Undefined method 'permissions_for' for Permissions:Module in Rails 6 - ruby-on-rails

Question

I am returning to Rails after 5 years out of it and trying to understand the changes. I am going through Ryan Bates' Railscasts looking to update a template I built some years ago and am getting the above error when initializing the permissions class for authentication. (See RC#386 about 18:00 into the playback.)
Rails has changed the before_filter to before_action (makes sense...) and I have the following in the ApplicationController:
class ApplicationController < ActionController::Base
before_action :authorize
delegate :allow?, to: :current_permission
helper_method :allow?
delegate :allow_param?, to: :current_permission
helper_method :allow_param?
private
def current_user
#current_user ||= User.find(session[:user_id]) if session[:user_id]
end
helper_method :current_user
def current_permission
#current_permission ||= Permissions.permission_for(current_user)
end
def current_resource
nil
end
def authorize
if current_permission.allow?(params[:controller], params[:action], current_resource)
current_permission.permit_params! params
else
redirect_to root_url, alert: "Not authorized."
end
end
end
My permissions.rb file has the following:
module Permissions
def self.permission_for(user)
if user.nil?
GuestPermission.new
elsif user.admin?
AdminPermission.new(user)
else
MemberPermission.new(user)
end
end
end
I'm getting the above error: NoMethodError at /undefined method "permission_for" for Permissions:Module from BetterErrors (and Puma). However the method should be defined in the Permissions module; it's right there. Yet somehow, something has changed in Rails that I can't figure out.
I have tried to require the file: nothing.
Any help?

Answer 1

You need to include a module in a class to use it. It then adds functionality to that class, you do not access methods in module itself.
I'm guessing you need to do something like this (not tested):
class ApplicationController < ActionController::Base
include Permissions
before_action :authorize
change your module to:
module Permissions
def permission_for(user)
...
and then permissions_for is available in your controller
def current_permission
#current_permission ||= permission_for(current_user)
end
The only thing that has changed in Rails is how folders and files are included. The lib folder inside your rails app is not autoloaded by default.
I think best practice is now to add a lib folder within the app folder and then put all your modules and other classes in there. They will be included as soon as you restart your server.