/// Copyright (c) 2012 Ecma International. All rights reserved. /// Ecma International makes this code available under the terms and conditions set /// forth on http://hg.ecmascript.org/tests/test262/raw-file/tip/LICENSE (the /// "Use Terms"). Any redistribution of this code must retain the above /// copyright and this notice and otherwise comply with the Use Terms. /** * @path ch15/15.4/15.4.4/15.4.4.19/15.4.4.19-9-11.js * @description Array.prototype.map - returns an empty array if 'length' is 0 (subclassed Array, length overridden with obj w/o valueOf (toString)) */ function testcase() { function Foo() { } Foo.prototype = [1, 2, 3]; var f = new Foo(); var o = { toString: function () { return '0'; } }; f.length = o; // objects inherit the default valueOf method of the Object object; // that simply returns the itself. Since the default valueOf() method // does not return a primitive value, ES next tries to convert the object // to a number by calling its toString() method and converting the // resulting string to a number. function cb() { } var a = Array.prototype.map.call(f, cb); if (Array.isArray(a) && a.length === 0) { return true; } } runTestCase(testcase);