Rails教程第7章练习4

Question

我在railstutorial.org的第7章中练习4时遇到了问题。

下面是测试：

describe "signup" do 
    before { visit signup_path } 

    describe "with invalid information" do 
     it "should not create a user" do 
      expect { click_button "Create my Account".not_to change(User, :count) } 
     end 
    end 

    describe "error messages" do 
     before { click_button "Create my account" } 

     it { should have_selector('title', text: "Sign up") } 
     it { should have_content('error') } 
    end 

    describe "with valid information" do 
     before do 
      fill_in "Name", with: "Example User" 
      fill_in "Email", with: "user@example.com" 
      fill_in "Password", with: "foobar" 
      fill_in "Confirmation", with: "foobar" 
     end 

     it "should create a user" do 
      expect do 
       click_button "Create my account" 
      end.to change(User, :count).by(1) 
     end 
    end 

    describe "after saving the user" do 
     before { click_button "Create my account" } 
     let(:user) { User.find_by_email('user@example.com') } 

     it { should have_selector('title', text: user.name) } 
     it { should have_selector('div.alert.alert-success', text: 'Welcome') } 
    end 
end 

这里是它应该测试，users_controller.rb：

def create 
@user = User.new(params[:user]) 
if @user.save 
    flash[:success] = "Welcome to the Sample App!" 
    redirect_to @user 
else 
    render 'new' 
end 
end 

这里的show.html.erb代码以及：

<% provide(:title, @user.name) %> 
<div class="row"> 
<aside class="span4"> 
    <section> 
     <h1> 
      <%= gravatar_for @user %> 
      <%= @user.name %> 
     </h1> 
    </section> 
</aside> 
</div> 

当我运行我的测试时，我得到这个：

$ bundle exec rspec spec/requests/user_pages_spec.rb 
........FF 

Failures: 

    1) User Pages signup after saving the user 
Failure/Error: it { should have_selector('title', text: user.name) } 
NoMethodError: 
    undefined method `name' for nil:NilClass 
# ./spec/requests/user_pages_spec.rb:57:in `block (4 levels) in <top (required)>' 

    2) User Pages signup after saving the user 
Failure/Error: it { should have_selector('div.alert.alert-success', text: 'Welcome') } 
    expected css "div.alert.alert-success" with text "Welcome" to return something 
# ./spec/requests/user_pages_spec.rb:58:in `block (4 levels) in <top (required)>' 

Finished in 0.86152 seconds 
10 examples, 2 failures 

Failed examples: 

rspec ./spec/requests/user_pages_spec.rb:57 # User Pages signup after saving the user 
rspec ./spec/requests/user_pages_spec.rb:58 # User Pages signup after saving the user 

它应该将测试用户保存到测试数据库，但由于某种原因，user.name变为零。有任何想法吗？

谢谢！

Answer 1

没有你的代码会在详细地了解一切的背景下，这并不是说user.name正在恢复nil，那就是user是nil，因此没有方法/属性name这里看到：

undefined method `name' for nil:NilClass 

你有这条线在这里测试案例之前定义符号:user：

let(:user) { User.find_by_email('user@example.com') } 

但你引用的对象user在您的测试：

it { should have_selector('title', text: user.name) } 

更改前的符号:user到user和你的测试应该通过。