/// 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 ch15/15.4/15.4.4/15.4.4.21/15.4.4.21-5-7.js * @description Array.prototype.reduce throws TypeError if 'length' is 0 (subclassed Array, length overridden with obj w/o valueOf (toString)), no initVal */ function testcase() { foo.prototype = new Array(1, 2, 3); function foo() {} 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(){} try { f.reduce(cb); } catch (e) { if (e instanceof TypeError) { return true; } } } runTestCase(testcase);