It doesn’t matter what you do in the controller, since this test tests the view, not the controller.
videos = [%Rumbl.Video{id: "1", title: "dogs"}, %Rumbl.Video{id: "2", title: "cats"}]
You need to preload the category for these videos (in the test itself). Here that could mean just hardcoding it like:
videos = [%Rumbl.Video{id: "1", title: "dogs", category: %Rumbl.Category{name: “Animals”}}, ...]
