make it possible to pass a file parameter to phpunit

Will that override just be the name of the file to run?

What I'd ideally like is for

> gitlab-ci-local phpunit path/to/folder-or-file

to behave the same way as on an OS:

> vendor/bin/phpunit path/to/folder-or-file

For that to work, the path/to/folder-or-file has to replace $DRUPAL_PROJECT_FOLDER, because that's the file parameter that phpunit gets.

What we could do is define a _PHPUNIT_TEST_SINGLE_FILE variable, which defaults to empty, then the call could be:
sudo -u www-data -H -E vendor/bin/phpunit $PHPUNIT_OPTIONS --bootstrap $PWD/$_WEB_ROOT/core/tests/bootstrap.php $DRUPAL_PROJECT_FOLDER$_PHPUNIT_TEST_SINGLE_FILE --log-junit $CI_PROJECT_DIR/junit.xml $WHAT_TO_RUN $_PHPUNIT_EXTRA || EXIT_CODE=$?

If somebody fills _PHPUNIT_TEST_SINGLE_FILE, it'll be something like /path/to/file.php.

Can the same be done for run-tests.sh?

> Can the same be done for run-tests.sh?

I think if someone's running a single test locally, they won't be using the concurrency feature, so run-tests.sh wouldn't matter.

We do have $_PHPUNIT_TESTGROUPS which filters on the @group defined in the test class.
See https://git.drupalcode.org/project/gitlab_templates/-/blob/main/includes...

I know that many test classes could have the same group, but if you are debugging one file locally then just temporarily edit that test file to have a distinct value for the @group. This also has the benefit that is works for both $_PHPUNIT_CONCURRENT:1 and $_PHPUNIT_CONCURRENT:0

I think it'd be a great idea to add the above information to https://project.pages.drupalcode.org/gitlab_templates/jobs/phpunit/

I think if someone's running a single test locally, they won't be using the concurrency feature, so run-tests.sh wouldn't matter.

It's not about the concurrency, it's about how they have configured their pipelines. gitlab-ci-local phpunit is running the GitLab "phpunit" CI job, not the binary. So if the project is configured to run with run-tests.sh, that's what will be used. It seems that a --file parameter can be passed, so the suggestion on #4 could be on one part of the if/else, and using this param should be on the other.

Re the first comment in #7, yes it is on my list of documentation updates to add $_PHPUNIT_TESTGROUPS to the phpunit page.