Breezejs unit test with jasmine karma angular - angularjs

Question

I'm building an app based in Breeze and Angular
They work pretty well together but the unit test is a problem.
This is a pretty vanilla test but Breeze keeps getting in the middle:
describe('myController', function () {
beforeEach(inject(function ($injector) {
module('app');
$httpBackend = $injector.get('$httpBackend');
authRequestHandler = $httpBackend.whenGET().respond(200,
{"someStrings": ["foo", "bar"]})
//more uninteresting code...
createController = function () {
return $controller('myController', { '$scope': $rootScope });
};
}));
it('should fetch authentication token', function () {
$httpBackend.expectGET('/auth.py');
var controller = createController();
$httpBackend.flush();
});
The problem is that Breeze keeps being initialized. At execution, I receive the following message:
Error: cannot execute _executeQueryCore until metadataStore is populated.
//or,with different get: ... $httpBackend.when('GET', '/auth.py')
// .respond({ userId: 'userX' });
Error: Unexpected request: GET breeze/Breeze/Metadata No more request expected
How do I prevent or mock or stub Breeze so doesn't interfere with my tests... For instance, these tests are aimed to authentication, not data.

Answer 1

Breeze is not "getting in the middle" on its own. Breeze would not get involved in your $http authorization call. I'll eat my hat if you can show me that it does. You haven't shown that it does here.
But you have surfaced a very interesting point about application bootstrap design and the consequences of that design for testing.
Evidently, either your app module's start method or your controller's creation logic executes a Breeze query (perhaps both of them do). I deduce this from two facts:
The exception comes from executeQueryCore which only happens when you explicitly execute a Breeze query
You don't touch the controller in your test, neither in the beforeEach nor in the it which means these calls (and your auth call too) are made by some kind of automatic startup logic that executes before your it spec.
In your test you have taken the trouble to mock the auth call (which is in your startup logic somewhere) but not the Breeze calls.
I don't know what you actually want to test. Why would you test that the controller fetches an auth token? Is that really the controller's concern?
Perhaps you present this test merely to illustrate the problems you're having testing a controller without getting the real server involved?
Let me step back and make a more important and more general point. We must be wary of automatic startup logic whether it hides in an app module start or a controller's constructor. Be wary in particular of startup logic that involves calls to the server.
I tend to disable automated startup logic in most of my tests. I often substitute test doubles for the troublesome dependent services during my test module setup ... before calling ngMock's inject function. I make sure that the app.start method's callback ONLY uses dependent services that are easy to fake.
I you want to forge ahead using the actual dependencies by mocking the HTTP responses with $httpBackend, then you'll have to prepare $httpBackend for every request it receives from the startup code ... including the requests YOU are making with Breeze.
I'll end by reiterating that Breeze only does what you tell it to do. It is completely unaware of your direct-to-$http calls.