Set up a CI pipeline with PHPUnit tests

[reimic]

🚧 Work in progress 🚧

Regarding #27 #25

I've encountered a major problem, when trying to use PHP 8.2, so to move downgrading to a different pr. My goal is to rewrite Pest tests into PHPUnit test, but I can't make them work.

The test are failing with:

PHP Fatal error: Cannot acquire reference to $GLOBALS in D:\blueprints\vendor\phpunit\phpunit\src\Util\Configuration.php on line 543

I've read up on it, and it seems to be connected with the workflow setting up with PHP 8.2. But I am stuck.

[reimic]

Full error log:

Run ./vendor/bin/phpunit
PHP Warning:  Private methods cannot be final as they are never overridden by other classes in /home/runner/work/blueprints/blueprints/vendor/phpunit/phpunit/src/Util/Configuration.php on line 176
PHP Fatal error:  Cannot acquire reference to $GLOBALS in /home/runner/work/blueprints/blueprints/vendor/phpunit/phpunit/src/Util/Configuration.php on line 543
Error: Process completed with exit code 255.

[adamziel]

Oh boy, PHPUnit has its own PHP version compatibility matrix: https://phpunit.de/supported-versions.html

I looked up what does WordPress core do and the composer.json file there seems to list the "yoast/phpunit-polyfills": "^1.1.0" package – perhaps that would help here? If not, you could ask on the #core channel on WP.org slack or #core-test