Can not control virtual time for multiple delay calls when using runTest

[byencho]

When using 0.12.0, it appears that the virtual time of the test cannot be controlled when using runTest after the first call to awaitItem when there are multiple delay calls. Consider the following test:

    @Test
    fun virtualTimeCanBeControlled() = runTest {
        flow {
            delay(5000)
            emit("1")
            delay(5000)
            emit("2")
        }
            .test {
                expectNoEvents()

                advanceTimeBy(5000)

                expectNoEvents()
                runCurrent()
                assertEquals("1", awaitItem())

                advanceTimeBy(5000)

                expectNoEvents() // <---------- Fails here
                runCurrent()
                assertEquals("2", awaitItem())

                awaitComplete()
            }
    }

This fails with the following error where indicated:

Expected no events but found Item(2)
app.cash.turbine.TurbineAssertionError: Expected no events but found Item(2)
	at app//app.cash.turbine.ChannelKt.unexpectedEvent(channel.kt:258)
	at app//app.cash.turbine.ChannelKt.unexpectedResult-JslgfBc(channel.kt:253)
	at app//app.cash.turbine.ChannelKt.expectNoEvents(channel.kt:71)
	at app//app.cash.turbine.ChannelTurbine.expectNoEvents(Turbine.kt:184)
	...

This test passes, however, when using runBlocking and a manually-supplied UnconfinedTestDispatcher:

    private val testDispatcher = UnconfinedTestDispatcher()

    @Test
    fun virtualTimeCanBeControlled() = runBlocking {
        flow {
            delay(5000)
            emit("1")
            delay(5000)
            emit("2")
        }
            .flowOn(testDispatcher)
            .test {
                expectNoEvents()

                testDispatcher.scheduler.advanceTimeBy(5000)

                expectNoEvents()
                testDispatcher.scheduler.runCurrent()
                assertEquals("1", awaitItem())

                testDispatcher.scheduler.advanceTimeBy(5000)

                expectNoEvents()
                testDispatcher.scheduler.runCurrent()
                assertEquals("2", awaitItem())

                awaitComplete()
            }
    }

This may be related to the changes in #151, which bases logic on whether the current scope is using a test scheduler.

• Kotlin version : 1.7.10
• Coroutines version : 1.6.4

[lucaskivi]

This also affects me! 👍

[JakeWharton]

Doesn't seem related to that PR. When I write a non-Turbine test using the unconfined test dispatcher for flow collection it still passes.

[JakeWharton]

Got it. The problem is in withWallclockTimeout. Fix incoming.

[byencho]

Thanks @JakeWharton !