Book Image

Drupal 8 Module Development - Second Edition

By : Daniel Sipos
Book Image

Drupal 8 Module Development - Second Edition

By: Daniel Sipos

Overview of this book

Drupal 8 comes with a release cycle that allows for new functionality to be added at a much faster pace. However, this also means code deprecations and changing architecture that you need to stay on top of. This book updates the first edition and includes the new functionality introduced in versions up to, and including 8.7. The book will first introduce you to the Drupal 8 architecture and its subsystems before diving into creating your first module with basic functionality. You will work with the Drupal logging and mailing systems, learn how to output data using the theme layer and work with menus and links programmatically. Then, you will learn how to work with different kinds of data storages, create custom entities, field types and leverage the Database API for lower level database queries. You will further see how to introduce JavaScript into your module, work with the various file systems and ensure the code you write works on multilingual sites. Finally, you will learn how to programmatically work with Views, write automated tests for your functionality and also write secure code in general. By the end, you will have learned how to develop your own custom module that can provide complex business solutions. And who knows, maybe you’ll even contribute it back to the Drupal community. Foreword by Dries Buytaert, founder of Drupal.
Table of Contents (20 chapters)

Kernel tests

Kernel tests are the immediate higher-level testing methodology we can have in Drupal 8 and are actually integration tests that focus on testing various components. They are faster than regular Functional tests as they don't do a full Drupal install, but use an in-memory pseudo installation that is much faster to bootstrap. For this reason, they also don't handle any browser interactions and don't install any modules automatically.

Apart from the code itself, Kernel tests also work with the database and allow us to load the modules that we need for running the test. However, unlike the Functional tests we will see next, Kernel tests also require us to manually trigger the installation of any database schemas we need. But we will see how we can do this in the two examples we cover in this section.

Before we can work with Kernel tests though, we need...