Unit tests are the simplest among Drupal's test types, ideal for verifying code that performs computations. This tutorial guides through writing unit tests for the anytown module, focusing on the ForecastClient service, and illustrates how to use mocks for dependencies.

In this tutorial, we'll:

• List potential unit tests for the anytown module.
• Write tests for ForecastClient service logic.
• Demonstrate how to mock services in unit tests.

By the end of this tutorial you should be able to write PHPUnit Unit tests for logic in the anytown module.

As of Drupal 10.2, most plugin types use PHP attributes for discovery and metadata.

In this tutorial, we'll:

• Provide a recipe for implementing PHP attribute-based plugins.
• Demonstrate how to figure out where the code and metadata should live for PHP attribute-based plugins.

By the end of this tutorial you should have a recipe for getting started with implementing PHP attribute-based plugins, and a better understanding of how to figure out the details required to implement a given plugin type.

PHP attributes are a native PHP language feature, introduced in PHP 8.0, that provide a way to add metadata to classes, methods, properties, and functions in PHP code.

In Drupal, this metadata is used by the plugin system to aid in the discovery and configuration of plugin instances. As a Drupal developer, it's important to understand how to recognize, read, and write PHP attributes, as you'll encounter them when working with plugins.

In this tutorial we'll look at:

• What PHP attributes are
• The use case for attributes in Drupal
• An overview of the attribute syntax

By the end of this tutorial, you should understand how attributes are used in Drupal and how to write them in your own code.

Prior to Drupal 10.2 most plugin implementations required the use of annotations alongside a PHP class. Now Drupal supports and recommends the use of PHP attributes instead. During the transition, most developers will still need to know how to recognize and implement annotation-based plugins.

In this tutorial we'll:

• Provide a recipe for implementing annotation-based plugins.
• Demonstrate how to figure out where the code and metadata should live for annotation-based plugins.

By the end of this tutorial you should have a recipe for getting started with implementing annotation-based plugins, and a better understanding of how to figure out the details required to implement a given plugin type.

Many of Drupal's APIs that look like a bunch of configuration in a YAML file (migrations, menu links, etc.) are actually plugins in disguise. The YAML from these files is used as arguments to a generic PHP plugin class which then behaves differently depending on the provided values. As a developer, you probably don't need to know that menu links are plugins, but it can be helpful when debugging or just trying to get a better understanding of the big picture.

In this tutorial, we'll:

• Learn about how YAML-based plugins work
• Discuss how to find the implementation details for YAML-based plugins
• Walk through an example of implementing a YAML-based plugin

By the end of this tutorial, you should be able to recognize a YAML-based plugin definition, and author your own.

There’s no one-size-fits-all path to upgrade from Drupal 10 to Drupal 11, but there is a set of common tasks that everyone will need to complete.

In this tutorial we’ll:

• Explain the differences between Drupal 10 and Drupal 11 that affect the upgrade path.
• Walk through the high-level steps required to upgrade from Drupal 10 to Drupal 11.
• Provide resources to help you create an upgrade checklist and start checking items off the list.

By the end of this tutorial you should be able to:

• Explain the major differences between Drupal 10 and 11.
• Audit your existing Drupal 10 projects for Drupal 11 readiness, and estimate the level of effort involved.
• Start the process of upgrading your site from Drupal 10 to Drupal 11.

Zen is a base, or parent, theme for Drupal that features lean, semantic HTML5 markup and a starter kit for custom theme development. In this tutorial, we will install Zen and create a subtheme for custom theme development using Drush. I use the Drush command provided by Zen because of all of the tedious renaming required when cloning the "STARTERKIT" into a subtheme. The Drush command provided by Zen automates this and makes it a relatively painless process. If you need to install Drush, see our related video tutorial, Installing Drush with Composer, or read the instructions for installation on the Drush web site.

In the next tutorial, I'll briefly explain why you might want to use a base theme and when it makes the most sense to do so. After that, I will walk through and highlight some of the HTML5 semantic markup in Zen's template files, contrasting the markup with the corresponding template files in the core Drupal 7 theme, Bartik.

Other tutorials in the Markup in Drupal series also use a subtheme of Zen, called zendemo, as a theme for the demo site. This was done to demonstrate how markup is first and foremost affected by the theme. It was also done to show how using a base theme that uses semantic HTML5 markup can be advantageous if you want to use HTML5 elements in the built-out components and pages of your Drupal site.

To follow along, download the latest version of Drupal 7, and follow the instructions in the video for installing Zen and a creating a subtheme.

In the downloads section below you'll find a database and files downloads, which is the state of the site after this tutorial, with Zen and the subtheme "zendemo" installed.

Additional resources

Zen theme — Drupal.org
Zen documentation — Drupal.org