Testing $mdMedia

As I mentioned before I'm working with Angular Material on my project.  Today I had cause to use the $mdMedia service, which accepts a string parameter and returns either true or false based on the screen size.  For example, $mdMedia('lg') will return true if the screen is between 1280px and 1919px.  The service is great, but testing it was - once again - tricky.

I ended up using the same trick I used to test $mdSidenav, but modified it just a little bit.  In the interests of making it easier on myself next time I have to test $mdMedia, here we go.

var mediaMock, mediaQueryResult;
beforeEach(module(function ($provide) {
  mediaMock = jasmine.createSpy('$mdMedia');
  $provide.factory('$mdMedia', function() {
    return function() {
      return mediaQueryResult;
    };
  });
}));

it('should do something when $mdMedia() returns false regardless of what is passed to it', function() {
  // arrange
  mediaQueryResult = false;

  // act
  myFactory.myFunction();

  // assert
  expect(myFactory.myOtherFunction).toHaveBeenCalled();
});

it('should do something when $mdMedia() returns true regardless of what is passed to it', function() {
  // arrange
  mediaQueryResult = true;

  // act
  myFactory.myFunction();

  // assert
  expect(myFactory.myOtherFunction).not.toHaveBeenCalled();
});

That's all I had to do to get it to work.  I'm sure there's a way to vary the result based on the parameter, but I didn't need to do that so I didn't solve that problem... yet.