ActiveRecord Mysql2 boolean casting error

ar_mysql2_bug.rb

# Must have mysql installed with user 'rails' and 'root', no password for either
# Tested on the rails dev box virtual machine - https://github.com/rails/rails-dev-box
#
# See https://github.com/rails/rails/issues/11119

TEST_DATABASE = 'ar_mysql2_boolean_quoting'

unless File.exists?('Gemfile')
  File.write('Gemfile', <<-GEMFILE
source 'https://rubygems.org'
gem 'rails', github: 'rails/rails'
gem 'mysql'
gem 'mysql2'
GEMFILE
)
  system 'bundle'
end

require 'bundler'
Bundler.setup

require 'mysql'
require 'mysql2'
require 'active_record'
require 'minitest/autorun'
require 'logger'

###########################

class Telephone < ActiveRecord::Base
  validates_uniqueness_of :active
end

class ARMysqlTest < MiniTest::Unit::TestCase
  def setup
    root_query("DROP DATABASE IF EXISTS #{TEST_DATABASE}")
    root_query("CREATE DATABASE #{TEST_DATABASE}")
  end

  def teardown
    root_query("DROP DATABASE #{TEST_DATABASE}")
  end

  #
  # The following tests use Mysql column type tinyint(1)
  #

  def test_mysql_tinyint_emulate
    # This is the default case using mysql adapter
    #  `t.boolean :active` in the migration
    #   ActiveRecord::ConnectionAdapters::MysqlAdapter.emulate_booleans = true (default value)
    _test_boolean_casting(:mysql, :tinyint, true)
  end

  def test_mysql2_tinyint_emulate
    # This is the default case using mysql2 adapter
    #  `t.boolean :active` in the migration
    #   ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans = true (default value)
    _test_boolean_casting(:mysql2, :tinyint, true)
  end

  def test_mysql_tinyint_no_emulate
    _test_boolean_casting(:mysql, :tinyint, false)
  end

  def test_mysql2_tinyint_no_emulate
    _test_boolean_casting(:mysql2, :tinyint, false)
  end

  #
  # The following use Mysql column type varchar(1)
  #

  def test_mysql_string_emulate
    _test_boolean_casting(:mysql, :string, true)
  end

  def test_mysql2_string_emulate
    _test_boolean_casting(:mysql2, :string, true)
  end

  def test_mysql_string_no_emulate
    _test_boolean_casting(:mysql, :string, false)
  end

  def test_mysql2_string_no_emulate
    _test_boolean_casting(:mysql2, :string, false)
  end

  def _test_boolean_casting(adapter, db_column_type, emulate_booleans)
    setup_connection(adapter, emulate_booleans, db_column_type)
    setup_telephones_table(db_column_type)
    Telephone.reset_column_information

    Telephone.create!(name: 'Nokia', active: true)
    assert !Telephone.new(name: 'Samsung', active: true).valid?, 'Record should not be valid since another record with active=true exists'
  end

  # Creates table with 'boolean' column
  def setup_telephones_table(db_column_type)
    ::ActiveRecord::Schema.define do
      create_table :telephones do |t|
        t.string :name
        case db_column_type
        when :string
          t.string :active, limit: 1
        when :tinyint
          t.boolean :active
        else
          raise ArgumentError
        end
      end
    end
  end

  # Setup ActiveRecord to use either mysql or mysql2 adapter
  def setup_connection(adapter, emulate_booleans, db_column_type = nil)
    ::ActiveRecord::Base.clear_all_connections!
    ::ActiveRecord::Base.establish_connection(adapter: adapter, user: 'rails', database: TEST_DATABASE)

    case adapter
    when :mysql2
      ::ActiveRecord::ConnectionAdapters::Mysql2Adapter.emulate_booleans = emulate_booleans
    when :mysql
      ::ActiveRecord::ConnectionAdapters::MysqlAdapter.emulate_booleans = emulate_booleans
    else
      raise ArgumentError
    end

    log_tag = "#{adapter}|#{db_column_type}|emulate_booleans(#{emulate_booleans ? 'T' : 'F'})"
    ::ActiveRecord::Base.logger = Logger.new(STDOUT)
    ::ActiveRecord::Base.logger.formatter = proc do |_, _, _, msg|
     "%s:%s\n\n" % ["\e[1m\e[33m#{log_tag}\e[0m", msg]
    end
  end

  def root_query(sql)
    @client ||= Mysql2::Client.new(username: 'root', host: 'localhost', password: nil)
    @client.query(sql)
  end
end