rails_self_join_alias.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(false) do
  source 'https://rubygems.org'
  gem 'activerecord', '4.2.6'
  gem 'sqlite3'
  gem 'pry'
end

require 'active_record'
require 'minitest/autorun'
require 'logger'
require 'pry'

Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :contents, force: true do |t|
    t.integer :content_id, index: true
    t.string :body
    t.string :type
  end

end

class Content < ActiveRecord::Base; end

class Post < Content
  has_many :comments, foreign_key: :content_id
  has_many :sub_comments, through: :comments
end

class Comment < Content
  belongs_to :post, foreign_key: :content_id
  has_many :sub_comments, foreign_key: :content_id
end

class SubComment < Content
  belongs_to :comment, foreign_key: :content_id
  has_one :post, through: :comment
end

class BugTest < Minitest::Test
  def test_association_stuff
    post = Post.create(body: 'post')
    comment = Comment.create(body: 'comment', post: post)
    sub_comment = SubComment.create(body: 'sub comment', comment: comment)
    
    assert_equal post.sub_comments.first, sub_comment
  end
end