PHPStan extension for final classes (in theory) that cannot be final (because of mocking, Doctrine proxies, etc)

[gnutix]

Hello there,

I was thinking about final classes, and how much I like them. And then I was thinking about the few classes in my projects that are not final and might, without further notice, be inherited from - even though they should not. The reason they are not final is always "technical" : they are Doctrine entities (which uses proxies), mocked by tests frameworks (PHPUnit & Prophecy), etc.

And then I was wondering if we could add a PHP8 attribute #[Final], that a PHPStan extension could use to look for classes extending the class having such an attribute, and triggering an error if it finds one (a PHPDoc block /** @phpstan-final */ would work too I guess).

What do you think ? Could this be an official PHPStan extension (or even part of core) ? I don't know much about the current ecosystem's approach to Attributes and how they are intended to be used. I'm eager to hear your opinions.

Thanks!
gnutix

[ondrejmirtes]

Hi, I shy away from introducing custom attributes like that because they'd create problems at runtime - since PHPStan is a dev dependency, instantiating those attributes would fail.

There's already some support for reading @final, the annotation just haven't been read by the corresponding rule. I just added the check. You'll see it if you enable bleeding edge: phpstan/phpstan-src@dffd2c2

[gnutix]

I need to merge a few PRs, probably on Thursday, then I can try it out ! Thanks :D

[gnutix]

I upgraded to 0.12.94 and it works perfectly, thanks ! 🙏