Testing service with $httpBackend in AngularJS - angularjs

Question

I'm new to AngularJS and running into some problems with unit testing. I've seen countless examples of mocking $httpBackend calls, but when I do that it won't work unless I also include $rootScope.$apply().
My service:
angular.module('myApp.services', ['ngResource'])
.factory('TestingService', ['$resource', function($resource) {
return $resource('/api/v1/values', {}, {
getValues: {
method: 'GET'
}
});
}]);
My unit test:
describe('Testing services', function() {
beforeEach(module('myApp.services'));
afterEach(function() {
inject(function($httpBackend) {
$httpBackend.verifyNoOutstandingExpectation();
$httpBackend.verifyNoOutstandingRequest();
});
});
describe('TestingService', function() {
it('would be nice to get an explanation for this',
inject(['$rootScope', '$httpBackend', 'TestingService',
function ($rootScope, $httpBackend, testingService) {
$httpBackend.expectGET('/api/v1/values').respond(100);
var result = testingService.getValues();
//$rootScope.$apply();
$httpBackend.flush();
expect(result).toBe(100);
alert(result);
}])
);
});
});
When Karma runs the test like this I get:
Error: No pending request to flush !
Error: Unsatisfied requests: GET /api/v1/values
And if I include the $rootScope.$apply(); I'll get this (and the alert of course also prints out a $promise):
Expected { $promise : { then : Function, catch : Function, finally : Function }, $resolved : true } to be 100.
Can anyone explain why I need "$rootScope.$apply();" to pass the expectGET?
And why the response is a promise instead of the mock response I've specified?

Answer 1

Found the problem after some sleep. Simple one fortunately.
I'm using Angular version 1.3.0-beta.2, but had an older version for angular-mocks. Updating the versions removes the need for "$root.$apply();".
The updated working test:
describe('Testing services', function() {
beforeEach(function(){
module('myApp.services');
this.addMatchers({
toEqualData: function(expected) {
return angular.equals(this.actual, expected);
}
});
});
afterEach(function() {
inject(function($httpBackend) {
$httpBackend.verifyNoOutstandingExpectation();
$httpBackend.verifyNoOutstandingRequest();
});
});
describe('TestingService', function() {
it('should work',
inject(['$rootScope', '$httpBackend', 'TestingService',
function ($rootScope, $httpBackend, testingService) {
$httpBackend.expectGET('/api/v1/values').respond( { key: 'value' } );
var result = testingService.getValues();
$httpBackend.flush();
expect(result).toEqualData( { key: 'value' } );
alert(angular.toJson(result, true));
}])
);
});
});