module BMC::SetupJobConcern extend ActiveSupport::Concern def perform(*args) setup(*args) call end def call raise NotImplementedError end class_methods do def setup_with(*attrs) attr_reader(*attrs) define_method(:setup) do |*args| if attrs.length != args.length message = "wrong number of arguments (given #{args.length}, expected #{attrs.length})" raise ArgumentError, message end attrs.length.times do |i| instance_variable_set("@#{attrs[i]}", args[i]) end end end private :setup_with def setup(*args) new.tap { |instance| instance.setup(*args) } end end # class_methods end