FlowOf_Cancel_Methods.kt

import kotlinx.coroutines.cancel
import kotlinx.coroutines.coroutineScope
import kotlinx.coroutines.flow.cancellable
import kotlinx.coroutines.flow.flowOf
import kotlinx.coroutines.flow.onCompletion
import kotlinx.coroutines.launch
import kotlin.coroutines.cancellation.CancellationException

suspend fun main(): Unit = coroutineScope {

    launch {
        flowOf(1,3,5)
            .onCompletion { cause ->
                if (cause is CancellationException) {
                    println("Flow cancelled $cause")
                }
            }
            .cancellable()
            .collect {
                println("Received $it")
                if (it == 3) {
                    cancel()
                }
            }
    }.join()

    /**
     * only using collect()
     * output :
     * Received 1
     * Received 3
     * Received 5
     *
     * using ensureActive() in onEach{}
     * Output:
     * Received 1
     * Received 3
     * Flow cancelled kotlinx.coroutines.JobCancellationException:
     * StandaloneCoroutine was cancelled; job=StandaloneCoroutine{Cancelling}@689a4a73
     *
     * using cancellable() instead of onEach{}
     *Output :
     * Received 1
     * Received 3
     * Flow cancelled kotlinx.coroutines.JobCancellationException:
     * StandaloneCoroutine was cancelled; job=StandaloneCoroutine{Cancelling}@45939480
     *
     */

}