This set of tutorials starts with helping explain why testing is a good idea in the first place, it then takes a look at the different types of tests that ship with Drupal core and the various frameworks that makes those tests possible. After that bit of groundwork orientation is done we'll learn how test files are organized in the Drupal codebase and how we can run existing tests using a few different methods. Once we know how to execute our test suite, we'll dig into implementation examples for functional and unit tests.
Primary Author, Paul Mitchum
Paul Mitchum (Mile23 on drupal.org) has done work on Drupal's continuous integration project, is an active core contributor, and is one of the maintainers of the Examples project among his other roles.
In this gentle introduction to testing, we'll walk through what testing is and why it's important to your project. Then we'll define some terms you'll be likely to see while working with tests so that we're all on the same page. After reading through this tutorial you'll understand enough of the basic vocabulary to get started running (and eventually writing) tests for your Drupal site.
This tutorial will clarify some basic ideas about software testing. We'll give some strategies for testing and illustrate types of tests and when and why you'd use them. This document is written with Drupal in mind, but the concepts apply for other development environments you'll encounter as well. The tools will be different, but the ideas apply universally. By the end of this tutorial, you should understand what testing is for and how different types of tests support different purposes and outcomes.
In this tutorial, we will look at the various types of tests and testing frameworks included in Drupal core. We'll also provide an overview of how the different frameworks operate and the types of situations where each of the different frameworks is useful.
In order to run tests, your Drupal site needs additional development requirements installed using Composer.
By default, when you download Drupal as a zip file or tarball, these packages will not be installed, since they're used for development purposes.
In this tutorial, we'll walk through the steps to make sure we've got Composer available. Next we'll install the dependencies. Then we'll talk about why you shouldn't have development dependencies available on your production site. Thankfully, Composer can help make this easy to manage.
In order for Drupal to be able to locate and run the tests you create, the files need to be put in the correct place. In this tutorial, we'll take a look at the different types of test frameworks that are included along with core. We'll also see how Drupal expects our test files to be organized so that the test runners can find them.
Drupal core comes with a run-tests.sh script to help with running tests. This script has some distinct advantages over running tests directly via PHPUnit. It runs all tests in their own separate process, and can therefore handle PHP fatal errors without killing the test run. It's also the mechanism that the Drupal CI tools use to run tests; so, it can be handy when debugging tests that are failing on Drupal.org.
In this tutorial we'll:
- Look at the available options for the core run-tests.sh script
- Go through some examples of running tests using run-tests.sh
By the end of this tutorial you'll know how to run your tests using run-test.sh.
In this tutorial, we'll run tests in several different ways using the PHPUnit tools available in Drupal. We'll learn about various environment variables you'll need to supply to the test runner depending on which type of test you're running. And we'll learn various ways to get reports on the test results. By the end of this tutorial, you should understand how to run Drupal tests using PHPUnit.
Simpletest has been removed from Drupal 9. If you're preparing to upgrade your site to the latest version of Drupal and you have Simpletests in your codebase that extend
WebTestBase you'll need to update them to use PHPUnit's
BrowserTestBase class instead. This will ensure your tests don't depend on a deprecated testing framework. By the end of this tutorial, you should be able to convert
WebTestBase-based Simpletests to use PHPUnit's
BrowserTestBase class instead.
When running tests with PHPUnit we need to specify a phpunit.xml file that contains the configuration that we want to use. Often times (and in much of the existing documentation) the recommendation is to copy the core/phpunit.xml.dist file to core/phpunit.xml and make your changes there. And this works fine, until something like a
composer install or
composer update ends up deleting your modified file. Instead, you should copy the file to a different location in your project and commit it to your version control repository.
In this tutorial we'll:
- Learn how to move, and modify, the phpunit.xml.dist file provided by Drupal core
- Understand the benefits of doing so
- Demonstrate how to run
phpunitwith an alternative configuration file
By the end of this tutorial you should be able to commit your phpunit.xml configuration file to your project's Git repository and ensure it doesn't get accidentally deleted.
In this tutorial, we'll walk through the process of setting up a functional test. Then, we'll learn how to run it using two different test runners. This setup process allows us to be sure we're not getting false positives from the test runners. We'll be working on a functional test, but these techniques apply with minimum modification to all the Drupal PHPUnit-based tests.
By the end of this tutorial, you should be able to set up and run functional tests in Drupal using two different test runners.
In this tutorial, We'll walk through the basics of how to implement a
BrowserTestBase functional test. We'll assume you've already determined that you need to write a functional test and that you've Set up a Functional Test.
In this tutorial, we'll:
- Determine the specifications of the test.
- Walk through the behavior we want to test.
- Document our test in the test class.
- Implement the testing steps.
- Make some decisions about how to deal with dependencies.
In the tutorial, Implement a Functional Test, we learned how to tell
BrowserTestBase to use the Standard installation profile in order to get our test passing and letting the Standard profile implicitly provide our dependencies. We also mentioned that doing so probably wasn't the best decision and that we should explicitly declare those dependencies in some way.
In this tutorial, we'll will walk through explicitly declaring those dependencies. When in doubt, it's generally considered a best practice to be as explicit about the dependencies of our tests as possible. By the end of this tutorial, you should be able to:
- Understand why we want to explicitly declare our dependencies.
- Determine what the dependencies really are and make a list of them.
- Implement each dependency in our list.
- Emerge with a thorough, passing test.
Let's write somewhat strict unit tests in a Drupal module. By the end of this tutorial, you will be able to:
- Understand what makes a unit test different from other types of tests.
- Determine the specifications of a unit test.
- Use mocking to isolate units under test, and to force code flow to achieve high coverage.
We'll start out with a brief introduction to unit tests. Then we'll look at a contrived example of a Drupal controller class for illustration purposes. Next, we'll test two units of this controller class, each requiring different mock styles.
The exact setup for running functional tests is dependent on your development environment. We'll walk through a couple of common examples including using Docker (via DDEV) and stand-alone applications.
In this tutorial we'll:
- Learn how to install and run ChromeDriver and other necessary tools either in a Docker environment, or locally.
- Configure the relevant PHPUnit environment variables so they contain values appropriate for our specific environment.