Break out testing library from ActiveSupport?

rubyonrails-core
1

I followed down the path of why my app was bringing in ‘minitest’ in production and noticed that activesupport has a dependency on minitest. I wondered why it wasn’t a development dependency and then it dawned on me that it was necessary for ActiveSupport::TestCase.

What does the core team think about breaking the testing-related stuff out of activesupport into a separate gem? It would eliminate the dependency on minitest and could load (probably a trival amount) of less code for production Rails apps. Is this a good idea and a worthwhile thing for me to spend some time on? Is this much more work than I think it might be?

Thanks in advance!

Brian

2

Hi Brian,

I think to we start to consider doing this we will need a stronger reason than load less code for production Rails apps. AFAIK, we don’t require active_support/test_case in production environment so we are not loading minitest at production too.

If that is the case we should fix this, but I don’t think we need to extract a new library.

3

Minitest is already in the standard library, so you're not really adding or removing any meaningful dependence.

4

I just found this thread after noticing the same dependency today and looking for a way to potentially remove this. I don’t quite see a dependency on minitest in the ‘standard library’ (by which I assume you mean the Rails gem itself). rails/rails.gemspec at main · rails/rails · GitHub Or is there another dependency I’m missing?

As far as I can tell we would need to not autoload test_case.rb and then wrap the ‘require’ call to give a more meaningful error. It’s not clear to me if we expect consumers of the gem to use the ActiveSupport::TestCase class, or is that purely for testing the library itself? I don’t see any explicit examples for it in the documentation, but I’m also not that familiar with MiniTest.

5

Minitest is already in the standard library, so you’re not really adding or removing any meaningful dependence.

I just found this thread after noticing the same dependency today and looking for a way to potentially remove this. I don’t quite see a dependency on minitest in the ‘standard library’ (by which I assume you mean the Rails gem itself). https://github.com/rails/rails/blob/master/rails.gemspec Or is there another dependency I’m missing?

When Steve wrote that sentence three+ years ago, minitest was still included as part of the Ruby standard library. It was removed in 2.2 - see this discussion for more details:

https://bugs.ruby-lang.org/issues/9711

As far as I can tell we would need to not autoload test_case.rb and then wrap the ‘require’ call to give a more meaningful error. It’s not clear to me if we expect consumers of the gem to use the ActiveSupport::TestCase class, or is that purely for testing the library itself? I don’t see any explicit examples for it in the documentation, but I’m also not that familiar with MiniTest.

ActiveSupport::TestCase can be used directly (see the example in the guides: http://guides.rubyonrails.org/testing.html#rails-meets-minitest ). The minitest plumbing is also used by Rspec (in at least some cases):

https://github.com/rspec/rspec-rails/blob/e8054a1cd03044f725030fe8315952cf3799a395/lib/rspec/rails/adapters.rb#L22

I’ll reiterate Rafael’s point from earlier in the thread: why is removing this dependency important?

—Matt Jones