decorator.rb

class Sugar
  def initialize(ingredients)
    @ingredient = ingredients
  end
  
  def cost 
    @ingredient.cost + 1
  end
end

class Milk
  def initialize(ingredients)
    @ingredient = ingredients
  end
  
  def cost
    @ingredient.cost + 2
  end
end

class Chocolate
  def initialize(ingredients)
    @ingredient = ingredients
  end
  
  def cost
    @ingredient.cost + 3
  end
end

class MilkChokoweit
  def cost
    0
  end
end


puts "Order Milk Chokoweit"
milk_chokoweit = MilkChokoweit.new
p Sugar.new(Milk.new(Chocolate.new(milk_chokoweit))).cost