Clean architecture viewModel test

RatingViewModelTest.kt

@ExperimentalCoroutinesApi
class RatingViewModelTest {

    @get:Rule
    val instantTaskExecutorRule = InstantTaskExecutorRule()

    private lateinit var viewModel: RatingViewModel
    private val  setRatedCase: SetRated = mock()

    private val testDispatcher = TestCoroutineDispatcher()

    @Before
    fun setup() {
        Dispatchers.setMain(testDispatcher)
        viewModel = spy(RatingViewModel(setRatedCase))
    }

    @After
    fun cleanUp() {
        Dispatchers.resetMain()
        testDispatcher.cleanupTestCoroutines()
    }

    @Test
    fun `set rate should call method`() = runBlocking {

        val result = ResultAsync.with(this, suspend { Unit })

        whenever(setRatedCase.invoke(any())).doReturn(result)

        viewModel.setRated()

        verify(setRatedCase).invoke(any())

        assertEquals(viewModel.ratedSuccess.await(), true)
    }
}

suspend fun <T> LiveData<T>.await(): T {
    return suspendCoroutine{ cont ->
        this.observeForever {
            cont.resume(it)
        }
    }
}