ruby-on-rails – 在rspec中删除测试 – 更改(模型,：计数)失败

我发现很多引用测试DELETE方法,如下所示：

expect { delete_request }.to change(App,:count).by(-1)

这是有道理的,并且适用于某些类似的场景.但是,在测试不应该工作的删除时,我发现了一个问题,例如没有用户登录时.

这是我开始的地方,有两种方法来测试同一件事：

require 'rails_helper'

RSpec.describe V1::AppsController,type: :controller do
  let(:user) { create(:user) }
  let(:app) { create(:app,account: user.account) }

  describe 'DELETE destroy when you are not logged in' do
    let(:delete_request) { delete :destroy,id: app,format: :json }

    it 'does not delete the app (.count)' do
      expect { delete_request }.not_to change(App,:count)
    end

    it 'does not delete the app (.exists?)' do
      delete_request
      expect(App.exists?(app.id)).to eq(true)
    end
  end
end

这就是rspec所说的：

V1::AppsController
  DELETE destroy when you are not logged in
    does not delete the app (.count) (FAILED - 1)
    does not delete the app (.exists?)

Failures:

  1) V1::AppsController DELETE destroy when you are not logged in does not delete the app (.count)
     Failure/Error: expect { delete_request }.not_to change(App,:count)
       expected #count not to have changed,but did change from 0 to 1
     # ./spec/controllers/v1/delete_test_1.rb:11:in `block (3 levels) in <top (required)>'

2 examples,1 failure

注意最令人困惑的部分：预期#count没有改变,但确实从0变为1.咦？我试图进行非法删除,我的记录数增加了一倍？另请注意,明确检查主题记录的检查仍然存在.

所以我玩了一些,发现我可以在expect()之前重新加载修复问题：

it 'does not delete the app (.count)' do
  puts "App.count is #{App.count} (after create(:app))"
  app.reload
  puts "App.count is #{App.count} (after reload)"
  expect { delete_request }.not_to change(App,:count)
  puts "App.count is #{App.count} (after request)"
end

现在rspec很高兴：

V1::AppsController
  DELETE destroy when you are not logged in
App.count is 0 (after create(:app))
App.count is 1 (after reload)
App.count is 1 (after request)
    does not delete the app (.count)
    does not delete the app (.exists?)

2 examples,0 failures

从这一切来看,我决定坚持存在？做法.但另一个(可能更大)的问题是,我在互联网上发现的所有测试样本都要测试创建记录,如期望{create_request}.更改(App,：count).by(1)可能是误报,如果他们我看到了与我相同的结果,并假设创建记录实际上它是一个缓存工件？

那么,任何想法为什么App.count需要重新加载来查看当前值？