这是我的第一个rspec测试，我使用Hurtl的教程，并认为它已经过时了。我想更改这一行，因为its不再是rspec的一部分：

its(:user) { should == user }

我试着这样做：

expect(subject.user).to eq(user)

但得到一个错误
RuntimeError：#let或#subject调用时不带块
这是我的完整的rspec测试，如果你需要它：

require 'spec_helper'
require "rails_helper" 

describe Question do

  let(:user) { FactoryGirl.create(:user) }
  before { @question = user.questions.build(content: "Lorem ipsum") }

  subject { @question }

  it { should respond_to(:body) }
  it { should respond_to(:title) }
  it { should respond_to(:user_id) }
  it { should respond_to(:user) }

  expect(subject.user).to eq(user)
  its(:user) { should == user }

  it { should be_valid }

  describe "accessible attributes" do
    it "should not allow access to user_id" do
      expect do
        Question.new(user_id: user.id)
      end.to raise_error(ActiveModel::MassAssignmentSecurity::Error)
    end
  end

  describe "when user_id is not present" do
    before { @question.user_id = nil }
    it { should_not be_valid }
  end
end