Can someone please enlighten me on unit testing with Kotlin multiplatform? As I understand it,

commonMain

and

commonTest

SourceSets

exist regardless of the target. If my project only has ios and android targets, does that mean I can't run unit tests on the common code contained in

commonTest/test

?

common code is executed for each platform you support. So commonTest will just be run for each platform that you run unit tests

"So commonTest will just be fun for each platform that you run unit tests" can you elaborate on this, please?

Whoops typo. Fixed.

So there's no way to just execute the tests that are in commonTest?

You could (with some configuring probably), but which platform would you run them on? There's no platform independent artifact. Ultimately, the code has to run on a particular platform

Interesting, I would have thought common has an implicit JVM platform being Kotlin and all

Nope. If you want that, you add JVM as a target, and then you run JVM tests

So I should conceptually imagine my common code to have a runtime of some platform rather than generic JVM code that can be compiled to a platform native binary.

Common misconception is that common implies some kind of platform-independent artifact or something. It's really more just about it being common to all sources, so it can't uses platform-specific code/libraries and must be compatible with all targets

^ exactly. Yeah, I guess I got bit by that misconception.

No prob 👍

interesting! does that imply, that tests in

commonTest

aren’t supposed to be runnable from AS/IDEA? i was wondering why the

run as test

button is not showing up for my common test

They should be runnable, but support varies based on the targets you have setup + bugs: 1. Native targets are newer, and IDEA support is still "up and coming" 2. JVM/android targets should work fine 3. Pretty sure there are new bugs in Kotlin 1.3.60 that broke support for 2. Should be fixed in 1.3.70

thought as much. thx!

FWIW, I usually use a JVM target for running tests while I’m developing because they run the fastest. Every once in a while I do a sanity check on the other platforms.

@Sam yeah, that's what I ended up doing. The unit tests I was writing were simple enough and basically sanity checks. I just needed fast feedback.