anchor.diff:  :marked
     ### Write Angular tests too
     
  -  ### 也编写Angular测试
  +  ### 同时也编写Angular测试
   
     These are tests of the pipe _in isolation_.
     They can't tell if the `TitleCasePipe` is working properly as applied in the application components.
  
positive.code:   This advantage is even more pronounced with complex components that 
    may require meticulous preparation with the Angular testing utilities.
  
    孤立组件单元测试用更少的代码以及几乎不存在的配置，提供了很多测试覆盖率。
    在测试复杂的组件时，这个优势显得更加明显，因为可能需要使用Angular测试工具进行精心准备。
  
    On the other hand, isolated unit tests can't confirm that the `ButtonComp` is 
  
negative.code:   Use the Angular testing utilities when writing tests that validate how a service interacts with components
    _within the Angular runtime environment_.
  
    这些**孤立**单元测试技巧是一个很好的方法，用来探索服务的内在逻辑，以及它与组件类简单的集成。
    当在**运行时间环境下**，使用Angular测试工具来验证一个服务是如何与组件互动的。
  
  #isolated-pipe-tests
  :marked
  