Tests are made up of Behat functional tests and PHPUnit unit tests.

These require that a Drupal site is installed. Tests can be run from tests/behat. After configuring, you can run tests from that directory with the command, vendor/bin/behat.

These tests do not require that a Drupal site is installed. To run these tests, you can run a command such as, phpunit -c [your-site-install]/core/phpunit.xml.dist --group d8e. If you are using PhpStorm, you can add the --group d8e to your test configuration under Test runner options.

The --group d8e will run only tests that are part of this module. This setup uses the Drupal 8 configuration file which sets up the testing environment.