anchor.diff:  
     We can make our own `my-uppercase` pipe that does exactly the same as the `uppercase` pipe and test that.
   
  -  我们可以做一个自己的`my-uppercase`管道兵测试它，该管道的功能和`uppercase`管道完全相同。
  +  我们可以做一个自己的`my-uppercase`管道并测试它，该管道的功能和`uppercase`管道完全相同。
   
     Since we're getting ready to write some code we want to test, let's take this opportunity to talk just a little bit about [Test Driven Development](https://en.wikipedia.org/wiki/Test-driven_development). There's a lot written about this topic so we don't want to have an exhaustive description here, but rather a practical application.
   
  
positive.code:   Yet we were able to load and test the application’s `Hero` interface.
  
    往回看`unit-tests.html`，我们认识到自己还没加载过Angular库。
    但我们甚至都已经能加载应用中`Hero`接口的测试了。
  
    **We were lucky!**  The `Hero` interface has no dependence on Angular.
    If it had depended on Angular, we’d still be staring at the Jasmine “big-time fail” screen:
  
negative.code: 
    An Angular pipe is a declarative way in HTML to transform some input into some displayable output.
  
    Angular管道一种以声明的方式，在HTML中把某些输入转换成易于显示的输出。
  
    We don't have a pipe though, since in Tour of Heroes we didn't create any pipes. It uses a pipe though, the `uppercase` pipe that comes with Angular 2.
  
  