Prepend module code to subclasses by prepending to it's instances singleton_class via inherited

prepend_to_singleton_class_via_inherited.rb

module InheritedHandler
  def inherited(subclass)
    subclass.instance_eval do
      alias :original_new :new

      def self.inherited(subsubclass)
        subsubclass.extend(InheritedHandler)
      end

      def self.new(*args, &block)
        (obj = original_new(*args, &block)).singleton_class.prepend(BarkLoud)
        return obj
      end
    end
  end
end

module BarkLoud
  def bark
    super.upcase + "!!!"
  end
end

# Since this works via inherited, there has to be some class in front
class Dog < Class.new.extend(InheritedHandler)
  def bark
    "wuff"
  end
end

puts Dog.new.bark # => "WUFF!!!"

class Pug < Dog
  def bark
    "aruff"
  end
end

puts Pug.new.bark # => "ARUFF!!!"