dagger android injector post main activity tests

MainActivityTests.kt

@RunWith(AndroidJUnit4::class)
class MainViewTests {
  val mockUserAction = mock(MainContract.UserAction::class.java)

  @get:Rule val activityTestRule = object : ActivityTestRule<MainActivity>(MainActivity::class.java, true, true) {
    override fun beforeActivityLaunched() {
      super.beforeActivityLaunched()
      val myApp = InstrumentationRegistry.getTargetContext().applicationContext as MyApp
      myApp.dispatchingActivityInjector = createFakeMainActivityInjector {
        userAction = mockUserAction
      }
    }
  }

  @Test
  fun clickOnFabCallToCreateTopic() {
    onView(withId(R.id.fab)).perform(click())

    verify(mockUserAction).createTopic(view = activityTestRule.activity)
  }
}