The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 /* See https://bugzilla.mozilla.org/show_bug.cgi?id=780370 */

 const Cu = Components.utils;

 // Use a COW to expose a function from a standard prototype, and make sure it's

 // still remapped.

 function run_test()

 {

   var sb = Cu.Sandbox("http://www.example.com");

   sb.obj = { foo: 42, __exposedProps__: { hasOwnProperty: 'r' } };

   do_check_eq(Cu.evalInSandbox('typeof obj.foo', sb), 'undefined', "COW works as expected");

   do_check_true(Cu.evalInSandbox('obj.hasOwnProperty === Object.prototype.hasOwnProperty', sb),

                 "Remapping happens even when the property is explicitly exposed");

   // NB: We used to test for the following, but such behavior became very

   // difficult to implement in a recent refactor. We're moving away from this

   // API anyway, so we decided to explicitly drop support for this.

   // do_check_eq(Cu.evalInSandbox('Object.prototype.bar = 10; obj.bar', sb), 10);

 }