I'd like a PHPUnitVersion class that works the same way PhpVersion works in PHPStan. Methods asking about specific features.

here you are

The majorVersion is nullable when we can't detect it? I wonder if we should make the user of PHPUnitVersion explicitly handle it, because otherwise we're basically lying. When we can't detect it, the thing might be supported.

Ok. Adding trinary then

I just had my first mutation testing experience on a phpstan/* repo :)

Perfect, thank you!

I just had my first mutation testing experience on a phpstan/* repo 😊

Let's record this here: https://github.com/phpstan/phpstan-phpunit/actions/runs/18886595907/job/53903464005

The log will disappear after some time so here's a screenshot:

This is what I had in mind the whole time, I'm glad it pays off 👏