Ref: https://docs.moodle.org/dev/PHPUnit composer install --dev php admin/tool/phpunit/cli/init.php vendor/bin/phpunit theme_squared_coursecattoolbox_testcase theme/squared/tests/coursecattoolbox_test.php or in Windows: vendor\bin\phpunit theme_squared_coursecattoolbox_testcase theme/squared/tests/coursecattoolbox_test.php vendor/bin/phpunit --group theme_squared or in Windows: vendor\bin\phpunit --group theme_squared