Improve detection for rails as the testing framework

[Earlopain]

Motivation

In some preparation of #2096

Note that this is only for detection of the testing framework, the issue is about installing ruby-lsp-rails. It may be relatively straight-forward to do this as well but I'm more familiar with this part of the code.

So, just do it here to talk roughtly about the implementation direction. I do plan to look properly at the issue after this and that should hopefully only involve moving a few things around.

Perhaps the GlobalState can even be created earlier so that SetupBundler has access to this method. Though the location of config/application.rb depend on workspace_uri which does get modified in apply_options .

Implementation

I created a listener for this which checks for Rails::Application inheritance.

This does parse the file twice, once on startup and once indexing actually starts. I don't see an easy way around this since proper indexing only starts once the server received initialized.

Automated Tests

One for the happy path, one for the other.

Manual Tests

I tested this out on my app which doesn't depend on rails but some subcompontents and that works fine.

[louim]

This is nice! It will only require a small addition to implement #2096. I can do so in a subsequent PR to keep things separate.

[louim]

I'm wondering if it's possible that the file is not right there, but would be nested deeper? I'm not too familiar with the different way people configure their project in relation with the workspace. At the same time, it might be best to stay with the simple solution.

[andyw8]

It's possible in theory for it to be in other locations, but would be very unusual, so I don't think we should worry about that.

[andyw8]

(and we already require that the Rails app is at the root of a workspace, so that's not a concern).

[louim]

I would probably have done it with a simple regex, but your solution looks much cleaner 👌🏼

[vinistock]

Sorry to jump in late, but if this is only related to the test framework detection then I believe we should first explore #1334.

Now that we can linearize ancestors for a class, we should use that information to determine which test framework is used for a given test.

Essentially something like this

ancestors = @index.linearized_ancestors_of("NameOfTestParentClass")

if ancestors.include?("ActiveSupport::TestCase")
  # rails
elsif ancestors.include?("Minitest::Test")
  # minitest
elsif ancestors.include?("Test::Unit::TestCase")
  # test-unit
else
  # rspec
end

Notice that linearizing ancestors is an expensive operation and using two test frameworks in the same project is quite uncommon, so we may want to use this as a detection mechanism only when someone opens a test file the first time and then memoize the framework we identified.

[Earlopain]

Right, if the testing framework detection is going to use some other logic for this, how about I just switch this over to SetupBundler to really fix the issue instead?

My main reason for not doing that in the first place was that I wasn't sure how to share the implementation between these two but if that isn't a concern then I can just move it over.

[Earlopain]

Continuing in #2218