In the last three chapters, we covered the topic of writing tests at different levels: unit, functional, and acceptance. So far, we have tested the new interface that we created, and we learned to apply all the new methods. This was a relatively easy task, but we don't know how good we did in our testing. There are some specific metrics that we can analyze to generate a direct and immediate report on the quality of the tests. These reports will help us in taking informed decisions regarding the architecture of our code.

Codeception is bundled with most of these report generation tools, and it's quite easy as it's been until now.

In this chapter, we will primarily cover the code coverage metrics, and we'll briefly touch on some other metrics, which can be obtained through various software.