During this chapter, you saw many important things, which are the base of what we're going to work on in the next chapters and the base of testing from a wider perspective: you learned the importance of our workflow and environment setup, you saw how to use Composer and use it to install Yii, and, finally, we've picked up the concepts detailed in Chapter 1, The Testing Mindset, and made them concrete, applying them to our specific application and the features that we're going to implement.

Now, before we dive into the actual implementation of the application, we need to get first into the testing suite Codeception, the jargon it uses, and the various features that it will provide, which we're going to use in the upcoming chapters.