ES6 symbols: prevent reflection and proxy APIs from leaking symbols

test/mjsunit/harmony/symbols.js

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 214 matching lines @@
 function TestKeyHas() {
   for (var i in symbols) {
     assertTrue(symbols[i] in obj)
     assertTrue(Object.hasOwnProperty.call(obj, symbols[i]))
   }
 }
 
 
 function TestKeyEnum(obj) {
   for (var name in obj) {
-    assertTrue(typeof name !== "symbol")
+    assertEquals("string", typeof name)
   }
 }
 
 
 function TestKeyNames(obj) {
   assertEquals(0, Object.keys(obj).length)
 
   var names = Object.getOwnPropertyNames(obj)
-  assertTrue(symbols.length <= names.length)
-  // TODO(rossberg): once we have iterators, the following would be:
-  //   var expected = new Set(symbols)
-  var expected = new Set
-  for (var i = 0; i < symbols.length; ++i) expected.add(symbols[i])
-  for (var i = 0; i < names.length; ++i) {
-    var name = names[i]
-    if (typeof name === 'symbol') {
-      assertTrue(expected.has(name))
-      expected.delete(name)
-    }
+  for (var i in names) {
+    assertEquals("string", typeof names[i])
   }
-  assertEquals(0, expected.size)
 }
 
 
 function TestKeyDescriptor(obj) {
   for (var i in symbols) {
     var desc = Object.getOwnPropertyDescriptor(obj, symbols[i]);
     assertEquals(i|0, desc.value)
     assertTrue(desc.configurable)
     assertEquals(i % 2 == 0, desc.writable)
     assertEquals(i % 2 == 0, desc.enumerable)
@@ skipping 19 matching lines @@
   var obj = objs[i]
   TestKeySet(obj)
   TestKeyDefine(obj)
   TestKeyGet(obj)
   TestKeyHas(obj)
   TestKeyEnum(obj)
   TestKeyNames(obj)
   TestKeyDescriptor(obj)
   TestKeyDelete(obj)
 }