[es6] implement Object.assign

src/v8natives.js

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 var $delete;
 var $functionSourceString;
 var $getIterator;
 var $getMethod;
 var $globalEval;
 var $installConstants;
 var $installFunctions;
 var $installGetter;
 var $isFinite;
 var $isNaN;
 var $newFunctionString;
 var $numberIsNaN;
 var $objectDefineProperties;
 var $objectDefineProperty;
 var $objectFreeze;
 var $objectGetOwnPropertyDescriptor;
 var $objectGetOwnPropertyKeys;
 var $objectHasOwnProperty;
 var $objectIsFrozen;
 var $objectIsSealed;
 var $objectLookupGetter;
 var $objectLookupSetter;
 var $objectToString;
 var $overrideFunction;
+var $ownPropertyKeys;
 var $setFunctionName;
 var $setUpLockedPrototype;
 var $toCompletePropertyDescriptor;
 var $toNameArray;
 
 (function() {
 
 %CheckIsBootstrapping();
 
 var GlobalArray = global.Array;
@@ skipping 1095 matching lines @@
       seenKeys[name] = true;
       propertyNames[j++] = name;
     }
     propertyNames.length = j;
   }
 
   return propertyNames;
 }
 
 
+// ES6 section 9.1.12 / 9.5.12
+function OwnPropertyKeys(obj) {
+  if (%_IsJSProxy(obj)) {
+    var handler = %GetHandler(obj);
+    // TODO(caitp): Proxy.[[OwnPropertyKeys]] can not be implemented to spec
+    // without an implementation of Direct Proxies.
+    var names = CallTrap0(handler, "ownKeys", UNDEFINED);
+    return ToNameArray(names, "getOwnPropertyNames", false);
+  }
+  return ObjectGetOwnPropertyKeys(obj, PROPERTY_ATTRIBUTES_PRIVATE_SYMBOL);
+}
+
+
 // ES5 section 15.2.3.4.
 function ObjectGetOwnPropertyNames(obj) {
   obj = TO_OBJECT_INLINE(obj);
   // Special handling for proxies.
   if (%_IsJSProxy(obj)) {
     var handler = %GetHandler(obj);
     var names = CallTrap0(handler, "getOwnPropertyNames", UNDEFINED);
     return ToNameArray(names, "getOwnPropertyNames", false);
   }
 
@@ skipping 782 matching lines @@
 $objectFreeze = ObjectFreezeJS;
 $objectGetOwnPropertyDescriptor = ObjectGetOwnPropertyDescriptor;
 $objectGetOwnPropertyKeys = ObjectGetOwnPropertyKeys;
 $objectHasOwnProperty = ObjectHasOwnProperty;
 $objectIsFrozen = ObjectIsFrozen;
 $objectIsSealed = ObjectIsSealed;
 $objectLookupGetter = ObjectLookupGetter;
 $objectLookupSetter = ObjectLookupSetter;
 $objectToString = ObjectToString;
 $overrideFunction = OverrideFunction;
+$ownPropertyKeys = OwnPropertyKeys;
 $setFunctionName = SetFunctionName;
 $setUpLockedPrototype = SetUpLockedPrototype;
 $toCompletePropertyDescriptor = ToCompletePropertyDescriptor;
 $toNameArray = ToNameArray;
 
 })();