I am running a simple Test on `LaunchedEffect`: `...

# compose

[ziv kesten]

I am running a simple Test on `LaunchedEffect`:

@Test
fun testSomeState() {
    composeTestRule.setContent {
        SomeComposable {
            println("click $it")
        }
    }
    composeTestRule.onNodeWithTag("Zivi")
        .performClick()
        .assertExists()
}

@Composable
fun SomeComposable(onClick: (Int) -> Unit) {
    var someState by remember { mutableStateOf(0) }

    Button(modifier = Modifier.testTag("Zivi").pointerInteropFilter {
        someState = when (it.action) {
            MotionEvent.ACTION_DOWN -> { 1 }
            MotionEvent.ACTION_UP -> { 2 }
            else -> { someState  }
        }
        true

    }, onClick = { }) {}

    LaunchedEffect(someState) {
        println("LaunchedEffect someState $someState") // prints "LaunchedEffect someState 0" 
                                                       // and then "LaunchedEffect someState 2"
        if (someState == 2) { onClick(someState) }
    }
}

------------
This works well, however, if i change Button to a Box, like this:
------------

@Composable
fun SomeComposable(onClick: (Int) -> Unit) {
    var someState by remember { mutableStateOf(0) }

    Box(modifier = Modifier.testTag("Zivi").pointerInteropFilter {
        someState = when (it.action) {
            MotionEvent.ACTION_DOWN -> { 1 }
            MotionEvent.ACTION_UP -> { 2 }
            else -> { someState  }
        }
        true

    }) {}

    LaunchedEffect(someState) {
        println("LaunchedEffect someState $someState") // prints "LaunchedEffect someState 0"
        if (someState == 2) { onClick(someState) }
    }
}

Then the LaunchedEffect is not called on performClick, can anyone help me understand why?

[Stylianos Gakis]

Is your Box clickable? Not super familiar with the pointerInteropFilter modifier, but Button under the hood calls a surface where a Modifier.clickable is attached to it. While the pointerInteropFilter modifier doesn’t seem to do that. That may be the issue at first glance.
Maybe the implementation of the test performClick relies on something that is set there?

[ziv kesten]

I use pointerInteropFilter since i am creating a custom button with "Hold" and "release" actions.

The functionality works, however when trying to UI test this i found this edge case where LaunchedEffect isnt called - only on the UI test.

I assume from you insight that performClick from the testRule is related to clickable somehow.

This might be a good lead.

[ziv kesten]

So the problem with my example was that Box had no size, when adding some size like `fillMaxSize`() to it, the LaunchedEffect is called.

Unfortunately in my original problem (which i simplified to this experiment for understanding) i still dont get the LaunchedEffect call

[Stylianos Gakis]

Aha so at least had nothing to do with my guess. Good to know.