Ref: https://docs.moodle.org/dev/PHPUnit

composer install

php admin/tool/phpunit/cli/init.php

vendor/bin/phpunit theme_foundation_privacy_testcase theme/foundation/tests/privacy_provider_test.php
or
vendor\bin\phpunit theme_foundation_privacy_testcase theme/foundation/tests/privacy_provider_test.php

vendor/bin/phpunit --group theme_foundation
or
vendor\bin\phpunit --group theme_foundation
