IssueTracker

Jetpack Compose release version: 1.0.0-beta05 Android Studio Build: Android Studio Arctic Fox | 2020.3.1 Canary 14 Build #AI-203.7717.56.2031.7260174, built on April 6, 2021 Runtime version: 11.0.9.1+0-b77-7246554 x86_64 VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o. macOS 10.16 GC: G1 Young Generation, G1 Old Generation Memory: 4096M Cores: 8 Registry: external.system.auto.import.disabled=true Non-Bundled Plugins: com.dubreuia, com.squareup.sqldelight, org.intellij.plugins.markdown

I have a slider that calls a callback only when the user releases their finger from the slider.

@Composable
internal fun MySlider(
    value: Float,
    onChangeValue: (Float) -> Unit
) {
    var sliderState by remember(value) { mutableStateOf(value) }

    Slider(
        value = sliderState,
        onValueChange = { sliderState = it },
        onValueChangeFinished = { onChangeValue(sliderState) }
    )
}

It works fine while running the app.

However when testing the component, the callback is not called:

@Test
fun sliderCallsCallback() {

    var newValue: Float? = null
    val callback = { value: Float -> newValue = value }

    composeTestRule.setContent {
        MaterialTheme {
            MySlider(value = 0.3f, onChangeValue = callback)
        }
    }

    // Find slider and move it
    val rangeInfoStart = ProgressBarRangeInfo(0.3f, 0.0f..1.0f)
    composeTestRule.onNode(hasProgressBarRangeInfo(rangeInfoStart))
        .performSemanticsAction(SemanticsActions.SetProgress) { it(0.8f) }

    // Make sure the slider was moved
    val endRangeInfo = ProgressBarRangeInfo(0.8f, 0.0f..1.0f)
    composeTestRule.onNode(hasProgressBarRangeInfo(endRangeInfo))
        .assertExists()

    // Make sure the callback was called
    assertNotNull(newValue)
}

You can find a reproducing project here: https://github.com/jschmid/ComposeSlider-BugUITest

The MainActivity shows the slider working in the logcat. However the intrumentation test does not pass.