IRB Session

# Playing with it in irb:

>> (class << Widget; self; end).ancestors
=> [BazWrapper, BarWrapper, FooWrapper, Class, Module, Object, Kernel]

>> widget = Widget.new
=> #<Widget:0x11771f8>

>> (class << widget; self; end).ancestors
=> [BazWrapper::WrappingB, BazWrapper::WrappingA, BarWrapper::Wrapping, FooWrapper::Wrapping, 
Widget, Object, Kernel]

>> widget.render_on(nil)
BazWrapper::WrappingB
BazWrapper::WrappingA
BarWrapper::Wrapping
FooWrapper::Wrapping
Original

super-extend-multiple.rb

class Widget
  def render_on(document, options = {})
    puts "Original"
  end
end

module FooWrapper
  def new(*args, &block)
    super.extend Wrapping
  end
  module Wrapping
    def render_on(*args)
      puts "FooWrapper::Wrapping"
      super
    end
  end
end

module BarWrapper
  def new(*args, &block)
    super.extend Wrapping
  end
  module Wrapping
    def render_on(*args)
      puts "BarWrapper::Wrapping"
      super
    end
  end
end
  
module BazWrapper
  def new(*args, &block)
    instance = super
    instance.extend(WrappingA)
    instance.extend(WrappingB)
  end
  module WrappingA
    def render_on(*args)
      puts "BazWrapper::WrappingA"
      super
    end
  end
  module WrappingB
    def render_on(*args)
      puts "BazWrapper::WrappingB"
      super
    end
  end
end

Widget.extend FooWrapper
Widget.extend BarWrapper
Widget.extend BazWrapper