Writing macro for activerecord

Question

I'm trying to write a new macro for my ActiveRecord model (User). Macro will be defined in my own gem which called Kart.

Below is my implementation for my gem Kart and User

kart.rb

require "kart/version"

module Kart
  extend ActiveSupport::Concern

  included do
    def goodbye
      p "Gooooood"
    end
  end
end

ActiveSupport.on_load :active_record do
  ActiveRecord::Base.send :include, Kart
end

user.rb

class User < ApplicationRecord
  goodbye # this is my macro, simply print "Goodbye"
end

For my understanding, when I run "rails c", "Gooooood" will be printed in the console but error message "method_missing': undefined local variable or methodgoodbye' for User" always shows up.

Answer 1

There are 2 main problems that I finally figure out:

• I need Railtie to integrate this gem with my rails app. You can find guidance in here: https://api.rubyonrails.org/classes/Rails/Railtie.html
• I forgot to rebuild and run bundle update after fixing code in my gem (beginner error but stuck for almost one day)