Array.prototype.{every, filter, find, findIndex, forEach, map, some}: Use fresh primitive wrapper f…

test/mjsunit/es6/collections.js

 // Copyright 2012 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 673 matching lines @@
   var accumulated = 0;
   set.forEach(function(v) {
     accumulated += v;
     if (v % 10 === 0) {
       gc();
     }
   });
   assertEquals(4950, accumulated);
 })();
 
+
+(function TestSetForEachReceiverAsObject() {
+  var set = new Set(["1", "2"]);
+
+  // Create a new object in each function call when receiver is a primitive value.

[wingo, 2014/09/30 16:01:36]

80 characters here and in other places in the tests

+  // See ECMA-262, Annex C.
+  var a = [];
+  set.forEach(function() { a.push(this) }, "");
+  assertTrue(a[0] !== a[1]);
+
+  // Do not create a new object otherwise.
+  a = [];
+  set.forEach(function() { a.push(this); }, {});
+  assertFalse(a[0] !== a[1]);
+})();
+
+
+(function TestSetForEachReceiverAsObjectInStrictMode() {
+  var set = new Set(["1", "2"]);
+
+  // In strict mode primitive values should not be coerced to an object.
+  var a = [];
+  set.forEach(function() { 'use strict'; a.push(this); }, "");
+  assertTrue(a[0] === "" && a[0] === a[1]);
+})();
+
+
 (function TestMapForEachInvalidTypes() {
   assertThrows(function() {
     Map.prototype.map.forEach.call({});
   }, TypeError);
 
   var map = new Map();
   assertThrows(function() {
     map.forEach({});
   }, TypeError);
 })();
@@ skipping 287 matching lines @@
       for (var i = 5; i < 16; i++) {
         map.delete(i);
       }
     }
   });
 
   assertArrayEquals([0, 1, 2, 3, 4], buffer);
 })();
 
 
+(function TestMapForEachReceiverAsObject() {
+  var map = new Map();
+  map.set("key1", "value1");
+  map.set("key2", "value2");
+
+  // Create a new object in each function call when receiver is a primitive value.
+  // See ECMA-262, Annex C.
+  var a = [];
+  map.forEach(function() { a.push(this) }, "");
+  assertTrue(a[0] !== a[1]);
+
+  // Do not create a new object otherwise.
+  a = [];
+  map.forEach(function() { a.push(this); }, {});
+  assertFalse(a[0] !== a[1]);
+})();
+
+
+(function TestMapForEachReceiverAsObjectInStrictMode() {
+  var map = new Map();
+  map.set("key1", "value1");
+  map.set("key2", "value2");
+
+  // In strict mode primitive values should not be coerced to an object.
+  var a = [];
+  map.forEach(function() { 'use strict'; a.push(this); }, "");
+  assertTrue(a[0] === "" && a[0] === a[1]);
+})();
+
+
 // Allows testing iterator-based constructors easily.
 var oneAndTwo = new Map();
 var k0 = {key: 0};
 var k1 = {key: 1};
 var k2 = {key: 2};
 oneAndTwo.set(k1, 1);
 oneAndTwo.set(k2, 2);
 
 
 function TestSetConstructor(ctor) {
@@ skipping 348 matching lines @@
 
   var map = new ctor(42);
   assertSize(2, map);
   assertEquals(1, map.get(k1));
   assertEquals(2, map.get(k2));
 
   delete Number.prototype[Symbol.iterator];
 }
 TestMapConstructorIterableValue(Map);
 TestMapConstructorIterableValue(WeakMap);