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.

In this tutorial, you’ll create and render a simple single directory component (SDC) in Drupal. You’ll set up the required files, call the component from a template, and confirm that Drupal renders it with its styles automatically attached.

By following along, you will:

• Scaffold the files for a basic card component.
• Reference the component in a node template.
• See how Drupal renders the component’s HTML and CSS together.

When you’re done, you’ll have a complete working example of a Drupal single directory component.

As a module developer, you output themed content from your module in the form of renderable arrays. When doing so, you can make use of single directory components (SDCs) by using the #type => 'component' render element type. This allows modules to dynamically select and configure a component based on configuration or specific PHP logic. You'll use this as the return value of a controller, or a configurable plugin related to display building, like custom blocks or field formatters. As an example, we'll author a custom block plugin that loads a specific node and outputs it using the card SDC we defined in a previous tutorial. We'll build a render array that supplies the values for the component's props and slots, and add some caching logic to the output.

In this tutorial, we will:

• Build a render array that targets an SDC via the #component property.
• Pass data into the component's props and slots, and demonstrate optional #propsAlter and #slotsAlter callbacks.
• Validate the output and cache it properly.

By the end of this tutorial, you'll be able to render any SDC via a module's PHP code using a well-structured and cache-friendly render array.

A Drupal single directory component (SDC) is Drupal's way of packaging the markup, metadata, styles, and behavior for a UI element in one self-contained folder inside a theme or module. This structure helps front-end developers and site builders keep all related files together for easier theming and reuse. A Drupal single directory component directory must be located in a specific place and its files named with a particular convention so that the system can discover it and use its assets.

In this tutorial, we'll:

• Show where Drupal discovers single directory components in your codebase.
• Explain the naming and organization conventions for Drupal single directory component directories and files.
• Outline key files for a component—both required and optional.

By the end of this tutorial, you'll be able to identify an SDC directory in a Drupal module or theme and know exactly what you're looking at.

Props and slots are the two ways that data can be provided to a single directory component (SDC). They are part of a component's schema definition, and are used to determine the names of variables passed to a component's template file. Props pass structured, validated data into a component, while slots allow us to inject flexible content such as HTML or nested components. Understanding when and how to use each ensures you can build reusable and adaptable components.

In this tutorial, we'll:

• Learn what props and slots are, and how they differ.
• Discuss how using one or the other impacts the developer experience and use of your components in a UI.
• Practice deciding when to use each for component design.

By the end of this tutorial, you'll know how to choose between props and slots when building components.

Learn how to generate menu links dynamically with plugin derivatives in a custom module. This tutorial walks through creating a single base menu link plugin definition and a deriver class that expands that definition into one menu link per content entity. The code will automatically generate links for all published basic pages, placing dynamic menu links in the main menu.

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

• Understand which files you need in order to define menu link plugin derivatives, also known as dynamic menu links
• Create the necessary code to define menu link plugin derivatives for an example use case

Drupal stores the settings that define how a site behaves as configuration data. Everything from the site name to image styles, roles, and view definitions are stored as configuration. The Configuration API gives modules, themes, and installation profiles a consistent way to store, retrieve, update, and provide this configuration in a structured and portable way.

In this tutorial, we'll:

• Provide a high-level overview of the features of Drupal's Configuration API
• Link to related tutorials where you can learn more and get hands-on practice working with configuration data in code.

Bundle classes are a feature of the Drupal Entity API that let you attach PHP classes to individual bundles (for example, content types) so you can keep site-specific business logic close to the data it acts on. Bundle classes are a powerful way to encapsulate site-specific business logic and bridge user-configured fields and PHP logic based on those fields. In this tutorial, you will build a reusable bundle base class that adds a generic share behavior for all node types on a site and then extend it for a specific node type.

In this tutorial, we will:

• Explore a real-world problem that bundle classes can help you solve.
• Create a bundle base class for common share features shared across multiple node types.
• Implement a node-type-specific class that extends the base class with behavior tailored to the underlying content type.

By the end of this tutorial, you'll be able to use bundle classes to encapsulate per-bundle logic, assume the presence of UI-configured fields when appropriate, and register those classes so Drupal uses them at runtime.

Drupal recipes provide a new way to package and share reusable features across Drupal sites. Unlike traditional install profiles or distributions, recipes are applied once to add functionality and then step out of the way, leaving you with a standard Drupal site that you can customize freely.

In this tutorial, we will:

• Understand what Drupal recipes are and how they differ from install profiles and distributions
• Learn the four core properties that make recipes powerful: applied (not installed), shareable, non-locking, and composable
• Explore real-world scenarios where recipes solve common platform and agency challenges

By the end of this tutorial you'll be able to explain what Drupal recipes are, identify features in your projects that are good candidates for recipes, and articulate the value of recipes to stakeholders.

Recipes transform your Drupal site by adding features and configuration. After downloading (or authoring) a recipe it needs to be applied to your Drupal project. This is analogous to following the step-by-step instructions in a recipe to make a dish. Only, we're not performing the steps on our own, but instead we're using Drupal's tools to apply the recipe. Applying the recipe adds its features to your Drupal project. This requires establishing safe workflows to apply recipes, verify their effects, and roll back changes if needed.

In this tutorial, we will:

• Apply a recipe in a non-production environment using a feature branch workflow.
• Review configuration changes using Git and verify functionality in the UI.
• Understand how to roll back recipe changes if needed.
• Learn safe workflows for both developers and non-developers.

By the end of this tutorial, you'll be able to safely apply recipes to your projects, review their impact, and decide whether to keep or roll back the changes.

The built-in config actions in Drupal core cover most common scenarios. But sometimes you need custom operations specific to your feature or the configuration your module relies on. You can create custom config actions by defining them as plugins or by adding PHP attributes to a configuration entity class's methods. Let's implement a custom config action to toggle an SEO strict mode setting to learn how to extend recipes with domain-specific configuration operations and make them reusable across your projects.

In this tutorial, we will:

• Identify scenarios where custom config actions are warranted.
• Understand the two implementation patterns: plugins and attributed methods.
• Implement a custom config action in a module.

By the end of this tutorial, you'll be able to implement custom config actions that extend the configuration API provided to your recipes, making platform-specific operations reusable and declarative.

The Configuration Actions API lets recipes modify existing configuration rather than just adding new configuration. By extending the SEO Article recipe created in a previous tutorial with config actions, you'll learn how to manipulate existing configuration objects in order to do things like grant permissions and modify entity display modes. This is necessary because sometimes a recipe needs to modify configuration that already exists on the site, not just add new configuration.

In this tutorial, we will:

• Add config actions to grant permissions to existing roles
• Modify entity displays using config actions
• Reapply recipes and observe idempotent behavior
• Experiment with new content types to understand recipe limitations

By the end of this tutorial, you'll be able to use common config actions in your recipes and understand how recipes behave when reapplied.

The Configuration Actions API is a powerful feature of Drupal recipes that allows you to modify existing configuration without replacing it entirely. While configuration exports let you add new configuration, config actions let you update what's already there—like granting permissions to an existing role or adjusting display settings. Effectively, config actions are a way for a recipe to declare a PHP method to run on a configuration object during recipe application and any arguments that method needs to run.

In this tutorial, we will:

• Understand what config actions are
• Learn how to read and write config actions in a recipe's YAML file
• Explore common patterns like granting permissions and modifying displays
• Understand the difference between generic and type-specific actions

By the end of this tutorial, you'll be able to read config actions in recipes, understand when to use them versus configuration exports, and recognize common config action patterns.

Creating your own recipes lets you package and reuse features across your projects. By building a simple SEO-focused recipe from scratch, you'll learn what goes into a recipe, how to declare dependencies, and how to test your work.

In this tutorial, we will:

• Understand what belongs in a recipe versus what belongs in modules
• Create a recipe structure with proper metadata and dependencies
• Export and package configuration into a recipe
• Test the recipe by applying it to a second site

By the end of this tutorial, you'll be able to create your own recipes, package them properly with dependencies, and apply them to other Drupal sites.