Does anyone know what artifact to use for MPP JVM + JS setup?

kotest-framework-engine-js for js and kotest-runner-junit5-jvm for jvm

What about my common sourceSet?

you can't test common without compiling it to a target, so one of those two deps will be used for common tests too

I mean what artifact do i add to common sourceSet dependencies?

nothing, add js to your js target build, and jvm to your jvm target build, and then when you run gradle test, it will run the common tests too

But then I won't have kotest dsl available in commonTest...

you will because kotest-framework-api brings that in

So i do need to add the framework artifact to common

framework-api yes

It doesn't until I add junit5 runtime artifact to jvm

then something is wrong in the build

Would be good to have all this in the docs for the future

Yep, if you want to contribute a PR that would be great