ruby和rspec - 测试失败

Question

我应该让这个测试通过。

describe 'new' do
    it "takes a parameter and returns a HangpersonGame object" do      
      @hangpersonGame = HangpersonGame.new('glorp')
      expect(@hangpersonGame).to be_an_instance_of(HangpersonGame)
      expect(@hangpersonGame.word).to eq('glorp')
      expect(@hangpersonGame.guesses).to eq('')
      expect(@hangpersonGame.wrong_guesses).to eq('')
    end
  end

我的代码就是这个，

class HangpersonGame


    attr_accessor :word
    attr_accessor :guesses
    attr_accessor :wrong_guesses

  def initialize(word)
    @word = word
    @guesses = nil
    @wrong_guesses = nil

  end
end

测试失败。为什么？我已经单独运行代码，它似乎工作。