However, I’m still confused about the `cancellatio...

# coroutines

[Aldo Wachyudi]

However, I’m still confused about the cancellation exception part. If I put try-catch on the code.

fun main() = runBlocking {
    val parentScope = CoroutineScope(SupervisorJob())
    parentScope.launch {
        try {
            println("#1")
            launch {
                try {
                    println("#3")
                    fetchDataOverNetwork()
                    println("#4")
                } catch (e: Exception) {
                    println("Child's Exception not printed")
                } finally {
                    println("Child's Finally not printed")
                }
            }
            println("#2")
        } catch (e: Exception) {
            println("Parent's Exception not printed")
        } finally {
            println("Parent's Finally is printed")
        }
    }
    delay(1_000)
    parentScope.cancel()
    delay(1_000)
    println("Bye")
}

The output is:

#1
#2
Parent's Finally is printed
#3
Bye

Why is the exception and finally block is not executed? Even though in the documentation it says..

They check for cancellation of coroutine and throw CancellationException when cancelled.

Under what condition the CancellationException is thrown?
Thread in Slack Conversation

[miqbaldc]

Would you mind sharing us the fetchDataOverNetwork() method body?

[Aldo Wachyudi]

Sure, I put the full code on the previous comment above.

suspend fun fetchDataOverNetwork() {
    val tenSecondInMillis = 10000
    val result = URL("<https://httpstat.us/200?sleep=$tenSecondInMillis>").readText()
    println("$result")
}