How to make an AJAX create or delete request to a nested resource in RSpec

Suppose you have a nested resource:

resources :photos do
  resources :likes, only: [:create, :destroy]
end

Let's say that in your view clicking on a like button of a photo triggers an
AJAX request to the LikesController. <!-- more --> The request either creates a like if
the user hasn't likes the photo yet or destroys it. The urls must look like
this:

Verb     | Action    | Path

post     | create   | /photos/:photo_id/likes

delete | destroy | /photos/:photo_id/like/:id

In that case you need to construct a request in your specs which has the
following characteristics:

• be an AJAX request;
• be a POST or DELETE request;
• contain the photo id;
• contain the like id in the case of destroy.

So the create requests will roughly look like that:

xhr :post, :create, photo_id: photo.id

where:

• xhr tells RSpec to make an AJAX request;
• :post is the request verb;
• :create is the controller action;
• photo_id is the id of the photo the like must be created on. This assumes you have fabricated a photo and assigned it to the instance variable photo.

The destroy request will be similar, but you also have to supply the like id:

xhr :delete, :destroy, photo_id: photo.id, id: like.id

It again assumes that you have fabricated a like and assigned it to like.