Does Kotest provide a coroutine scope I should use...

# kotest

[Wesley Hartford]

Does Kotest provide a coroutine scope I should use to launch a task that I want to run in the background while all tests in a Spec are being executed?

[Wesley Hartford]

Currently, I'm launching a job in a beforeSpec using the GlobalScope , and cancelling that job in an afterSpec . Is there a cleaner way to do that without GlobalScope?

[sam]

you can launch a corotuine directly inside a test

[sam]

every test scope in kotest is a coroutine scope

[Wesley Hartford]

Right, but I'm trying to launch a coroutine once before the first test to that the same background task is running for the whole spec. I don't seem to have a coroutine scope available in a beforeSpec block. Ideally, there would be a scope that ends after the last test ends, or after all the afterSpec blocks or something.

[sam]

Ah i see what you mean

[sam]

What you're doing is the right way then. There's no scope provided to those callbacks, you need to make your own.

[Wesley Hartford]

OK, thanks for your advice.

[Oleksii Malovanyi]

actually, you could use backgroundScope (kotlinlang.org)
kotest has it too via own TestScope impl. The only thing to be aware of is to understand the lifecycle of particular TestCope you gonna use – if you acquire backgroundScope from the ContainerScope it would have a lifecycle of the container, not a particular test, and probably this is not something you gonna want

[Oleksii Malovanyi]

or you could have something like this, but beware of the dispatcher (probably UnconfinedTestDispatcherImpl is what you want, but then you'll have to dance a bit with the single instance of TestCoroutineScheduler

fun Spec.SpecCancellableScope(dispatcher: CoroutineDispatcher = Dispatchers.Default) =
    CoroutineScope(Job() + dispatcher).also { scope ->
        val doCancel = { scope.cancel("Cleanup scope with test finishes") }
        when (isolationMode ?: AppKotestProjectConfig.isolationMode) {
            IsolationMode.SingleInstance -> {
                afterSpec { doCancel() }
            }

            IsolationMode.InstancePerLeaf, IsolationMode.InstancePerTest -> {
                afterTest { doCancel() }
            }
        }
    }