Example of wrapping methods using mixins (more complicated than it should be)

verbose_job.rb

module VerboseJob
  module ClassMethods
    def wrap_perform!
      class << self
        def perform_with_verbose(*args)
          JobLogger.verbose { perform_without_verbose(*args) }
        end

        alias_method_chain :perform, :verbose \
          unless instance_method(:perform) == instance_method(:perform_with_verbose)
      end
    end

    def singleton_method_added(name)
      wrap_perform! if name == :perform
    end
  end

  def self.included(job_class)
    job_class.extend ClassMethods
    job_class.wrap_perform! if job_class.respond_to?(:perform)
  end
end