Migrations and test code for reverse polymorphic association.

Reverse polymorphic association.

unless File.exist?('Gemfile')
  File.write('Gemfile', <<-GEMFILE)
    source 'https://rubygems.org'
    gem 'rails', '~> 5.0.1'
    gem 'sqlite3'
  GEMFILE

  system 'bundle install'
end

require 'bundler'
Bundler.setup(:default)

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

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :versions do |t|
  end

  create_table :articles do |t|
  end

  create_table :pages do |t|
  end

  create_table :contents do |t|
    t.integer  "page_id",       null: false
    t.integer  "content_id"
    t.string   "content_type"
  end

end

class Page < ActiveRecord::Base
  has_many  :contents
  has_many  :articles, through: :contents, source: :content, source_type: "Article"
  has_many  :versions, through: :contents, source: :content, source_type: "Version"
end

class Content < ActiveRecord::Base
  belongs_to :page
  belongs_to :content, polymorphic: true
end

class Article < ActiveRecord::Base
  has_one :content, as: :content
  has_one :page, through: :content
end

class Version < ActiveRecord::Base
  has_one :content, as: :content
  has_one :page, through: :content
end

class BugTest < Minitest::Test
  def test_polymorphic_join_conditions
    page = Page.create
    page.versions.create
    page.articles.create

    page.reload
    assert_equal 1, page.versions.count
    assert_equal page.versions.first, Version.last
    assert_equal 1, page.articles.count
    assert_equal page.articles.first, Article.last
    assert_equal 2, page.contents.count
    assert_equal Version.last.page, page
    assert_equal Article.last.page, page
  end
end