fizzbuzz5.rb

module FizzBuzzGame
  class Number
    def initialize(number)
      @value= number
    end

    def answer_for
      return FIZZBUZZ if divisible_by?(3) and divisible_by?(5)
      return FIZZ if divisible_by?(3)
      return BUZZ if divisible_by?(5)
      number
    end

    private:
      FIZZ = 'fizz'
      BUZZ = 'buzz'
      FIZZBUZZ = 'fizzbuzz'
   
      def divisible_by?(n)
        @value % n == 0
      end
  end 
  

  def answer_for(number)
    FizzBuzzGame::Number.new(number).answer_for
  end
end

Ni siquiera lo he probado, ¡ puede que no funcione !