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

src/harmony-array.js

 // Copyright 2013 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.
 
 'use strict';
 
 // This file relies on the fact that the following declaration has been made
 // in runtime.js:
 // var $Array = global.Array;
 
 // -------------------------------------------------------------------
 
 // ES6 draft 07-15-13, section 15.4.3.23
 function ArrayFind(predicate /* thisArg */) {  // length == 1
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.find");
 
   var array = ToObject(this);
   var length = ToInteger(array.length);
 
   if (!IS_SPEC_FUNCTION(predicate)) {
     throw MakeTypeError('called_non_callable', [predicate]);
   }
 
   var thisArg;
   if (%_ArgumentsLength() > 1) {
     thisArg = %_Arguments(1);
   }
 
   if (IS_NULL_OR_UNDEFINED(thisArg)) {
-    thisArg = %GetDefaultReceiver(predicate) || thisArg;
-  } else if (!IS_SPEC_OBJECT(thisArg) && %IsSloppyModeFunction(predicate)) {
-    thisArg = ToObject(thisArg);
+    thisArg = %GetDefaultthisArg(predicate) || thisArg;

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

Typo.  Did these tests pass for you? :)

   }
+  var needs_wrapper = SHOULD_CREATE_WRAPPER(predicate, thisArg);

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

Here we are adding a test; SHOULD_CREATE_WRAPPER looks like this:

 macro SHOULD_CREATE_WRAPPER(functionName, receiver) =
(!IS_NULL_OR_UNDEFINED(rec
     eiver) && !IS_SPEC_OBJECT(receiver) &&
%IsSloppyModeFunction(functionName));

so we're adding the duplicate IS_NULL_OR_UNDEFINED check, and if the thisArg was
initialized in the previous if to the global object then we also go to the
!IS_SPEC_OBJECT case.  Probably this needs_wrapper initialization should be in
an else{}.

 
   for (var i = 0; i < length; i++) {
     if (i in array) {
       var element = array[i];
-      if (%_CallFunction(thisArg, element, i, array, predicate)) {
+      var newThisArg = needs_wrapper ? ToObject(thisArg) : thisArg;
+      if (%_CallFunction(newThisArg, element, i, array, predicate)) {
         return element;
       }
     }
   }
 
   return;
 }
 
 
 // ES6 draft 07-15-13, section 15.4.3.24
 function ArrayFindIndex(predicate /* thisArg */) {  // length == 1
   CHECK_OBJECT_COERCIBLE(this, "Array.prototype.findIndex");
 
   var array = ToObject(this);
   var length = ToInteger(array.length);
 
   if (!IS_SPEC_FUNCTION(predicate)) {
     throw MakeTypeError('called_non_callable', [predicate]);
   }
 
   var thisArg;
   if (%_ArgumentsLength() > 1) {
     thisArg = %_Arguments(1);
   }
 
   if (IS_NULL_OR_UNDEFINED(thisArg)) {
-    thisArg = %GetDefaultReceiver(predicate) || thisArg;
-  } else if (!IS_SPEC_OBJECT(thisArg) && %IsSloppyModeFunction(predicate)) {
-    thisArg = ToObject(thisArg);
+    thisArg = %GetDefaultthisArg(predicate) || thisArg;
   }
+  var needs_wrapper = SHOULD_CREATE_WRAPPER(predicate, thisArg);

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

same here and in similar places in the patch

 
   for (var i = 0; i < length; i++) {
     if (i in array) {
       var element = array[i];
-      if (%_CallFunction(thisArg, element, i, array, predicate)) {
+      var newThisArg = needs_wrapper ? ToObject(thisArg) : thisArg;
+      if (%_CallFunction(newThisArg, element, i, array, predicate)) {
         return i;
       }
     }
   }
 
   return -1;
 }
 
 
 // ES6, draft 04-05-14, section 22.1.3.6
@@ skipping 64 matching lines @@
 
   // Set up the non-enumerable functions on the Array prototype object.
   InstallFunctions($Array.prototype, DONT_ENUM, $Array(
     "find", ArrayFind,
     "findIndex", ArrayFindIndex,
     "fill", ArrayFill
   ));
 }
 
 HarmonyArrayExtendArrayPrototype();