bug.rb

# frozen_string_literal: true

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"

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

  # Activate the gem you are reporting the issue against.
  gem "activerecord", "5.2.0"
  gem "sqlite3"
  gem "byebug"
end

require "active_record"
require "logger"
require "byebug"

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")

ActiveRecord::Schema.define do
  create_table :posts, force: true do |t|
    t.integer :another_post_id
    t.string :title
  end
end

class Post < ActiveRecord::Base
  belongs_to :another_post, class_name: "Post", foreign_key: "another_post_id"

  before_update :log_data


  def update_all_posts(except_ids)
    Post.where.not(id: except_ids).update(title: "hello")
  end

  def log_data
    if id == 2
      # as a result of update_all_posts, all queries for Post, have default query scope of "id != 1"
      # so we can't find another_post (since it's id 1)
      puts "Me: #{id}, Another Post (#{another_post_id}): #{another_post.inspect}"
      # Post.count is 1, but actually it's 2
      puts "Post.count: #{Post.count}"
    end
  end
end

ActiveRecord::Base.logger = Logger.new(STDOUT)

post1 = nil
post2 = nil

Post.transaction do
  post1 = Post.create!
  post2 = Post.create!
  post2.another_post_id = post1.id
  post2.save
end

post2.update_all_posts([post1.id])