Object implementing mixed type of a generic interface is not considered as a sub type of the interface.

[JoyceBabu]

Bug report

PHPStan does not correctly detect Objects implementing generic type mixed of an interface, as a super type of the interface.

If I use any other type, say array<string,string> or list<string>, it works.

Code snippet that reproduces the problem

https://phpstan.org/r/f317cce1-39d8-47a4-a397-5e8c79c69c96

Expected output

The code to pass validation as Object<mixed> is a super type of Interface<mixed>.

[rajyan]

This looks like an error from strict mixed, because changing the level to 8 can suppress the error. Although, not sure this is an intended behavior or not.

[ondrejmirtes]

You need @template-covariant: https://phpstan.org/r/66732210-53ed-4dd6-ae28-725bc4ea1853

See: https://phpstan.org/blog/whats-up-with-template-covariant

[mad-briller]

this gets posted once a day on here it feels like @ondrejmirtes , is it maybe worth adding a link to that article in the tip of related errors at all?

[ondrejmirtes]

It's planned, I'll have to add something like acceptsWithReason(): AcceptsResult to Type interface.

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.