Why doesn't Rails autoload classes from app/services?

Question

I'm working on a Rails 4.2 app and have just added app/services/fetch_artists.rb to the structure. Inside this file, I have defined a class FetchArtists; end.

When trying to run rails r 'FetchArtists' it gives me a NameError: uninitialized constant FetchArtists.

I've tried looking at ActiveSupport::Dependencies.autoload_paths and indeed, app/services is not there:

/.../app/assets /.../app/controllers /.../app/helpers /.../app/jobs /.../app/mailers /.../app/models /.../app/controllers/concerns /.../app/models/concerns /.../spec/mailers/previews 

My question is, why isn't this folder automatically loaded, and what should I do for it to be?

EDIT

Very strange, after repeatedly running the above command with rails runner, the new folder appears on the autoload paths. I have no idea why this happened with such a lag.

Someone suggested this may deal with spring. I would like to hear more on this, since it can possibly help many others in this situation too.

Answer 1

I encountered the same problem and it seems to be a caching issue with Spring, a process which handles preloading your app. It's used for the web server as well as the console and Rake tasks.

Stopping Spring with bin/spring stop will force Spring to load your app fresh. Now running rails console and inspecting ActiveSupport::Dependencies.autoload_paths will successfully show app/services.

Answer 2

In my case spring was not watching the app/services directory for changes - restarting Spring would load the class but changes to an existing class or new class would require a restart of Spring for them to apply.

To resolve this issue I added it to the list of directories watched by Spring in config/spring.rb:

%w(   .ruby-version   .rbenv-vars   tmp/restart.txt   tmp/caching-dev.txt   app/services ).each { |path| Spring.watch(path) } 

and restarted Spring one more time.