So far, we have seen how to write simple unit tests, advance them using some actions and assertions. This chapter showcased tests, actions, and assertions using YUI. YUI is used to give an idea of how all this happens and works together through the TDD life cycle. Then you learned about some benefits and pitfalls.
In the next chapter, you will learn about popular JavaScript tools and frameworks. YUI was a browser-based testing framework, but later we will also check tools, which don't need you to run test cases in the browser.