cancancan.rb

begin
  require 'bundler/inline'
rescue LoadError => e
  $stderr.puts 'Bundler version 1.10 or later is required. Please update your Bundler'
  raise e
end

gemfile(true) do
  source 'https://rubygems.org'
  gem 'rails', '6.1.1' # use correct rails version
  gem 'activemodel'
  gem 'cancancan', path: "./" # use correct cancancan version
  gem 'mysql2' # use another DB if necessary
  gem 'mysql-binuuid-rails', require: false
  gem 'pry-rails'
end

require 'active_record'
require 'active_model'
require 'cancancan'
require 'cancan/model_adapters/active_record_adapter'
require 'cancan/model_adapters/active_record_4_adapter'
require 'minitest/autorun'
require 'logger'
require 'mysql-binuuid-rails'
require_relative 'lib/cancan/model_adapters/active_record_5_adapter'
require_relative 'lib/cancan/model_adapters/sti_normalizer'
require_relative 'lib/cancan/model_adapters/conditions_normalizer'
require_relative 'lib/cancan/model_adapters/conditions_extractor'

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(
  adapter: 'mysql2',
  database: 'cancancan',
  host: 'mysql',
  username: 'root',
  password: 'password'
)
ActiveRecord::Base.logger = Logger.new(STDOUT)

# create your tables here
ActiveRecord::Schema.define do
  drop_table :books if table_exists? :books
  drop_table :authors if table_exists? :authors
  drop_table :users if table_exists? :users

  create_table :users, id: {limit: 16, type: :binary}, force: true do |t|
    t.string :name
  end

  create_table :authors, id: {limit: 16, type: :binary}, force: true do |t|
    t.references :user, limit: 16, type: :binary
  end

  create_table :books, id: {limit: 16, type: :binary}, force: true do |t|
    t.references :author, limit: 16, type: :binary
  end

  add_foreign_key :books, :authors
  add_foreign_key :authors, :users
end

class ApplicationRecord < ActiveRecord::Base
  self.abstract_class = true

  attribute :id, MySQLBinUUID::Type.new

  before_validation do
    self.id = SecureRandom.uuid if new_record? && !id?
  end

  # Hack to automatically do the UUID stuff for all relationships
  def self.belongs_to(relationship_name, *args, &blk)
    super
    attribute :"#{relationship_name}_id", MySQLBinUUID::Type.new
  end
end

class Author < ApplicationRecord
  belongs_to :user

  has_many :books
end

class Book < ApplicationRecord
  belongs_to :author
end

class User < ApplicationRecord
  has_many :authors
end

class Ability
  include CanCan::Ability

  def initialize(user)
    can :read, Book, author: {user_id: user.id}
  end
end

class BugTest < Minitest::Test
  def test_bug
    user1 = User.create!
    user2 = User.create!
    author1 = Author.create!(user: user1)
    author2 = Author.create!(user: user2)
    book1 = Book.create!(author: author1)
    book2 = Book.create!(author: author2)
    ability = Ability.new(user1)
    books = Book.accessible_by(ability, :read).count

    puts "SQL: #{Book.accessible_by(ability, :read).to_sql}"
    assert_equal 1, books
  end
end

# class TestApp < Rails::Application
#   config.root = File.dirname(__FILE__)
#   config.session_store :cookie_store, key: "cookie_store_key"
#   secrets.secret_token    = "secret_token"
#   secrets.secret_key_base = "secret_key_base"

#   config.logger = Logger.new($stdout)
#   Rails.logger  = config.logger

#   routes.draw do
#     resources :libraries do
#       resources :books
#     end
#   end
# end

# class ExampleController < ActionController::Base
#   include CanCan::ControllerAdditions
# end

# class ExampleControllerTest < ActionController::TestCase

#   setup do
#     @controller = ExampleController.new
#     @routes = Rails.application.routes
#   end

#   def test_action
# #     ...
#   end
# end