Jetpack Compose back button press in automation test

Question

What is the recommended way to trigger a back button press in a jetpack compose test (running on a real device)?

I'm trying:

@get:Rule()
val composeTestRule = createAndroidComposeRule(MyActivity::class.java)

@Test
fun test() {
    // Here would be some setup code, assertions and navigating into a second screen
     
    // Navigate back to previous screen
    composeTestRule.onRoot().performKeyPress(KeyEvent(NativeKeyEvent(0, KeyEvent.KEYCODE_BACK)))

    // continue... 
}

But I get the error:

java.lang.IllegalStateException: KeyEvent can't be processed because this key input node is not active.

I don't have any special logic for the key presses / navigation and only use out-of-the box functionality of the navigation compose library.

Oliver Metz · Answer 1 · 2022-10-19T19:51:28.257

9

I ended up using the ActivityScenarioRule:

composeTestRule.activityRule.scenario.onActivity { activity ->
   activity.onBackPressedDispatcher.onBackPressed()
}

Not sure if this is the right way to do it but it works.

EDIT: As pointed out correctly by LN-12 you should be using the onBackPressedDispatcher to support API 33's predictive back gestures.

edited Oct 19 '22 at 19:51

answered Jul 14 '22 at 00:30

Oliver Metz

2,712
2
20
32

`activity.onBackPressed()` is deprecated. You should now use `activity.onBackPressedDispatcher.onBackPressed()`. – LN-12 Oct 18 '22 at 06:28

score 4 · Accepted Answer · answered Oct 01 '22 at 20:25

4

We can use below code to test device back button from composable screen

Espresso.pressBack()

answered Oct 01 '22 at 20:25

Chait

537
6
15

Works and is so much cleaner. Thanks! Don't know how I missed this one. – Oliver Metz Oct 02 '22 at 23:14
1

Keep in mind, this solution doesn't work on Firebase Test labs (Tested on Pixel 5 physical device). @OliverMetz's solution works in all the cases. – Karthik Jan 09 '23 at 17:02

score -1 · Answer 3 · answered May 22 '23 at 11:35

This works for me:

composeTestRule.onAllNodes(isRoot())[0].performKeyPress(
            KeyEvent(
                android.view.KeyEvent(
                    android.view.KeyEvent.ACTION_DOWN,
                    android.view.KeyEvent.KEYCODE_BACK
                )
            )
        )

Jetpack Compose back button press in automation test

3 Answers3