StackQuesion_34773958.kt

package sample.stackanswers;

import android.app.Activity
import org.junit.Assert
import org.junit.Before;
import org.junit.Rule
import org.junit.Test
import org.junit.runner.RunWith;
import org.mockito.*
import org.mockito.junit.MockitoJUnit
import org.robolectric.RobolectricGradleTestRunner;
import org.robolectric.annotation.Config;

@RunWith(RobolectricGradleTestRunner::class)
@Config(sdk = intArrayOf(21), constants = BuildConfig::class)
class MyViewModelTest {
    @Mock
    lateinit var activityHandlerMock: IActivityHandler;

    @Captor
    lateinit var classCaptor: ArgumentCaptor<Class<Activity>>

    @Captor
    lateinit var booleanCaptor: ArgumentCaptor<Boolean>

    lateinit var objectUnderTest: MyViewModel

    @Before
    fun setUp() {
        MockitoAnnotations.initMocks(this)
//        initMocks(this)
//        ...
        objectUnderTest = MyViewModel(activityHandlerMock)
    }

    @Test
    fun thatNavigatesToAddListScreenOnAddClicked(){
        //given

        //when
        objectUnderTest.addNewList()

        //then
        Mockito.verify(activityHandlerMock).navigateTo(classCaptor.capture(), booleanCaptor.capture())
        var clazz = classCaptor.value
        Assert.assertNotNull(clazz);
        Assert.assertFalse(booleanCaptor.value);
    }
}

class MyViewModel(val handler: IActivityHandler) {
    fun addNewList() {
        handler.navigateTo(Activity::class.java, false)
    }

}

interface IActivityHandler {
    fun navigateTo(capture: Class<Activity>?, capture1: Boolean)
}