Is it possible to mock a Java static function, there doesn't seem to be any mention of this in the docs?

Yes, I think that's a purpose of mockkStatic

In the docs, it just mentions extension functions, might be nice to have a mention of this...

The thing is that mockkStatic is needed to mock extension functions. But that doesnt matter if you would like to mock static function

Although you're right, conceptually they should be the same, but then, I won't come close to ever understanding how Mockk's inners work so you never know 😉.

Will see