I have a multiplatform module with just jvmMain an...

# multiplatform

[Michal Klimczak]

I have a multiplatform module with just jvmMain and jvmTest source sets. It contains a kapt / ksp annotation processor which generates code based on common source set. I use tschuchortdev:kotlin-compile-testing library to test the processor.
It all works fine until I start to use expect keyword in my jvmTest tested source. It complains that The feature "multi platform projects" is experimental and should be enabled explicitly.
Fail even if I add kotlin.mpp.stability.nowarn=true to gradle.properties and gradle-wrapper.properties. Any ideas what might be wrong or how can I structure my tests differently?

[ephemient]

the usage is expect in common sourceset, actual in jvm or other platform-specific sourcesets. if you have no common sourceset, there's no place for expect.

[Michal Klimczak]

Is it a rule, though? You can compile project with both expect and actual in common code - I checked that recently. And if I have multi layered structure like common-ios-iosArm64/iosX64 then I should be able to use expect in ios and actual in iosArm64 and iosX64? There's probably hardly any use case for that, but nevertheless?

[ephemient]

in a hierarchy (which is the default now) then yes, you can expect in any sourceset that has children. but jvm doesn't

[Michal Klimczak]

OK, I will just try to use commonTest instead, wonder how that goes. Thank you :)

[Michal Klimczak]

That didn't work either, unfortunately. I moved all the tests to commonTest and they can be run, but the tests that try to compile stuff with expect fail exactly the same (other tests continue to work just fine). The compiled code looks sth like this but with expect interface InterfaceGenerationExample. I assume the problem is that this source file from kotline-compile-testing is not really the same thing as the original source set that runs the tests and therefore different rules apply

[ephemient]

are you trying to expect in your code at compile-time and actual in runtime-generated code? that won't work

[Michal Klimczak]

not really. right now I'm just trying to test-compile an expect type. ultimately the library will only probably generate code without expect/actual, even if the annotated type is expect. But right now I'm just trying to write a failing, but compiling test for this.

[ephemient]

ah. I don't know if kotlin-compile-testing works for that; may have to ask the developer

[Michal Klimczak]

tbh, wouldn't even be mad if it complained about having an expect type without actual. but I only got The feature "multi platform projects" is experimental and should be enabled explicitly which doesn't sound right

[Michal Klimczak]

yeah, I might end up filing an issue there

[ephemient]

that is a message you get when trying to use expect in a JVM-only project (yes, it's misleading)