Suspending functions + unit tests An important piece of my c kotlinlang #coroutines

Suspending functions + unit tests An important piece of my code was buggy but covered by a correct test ... that was ignored because I mistakenly use a suspending function in a JUnit class Gosh it would be so much better if suspending functions were supported directly in Junit instead of the

runTest { ... }

hack The issue is there https://github.com/junit-team/junit5/issues/1914 but very little happened since 3 years I created an issue, please star ⭐️ https://youtrack.jetbrains.com/issue/KT-52818/Provide-a-quick-fix-against-using-suspending-functions-in-Unit-Test

stojan

06/16/2022, 10:31 AM

not sure if changing the test framework is an option for you, but #kotest supports suspend functions by default

jmfayard

06/16/2022, 10:32 AM

I love kotest but here not really an option

👍 1

ephemient

06/16/2022, 11:56 AM

you can explore whether JUnit 5's extension system will allow you to handle suspend tests, but I suspect it's not possible

jmfayard

06/16/2022, 12:27 PM

I guessed the issue above would be marked as fixed if that was possible 🙂

ephemient

06/16/2022, 6:33 PM

so I played around with it a little • the IDE already displays an error on

@kotlinx.test.Test suspend fun

• a JUnit5 extension could wrap every test in

runTest

and inject scope/continuation parameters, but it can't change test discovery, which means no way around JUnit ignoring all suspend funs

jmfayard

06/17/2022, 8:47 AM

Importing

@Test

from

kotlin.test

doesn't work, it always import

org.unit.jupiter.api.Test

which doesn't give me the error, unless I expeclitely type

@kotlin.test.Test

which is not very convenient....

ephemient

06/20/2022, 10:59 PM

that error might be down to your IDE configuration; auto-complete allows both for me

I did think of a way to get JUnit to run suspend tests, though. it involves a couple of nested extensions, and isn't able to fully participate in the JUnit test lifecycle, but it is possible to write the following test:

class ExampleTest : CoroutineTest {
    @Test
    suspend fun test() {
        println("OK")
    }
}

CoroutineTest_kt.kt

jmfayard

06/21/2022, 12:58 AM

wow, thanks!

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