How it works...

The run-tests.sh script has been shipped with Drupal since 2008, then named
run-functional-tests.php. This command interacts with the test suites in Drupal to run all or specific tests and sets up other configuration items.

There are several different test suites that operate in specific ways:

• Simpletest: The deprecated test system, full bootstraps and installs Drupal and uses its own browser emulator pattern using curl and XPath.
• PHPUnit-Unit: Unit tests backed by PHPUnit. These are intended to test specific classes and not interact with the database.
• PHPUnit-Kernel: Integration-level tests backed by PHPUnit. It is a test that has the ability to install schema and configuration to the database, minimally bootstrapping Drupal for basic integration testing.
• PHPUnit-Functional: Functional tests are tests that require a fully bootstrapped Drupal and provide browser emulation via Mink. These can be considered a direct replacement of Simpletest tests but leveraging third-party testing libraries.
• PHPUnit-FunctionalJavascript: Functional tests that have the ability to interact with PhantomJS in order to test JavaScript, such as AJAX operations and specific user interface interactions.

The following are some of the useful options:

• --help: This displays the items covered in the following bullets
• --list: This displays the available test groups that can be run
• --url: This is required unless the Drupal site is accessible through http://localhost:80
• --sqlite: This allows you to run tests without having Drupal installed
• --concurrency: This allows you to define how many tests run in parallel