class RuboCop::Cop::Rails::ApplicationController

end
# …
class MyController < ActionController::Base
# bad
end
# …
class MyController < ApplicationController
# good
@example
sneak into a controller that is not purposed to inherit logic common among other controllers.
This cop’s autocorrection is unsafe because it may let the logic from ‘ApplicationController`
@safety
Checks that controllers subclass `ApplicationController`.