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I’m sure this has been asked to death, but should I always rethrow the `CancellationException` ?

<https://medium.com/androiddevelopers/cancellation-in-coroutines-aa6b90163629#34ef|https://medium.com/androiddevelopers/cancellation-in-coroutines-aa6b90163629#34ef>

That's been my experience: always rethrow. If your coroutine is cancelled then you could mess up cancellation by swallowing it.

I can kinda imagine code where you do want to catch it based on some child job being cancelled. Consider:
```val task = async {
    figureSomethingOut()
}
otherThing.doOnSomeEvent {
    result.cancel()
}
val result = try {
    task.await()
} catch (e: CancellationException) {
    ensureActive()
    figureOutSomethingElse()
}```
The `ensureActive` call will rethrow the `CancellationException` if it is meant for the "outer" coroutine.

I'd definitely look for an alternative though rather than write such code just for clarity. For example, `join` does throw like `await`, and then the `Deferred` could be inspected to see if it was cancelled or finished.