JSTests/test262/test/built-ins/Object/keys/15.2.3.14-5-a-4.js

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

/*---
es5id: 15.2.3.14-5-a-4
description: >
    Object.keys - Verify that 'configurable' attribute of element of
    returned array is correct
---*/

        var obj = { prop1: 100 };

        var array = Object.keys(obj);
        var desc = Object.getOwnPropertyDescriptor(array, "0");

        delete array[0];

assert.sameValue(typeof array[0], "undefined", 'typeof array[0]');
assert(desc.hasOwnProperty("configurable"), 'desc.hasOwnProperty("configurable") !== true');
assert.sameValue(desc.configurable, true, 'desc.configurable');