使用 rspec 运行 Rails-tutorial 时 nil:NilClass 的未定义方法“文档”

Question

我正在关注railstutorial by Michael Hartl，但我不明白第 5 章中测试失败的原因。这本书使用了 minitest 框架，但我决定使用 RSpec。为此，我删除了 test 文件夹并将其包含rspec-rails在我的 Gemfile 中，然后运行 ​​bundle install 并rails g rspec:install生成我的 spec 文件夹。但是，我觉得使用 minitest 语法运行一些测试很方便，例如assert_select在static_pages_controller_spec.rb文件中。这是我的规范文件的样子：

require "rails_helper"

RSpec.describe StaticPagesController, type: :controller do
  describe "GET #home" do
    it "returns http success" do
      get :home
      expect(response).to have_http_status(:success)
    end
    it "should have the right title" do
      get :home
      assert_select "title", "Ruby on Rails Tutorial Sample App"
    end
  end

  describe "GET #help" do
    it "returns http success" do
      get :help
      expect(response).to have_http_status(:success)
    end
    it "should have the right title" do
      get :help
      assert_select "title", "Help | Ruby on Rails Tutorial Sample App"
    end
  end

  describe "GET #about" do
    it "returns http success" do
      get :about
      expect(response).to have_http_status(:success)
    end
    it "should have the right title" do
      get "about"
      assert_select "title", "About | Ruby on Rails Tutorial Sample App"
    end
  end
end

当我使用 RSpec 运行测试时，这是我得到的失败错误：

StaticPagesController GET #home should have the right title
 Failure/Error: assert_select "title", "Ruby on Rails Tutorial Sample App"

 NoMethodError:
   undefined method `document' for nil:NilClass
# ./spec/controllers/static_pages_controller_spec.rb:11:in `block (3 levels)
in <top (required)>'

(No Method error)每个失败的测试中都会出现相同的错误消息。

我该如何解决？是不是我做错了什么。

Answer 1

出现此错误的原因是 RSpec 默认情况下不渲染控制器规格的视图。您可以为特定组的规格启用视图渲染，如下所示：

describe FooController, type: :controller do
  render_views

  # write your specs
end

或者您可以通过将其添加到 RSpec 配置中的某个位置来全局启用它：

RSpec.configure do |config|
  config.render_views
end

请参阅https://www.relishapp.com/rspec/rspec-rails/v/2-6/docs/controller-specs/render-views了解更多信息。