Android Espresso: How do I test a specific Fragment when following one activity to several fragment architecture

Question

My app consists of one Activity for many Fragments.

I wish to use Espresso to test the UI of the Fragments. However I ran into a p

Answer 1

Just show the Fragment using the Activity's SupportFragmentManager.

For example (Kotlin) with ActivityTestRule:

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

Just do this before your tests:

@Before
fun setup() {
    activityRule.activity.supportFragmentManager.beginTransaction().replace(R.id.main_activity_container_for_your_fragments, FragmentToShow(), "fragment-tag").commitAllowingStateLoss()
    Thread.sleep(500)
}