Dusan Orlovic

If you receive warning about

DEPRECATION WARNING: Initialization autoloaded the constants ApplicationHelper, FormHelper, Stimulus::StimulusHelper, DeviseHelper, ApplicationController, and ActionText::ContentHelper.

Being able to do this is deprecated. Autoloading during initialization is going
to be an error condition in future versions of Rails.

Reloading does not reboot the application, and therefore code executed during
initialization does not run again. So, if you reload ApplicationHelper, for example,
the expected changes won't be reflected in that stale Module object.

These autoloaded constants have been unloaded.

In order to autoload safely at boot time, please wrap your code in a reloader
callback this way:

    Rails.application.reloader.to_prepare do
      # Autoload classes and modules needed at boot time here.
    end

That block runs when the application boots, and every time there is a reload.
For historical reasons, it may run twice, so it has to be idempotent.

Check the "Autoloading and Reloading Constants" guide to learn more about how
Rails autoloads and reloads.
 (called from <main> at /home/orlovic/rails/gofordesi-webapp/config/environment.rb:5)

than simply wrap the code inside Rails.application.reloader.to_prepare do like

Rails.application.reloader.to_prepare do
  class TurboFailureApp < Devise::FailureApp
    def respond
      ...
  end
  class TurboController < ApplicationController
      ...
  end
end

I solved by upgrading stimulus, for example put "stimulus": "^2.0.0", in package.json and run yarn upgrade stimulus