bug 1092231 - fix traits to work with Symbols

lib/sdk/deprecated/traits.js

@@ -1,7 +1,6 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
 "use strict";
 
 module.metadata = {
@@ -17,9 +16,10 @@ const {
   required,
 } = require('./traits/core');
 
-const defineProperties = Object.defineProperties,
-      freeze = Object.freeze,
-      create = Object.create;
+const { getOwnPropertyIdentifiers } = require('../util/object');
+const defineProperties = Object.defineProperties;
+const freeze = Object.freeze;
+const create = Object.create;
 
 /**
  * Work around bug 608959 by defining the _create function here instead of
@@ -31,7 +31,7 @@ const defineProperties = Object.defineProperties,
  */
 function _create(proto, trait) {
   let properties = {},
-      keys = Object.getOwnPropertyNames(trait);
+      keys = getOwnPropertyIdentifiers(trait);
   for (let key of keys) {
     let descriptor = trait[key];
     if (descriptor.required &&
@@ -72,9 +72,9 @@ function TraitDescriptor(object)
 
 function Public(instance, trait) {
   let result = {},
-      keys = Object.getOwnPropertyNames(trait);
+      keys = getOwnPropertyIdentifiers(trait);
   for (let key of keys) {
-    if ('_' === key.charAt(0) && '__iterator__' !== key )
+    if (typeof key === 'string' && '_' === key.charAt(0) && '__iterator__' !== key )
       continue;
     let property = trait[key],
         descriptor = {
@@ -184,4 +184,3 @@ const Trait = Composition({
 });
 TraitProto = Trait.prototype;
 exports.Trait = Trait;
-

lib/sdk/deprecated/traits/core.js

@@ -1,7 +1,6 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
 "use strict";
 
 module.metadata = {
@@ -10,11 +9,10 @@ module.metadata = {
 
 // Design inspired by: http://www.traitsjs.org/
 
-// shortcuts
-const getOwnPropertyNames = Object.getOwnPropertyNames,
-      getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor,
-      hasOwn = Object.prototype.hasOwnProperty,
-      _create = Object.create;
+const { getOwnPropertyIdentifiers } = require('../../util/object');
+const getOwnPropertyDescriptor = Object.getOwnPropertyDescriptor;
+const hasOwn = Object.prototype.hasOwnProperty;
+const _create = Object.create;
 
 function doPropertiesMatch(object1, object2, name) {
   // If `object1` has property with the given `name`
@@ -114,12 +112,12 @@ function Conflict(name) {
  */
 function trait(properties) {
   let result = {},
-      keys = getOwnPropertyNames(properties);
- for (let key of keys) {
-   let descriptor = getOwnPropertyDescriptor(properties, key);
-   result[key] = (required === descriptor.value) ? Required(key) : descriptor;
- }
- return result;
+      keys = getOwnPropertyIdentifiers(properties);
+  for (let key of keys) {
+    let descriptor = getOwnPropertyDescriptor(properties, key);
+    result[key] = (required === descriptor.value) ? Required(key) : descriptor;
+  }
+  return result;
 }
 exports.Trait = exports.trait = trait;
 
@@ -140,7 +138,7 @@ function compose(trait1, trait2) {
   let traits = Array.slice(arguments, 0),
       result = {};
   for (let trait of traits) {
-    let keys = getOwnPropertyNames(trait);
+    let keys = getOwnPropertyIdentifiers(trait);
     for (let key of keys) {
       let descriptor = trait[key];
       // if property already exists and it's not a requirement
@@ -174,7 +172,7 @@ function exclude(keys, trait) {
   let exclusions = Map(keys),
       result = {};
 
-  keys = getOwnPropertyNames(trait);
+  keys = getOwnPropertyIdentifiers(trait);
 
   for (let key of keys) {
     if (!hasOwn.call(exclusions, key) || trait[key].required)
@@ -210,7 +208,7 @@ function override() {
   let traits = Array.slice(arguments, 0),
       result = {};
   for (let trait of traits) {
-    let keys = getOwnPropertyNames(trait);
+    let keys = getOwnPropertyIdentifiers(trait);
     for (let key of keys) {
       let descriptor = trait[key];
       if (!hasOwn.call(result, key) || result[key].required)
@@ -236,7 +234,7 @@ exports.override = override;
  */
 function rename(map, trait) {
   let result = {},
-      keys = getOwnPropertyNames(trait);
+      keys = getOwnPropertyIdentifiers(trait);
   for (let key of keys) {
     // must be renamed & it's not requirement
     if (hasOwn.call(map, key) && !trait[key].required) {
@@ -281,7 +279,7 @@ function rename(map, trait) {
 function resolve(resolutions, trait) {
   let renames = {},
       exclusions = [],
-      keys = getOwnPropertyNames(resolutions);
+      keys = getOwnPropertyIdentifiers(resolutions);
   for (let key of keys) {  // pre-process renamed and excluded properties
     if (resolutions[key])       // old name -> new name
       renames[key] = resolutions[key];
@@ -306,7 +304,7 @@ exports.resolve = resolve;
  */
 function create(proto, trait) {
   let properties = {},
-      keys = getOwnPropertyNames(trait);
+      keys = getOwnPropertyIdentifiers(trait);
   for (let key of keys) {
     let descriptor = trait[key];
     if (descriptor.required && !hasOwn.call(proto, key))
@@ -319,4 +317,3 @@ function create(proto, trait) {
   return _create(proto, properties);
 }
 exports.create = create;
-

lib/sdk/util/iteration.js

@@ -7,20 +7,13 @@ module.metadata = {
   "stability": "experimental"
 };
 
-// This is known as @@iterator in the ES6 spec.  Until it is bound to
-// some well-known name, find the @@iterator object by expecting it as
-// the first property accessed on a for-of iterable.
-const iteratorSymbol = (function() {
-  try {
-    for (var _ of Proxy.create({get: function(_, name) { throw name; } }))
-      break;
-  } catch (name) {
-    return name;
-  }
-  throw new TypeError;
-})();
+// test if JS has Symbols and uses them for iteration
+const JS_USE_SYMBOLS = typeof Symbol === "function" &&
+                       Symbol.iterator in Array.prototype;
 
-exports.iteratorSymbol = iteratorSymbol;
+// This is known as @@iterator in the ES6 spec. In builds that have and use
+// it for iteration, return that; otherwise return the legacy method name.
+exports.iteratorSymbol = JS_USE_SYMBOLS ? Symbol.iterator : "@@iterator";
 
 // An adaptor that, given an object that is iterable with for-of, is
 // suitable for being bound to __iterator__ in order to make the object

lib/sdk/util/object.js

@@ -1,7 +1,6 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
 "use strict";
 
 module.metadata = {
@@ -90,3 +89,14 @@ function omit(source, ...values) {
   return copy;
 }
 exports.omit = omit;
+
+// get object's own property Symbols and/or Names, including nonEnumerables by default
+function getOwnPropertyIdentifiers(object, options = { names: true, symbols: true, nonEnumerables: true }) {
+  const symbols = !options.symbols ? [] :
+                  Object.getOwnPropertySymbols(object);
+  const names = !options.names ? [] :
+                options.nonEnumerables ? Object.getOwnPropertyNames(object) :
+                Object.keys(object);
+  return [...names, ...symbols];
+}
+exports.getOwnPropertyIdentifiers = getOwnPropertyIdentifiers;