Cancelled scopes can be reused

[ZakTaccardi]

It's a bit odd that cancelled scopes can be reused.

Example

val scope = CoroutineScope(Dispatchers.Unconfined + Job())

scope.launch { println("hello!") }

scope.coroutineContext[Job]!!.cancel()

// I expect this not to print, because the scope has been cancelled
scope.launch { println("goodbye!") }

Expected

hello!

Actual

hello!
goodbye!

EDIT: It seems the issue is that before launching a coroutine, the launch does not check if the scope has been cancelled or not:

yield example

val scope = CoroutineScope(Dispatchers.Unconfined + Job())

scope.launch { println("hello!") }

scope.coroutineContext[Job]!!.cancel()

scope.launch {
    yield()
    println("goodbye!")
}

result

hello!

Is this intentional?

[elizarov]

This happens because you are using Dispatchers.Unconfined. Please, don't use Dispatchers.Unconfined it may result is other weird and unexplicable behaviors, beyond the one you had demonstrated.

[elizarov]

This is not intentional, though. Just a side-effect. We might be able to fix it.