I'll add some tests for the feature.

It might be better to make this as an option for AccessPropertiesRule and AccessStaticPropertiesRule?

I worry that this logic needs to be deep in NodeScopeResolver, or not?

If not then yeah, parameter for a rule is nicer.

I worry that this logic needs to be deep in NodeScopeResolver, or not?

I think it's possible now. currentlyAllowedUndefinedExpressions in NodeScopeResolver is saying that dynamic property inside isset is a valid PHP with no error. I believe it would be valid even after dynamic properties is deprecated/removed after PHP 8.2. AccessPropertiesRule can check the currentlyAllowedUndefinedExpressions and change the behavior by $checkDynamicProperties like this, which I think makes more sense 👍

While this option can optionally restore the behavior before #1223 (comment), it would restore the false positive phpstan/phpstan#3171 too.
It's because AccessPropertiesRule is currently treating Class|null and dynamic property on Class (which are both $type->canAccessProperties()->maybe()) in the same way. It's a different issue and I'll fix it separately.

Thank you! Can you please send an update to https://phpstan.org/config-reference#stricter-analysis as well? There's an "Edit this page" link at the bottom :)

I'll update phpstan-strict-rules so that the playground with strict rules + bleedingEdge enabled will have this option on.

Done: phpstan/phpstan-strict-rules@afbe1e3

I'm testing this in the real world and it's really nicely done! The impact is really minimal and exactly in the right weird places where I'd expect it 👍

Thanks! I'm glad that I could help solving dynamic properties related issues 😄