module ActiveRecord::Transactions::ClassMethods

def after_commit(*args, &block)

use the +test_after_commit+ gem to have these hooks fired in tests.
Note that transactional fixtures do not play well with this feature. Please

after_commit :do_bar_baz, on: [:update, :destroy]
after_commit :do_foo_bar, on: [:create, :update]

after_commit :do_baz, on: :destroy
after_commit :do_bar, on: :update
after_commit :do_foo, on: :create

the +:on+ option:
You can specify that the callback should only be fired by a certain action with

This callback is called after a record has been created, updated, or destroyed. 
def after_commit(*args, &block)
  set_options_for_callbacks!(args)
  set_callback(:commit, :after, *args, &block)
  unless ActiveRecord::Base.raise_in_transactional_callbacks
    ActiveSupport::Deprecation.warn(CALLBACK_WARN_MESSAGE)
  end
end

def after_rollback(*args, &block)

Please check the documentation of +after_commit+ for options.

This callback is called after a create, update, or destroy are rolled back. 
def after_rollback(*args, &block)
  set_options_for_callbacks!(args)
  set_callback(:rollback, :after, *args, &block)
  unless ActiveRecord::Base.raise_in_transactional_callbacks
    ActiveSupport::Deprecation.warn(CALLBACK_WARN_MESSAGE)
  end
end

def assert_valid_transaction_action(actions) 

def assert_valid_transaction_action(actions)
  if (actions - ACTIONS).any?
    raise ArgumentError, ":on conditions for after_commit and after_rollback callbacks have to be one of #{ACTIONS}"
  end
end

def set_options_for_callbacks!(args) 

def set_options_for_callbacks!(args)
  options = args.last
  if options.is_a?(Hash) && options[:on]
    fire_on = Array(options[:on])
    assert_valid_transaction_action(fire_on)
    options[:if] = Array(options[:if])
    options[:if] << "transaction_include_any_action?(#{fire_on})"
  end
end

def transaction(options = {}, &block)

See ActiveRecord::Transactions::ClassMethods for detailed documentation. 
def transaction(options = {}, &block)
  # See the ConnectionAdapters::DatabaseStatements#transaction API docs.
  connection.transaction(options, &block)
end