Is it advisable to test routes in Rails 4 using Minitest?

Question

In Rails 3, when writing functional tests in MiniTest, I used to test routes separately from testing my actions with the controller. I got the idea from the Rails Guide on Testing - Section 9: Testing Routes . However, after upgrading my application to Rails 4, I noticed that the tests with the controller themselves began to deviate from unknown routes if I did not provide the get|patch|post|delete method with the correct set of parameters.

For example, given routes:

 # config/routes.rb namespace "api" do namespace "v2", defaults: { format: :json } do resources :users do resources :posts do resources :comments end end end end 

And a functional test:

 # test/controllers/api/v2/comments_controller_test.rb describe Api::V2::CommentsController it "does something" do get :index end end 

In Rails 3, this will work. But in Rails 4, I get a URL generation error:

ActionController :: UrlGenerationError: route mapping {: action => "index" ,: controller => "api / v2 / comments"}

From this, I can conclude that the get helper simply could not map the route to the routes file when trying to find the controller and action. Fair. I can fix this by changing the get call to include the parameters needed to satisfy the nested route, for example:

 # test/controllers/api/v2/comments_controller_test.rb describe Api::V2::CommentsController it "does something" do get :index, { user_id: "1", post_id: "1" } end end 

... then everything is fine again.

So my question is that this was not the case in Rails 3, can I now trust the validation of the controller actions to fully validate / verify my routes in Rails 4+? Or is there an added advantage when testing routes, as well as more? Is there perhaps some other angle that covers route tests that are not verified by controller control tests? (Note: I am not asking for the opinion that it is good to test, I am asking for functional differences between the route integration tests and the controller actions tests regarding route requirements).

Also, I couldn't find a specific link to this behavior change in the Rails 4 release notes (or in Minitest), so I wonder why this change was made in the first place. I don’t think it’s bad, I think it’s good, but I feel strange not seeing that he is mentioned in the changelog somewhere. And I thought that the half point of the get|patch|post|delete methods should free you from having to think about which parameters are needed for routing in the first place.

For completeness, here is a route test that I would use for this:

 describe "CommentsController Route Integration Test" do let(:default_options) { { controller: "api/v2/comments", user_id: "1", posts_id: "1", format: :json } } it "#index" do assert_routing "/api/v2/users/1/posts/1/comments", default_options.merge(action: "index") end end 

---

UPDATE

I was looking at the ActionDispatch code for the answer ... the only thing I can see so far is that the url_for has changed a lot from Rails 3 and that the ActionController :: UrlGenerationError class itself has been added to Rails 4. So it’s possible that these new, more stringent routing requirements are a random change to the decoupling of ActionView and ActionController.

Answer 1

After writing functional tests for several new controllers recently without writing any route integration tests, I am pretty sure that the extra work of testing routes is excessive. Given, that is, if there are functional tests covering all routes.

My reasoning basically is that ... anyway, when I passed the wrong parameters to the get|patch|post|delete call to the controller action, it always failed. And whenever I write a test for a controller action that exists but does not have an appropriate route, it always fails. Thus, it seems that higher-level functional tests also perform integration tests at a lower level just like that, so why bother with duplication of effort?

I think that in the future I will look for an updated “official” word, but for now I decided to stop worrying about directly testing my routes whenever there are matching functional tests.

UPDATE

I also decided that testing API routes might still be useful. This helps ensure that the actual URL string published with the API is actually correct and working. Note that it is important to check the string, not the named route, because the named route can change with changes in resources in the routes file.

Answer 2

I believe that testing routes and controllers is completely unnecessary, since you have functional tests. This does not directly answer your question, but it should solve your dilemma. I recommend doing some readings on various testing philosophies and (further) formulating an ideological opinion on how and what to test.