Controller instance variables return `nil` systematically and ActionView::Helpers methods are overriden

[EmCousin]

Hi,

I'm having an issue when trying to access the AMP version of a Rails view in my local environement

What happens is :

• For a given url : http://localhost:3000/pages/my-action
• The AMP url is http://localhost:3000/pages/my-action.amp
• Going to this URL throws an error, because all the instance variables return nil
• My guess is, it might have something to do with the overriding of the controller actions that is done there : https://github.com/takafumir/rails_amp/blob/master/lib/rails_amp/overrider.rb#L16
• Some helpers also happen to be overridden in a weird way (ex: using number_with_delimiter) with AMP format returns an ArgumentError exception (wrong number of arguments, given 2, expected 0)

# app/controllers/pages_controller.rb
class PagesController < ApplicationController
  def my_action
    @my_instance_var = "some data"
  end
end

# app/views/pages/my_action.html.erb
<%= @my_instance_var %> #=> returns nil

Context :

• Bug happening on multipleRails projects, all of which version is 4.2.10
• Ruby version is 2.6.2

Any insights?