What is an alternative for back handling in UI tes...

# compose

[Jan Skrasek]

What is an alternative for back handling in UI tests? Previously I used:

Espresso.onView(ViewMatchers.isRoot()).perform(ViewActions.pressBack())

With Compose I'm trying this:

val keyEvent = NativeKeyEvent(NativeKeyEvent.ACTION_DOWN, NativeKeyEvent.KEYCODE_BACK)
composeTestRule.onRoot().performKeyPress(KeyEvent(keyEvent))

but getting:

KeyEvent can't be processed because this key input node is not active.

[Ian Lake]

Are you trying to test a BackHandler? https://developer.android.com/reference/kotlin/androidx/activity/compose/package-summary#backhandler

[Ian Lake]

If so, you could provide your own LocalOnBackPressedDispatcher and your code will use that - then you can just call onBackPressedDispatcher.onBackPressed() from your test

[Ian Lake]

Or, since your tests are running in a ComponentActivity anyways, you can just retrieve it via LocalOnBackPressedDispatcherOwner.current!!.onBackPressedDispatcher inside your composeTestRule.setContent

[Ian Lake]

Then call onBackPressed() on that

[Jan Skrasek]

No, I'm running fairly full-setup UI tests - i.e. I'm rather testing compose navigation.

[Jan Skrasek]

So I'm using createEmptyComposeRule() and just accommodating the way the screen was tested for new composer rewrite.

[Ian Lake]

Navigation Compose also uses the same OnBackPressedDispatcher

[Jan Skrasek]

Is there other way to obtain it since I do not have any composable lambda available because there is no setContent for me.

[Ian Lake]

Do you have a reference to your activity? If so, then you can get the onBackPressedDispatcher directly from the activity (ComponentActivity implements OnBackPressedDispatcherOwner)

[Jan Skrasek]

Thanks, that works!

activity.runOnUiThread {
  val dispatcherOwner = (activity as OnBackPressedDispatcherOwner)
  val dispatcher = dispatcherOwner.onBackPressedDispatcher
  dispatcher.onBackPressed()
}