Testing service that returns promise in Angular

I'm trying to test my services and the data they return. I'm using Angular, Typescript and Karma. This is my service

/// <reference path="../../../typings/index.d.ts" />

class WeatherDataService {

  static $inject = ['$http', '$log', '$q'];

  constructor(private $http: ng.IHttpService,
              private $log: ng.ILogService,
              private $q: ng.IQService) {
    this.$http = $http;
    this.$log = $log;
    this.$q = $q;
  }

  get(params: string): ng.IPromise<{}> {
    var self = this;
    var deferred = this.$q.defer();

    this.$http.get('http://ift.tt/1mGUATE?' + params + '&appid=' + API_KEY)
      .then((response) => {
        deferred.resolve(response.data);
      }, (errors) => {
        self.$log.debug(errors);
        deferred.reject(errors.data);
      });

    return deferred.promise;
  }
}

And this is the WeatherDataService.spec.ts

/// <reference path="../../../typings/index.d.ts" />

describe('WeatherDataService', () => {
  let weatherDataService;

  var $http, $log, $q;

  beforeEach(angular.mock.module('app'));

  beforeEach(inject(function (_$http_: ng.IHttpService, _$log_: ng.ILogService, _$q_: ng.IQService) {
    $http = _$http_;
    $log = _$log_;
    $q = _$q_;

    weatherDataService = new WeatherDataService($http, $log, $q);
  }));

  describe('testing karma', function () {
    it('Geolocation response should have a valid structure', function () {
      weatherDataService.get('lat=42.683529199999995&lon=26.309871599999997').then((response) => {
        expect(response).toBe('object');
      });
    });
  });
});

My main question is how to test the deferred.promise and check the structure of the received data.