Spec adjustments for well-known 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 TestWellKnown() {
+  var symbols = [
+    "create", "hasInstance", "isConcatSpreadable", "isRegExp",
+    "iterator", "toStringTag", "unscopables"
+  ]
+
+  for (var i in symbols) {
+    var name = symbols[i]
+    var desc = Object.getOwnPropertyDescriptor(Symbol, name)
+    assertSame("symbol", typeof desc.value)
+    assertSame("Symbol(Symbol." + name + ")", desc.value.toString())
+    assertFalse(desc.writable)
+    assertFalse(desc.configurable)
+    assertFalse(desc.enumerable)
+
+    assertFalse(Symbol.for("Symbol." + name) === desc.value)
+    assertTrue(Symbol.keyFor(desc.value) === undefined)
+  }
+}
+TestWellKnown()
+
+
 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))
@@ skipping 13 matching lines @@
   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))
 }
 TestRegistry()