How do I test $scope.$on in AngularJS

Question

How do I test that the scope is populated after the broadcast? I\'ve searched and found a few QA\'s here in stackexchange, but none answered my problem. The code is working

Answer 1

If want to fake the returnValue from $scope.$broadcast() you can do something like these two cases:

Case 1:

scope.$broadcast('TEST_CHANGED', {test: 'test1'});
spyOn(scope, '$broadcast').and.callThrough();
expect(something).toEqual('something');

Case 2:

scope.$broadcast('TEST_CHANGED', {test: 'test2'});
spyOn(scope, '$broadcast').and.callThrough();
expect(something2).toEqual('something2');

Answer 2

As far as "toHavebeenCalled" concerned, there is no need of "andCallThrough()". Simple spy would work. In your case your arguments are different.

You are broadcasting like, rootScope.$broadcast('updatecrappy', [{id : 2, name : 'crappy'}]);

But you expect :

expect(rootScope.$broadcast).toHaveBeenCalledWith('updscenes', [{id : 2, name : 'crappy'}]);

look at argument " updarecrappy" but in tohavebeencalled it is "updscenes".

Answer 3

You need to tell Jasmine to let the spy call the actual $broadcast function

spyOn($rootScope, '$broadcast').andCallThrough();

If you don't use andCallThrough() the spy does nothing.

Jasmine Docs

EDIT

With Jasmine 2, the syntax would be

spyOn($rootScope, '$broadcast').and.callThrough();

Answer 4

Look at the sample code below, it works well for me.

Emitting sample event 'onTimeChanged' from $rootScope. My controller has a listener 'onTimeChanged' and I am calling a method timeChanged() inside it.

describe('onTimeChanged()', function() {
    it('should call another method or controller', function() {
        spyOn(searchCtrl, 'timeChanged');
        $rootScope.$emit('onTimeChanged');
        expect(searchCtrl.timeChanged).toHaveBeenCalled();
    });
});

Note that I did not spy on method '$emit' of rootScope.