fake_objects.js revision 1320f92c476a1ad9d19dba2a48c72b75566198e9 
1// Copyright 2014 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5/**
6 * Fakes a Chrome event that supports one listener.
7 * @constructor
8 * @extends {ChromeEvent}
9 */
10function FakeChromeEvent() {
11  /**
12   * @private
13   * @type {Function}
14   */
15  this.listener_ = null;
16}
17
18FakeChromeEvent.prototype = {
19  /**
20   * Fakes the corresponding call on a Chrome event.  Sets the listener and
21   * fails the test if it is already set.
22   * @param {Function} listener The new listener.
23   */
24  addListener: function(listener) {
25    this.assertNoListener();
26    this.listener_ = listener;
27  },
28
29  /**
30   * Gets the listener of the event, failing the test if there's none.
31   * @return {Function} The event's listener.
32   */
33  getListener: function() {
34    assertNotEquals(null, this.listener_);
35    return this.listener_;
36  },
37
38  /**
39   * Asserts that this object doesn't have any listener added.
40   */
41  assertNoListener: function() {
42    assertEquals(null, this.listener_);
43  }
44};
45