Integrating PHPUnit

Writing tests is a task that you could do by yourself; you just need to write code that throws exceptions when conditions are not met and then run the script any time you need. Luckily, other developers were not satisfied with this manual process, so they implemented tools to help us automate this process and get good feedback. The most used in PHP is PHPUnit. PHPUnit is a framework that provides a set of tools to write tests in an easier manner, gives us the ability to run tests automatically, and delivers useful feedback to the developer.

In order to use PHPUnit, traditionally, we installed it on our laptop. In doing so, we added the classes of the framework to include the path of PHP and also the executable to run the tests. This was less than ideal as we forced developers to install one more tool on their development machine. Nowadays, Composer (refer to Chapter 6, Adapting to MVC, in order to refresh your memory) helps us in including PHPUnit as a dependency of the...