text: // Copyright 2010 The Closure Library Authors. All Rights Reserved.
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //      http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing, software
  // distributed under the License is distributed on an "AS-IS" BASIS,
  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  // See the License for the specific language governing permissions and
  // limitations under the License.
  
  /**
   * @fileoverview Defines DeferredTestCase class. By calling waitForDeferred(),
   * tests in DeferredTestCase can wait for a Deferred object to complete its
   * callbacks before continuing to the next test.
   *
   * Example Usage:
   *
   *   var deferredTestCase = goog.testing.DeferredTestCase.createAndInstall();
   *   // Optionally, set a longer-than-usual step timeout.
   *   deferredTestCase.stepTimeout = 15 * 1000; // 15 seconds
   *
   *   function testDeferredCallbacks() {
   *     var callbackTime = goog.now();
   *     var callbacks = new goog.async.Deferred();
   *     deferredTestCase.addWaitForAsync('Waiting for 1st callback', callbacks);
   *     callbacks.addCallback(
   *         function() {
   *           assertTrue(
   *               'We\'re going back in time!', goog.now() >= callbackTime);
   *           callbackTime = goog.now();
   *         });
   *     deferredTestCase.addWaitForAsync('Waiting for 2nd callback', callbacks);
   *     callbacks.addCallback(
   *         function() {
   *           assertTrue(
   *               'We\'re going back in time!', goog.now() >= callbackTime);
   *           callbackTime = goog.now();
   *         });
   *     deferredTestCase.addWaitForAsync('Waiting for last callback', callbacks);
   *     callbacks.addCallback(
   *         function() {
   *           assertTrue(
   *               'We\'re going back in time!', goog.now() >= callbackTime);
   *           callbackTime = goog.now();
   *         });
   *
   *     deferredTestCase.waitForDeferred(callbacks);
   *   }
   *
   * Note that DeferredTestCase still preserves the functionality of
   * AsyncTestCase.
   *
   * @see.goog.async.Deferred
   * @see goog.testing.AsyncTestCase
   */
  
  goog.provide('goog.testing.DeferredTestCase');
  
  goog.require('goog.async.Deferred');
  goog.require('goog.testing.AsyncTestCase');
  goog.require('goog.testing.TestCase');
  
  
  
  /**
   * A test case that can asynchronously wait on a Deferred object.
   * @param {string=} opt_name A descriptive name for the test case.
   * @constructor
   * @extends {goog.testing.AsyncTestCase}
   */
  goog.testing.DeferredTestCase = function(opt_name) {
    goog.testing.AsyncTestCase.call(this, opt_name);
  };
  goog.inherits(goog.testing.DeferredTestCase, goog.testing.AsyncTestCase);
  
  
  /**
   * Preferred way of creating a DeferredTestCase. Creates one and initializes it
   * with the G_testRunner.
   * @param {string=} opt_name A descriptive name for the test case.
   * @return {goog.testing.DeferredTestCase} The created DeferredTestCase.
   */
  goog.testing.DeferredTestCase.createAndInstall = function(opt_name) {
    var deferredTestCase = new goog.testing.DeferredTestCase(opt_name);
    goog.testing.TestCase.initializeTestRunner(deferredTestCase);
    return deferredTestCase;
  };
  
  
  /**
   * Handler for when the test produces an error.
   * @param {Error|string} err The error object.
   * @protected
   * @throws Always throws a ControlBreakingException.
   */
  goog.testing.DeferredTestCase.prototype.onError = function(err) {
    this.doAsyncError(err);
  };
  
  
  /**
   * Handler for when the test succeeds.
   * @protected
   */
  goog.testing.DeferredTestCase.prototype.onSuccess = function() {
    this.continueTesting();
  };
  
  
  /**
   * Adds a callback to update the wait message of this async test case. Using
   * this method generously also helps to document the test flow.
   * @param {string} msg The update wait status message.
   * @param {goog.async.Deferred} d The deferred object to add the waitForAsync
   *     callback to.
   * @see goog.testing.AsyncTestCase#waitForAsync
   */
  goog.testing.DeferredTestCase.prototype.addWaitForAsync = function(msg, d) {
    d.addCallback(goog.bind(this.waitForAsync, this, msg));
  };
  
  
  /**
   * Wires up given Deferred object to the test case, then starts the
   * goog.async.Deferred object's callback.
   * @param {!string|goog.async.Deferred} a The wait status message or the
   *     deferred object to wait for.
   * @param {goog.async.Deferred=} opt_b The deferred object to wait for.
   */
  goog.testing.DeferredTestCase.prototype.waitForDeferred = function(a, opt_b) {
    var waitMsg;
    var deferred;
    switch (arguments.length) {
      case 1:
        deferred = a;
        waitMsg = null;
        break;
      case 2:
        deferred = opt_b;
        waitMsg = a;
        break;
      default: // Shouldn't be here in compiled mode
        throw Error('Invalid number of arguments');
    }
    deferred.addCallbacks(this.onSuccess, this.onError, this);
    if (!waitMsg) {
      waitMsg = 'Waiting for deferred in ' + this.getCurrentStepName();
    }
    this.waitForAsync( /** @type {!string} */ (waitMsg));
    deferred.callback(true);
  };
  