Augmenting an instance with methods defined in a helper module

augment.rb

class Loop
  attr_accessor :name
  def initialize name
    self.name = name
  end
end

module LoopDecoratorHelper
  def loop_delete_link loop
    "Delete #{loop.name}"
  end

  def frog_breath
    "Disgusting"
  end
end

module HelperAugmenter
  class << self
    def augment mod, prefix, instance
      curry_mod = Module.new
      carrier = Class.new
      carrier.extend mod

      matcher = /^#{Regexp.quote(prefix)}_(.*)$/
      matching_methods = mod.instance_methods.select do |method_name|
        method_name.to_s.match(matcher)
      end.each do |method_name|
        curried_method_name = method_name.to_s.match(matcher)[1]
        curry_mod.instance_eval do
          define_method curried_method_name do
            carrier.method(method_name).call(instance)
          end
        end
      end
      instance.extend(curry_mod)
    end
  end
end

augment_test.rb

require 'test/unit'
require './augment'

class LoopDecoratorHelperTest < Test::Unit::TestCase
  def test_loop_name
    assert Loop.new('hi').name == 'hi'
  end

  def test_augment_preserves_methods
    loop = Loop.new('oranges')
    HelperAugmenter.augment LoopDecoratorHelper, 'loop', loop
    assert loop.name == 'oranges'
  end

  def test_augment_adds_methods
    loop = Loop.new('apples')
    HelperAugmenter.augment LoopDecoratorHelper, 'loop', loop
    assert loop.delete_link == "Delete apples"
  end

  def test_augment_does_not_add_non_matching_methods_or_original_helper_methods
    loop = Loop.new('bananas')
    HelperAugmenter.augment LoopDecoratorHelper, 'loop', loop
    assert !loop.respond_to?(:loop_delete_link)
    assert !loop.respond_to?(:frog_breath)
  end
end