AngularJs: Test service with Jasmine - angularjs

Question

I did this controller
app.controller('controller',['$scope','httpServices',function($scope,httpServices){
$scope.items= undefined;
httpServices.getItems( function(items){
$scope.items= items;
});
}]);
and I wrote this test
describe('controller', function () {
beforeEach(inject(function ($rootScope, $controller) {
scope = $rootScope.$new();
controller = $controller('controller', {
'$scope': scope
});
}));
it('defined', function () {
expect(scope.items).toBeUndefined();
})
});
How I can test the scope.items after to have called the service?

Answer 1

I assume that your service httpServices is making some http requests. Therefore you should use the mock-backend service in order to test your controller.
Something like this, pay attention to the comments that I've made inside the code:
describe('Your specs', function() {
var $scope,
$controller,
$httpBackend;
// Load the services's module
beforeEach(module('yourApp'));
beforeEach(inject(function(_$controller_, $rootScope, _$httpBackend_) {
$scope = $rootScope.$new();
$httpBackend = _$httpBackend_;
$controller = _$controller_;
//THIS LINE IS VERY IMPORTANT, HERE YOU HAVE TO MOCK THE RESPONSE FROM THE BACKEND
$httpBackend.when('GET', 'http://WHATEVER.COM/API/SOMETHING/').respond({});
var createController = function(){
$controller('controller', {$scope: $scope});
}
}));
describe('Your controller', function() {
it('items should be undefined', function() {
createController();
expect(scope.items).toBeUndefined();
});
it('items should exist after getting the response from the server', function () {
//THIS LINE IS ALSO VERY IMPORTANT, IT EMULATES THE RESPONSE FROM THE SERVER
$httpBackend.flush();
expect(scope.items).toBeDefined();
});
});
});

Answer 2

The question title states this is to test a service, but the code of the question looks like an attempt is being made to test the controller. This answer describes how to test the controller.
If you're testing the controller that calls httpServices.getItems, then you need to mock it/stub getItems in order to
Control it on the test
Not assume any behaviour of the real httpServices.getItems. After all, you're testing the controller, and not the service.
A way to do this is in a beforeEach block (called before the controller is created) provide a fake implementation of getItems that just saves the callback passed to it.
var callback;
beforeEach(inject(function(httpServices) {
callback = null;
spyOn(httpServices, 'getItems').and.callFake(function(_callback_) {
callback = _callback_;
});
});
In the test you can then call this callback, passing in some fake data, and test that this has been set properly on the scope.
it('saves the items passed to the callback on the scope', function () {
var testItems = {};
callback(testItems);
expect($scope.items).toBe(testItems);
});
This can be seen working at http://plnkr.co/edit/Z7N6pZjCS9ojs9PZFD04?p=preview
If you do want to test httpServices.getItems itself, then separate tests are the place for that. Assuming getItems calls $http, then you are most likely to need to use $httpBackend to handle mock responses. Most likely, these tests would not instantiate any controller, and I suspect not need to do anything on any scope.