Ship ES2015 Symbol.species

test/mjsunit/es6/array-concat.js

 // Copyright 2014 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.
 
 // Flags: --harmony-proxies --harmony-reflect
 
 (function testArrayConcatArity() {
   "use strict";
   assertEquals(1, Array.prototype.concat.length);
 })();
@@ skipping 793 matching lines @@
   var obj = new Proxy(target, handler);
 
   log.length = 0;
   assertEquals([obj], [].concat(obj));
   assertEquals(1, log.length);
   for (var i in log) assertSame(target, log[i][1]);
   assertEquals(["get", target, Symbol.isConcatSpreadable, obj], log[0]);
 
   log.length = 0;
   assertEquals([obj], Array.prototype.concat.apply(obj));
-  assertEquals(1, log.length);
+  assertEquals(2, log.length);  // An extra read for the constructor
   for (var i in log) assertSame(target, log[i][1]);
-  assertEquals(["get", target, Symbol.isConcatSpreadable, obj], log[0]);
+  assertEquals(["get", target, "constructor", obj], log[0]);
+  assertEquals(["get", target, Symbol.isConcatSpreadable, obj], log[1]);
 })();
 
 
 (function testSpreadableArrayLikeProxy() {
   var target = ["a", "b"];
   target[Symbol.isConcatSpreadable] = undefined;
   var obj = new Proxy(target, handler);
 
   log.length = 0;
   assertEquals(["a", "b"], [].concat(obj));
   assertEquals(6, log.length);
   for (var i in log) assertSame(target, log[i][1]);
   assertEquals(["get", target, Symbol.isConcatSpreadable, obj], log[0]);
   assertEquals(["get", target, "length", obj], log[1]);
   assertEquals(["has", target, "0"], log[2]);
   assertEquals(["get", target, "0", obj], log[3]);
   assertEquals(["has", target, "1"], log[4]);
   assertEquals(["get", target, "1", obj], log[5]);
 
   log.length = 0;
   assertEquals(["a", "b"], Array.prototype.concat.apply(obj));
-  assertEquals(6, log.length);
+  assertEquals(7, log.length);
   for (var i in log) assertSame(target, log[i][1]);
-  assertEquals(["get", target, Symbol.isConcatSpreadable, obj], log[0]);
-  assertEquals(["get", target, "length", obj], log[1]);
-  assertEquals(["has", target, "0"], log[2]);
-  assertEquals(["get", target, "0", obj], log[3]);
-  assertEquals(["has", target, "1"], log[4]);
-  assertEquals(["get", target, "1", obj], log[5]);
+  assertEquals(["get", target, "constructor", obj], log[0]);
+  assertEquals(["get", target, Symbol.isConcatSpreadable, obj], log[1]);
+  assertEquals(["get", target, "length", obj], log[2]);
+  assertEquals(["has", target, "0"], log[3]);
+  assertEquals(["get", target, "0", obj], log[4]);
+  assertEquals(["has", target, "1"], log[5]);
+  assertEquals(["get", target, "1", obj], log[6]);
 })();
 
 
 (function testSpreadableArrayLikeProxyWithNontrivialLength() {
   var getTrap = function(t, key) {
     if (key === "length") return {[Symbol.toPrimitive]() {return 3}};
     if (key === "2") return "baz";
     if (key === "3") return "bar";
   };
   var target = [];
   var obj = new Proxy(target, {get: getTrap, has: () => true});
 
   assertEquals([undefined, undefined, "baz"], [].concat(obj));
   assertEquals([undefined, undefined, "baz"], Array.prototype.concat.apply(obj))
 })();
 
 
 (function testSpreadableArrayLikeProxyWithBogusLength() {
   var getTrap = function(t, key) {
     if (key === "length") return Symbol();
     if (key === "2") return "baz";
     if (key === "3") return "bar";
   };
   var target = [];
   var obj = new Proxy(target, {get: getTrap, has: () => true});
 
   assertThrows(() => [].concat(obj), TypeError);
   assertThrows(() => Array.prototype.concat.apply(obj), TypeError);
 })();