How would I add cleanup code to a `CoroutineScope`...

# coroutines

[reactormonk]

How would I add cleanup code to a CoroutineScope to be executed when cancel() is invoked on it?

[jw]

scope.launch {
  try {
    awaitCancelation()
  } finally {
    doCleanup()
  }
}

[reactormonk]

Thanks. Tried with connectionScope.coroutineContext.job.invokeOnCompletion, that didn't catch

[jw]

although that will keep the scope alive, so you basically have to call cancel() on it both in the success path and any early-exit paths

[Zach Klippenstein (he/him) [MOD]]

If you're in a parent of the scope you're waiting for, you could just join on the child job

[Dmitry Khalanskiy [JB]]

Jake's suggestion is good, but you may need to call launch like this: scope.launch(start = CoroutineStart.ATOMIC) {. Otherwise, cancellation can happen before the cleanup coroutine is started, so the cleanup code will never run.