Warnings on simple static interface

[M1ke]

I have an interface for a static factory method, and am struggling to see how to stop Psalm showing warnings:

https://psalm.dev/r/ed9e2857f7

In this case we have an interface that declares a public static returning static and then the implementor. If the implementor returns self we get warnings on both the method type and the return line. However if we declare @return self in a docblock, we get an error.

Is there a way to make this structure work without Psalm complaining?

[AndrolGenhald]

This is invalid because you could have Qux extends Baz and it would inherit the method returning self, so it would not return static as required. You can either mark Baz as final to rule out this possibility, or use @psalm-consistent-constructor and have the method construct static instead of self.

[M1ke]

Thanks, those solutions both make sense.