Uninitialized constant Devise::SessionsController when extending controller

[mcfoton]

Issue happens when changing Rails version from 6.x to 7.x
To enable 2FA for admin dashboard we are overriding the SessionsController.

# /app/controllers/active_admin/devise/sessions_controller.rb

module ActiveAdmin
  module Devise
    class SessionsController < ::Devise::SessionsController
      before_action :authenticate_with_two_factor, only: :create

      def authenticate_with_two_factor
        # do something 
      end

    end
  end
end

Simply having this file produces an error with rails 7.x

.../gems/activeadmin-3.1.0/lib/active_admin/devise.rb:54:in `<module:Devise>': uninitialized constant Devise::SessionsController (NameError)

    class SessionsController < ::Devise::SessionsController
                                       ^^^^^^^^^^^^^^^^^^^^

Seems to be related to the loading process, but this setup works with rails 6.x and zeitwerk enabled 🤔

---

Reproduced with blank Rails app

rails 7.1.2
activeadmin 3.1.0
devise 4.9.3

[mcfoton]

update:

The custom controller code does register if I

1. Put the code inside an initializer under /config/initializers instead of /app/controllers
2. Wrap the code with Rails.application.config.after_initialize do as suggested here

Not sure if this a proper solution here or simply a walk around. Also not sure if I am restricted to have the code under initializers folder only.

Would appreciate any suggestions.

[javierjulio]

A few things to note. I believe the approach has to be class ActiveAdmin::Devise::SessionsController instead of a module with Zeitwerk but not sure if that will help much based on the Rails guide. It could be that it occurs because those files are in our lib and not in the app folder so I wonder if related to that. I've seen past issues bring this up.

All I can do is share what I've done in my app for a long time now and it works fine with Rails 7 and Zeitwerk. Also, I think this would be preferred since you'd want to customize most things like the view too. We take this approach to use Okta for admin login.

In routes, declare the new sessions controller:

  devise_for :admin_users, ActiveAdmin::Devise.config.merge(
    controllers: {
      sessions: 'active_admin/sessions',
      # ...
    }
  )

Then declare a controller in app/controllers/active_admin/sessions_controller.rb as you would normally along with the view in app/views/active_admin/sessions/new.html.erb so you can customize.

class ActiveAdmin::SessionsController < ActiveAdmin::Devise::SessionsController
  # ...
end

From there it should be ok.

[mcfoton]

Awesome, thanks for the prompt response. Your suggested solution works well for me.

It seems that simply having any .rb file inside /controllers/active_admin/devise is throwing off the loader.
Works no problem with files under /controller/active_admin, as you suggested.