`delay` is not respected with `runComposeUiTest` about compose-multiplatform HOT 3 CLOSED

Reproduced the on Desktop as well:

• delay is not respected
• while loop never stops

It makes sense because runComposeUiTest is implemented by SkikoComposeUiTest on all platforms except Android.

My undersanding of the behaviour:
SkikoComposeUiTest uses UnconfinedTestDispatcher() and it's applied to composition too. UnconfinedTestDispatcher doesn't follow the real time, it uses virtual time instead to allow "faster" tests for time-based behaviour. By defualt it skips delays.

As I remember, it was possible to disable autoAdvance of time and to manage it manually by adding:
mainClock.autoAdvance = false at the top of your test.

I tried it now, and indeed it makes the test complete. But it seems I can't manage the time manually: mainClock.advanceTimeBy(20000) - doesn't make the coroutine in LaunchedEffect resume its execution.

Perhaps @m-sasha, Could you please take a look here?
I think even if the workaround with disabling autoAdvance was helpful, it would still mean the code for android vs non-android tests is not identical?
I remember when porting some tests we indeed had to change the code a bit, but I'm not sure about current state of the tests API and its implementation.

from compose-multiplatform.

Everything seems to be working as expected here (tested with compose-plugin = "1.6.10").

delay is intentionally skipped in UI tests, on both Android and in Compose Multiplatform. On Android, the existence of suspended coroutines in a LaunchedEffect does not prevent waitForIdle from returning. Because of this, the test finishes on Android. I've reported this here, and it appears this has been reported by others as well.

Using mainClock.autoAdvance = false and mainClock.advanceTimeBy appears to also be working correctly. The code below prints once when run without mainClock.advanceTimeBy(11_000) and twice with.

internal class DelayTest {

    @OptIn(ExperimentalTestApi::class)
    @Test
    fun test_delay() = runComposeUiTest {
        mainClock.autoAdvance = false
        setContent {
            println("setContent ${getCurrentTime()}")
            var refreshKey by mutableStateOf(0)
            LaunchedEffect(Unit) {
                while (true) {
                    println("LaunchedEffect - key $refreshKey - ${getCurrentTime()}")
                    delay(10_000)
                    refreshKey++
                }
            }
            Text("Hello, World!")
            assertTrue(true)
        }

//        mainClock.advanceTimeBy(11_000)
    }

    private fun getCurrentTime(): Long {
        return Clock.System.now().toEpochMilliseconds()
    }
}

from compose-multiplatform.

Please check the following ticket on YouTrack for follow-ups to this issue. GitHub issues will be closed in the coming weeks.

from compose-multiplatform.