We have code similar to this:

val job = launch {
    val flow = slowBlockingCallThatReturnsIterator().asFlow()
    flow.collect { 
        yield() // allows for cancel() to work
        channel.send(it) 
    }
}

If we call

job.cancel()

during the slowBlockingCall (or while the flow is collecting) without the

yield()

call, all entries in the iterator still get sent to the channel. If we add back the yield call, then the collection aborts as we initially expected to happen without the yield(). Since channel.send is a suspend function, shouldn't calling it check the coroutine active state?

No, suspension on its own does not check for cancellation, because that's not part of the language, it's part of coroutines lib

ah ok, thanks. I missed that, but saw the

All the suspending functions in kotlinx.coroutines are cancellable

doc that made me think otherwise