rails_relation_class_method.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(true) do
  source "https://rubygems.org"
  # Activate the gem you are reporting the issue against.
  gem "activerecord", "5.1.2"
  gem "sqlite3"
end

require "active_record"
require "minitest/autorun"
require "logger"

# Ensure backward compatibility with Minitest 4
Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

# 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 :posts, force: true do |t|
    t.integer :parent_id
  end
end

class Post < ActiveRecord::Base
  belongs_to :parent, class_name: name, optional: true, inverse_of: :children
  has_many :children, class_name: name, primary_key: "id", foreign_key: "parent_id",
                      inverse_of: :parent

  def self.pluck_id
    all.pluck(:id)
  end
end

class BugTest < Minitest::Test
  def test_association_stuff
    Post.where(parent_id: nil).joins(:children).limit(20).offset(0).pluck(:id)
    Post.where(parent_id: nil).joins(:children).limit(20).offset(0).pluck_id
  end
end