test/built-ins/Array/prototype/lastIndexOf/15.4.4.15-8-a-13.js


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// 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.

/*---
es5id: 15.4.4.15-8-a-13
description: >
    Array.prototype.lastIndexOf -  deleting property of prototype
    causes prototype index property not to be visited on an Array-like
    Object
includes: [runTestCase.js]
---*/

function testcase() {

        var arr = { 2: 2, length: 20 };

        Object.defineProperty(arr, "3", {
            get: function () {
                delete Object.prototype[1];
                return 0;
            },
            configurable: true
        });

        try {
            Object.prototype[1] = 1;
            return -1 === Array.prototype.lastIndexOf.call(arr, 1);
        } finally {
            delete Object.prototype[1];
        }
    }
runTestCase(testcase);