UserServiceTest.kt

class UserServiceTest {
        @Mock internal var context: Context? = null
        @InjectMocks internal var userService: UserService? = null
        @Before
        fun setup() {
            MockitoAnnotations.initMocks(this)
        }
     
        @Test
        fun displayUserName() {
            doReturn("Hello %s!").`when`(context)!!.getString(any(Int::class.java))
            val displayUserName = userService!!.displayUserName("Test")
            assertEquals(displayUserName, "Hello Test!")
        }
    }