What's the correct way to call cancel on a job giv...

# coroutines

[coder82]

What's the correct way to call cancel on a job giving another cause so that the coroutine will fail? I tried everything but it looks like that in case of CancellationException with custom cause the coroutine doesn't trigger CoroutineFailureException, so to me it doesn't really fail..., it just cancels... the documentation says it should fail the coroutine. In my case such coroutine is a SupervisorJob child (but that shouldn't affect this behaviour).

[kingsley]

cancel always cancels the job with a cancellation exception. The coroutine will only fail if it were to throw an exception within itself other than a cancellation exception

the documentation says it should fail the coroutine

Hmm… I found this

If the cause of cancellation is a different exception, then the job is considered to have failed

but it also says

This usually happens when the code of the job encounters some problem and throws an exception.

Looking at the code for cancel(Throwable) which is now deprecated, I found this:

This method has bad semantics when cause is not a [CancellationException]

So, either you use a cancel(CancellationException) or a cancel(message: String, cause: Throwable) which gets wrapped in a CancellationException. There’s really no way to fail the coroutine from outside AFAIK