AngularJS,Unit测试使用依赖于某些资源的服务的指令

我试图通过使用spyOn来建模资源,如建议的here,以及$httpBackend.when,但都没有用.当我调试代码时,它将转到get方法但get调用函数永远不会被调用,因此,设置我的值的内部回调myCallback永远不会被调用.
我不确定我的方法是否正确,我感谢您的建议.

/资源

.factory ('AirportTimeZone',function($resource){
  return $resource('/api/airport/:airportId/timezone',{airportId: '@airportId'});
})

/使用我的资源的服务：

angular.module('localizationService',[])
.factory('LocalizationService',['AirportTimeZone','CurrentLocalization',function (AirportTimeZone,CurrentLocalization) {

    function getAirportTimeZone(airport,myCallback){
      var options = {}
      var localOptions = AirportTimeZone.get({airportId:airport},function(data){
          options.timeZone = data.timeZoneCode
          myCallback(options)
      });
    }
})

/指令

.directive('date',function (LocalizationService) {
    return function(scope,element,attrs) {
        var airTimeZone
         function updateAirportTimeZone(_airportTimeZone){
            airTimeZone = _airportTimeZone.timeZone
            // call other stuff to do here
        }
        ....
        LocalizationService.getAirportTimeZone(airport,updateAirportTimeZone)
        ....
        element.text("something");
    }
});

/测试

describe('Testing date directive',function() {
    var $scope,$compile;
    var $httpBackend,airportTimeZone,currentLocalization

    beforeEach(function (){
        module('directives');
        module('localizationService');
        module('resourcesService');
    });

    beforeEach(inject(function (_$rootScope_,_$compile_,AirportTimeZone,CurrentLocalization) {
        $scope = _$rootScope_;
        $compile = _$compile_;
        airportTimeZone=AirportTimeZone;
        currentLocalization = CurrentLocalization;

 //        spyOn(airportTimeZone,'get').andCallThrough();
 //        spyOn(currentLocalization,'get').andCallThrough();

    }));

    beforeEach(inject(function($injector) {
        $httpBackend = $injector.get('$httpBackend');
//        $httpBackend.when('GET','/api/timezone').respond({timeZone:'America/New_York',locale:'us-en'});
//        $httpBackend.when('GET','/api/airport/CMH/timezone').respond({timeZone:'America/New_York'});
    }))

    describe('Date directive',function () {
        var compileButton = function (markup,scope) {
            var el = $compile(markup)(scope);
            scope.$digest();
            return el;
        };

        it('should',function() {
            var html = "<span date tz='airport' format='short' airport='CMH' >'2013-09-29T10:40Z'</span>"
            var element = compileButton(html,$scope)
            $scope.$digest();

            expected = "...."
            expect(element.html()).toBe(expected);


        });
    });
})