Rails初学者-为什么这个控制器测试用例失败了

Question

好吧，所以我正在开发我的第一个单独的Rails应用程序，一个URL缩写器，我已经很困惑了。在我的模型中，我使用domain和key属性存储了一个简短的URL。这是我的型号：

# == Schema Information
# Schema version: 20110601022424
#
# Table name: shorteners
#
#  id         :integer         not null, primary key
#  url        :string(255)
#  key        :string(255)
#  created_at :datetime
#  updated_at :datetime
#  domain     :string(255)
#
class Shortener < ActiveRecord::Base
  attr_accessible :url
  validates :url, :presence => true, :uniqueness => true, :uri_format => true
  before_save :set_autogenerated_info
  def shortlink
    "http://#{domain}/#{key}"
  end
  private
    def set_autogenerated_info
      return unless new_record? #This only gets set one time
      domain = get_random_domain
      key = get_next_key(domain)
      write_attribute(:domain, domain)
      write_attribute(:key, key)
    end
    def get_random_domain
      #commented out magic to grab random domain from pool
    end
    def get_next_key(domain)
      #commented out magic to generate next unique key
    end
end

我目前的方法似乎把我的controller_spec:中的这个测试用例搞砸了

require 'spec_helper'
describe ShortenersController do
  render_views
  describe "GET show" do
    before(:each) do
      @shortener = Factory(:shortener)
    end
    it "should find the right shortener" do
      get :show, :id => @shortener
      assigns(:shortener).should == @shortener
    end
  end
end

它给我的错误信息是：

Failures:
  1) ShortenersController GET show should find the right shortener
     Failure/Error: get :show, :id => @shortener
     ActionView::Template::Error:
       undefined local variable or method `domain' for #<Shortener:0x00000004a04548>
     # ./app/models/shortener.rb:25:in `shortlink'
     # ./app/views/shorteners/show.html.erb:10:in `_app_views_shorteners_show_html_erb___556550686459204284_38799300_3170414004415921977'
     # ./spec/controllers/shorteners_controller_spec.rb:32:in `block (3 levels) in <top (required)>'

我可以通过在attr_accessible行上方添加以下内容来通过测试用例：

attr_reader :domain, :key

但这确实做了一些非常疯狂的事情，比如不在应用程序的视图中显示域/密钥属性，甚至不允许我直接从Rails控制台中的模型访问它们：

Loading development environment (Rails 3.0.7)
>> s = Shortener.new(:url => 'http://www.stackoverflow.com')
 => #<Shortener id: nil, url: "http://www.stackoverflow.com", key: nil, created_at: nil, updated_at: nil, domain: nil> 
>> s.save
 => true 
>> s
 => #<Shortener id: 12, url: "http://www.stackoverflow.com", key: l, created_at: "2011-06-02 16:35:01", updated_at: "2011-06-02 16:35:01", domain: "localhost"> 
>> s.domain
 => nil 
>> s.key
 => nil
>> s.shortlink
 => "http:///"

更新-添加的视图：

<p id="notice"><%= notice %></p>
<p>
  <b>Url:</b>
  <%= @shortener.url %>
</p>
<p>
  <b>Shortened Link:</b>
  <a href="<%= @shortener.shortlink %>"><%= @shortener.shortlink %></a>
</p>
<%= link_to 'Edit', edit_shortener_path(@shortener) %> |
<%= link_to 'Back', shorteners_path %>

Answer 1

在测试中，Shortener类似乎无法访问域变量。你检查过你的测试数据库了吗？