I am testing a ViewModel using a fake repository which uses a StateFlow to store the fake data. This StateFlow is exposed as a normal Flow from the repository. In the ViewModel, I am mapping the received data from repository to a UiState class. When I test the UiState using a local test, I am not getting the updated UiState after adding a new entry i.e. I am stuck on the Loading state and not getting any new updates. Here are the files for viewmodel, repository and the test class.

FakeMedicinesRepository

class FakeMedicineRepository : MedicineRepository {

    private val _medicines = MutableStateFlow<List<Medicine>>(emptyList())
    override val allMedicines: Flow<List<Medicine>> = _medicines.asStateFlow()

    suspend fun emit(value: List<Medicine>) = _medicines.emit(value)

    override suspend fun addMedicine(
        name: String,
        purchasePrice: BigDecimal,
        sellingPrice: BigDecimal
    ) {
        _medicines.update {
            it.plus(
                Medicine(
                    it.size + 1L,
                    name,
                    purchasePrice,
                    sellingPrice
                )
            )
        }
    }

    override suspend fun isNameTaken(name: String): Boolean {
        return _medicines.value.any { it.name == name }
    }
}

MedicinesViewModel

class MedicinesViewModel(
    medicineRepository: MedicineRepository
) : ViewModel() {
    val uiState = medicineRepository.allMedicines
        .map {
            MedicinesUiState.Success(it.map { it.toUiState() })
        }
        .stateIn(
            scope = viewModelScope,
            started = SharingStarted.WhileSubscribed(5000),
            initialValue = MedicinesUiState.Loading
        )
}

MedicinesViewModelTest

class MedicinesViewModelTest {

    private lateinit var repository: FakeMedicineRepository
    private lateinit var viewModel: MedicinesViewModel

    @Before
    fun setup() {
        repository = FakeMedicineRepository()
        viewModel = MedicinesViewModel(repository)
    }

    @OptIn(ExperimentalCoroutinesApi::class)
    @Test
    fun `when observe medicines should return empty list`() = runTest {
        backgroundScope.launch(UnconfinedTestDispatcher(testScheduler)) {
            viewModel.uiState.collect {
                println("State: $it")
            }
        }

        var uiState = viewModel.uiState.value
        uiState.shouldBeTypeOf<MedicinesUiState.Loading>()

        repository.addMedicine("Test", 0.toBigDecimal(), 0.toBigDecimal())

        // This assertion fails
        viewModel.uiState.value.shouldBeTypeOf<MedicinesUiState.Success>()
    }

}

I followed the testing guidance from Testing Kotlin flows on Android. I am using the exact steps as mentioned there, the only difference being they use a SharedFlow in the repository. But I also tried replacing the StateFlow in the fake repository with a SharedFlow with no success.