test_include_has_many_through.rb

# Activate the gem you are reporting the issue against.
gem 'activerecord', '3.2.13'
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 :posts do |t|
  end

  create_table :comments do |t|
    t.integer :post_id
    t.integer :user_id
  end
  create_table :users do |t|
  end
end

class Post < ActiveRecord::Base
  has_many :comments
  has_many :users, :through => :comments
end

class Comment < ActiveRecord::Base
  belongs_to :post
  belongs_to :user
end

class User < ActiveRecord::Base
  has_many :comments
end

class BugTest < MiniTest::Unit::TestCase
  def test_association_stuff
    post = Post.create!
    user = User.create!
    post.comments << Comment.create!(:user_id => user.id)

    posts = Post.includes(:users, :comments).all
    assert posts.first.users.loaded?
    assert posts.first.comments.loaded?

    posts = Post.includes(:comments, :users).all
    assert posts.first.users.loaded?
    assert posts.first.comments.loaded?
  end
end