has_many_through.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', :git => 'https://github.com/rails/rails',
    :branch => '4-2-stable', :ref => '2aa27582c202148296bb169159b0bf9a47a7bd80'
  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 :list_items, force: true do |t|
    t.string :type
    t.string :name
  end

  create_table :list_item_relationships, force: true do |t|
    t.integer :list_item_id
    t.string :list_item_type
    t.integer :listable_id
    t.string :listable_type
  end

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

class ListItem < ActiveRecord::Base;
end

class Feeling < ListItem;
end

class ListItemRelationship < ActiveRecord::Base
  belongs_to :list_item, :polymorphic => true
  belongs_to :listable, :polymorphic => true

  validates :list_item_id, :uniqueness => { :scope => [:list_item_type, :listable_id, :listable_type] }
end

class StressTest < ActiveRecord::Base
  has_many :list_item_relationships, :as => :listable, :dependent => :destroy
  has_many :feelings, :through => :list_item_relationships, :source => :list_item, :source_type => "Feeling"
end

class BugTest < Minitest::Test
  def test_has_many_through
    feeling = Feeling.create!(:name => "Feeling lucky")
    test = StressTest.create!

    test.feelings << feeling

    assert_equal 1, test.list_item_relationships.count
    assert_equal 1, test.feelings.size
    assert_equal 1, test.feelings.count

    test.feeling_ids = []

    assert_equal 0, test.feelings.size
    assert_equal 0, test.feelings.count
  end
end