Simple Jasmine Ajax Mock

jasmineAjaxMock.js

'use strict';

var routes = [];

/**
 * Simple jQuery ajax mock for jasmine
 * 
 * @example
 * 
 * ## Create a mocked route
 * 
 * ```js
 * jasmine.ajaxMock()
 *  .when('GET', 'http://my-awesome.api/metadata.json', function() {
 *    // return response for success call
 *    return {
 *      id: 1
 *    };
 *  });
 * ```
 * 
 * ## Test
 * 
 * ```js
 * it('should get metadata with id 1', function() {
 * 
 *  $.get('http://my-awesome.api/metadata.json', function(response) {
 *    expect(response.id.toEqual(1));
 *  });
 * 
 * });
 * ```
 * 
 * 
 * @param keepRoutes
 * @returns {{when: when}}
 */
jasmine.ajaxMock = function (keepRoutes) {
  // clear routes
  if (true !== keepRoutes) {
    routes = [];
  }

  if (!$._ajax) {
    $._ajax = $.ajax;

    $.ajax = function (url, settings) {
      if (settings) {
        settings.url = url;
      } else {
        settings = url;
      }

      for (var i = 0; i < routes.length; i++) {
        if (routes[i].url === settings.url && routes[i].method.toLowerCase() === settings.type.toLowerCase()) {
          var defer = jQuery.Deferred();
          defer.resolveWith(routes[i].response());

          if (settings.success) {
            settings.success(routes[i].response());
          }
          return defer.promise();
        }
      }

      return $._ajax(settings);
    };
  }

  return {
    when: function (method, url, response) {
      routes.push({
        method:   method,
        url:      url,
        response: response
      });

      return this;
    }
  };
};