I'm starting to explore flows and I've decided to try and deliver android view clicks with it. Here what I've come up with. It works great in android but the

runBlocking

block in test gets stuck at

collect

call. I think the

awaitClose

call suspends the

runBlocking

scope but doesn't affect the android code somehow. Can you please tell me if I'm doing it right and how I can write unit tests for it?

This is expected. Collect suspends until the flow is completed, which here is never the case. You probably want to use

take(5)

or launch 2 coroutines in parallel.

Is it collect's general behavior o is it because of awaitClose? Also why androids lifecycleScope isn't affected?

It's because your

Flow

is infinite. It can always have new elements caused by new clicks, unless you stop collecting by using another operator or by throwing or cancelling.

lifecycleScope

isn't much related. It's an auto-cancelling root scope to launch your lifecycle bound coroutines in.

the thing is that it never gets to having elements. Code on line 38 wasn't getting called

Use

collect

extension instead of

FlowCollector

.

yeah that works. thank you!

BTW, if you want to support backpressure by disabling the button until the click is processed, you can use this snippet:

fun View.clicksFlow(
    disableAfterClick: Boolean = true,
    hideAfterClick: Boolean = false
): Flow<Unit> = flow {
    while (true) emit(
        awaitOneClick(
            disableAfterClick = disableAfterClick,
            hideAfterClick = hideAfterClick
        )
    )
}

suspend fun View.awaitOneClick(
    disableAfterClick: Boolean = true,
    hideAfterClick: Boolean = false
) = try {
    if (disableAfterClick) isEnabled = true
    if (hideAfterClick) isVisible = true
    suspendCancellableCoroutine<Unit> { continuation ->
        setOnClickListener {
            setOnClickListener(null) // Ensure we can't get two clicks in a row.
            continuation.resume(Unit)
        }
    }
} finally {
    setOnClickListener(null)
    if (disableAfterClick) isEnabled = false
    if (hideAfterClick) isVisible = false
}

that's super helpful thank you!