JSTests/test262/test/built-ins/Array/prototype/filter/15.4.4.20-9-c-i-4.js

// Copyright (c) 2012 Ecma International.  All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
esid: sec-array.prototype.filter
es5id: 15.4.4.20-9-c-i-4
description: >
    Array.prototype.filter - element to be retrieved is own data
    property that overrides an inherited data property on an Array
---*/

        function callbackfn(val, idx, obj) {
            return (idx === 0) && (val === 12);
        }

            Array.prototype[0] = 11;
            var newArr = [12].filter(callbackfn);

assert.sameValue(newArr.length, 1, 'newArr.length');
assert.sameValue(newArr[0], 12, 'newArr[0]');