rails/rails#20718 reproduction script

active_record_gem.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', '4.2.3'
  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 :users, force: true do |t|
  end

  create_table :subscriptions, force: true do |t|
    t.integer :user_id
    t.integer :package_id
  end

  create_table :packages, force: true do |t|
  end
end

class User < ActiveRecord::Base
  has_one :subscription, -> { where(package_id: Package.permanent) }
  has_one :package, through: :subscription
end

class Subscription < ActiveRecord::Base
  belongs_to :user
  belongs_to :package
end

class Package < ActiveRecord::Base
  has_many :subscriptions
  scope :permanent, -> { where(id: 1) }
end

class BugTest < Minitest::Test
  def test_association_stuff
    user = User.create!
    package = Package.create!
    subscription = Subscription.create!(user_id: user.id, package_id: package.id)

    user.reload

    assert_equal 1, User.count
    assert_equal 1, Package.count
    assert_equal 1, Subscription.count

    assert_equal 1, Package.permanent.count

    assert_equal user.subscription, subscription
    assert_equal user.package, package
  end
end