ar-gh-30722-testcase.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 :posts, force: true do |t|
    t.boolean :published
  end
end

class Post < ActiveRecord::Base
  scope :published, -> { where(published: true) }
end

class BugTest < Minitest::Test
  def test_unscope_should_not_modify_source_relation
    Post.create! published: false
    Post.create! published: true

    published_posts = Post.published
    assert_equal 1, published_posts.count

    all_posts = published_posts.unscope(where: :published)
    assert_equal 2, all_posts.count
    assert_equal 1, published_posts.count
  end
end

This bug has been fixed in rails 4.2.4.