test_transactions_without_rails.rb

# Snippet to wrap tests with ActiveRecord db transactions outside Rails.
#
# references:
#   https://github.com/rails/rails/blob/master/railties/lib/rails/test_help.rb#L27
#   https://github.com/rails/rails/blob/master/activerecord/lib/active_record/fixtures.rb#L704
#   
# TestFixtures checks whether configurations is blank
# to determine whether to use transactions/fixtures or not.
# which is why we need to set it to something.
ActiveRecord::Base.configurations= {test: {
    database: 'something_test',
    adapter: 'mysql',
    # ...
}}
ActiveRecord::Base.establish_connection ActiveRecord::Base.configurations[:test]
class ActiveSupport::TestCase < ::Test::Unit::TestCase
  include ActiveRecord::TestFixtures
  setup do
    ActiveRecord::IdentityMap.clear
  end
# if you want to use fixtures you can set the fixture path, and it'll load them like rails does.
# self.fixture_path = "my_fixtures"
end