Implement ES6 symbol registry and predefined 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 392 matching lines @@
   var objectOwnSymbols = Object.getOwnPropertySymbols(object)
   assertEquals(objectOwnSymbols.length, syms.length / 2)
 
   for (var i = 0; i < objectOwnSymbols.length; i++) {
     assertEquals(objectOwnSymbols[i], syms[i * 2])
   }
 }
 TestGetOwnPropertySymbolsWithProto()
 
 
-function TestGetOwnPropertySymbolsWithPrivateSymbols() {
-  var privateSymbol = %CreatePrivateSymbol("private")
-  var publicSymbol = Symbol()
-  var publicSymbol2 = Symbol()
-  var obj = {}
-  obj[publicSymbol] = 1
-  obj[privateSymbol] = 2
-  obj[publicSymbol2] = 3
-  var syms = Object.getOwnPropertySymbols(obj)
-  assertEquals(syms, [publicSymbol, publicSymbol2])
+function TestRegistry() {
+  assertFalse(Symbol.for("@@create") === Symbol.create)
+  assertFalse(Symbol.for("@@iterator") === Symbol.iterator)
+  assertTrue(Symbol.keyFor(Symbol.create) === undefined)
+  assertTrue(Symbol.keyFor(Symbol.iterator) === undefined)
+
+  var symbol1 = Symbol.for("x1")
+  var symbol2 = Symbol.for("x2")
+  assertFalse(symbol1 === symbol2)
+
+  assertSame(symbol1, Symbol.for("x1"))
+  assertSame(symbol2, Symbol.for("x2"))
+  assertSame("x1", Symbol.keyFor(symbol1))
+  assertSame("x2", Symbol.keyFor(symbol2))
+
+  assertSame(Symbol.for("1"), Symbol.for(1))
+  assertThrows(function() { Symbol.keyFor("bla") }, TypeError)
+  assertThrows(function() { Symbol.keyFor({}) }, TypeError)
+
+  var realm = Realm.create()
+  assertFalse(Symbol === Realm.eval(realm, "Symbol"))
+  assertFalse(Symbol.for === Realm.eval(realm, "Symbol.for"))
+  assertFalse(Symbol.keyFor === Realm.eval(realm, "Symbol.keyFor"))
+  assertSame(Symbol.create, Realm.eval(realm, "Symbol.create"))
+  assertSame(Symbol.iterator, Realm.eval(realm, "Symbol.iterator"))
+
+  assertSame(symbol1, Realm.eval(realm, "Symbol.for")("x1"))
+  assertSame(symbol1, Realm.eval(realm, "Symbol.for('x1')"))
+  assertSame("x1", Realm.eval(realm, "Symbol.keyFor")(symbol1))
+  Realm.shared = symbol1
+  assertSame("x1", Realm.eval(realm, "Symbol.keyFor(Realm.shared)"))
+
+  var symbol3 = Realm.eval(realm, "Symbol.for('x3')")
+  assertFalse(symbol1 === symbol3)
+  assertFalse(symbol2 === symbol3)
+  assertSame(symbol3, Symbol.for("x3"))
+  assertSame("x3", Symbol.keyFor(symbol3))
 }
-TestGetOwnPropertySymbolsWithPrivateSymbols()
+TestRegistry()