ExampleTest.kt

class DataViewModelTest {
  
    @Mock
    lateinit var mockedDataSource: DataSource // Our mocked dependency
 
    lateinit var dataViewModel: DataViewModel
    
    @Before
    fun setup() {
        dataViewModel = DataViewModel(mockedDataSource) // This will now work!
    } 
  
    fun testCorrectCall() {
        // Let's first tell Mockito what our mocked dependency should return when queried
        Mockito.`when`(mockedDataSource.getCachedData()).thenReturn("Mocked json value")

        // Let's trigger the action on the ViewModel
        dataViewModel.getCachedData()
                       
        // And finally let's test that our ViewModel called the right methods on its dependency
        Mockito.verify(mockedDataSource).getCachedData()
    }
  
}