#13071

test.rb

# frozen_string_literal: true

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  gem "rails", github: "rails/rails", branch: "main"
  gem "sqlite3"
end

require "active_record"
require "minitest/autorun"
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 :authors, force: true do |t|
  end
  create_table :posts, force: true do |t|
    t.bigint :num
    t.references :author
  end
end

class Author < ActiveRecord::Base
  has_many :posts
end

class Post < ActiveRecord::Base
  include Comparable
  belongs_to :author

  # if you uncomment this method, it'll get used. but if you leave it commented,
  # <=> is used. if you remove the `Comparable` include, then `<=>` *never* gets called.
  # def ==(other)
  #   puts "called =="
  #   num == other.num
  # end

  def <=>(other)
    puts "called <=>"
    num - other.num
  end
end

class BugTest < Minitest::Test
  def test_association_stuff
    author = Author.new

    Post.create!(num: 1, author: author)
    Post.create!(num: 2, author: author)
    Post.create!(num: 3, author: author)

    author.posts.build(num: 4)
    author.posts.build(num: 5)
  end
end