ar_test_belongs_to

unless File.exist?('Gemfile')
  File.write('Gemfile', <<-GEMFILE)
    source 'https://rubygems.org'
    gem 'rails', '6.1.1'
    gem 'sqlite3'
  GEMFILE

  system 'bundle'
end

require 'bundler'
Bundler.setup(:default)

require 'active_record'
require 'minitest/autorun'

# 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 :pages do |t|
    t.references :page
    t.timestamps
  end
end

class Page < ActiveRecord::Base
  belongs_to :page, optional: true
end

class BugTest < Minitest::Test
  def test_association_stuff
    p = Page.create
    assert_nil p.page
    Page.new.page = p
    assert_nil p.page
  end
end