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:         When a `fakeAsync` test ends with pending _micro-tasks_ such as unresolved promises,
          the test fails with a clear error message.
  
          当`fakeAsync`测试程序以待执行**微任务**（比如未解析的承诺）结束时，测试会失败并显示明确的错误信息。
          
          In general, a test should wait for micro-tasks to finish.
          When pending microtasks are expected, call `flushMicrotasks` to flush the  _micro-task_ queue
  