just a PSA: be careful when you create a new

CoroutineScope

and make sure realize the side effects of breaking structured concurrency. ex:

CoroutineScope(Dispatchers.Default)

explicitly breaks structured concurrency. This has testing implications like passing tests even when exceptions are thrown https://gist.github.com/ZakTaccardi/e77d5983660ce4e8e0fa2f2ef0d582ea

FYI a better way to do the second test is:

parentScope.launch(Dispatcher.UNCONFINED) {
            throw Exception("fail")
        }
            .join()

no reason to do the addition yourself

Yup. Using another/new CoroutineScope instance is like switching to another/new lifecycle. The calling CoroutineScope’s lifecycle is no longer honored inside the new one. If you want to switch dispatcher or something, use

withContext(myDispatcher)

or

launch(myDispatcher)

etc.

IMO structured concurrency is very fragile and you need to be very careful not to break it. Without experience is not possible to maintain structured concurrency and you barely can know is it works or not. E.g. when you are doing CoroutineScope.launch(context + Job()) structure concurrency is immediately So actually CoroutineScope.launch(context + Job()) is equals to GlobalScope.launch(context + Job())