Can I use JUnit5 Extensions with KoTest? If yes, how? Just adding the annotation for an Extension do...

# kotest

[Henning B]

Can I use JUnit5 Extensions with KoTest? If yes, how? Just adding the annotation for an Extension does not seem to execute it for me.

[sam]

No, we have a wrapper but it's not very well tested.

[sam]

What rule is it you want to use, there might be a port of it

[Henning B]

Thanks for the quick reply. Is there another way to reuse code which is used in multiple test classes?

The extension I am using is described in this blog post:

[Henning B]

https://jeroenmols.com/blog/2019/01/17/livedatajunit5/

[sam]

Kotest is just Kotlin so you have way more options to sharing code.

[sam]

If you want to reuse code, pull it into a function ?

[Henning B]

Extensions have the benefit that you can group setup and teardown code together and than apply them together.
When I offer common code I would have to make sure to use the correct setup and teardown method manually in my tests.

But maybe it is possible to create a pattern where you call external berfore {} / after {} blocks. I will tinker a bit 🙂

[sam]

Got it.

So what you might wanna do in Kotest is create a TestListener.

class/object Foo : TestListener {
  override fun beforeTest ... // set up
  override fun afterTest ... // tear down
}

Then you can add that to whatever tests you want.

class MyTest : FunSpec({
   listener(Foo())
   test("....) { }
})

[sam]

Not the best docs but more info here: https://kotest.io/docs/framework/listeners.html

[Henning B]

Yes, perfect! Thanks 🙂

[sam]

Cool, feel free to hit me up if you have anymore questions

[LeoColman]

specifically for LiveData, I wrote this listener and use it on a daily basis. Not sure why I didn't ship it to Kotest yet, but it works for my usecase

[LeoColman]

https://github.com/LeoColman/rpg-npc-generator/blob/master/app/src/test/java/io/kotest/android/InstantLivedataListener.kt

[Henning B]

Haha that looks exactyl like the code I ended up with. I did add super calls because the IDE generated them for me. Not sure if needed though.