Can somebody explain me why this fails with `Test ...

# coroutines

[Davide Giuseppe Farella]

Can somebody explain me why this fails with Test finished with active jobs

scope.launch(Io) {
    withTimeout(500) {
        while (stack.isEmpty()) {
            delay(1) // await
        }
        result.data = stack.removeFirst()
    }
}

While this completes successfully

val j = scope.launch(Io) {
    while (stack.isEmpty()) {
        delay(1) // await
    }
    result.data = stack.removeFirst()
}
scope.launch {
    delay(500)
    j.cancel()
}

[tseisel]

Check that one of those coroutines is not stuck in a while loop.
If you are looking for a way to suspend consumers until an element has been pushed onto the stack, I suggest that you have a look at `Channel`s instead, they do exactly that !

[Davide Giuseppe Farella]

The delay should be my way out.
I tried with Channel but I had trouble https://github.com/Kotlin/kotlinx.coroutines/issues/2202 and my code was buggy, so I tried to start from basic things for now

[tseisel]

Indeed, runBlockingTest has some flaws currently, it is unable to work with alternative dispatchers like <http://Dispatchers.IO|Dispatchers.IO>.
The trick is to inject those `CoroutineDispatcher`s so that you could inject a TestCoroutineDispatcher in tests.

[Davide Giuseppe Farella]

Yup, that’s what I’m doin, it is Io , not IO 🙂

interface DispatchersProvider {

    val Main: CoroutineDispatcher
    val Comp: CoroutineDispatcher
    val Io: CoroutineDispatcher
}