fo2rist

@RunWith(AndroidJUnit4::class)
class BaseMainActivityTest {

    @get:Rule
    var activityRule = ActivityTestRule(MainActivity::class.java)

    // the context is often needed in more complex Espresso tests
    protected val context: Context by lazy { activityRule.activity }
    
    @Test

fo2rist

@RunWith(AndroidJUnit4::class)
class BaseMainActivityTest {

    @get:Rule
    var activityRule = ActivityTestRule(MainActivity::class.java)
    
    @Test
    fun acitivityIsRunning() {
        if (true) while(true) Thread.sleep(100); /*DEBUG*/
    }

fo2rist

@RunWith(AndroidJUnit4::class)
class BaseMainActivityTest {

    @get:Rule
    var activityRule = ActivityTestRule(MainActivity::class.java)

    protected val context: Context by lazy { activityRule.activity }
    
    // test goes here just like this example from Espresso documentation
}