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kotlinlang

Hi guys, I am getting strange issue using `runTest` . I have a simple viewModel
```class LoadingViewModel(
    private val ioDispatcher: CoroutineDispatcher,
) : ViewModel() {

    var xyz by mutableStateOf(false)
    fun checkXyz() {
        viewModelScope.launch {
            delay(1000L)
            xyz = true
        }
    }
}```
more code in :thread:

```@OptIn(ExperimentalCoroutinesApi::class)
class LoadingViewModelTest {

    private val subject by lazy {
        spyk(LoadingViewModel(UnconfinedTestDispatcher()))
    }

@Before
    fun setUp() {
        MockKAnnotations.init(this, relaxed = true)
    }

    @Test
    fun `xyz - when method called then should assign value on xyz`() = runTest {

        subject.checkXyz()
        verify {
            <http://subject.xyz|subject.xyz> = true
        }
    }
}```

*Getting error* 
```Verification failed: call 1 of 1: LoadingViewModel(#3).setXyz(eq(true))) was not called.

Calls to same mock:
1) LoadingViewModel(#3).checkXyz()
2) LoadingViewModel(#3).getTag(androidx.lifecycle.ViewModelCoroutineScope.JOB_KEY)
3) LoadingViewModel(#3).setTagIfAbsent(androidx.lifecycle.ViewModelCoroutineScope.JOB_KEY, androidx.lifecycle.CloseableCoroutineScope@2d5580f6)```

I checked and If removed `delay` it working fine.

Well if you have a delay, you're not setting `xyz` immediately, so why do you think you can immediately verify that it has been set?

also the delay in `viewModelScope` doesn't use the `TestCoroutineScheduler`, so this isn't testable anyway

Even if it were using the test scheduler, the test doesn't wait for this delay (even virtually)

yep. `advanceTimeBy` can move virtual time to allow you to observe the post-delay effects, but not in this case because `viewModelScope` is totally separate

Yes, what I meant is that the test doesn't even attempt to do it, but yeah it wouldn't work anyway. Not only the subject doesn't pass the given test dispatcher to the `launch` internally, but also it's given a different test dispatcher than the one from the `runTest` call, so I don't think it would work even if `subject` used its `ioDispatcher` property in the `launch`.

Hi Joffrey `why do you think you can immediately verify that it has been set?` I am just testing the function and see in the document `delay` can we skip by using `runTest`.

I tried to use `ioDispatcher` inside my `viewModelScope` but still I am getting error.
```fun checkXyz() {
     viewModelScope.launch(ioDispatcher) {
        delay(1000L)
        xyz = true
     }
 }```
what else I need to add in test?