Different behaviour when using coroutines 1.6.0

As an example I would like to suggest following test:

private val stateFlow = MutableStateFlow(0)
private val flow: Flow<Int> = stateFlow

@Test
fun `turbine test`() = runBlockingTest {
    Dispatchers.setMain(TestCoroutineDispatcher())

    val scope = CoroutineScope(Job() + Dispatchers.Main)

    flow.test {
        flowOf(1, 2, 3)
            .onEach { stateFlow.value = it }
            .launchIn(scope)

        val events = cancelAndConsumeRemainingEvents()
    }

    Dispatchers.resetMain()
}

When using coroutines 1.5.2, as expected events variable will be a list with size of 4 which contains integers wrapped in Item class: [Item(0), Item(1), Item(2), Item(3)]

But when using coroutines 1.6.0 like so:

private val stateFlow = MutableStateFlow(0)
private val flow: Flow<Int> = stateFlow

@Test
fun `turbine test`() = runTest {
    Dispatchers.setMain(UnconfinedTestDispatcher())

    val scope = CoroutineScope(Job() + Dispatchers.Main)

    flow.test {
        flowOf(1, 2, 3)
            .onEach { stateFlow.value = it }
            .launchIn(scope)

        val events = cancelAndConsumeRemainingEvents()
    }

    Dispatchers.resetMain()
}

events will contain only the first and last items: [Item(0), Item(3)].

Also if I use StandardTestDispatcher instead of UnconfinedTestDispatcher, events will contain only the first item: [Item(0)].

Is it expected behaviour? Do I need to adjust my test somehow to get the same results as for coroutines version 1.5.2?

[JakeWharton]

The timeout is gone on trunk as it is now provided by runTest automatically.

[alterpie]

Thank you for your reply @mhernand40 but I see only the first and the last values in case I use UnconfinedTestDispatcher, not the StandardTestDispatcher. Also it does not matter if I use Dispatchers.setMain inside the test or using @Before function - the result is the same, I receive only the first and the last emission. You can see that I don’t use scope provided by runTest, I create a scope manually using Job() + Dispatchers.Main and at the time of creating this scope Dispatchers.Main is already substituted with UnconfinedTestDispatcher.