Types of tests
There are five types of tests you can run and write in Drupal – unit tests, kernel tests, functional tests, functional JavaScript tests, and NightwatchJS tests. Which ones you write will depend on the kind of feature(s) you are creating and the level of test coverage you are willing to accept to prove your code is working. Let’s take a look at each of these types of tests. You can find the full code used in this chapter on GitHub: https://github.com/PacktPublishing/Drupal-10-Development-Cookbook/tree/main/chp13
Unit tests
Unit tests are tests that do not need a Drupal installation to evaluate because they test code that executes code only. They are the lowest-level test you can write. Unit tests are useful for testing plugins, services, or other code that do not require interaction with the database. If you need to write tests that require a database or Drupal environment in some way, you would write a kernel test.
Kernel tests
Kernel tests...