unit-testing - 测试使用 after_create 回调的模型规范

Question

这是我正在使用的模型，我已将其简化为最简单的形式，但仍然无法满足我的示例:

class User <  ActiveRecord::Base
  after_create :setup_lists

  def setup_lists
    List.create(:user_id => self.id, :name => "current")
    List.create(:user_id => self.id, :name => "master")
  end
end

我想对示例进行如下说明:

require 'spec_helper'

describe User do
  before(:each) do
    @user = Factory(:user)
  end

  describe "#setup_lists" do
    before(:each) do  
     List.stub(:create).with(:name => "current")
     List.stub(:create).with(:name => "master")

     it "creates a new master list" do
        List.should_receive(:create).with(:name => "master")
     end

     it "creates a new current list" do
        List.should_receive(:create).with(:name => "current")
     end
  end
end

我期望的工作正常，但我留下了以下错误:

Failures:
  1) User#setup_lists creates a new master list
     Failure/Error: List.should_receive(:create).with(:name => "current")
     (<List(id: integer, name: string, created_at: datetime, updated_at: datetime, user_id: integer) (class)>).create({:name=>"current"})
      expected: 1 time
      received: 0 times
    # ./spec/models/user_spec.rb:44

  2) User#setup_lists creates a new current list
     Failure/Error: List.should_receive(:create).with(:name => "master")
     (<List(id: integer, name: string, created_at: datetime, updated_at: datetime,        user_id: integer) (class)>).create({:name=>"master"})
     expected: 1 time
     received: 0 times
  # ./spec/models/user_spec.rb:48

有人能帮我理解为什么会这样吗？

Answer 1

三个问题:

1) User 对象是在设置消息期望之前创建的，所以 should_receive永远不会看到消息；

2)您正在淘汰您也为其设定期望的方法。您想剔除您没有设置期望但测试通过所需的方法

3)需要传入所有参数

要修复，请在设置期望后创建 User 对象，并依次 stub 每个方法(因为您的模型调用 List.create 两次):

describe User do
  describe "#setup_lists" do
    it "creates a new master list" do
      List.stub(:create).with(:user_id=>1,:name => "current")
      List.should_receive(:create).with(:user_id=>1,:name => "master")
      @user = User.create
    end

    it "creates a new current list" do
      List.stub(:create).with(:user_id=>1,:name => "master")
      List.should_receive(:create).with(:user_id=>1,:name => "current")
      @user = User.create
    end
  end
end

虽然这确实是一个风格问题，但在这里使用真正的 User 对象而不是工厂更有意义，因为您正在测试模型本身。