynamic(node.expression);
+  } else if (t.isIdentifier(node) || t.isLiteral(node) || t.isThisExpression(node)) {
     return false;
   } else if (t.isMemberExpression(node)) {
     return t.isDynamic(node.object) || t.isDynamic(node.property);
@@ -135,6 +163,10 @@ t.toIdentifier = function (name) {
   return name;
 };
 
+t.isValidIdentifier = function (name) {
+  return _.isString(name) && esutils.keyword.isIdentifierName(name) && !esutils.keyword.isKeywordES6(name, true);
+};
+
 t.ensureBlock = function (node) {
   node.body = t.toBlock(node.body, node);
 };

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

@@ -5,6 +5,7 @@
   "AssignmentExpression":      ["left", "right"],
   "AwaitExpression":           ["argument"],
   "BinaryExpression":          ["left", "right"],
+  "BindMemberExpression":      ["object", "property", "arguments"],
   "BlockStatement":            ["body"],
   "BreakStatement":            ["label"],
   "CallExpression":            ["callee", "arguments"],

lib/6to5/util.js

@@ -219,6 +219,7 @@ exports.parse = function (opts, code, callback) {
       allowReturnOutsideFunction: true,
       preserveParens:             true,
       ecmaVersion:                opts.experimental ? 7 : 6,
+      playground:                 opts.playground,
       strictMode:                 true,
       onComment:                  comments,
       locations:                  true,

package.json

@@ -1,7 +1,7 @@
 {
   "name": "6to5",
   "description": "Turn ES6 code into readable vanilla ES5 with source maps",
-  "version": "1.13.12",
+  "version": "1.14.2",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://github.com/6to5/6to5",
   "repository": {
@@ -47,7 +47,7 @@
     "chokidar": "0.11.1",
     "source-map-support": "0.2.8",
     "esutils": "1.1.6",
-    "acorn-6to5": "0.9.1-7",
+    "acorn-6to5": "0.9.1-8",
     "estraverse": "1.8.0",
     "private": "0.1.6"
   },

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

@@ -1,5 +1,5 @@
 class Test {
   constructor() {
-  arr.map(x => x * x);
+    arr.map(x => x * x);
   }
 }

test/fixtures/transformation/es6-classes/accessing-super-class/expected.js

@@ -1,14 +1,6 @@
 "use strict";
 
-var _argumentsToArray = function (args) {
-  var target = new Array(args.length);
-  for (var i = 0; i < args.length; i++) {
-    target[i] = args[i];
-  }
-
-  return target;
-};
-
+var _slice = Array.prototype.slice;
 var _classProps = function (child, staticProps, instanceProps) {
   if (staticProps) Object.defineProperties(child, staticProps);
   if (instanceProps) Object.defineProperties(child.prototype, instanceProps);
@@ -33,11 +25,11 @@ var Test = (function (Foo) {
     Foo.prototype.test.call(this);
     foob(Foo);
 
-    Foo.call.apply(Foo, [this].concat(_argumentsToArray(arguments)));
-    Foo.call.apply(Foo, [this, "test"].concat(_argumentsToArray(arguments)));
+    Foo.call.apply(Foo, [this].concat(_slice.call(arguments)));
+    Foo.call.apply(Foo, [this, "test"].concat(_slice.call(arguments)));
 
-    Foo.prototype.test.call.apply(Foo.prototype, [this].concat(_argumentsToArray(arguments)));
-    Foo.prototype.test.call.apply(Foo.prototype, [this, "test"].concat(_argumentsToArray(arguments)));
+    Foo.prototype.test.call.apply(Foo.prototype, [this].concat(_slice.call(arguments)));
+    Foo.prototype.test.call.apply(Foo.prototype, [this, "test"].concat(_slice.call(arguments)));
   };
 
   _extends(Test, Foo);
@@ -47,8 +39,8 @@ var Test = (function (Foo) {
       writable: true,
       value: function () {
         Foo.foo.call(this);
-        Foo.foo.call.apply(Foo.foo, [this].concat(_argumentsToArray(arguments)));
-        Foo.foo.call.apply(Foo.foo, [this, "test"].concat(_argumentsToArray(arguments)));
+        Foo.foo.call.apply(Foo.foo, [this].concat(_slice.call(arguments)));
+        Foo.foo.call.apply(Foo.foo, [this, "test"].concat(_slice.call(arguments)));
       }
     }
   }, {
@@ -56,8 +48,8 @@ var Test = (function (Foo) {
       writable: true,
       value: function () {
         Foo.prototype.test.call(this);
-        Foo.prototype.test.call.apply(Foo.prototype.test, [this].concat(_argumentsToArray(arguments)));
-        Foo.prototype.test.call.apply(Foo.prototype.test, [this, "test"].concat(_argumentsToArray(arguments)));
+        Foo.prototype.test.call.apply(Foo.prototype.test, [this].concat(_slice.call(arguments)));
+        Foo.prototype.test.call.apply(Foo.prototype.test, [this, "test"].concat(_slice.call(arguments)));
       }
     }
   });

test/fixtures/transformation/es6-destructuring/assignment-expression/expected.js

@@ -1,9 +1,8 @@
 "use strict";
 
-var _ref;
+var _temp, _ref;
 var _toArray = function (arr) {
   return Array.isArray(arr) ? arr : Array.from(arr);
 };
 
-var _temp;
 console.log((_temp = [123], _ref = _toArray(_temp), x = _ref[0], _temp));

test/fixtures/transformation/es6-rest-parameters/arrow-functions/expected.js

@@ -1,14 +1,6 @@
 "use strict";
 
-var _argumentsToArray = function (args) {
-  var target = new Array(args.length);
-  for (var i = 0; i < args.length; i++) {
-    target[i] = args[i];
-  }
-
-  return target;
-};
-
+var _slice = Array.prototype.slice;
 var concat = function () {
-  var arrs = _argumentsToArray(arguments);
+  var arrs = _slice.call(arguments);
 };

test/fixtures/transformation/es6-rest-parameters/multiple/expected.js

@@ -1,18 +1,10 @@
 "use strict";
 
-var _argumentsToArray = function (args) {
-  var target = new Array(args.length);
-  for (var i = 0; i < args.length; i++) {
-    target[i] = args[i];
-  }
-
-  return target;
-};
-
+var _slice = Array.prototype.slice;
 var t = function (f) {
-  var items = _argumentsToArray(arguments).slice(1);
+  var items = _slice.call(arguments, 1);
 };
 
 function t(f) {
-  var items = _argumentsToArray(arguments).slice(1);
+  var items = _slice.call(arguments, 1);
 }

test/fixtures/transformation/es6-rest-parameters/single/expected.js

@@ -1,18 +1,10 @@
 "use strict";
 
-var _argumentsToArray = function (args) {
-  var target = new Array(args.length);
-  for (var i = 0; i < args.length; i++) {
-    target[i] = args[i];
-  }
-
-  return target;
-};
-
+var _slice = Array.prototype.slice;
 var t = function () {
-  var items = _argumentsToArray(arguments);
+  var items = _slice.call(arguments);
 };
 
 function t() {
-  var items = _argumentsToArray(arguments);
+  var items = _slice.call(arguments);
 }

test/fixtures/transformation/es6-spread/arguments/expected.js

@@ -1,16 +1,8 @@
 "use strict";
 
-var _argumentsToArray = function (args) {
-  var target = new Array(args.length);
-  for (var i = 0; i < args.length; i++) {
-    target[i] = args[i];
-  }
-
-  return target;
-};
-
+var _slice = Array.prototype.slice;
 function foo() {
-  return bar.apply(null, ["test"].concat(_argumentsToArray(arguments)));
+  return bar.apply(null, ["test"].concat(_slice.call(arguments)));
 }
 
 function bar(one, two, three) {

test/fixtures/transformation/misc/_member-expression-keywords/expected.js

@@ -1,6 +0,0 @@
-"use strict";
-
-test["catch"];
-test["catch"]["foo"];
-test["catch"];
-test["catch"]["foo"];

test/fixtures/transformation/misc/_member-expression-literals/actual.js

@@ -1,3 +1,5 @@
+obj["x"] = 2;
+
 test.catch;
 test.catch["foo"];
 test["catch"];

test/fixtures/transformation/misc/_member-expression-literals/expected.js

@@ -0,0 +1,8 @@
+"use strict";
+
+obj.x = 2;
+
+test["catch"];
+test["catch"].foo;
+test["catch"];
+test["catch"].foo;

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

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

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

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

test/fixtures/transformation/playground/memoization-assignment-operator/actual.js

@@ -0,0 +1,13 @@
+var obj = {};
+
+obj.x ?= 2;
+
+console.log(obj.x ?= 2);
+
+obj[x()] ?= 2;
+
+console.log(obj[x()] ?= 2);
+
+obj[y()][x()] ?= 2;
+
+console.log(obj[y()][x()] ?= 2);

test/fixtures/transformation/playground/memoization-assignment-operator/exec.js

@@ -0,0 +1,20 @@
+var obj = {};
+obj.x ?= 2;
+assert.equal(obj.x, 2);
+
+obj = {};
+assert.equal(obj.x ?= 2, 2);
+
+obj = { x: 1 };
+obj.x ?= 2;
+assert.equal(obj.x, 1);
+
+obj = { x: 1 };
+assert.equal(obj.x ?= 2, 1);
+
+obj = { x: undefined }
+obj.x ?= 2;
+assert.equal(obj.x, undefined);
+
+obj = { x: undefined }
+assert.equal(obj.x ?= 2, undefined);

test/fixtures/transformation/playground/memoization-assignment-operator/expected.js

@@ -0,0 +1,25 @@
+"use strict";
+
+var _propKey2, _obj2, _propKey4;
+var _hasOwn = Object.prototype.hasOwnProperty;
+var obj = {};
+
+if (!_hasOwn.call(obj, "x")) obj.x = 2;
+
+
+console.log((!_hasOwn.call(obj, "x") && (obj.x = 2), obj.x));
+
+var _propKey = x();
+
+if (!_hasOwn.call(obj, _propKey)) obj[_propKey] = 2;
+
+
+console.log((_propKey2 = x(), !_hasOwn.call(obj, _propKey2) && (obj[_propKey2] = 2), obj[_propKey2]));
+
+var _obj = obj[y()];
+var _propKey3 = x();
+
+if (!_hasOwn.call(_obj, _propKey3)) _obj[_propKey3] = 2;
+
+
+console.log((_obj2 = obj[y()], _propKey4 = x(), !_hasOwn.call(_obj2, _propKey4) && (_obj2[_propKey4] = 2), _obj2[_propKey4]));

test/fixtures/transformation/playground/method-binding/actual.js

@@ -0,0 +1,5 @@
+var fn = obj:method;
+var fn = obj:method("foob");
+var fn = obj[foo]:method;
+var fn = obj.foo:method;
+var fn = obj[foo()]:method;

test/fixtures/transformation/playground/method-binding/exec.js

@@ -0,0 +1,22 @@
+var obj = {
+  foo: "foo",
+  bar: "bar",
+  getFoo: function () {
+    return this.foo;
+  },
+  getBar: function (arg) {
+    return arg + " " +  this.bar;
+  },
+  getZoo: function (a, b) {
+    return this.foo + " " + this.bar + " " + a + " " + b;
+  }
+};
+
+var foo = obj:getFoo;
+assert.equal(foo(), "foo");
+
+var bar = obj:getBar("foo");
+assert.equal(bar(), "foo bar");
+
+var zoo = obj:getZoo("foo");
+assert.equal(zoo("bar"), "foo bar foo bar");

test/fixtures/transformation/playground/method-binding/expected.js

@@ -0,0 +1,8 @@
+"use strict";
+
+var _temp;
+var fn = obj.method.bind(obj);
+var fn = obj.method.bind(obj, "foob");
+var fn = obj[foo].method.bind(obj[foo]);
+var fn = obj.foo.method.bind(obj.foo);
+var fn = (_temp = obj[foo()], _temp.method.bind(_temp));

test/fixtures/transformation/playground/options.json

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

test/transformation.js

@@ -37,10 +37,11 @@ var run = function (task, done) {
       err.message += util.codeFrame(execCode);
       throw err;
     }
-  } else {
-    var actualCode = actual.code;
-    var expectCode = expect.code;
+  }
 
+  var actualCode = actual.code;
+  var expectCode = expect.code;
+  if (!execCode || actualCode) {
     result     = transform(actualCode, getOpts(actual));
     actualCode = result.code;