Rails 4.0 has_many association include?() return type test

has_many_include_test.rb

# Activate the gem you are reporting the issue against.
gem 'activerecord', '4.0.0'
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
  end
end

class Post < ActiveRecord::Base
  has_many :comments
end

class Comment < ActiveRecord::Base
  belongs_to :post
end

class HasManyDeleteIfTest < MiniTest::Unit::TestCase
  def test_has_many_delete_if
    post = Post.create!
    comment = Comment.create!
    post.comments << comment

    assert_equal 1, post.comments.count
    assert_equal 1, Comment.count
    assert_equal post.id, Comment.first.post.id
    
    assert_equal true, post.comments.include?(comment) # true expected
    assert_equal false, post.comments.include?(Comment.create!) # false expected
  end
end