How can I preload concerns in a rails initializer using Rails 6/Zeitwerk?

Question

I\'m working with an initializer that does some monkey patching on app start by including some app concerns into a third party lib. Basically:

# config/initi         


        

Answer 1

As described by @Glyoko's answer, using require on dependencies prevents autoloading in initializers. However, doing so leads to problems during reloading as @Puhlze mentioned in his comment.

I stumbled across an alternate approach that utilizes Rails.configuration.to_prepare in this post.

An example would be:

# config/initializers/my_initializer.rb

Rails.configuration.to_prepare do
  class SomeExternalLib
    include MyConcern1
    include MyConcern2
  end
end

Note that this runs before every request in development but only once before eager loading in production.

Edit: it appears to also work with reloading.