text: // Copyright 2007 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 Generic queue for writing unit tests.
   */
  
  goog.setTestOnly('goog.testing.TestQueue');
  goog.provide('goog.testing.TestQueue');
  
  
  
  /**
   * Generic queue for writing unit tests
   * @constructor
   */
  goog.testing.TestQueue = function() {
    /**
     * Events that have accumulated
     * @type {Array<Object>}
     * @private
     */
    this.events_ = [];
  };
  
  
  /**
   * Adds a new event onto the queue.
   * @param {Object} event The event to queue.
   */
  goog.testing.TestQueue.prototype.enqueue = function(event) {
    this.events_.push(event);
  };
  
  
  /**
   * Returns whether the queue is empty.
   * @return {boolean} Whether the queue is empty.
   */
  goog.testing.TestQueue.prototype.isEmpty = function() {
    return this.events_.length == 0;
  };
  
  
  /**
   * Gets the next event from the queue. Throws an exception if the queue is
   * empty.
   * @param {string=} opt_comment Comment if the queue is empty.
   * @return {Object} The next event from the queue.
   */
  goog.testing.TestQueue.prototype.dequeue = function(opt_comment) {
    if (this.isEmpty()) {
      throw new Error('Handler is empty: ' + opt_comment);
    }
    return this.events_.shift();
  };
  