IssueTracker

Also doesn't work in AS 2024.3.2 Canary 4 and Compose 1.8.0-beta01

Andrei: Is this the same as b/388030459?

Triage notes: Needs investigation. Assigning for later.

Could you share the AppScaffoldTopBar function that fails here? This seems different from b/388030459 since it fails with expression that is not captured.

Reconstructed from IR:

@Composable
fun AppScaffoldTopBar(
    showBackArrow: Boolean,
    showSearch: Boolean,
    title: String?,
    onBackClick: () -> Unit,
    modifier: Modifier = Modifier,
    actions: ImmutableList<AppScaffoldNavigationAction>
) {
    if (!showSearch) {
        TitledTopAppBar(
            title = title,
            showBackArrow = showBackArrow,
            modifier = modifier,
            actions = actions,
            onBackClick = onBackClick
        )
    } else {
        TopAppBar(
            title = {
                // Composable lambda for title
                AppScaffoldTopBarTitle(showBackArrow)
            },
            modifier = modifier,
            navigationIcon = {
                // Composable lambda for navigation icon
                AppScaffoldTopBarNavigationIcon(showBackArrow, onBackClick)
            },
            actions = {
                // Composable lambda for actions
                AppScaffoldTopBarActions(actions)
            }
        )
    }
}

This seems /extremely/ weird to me, because showSearch is just a regular parameter that is used in function body only once. We need more context about surrounding code to figure out why it crashed the compiler.

sure i can paste more source. let me see what I can give you. do you need internals or externals?

Triage notes: We're still lacking the necessary Kotlin compiler hooks to implement this, but it's still something we'd like to fix. Low priority since it wouldn't be a huge performance win -- moving to backlog.

Triage notes: Dependent on K2.

Is there a issue on Kotlin's YouTrack we can follow for this?

If it helps, my use case is more about usability, e.g. I have this test helper:

inline fun <Intent, ViewState> intentTest(
    composeTestRule: ComposeContentTestRule,
    state: ViewState,
    crossinline view: @Composable (ViewState, (Intent) -> Unit) -> Unit,
    block: IntentTest<Intent>.() -> Unit,
  ) = IntentTest<Intent>(composeTestRule).apply {
    composeTestRule.setContent {
      view(
        state,
      ) { lastIntent = it }
    }

    block()
  }

which I would prefer to use like this:

intentTest(
  composeTestRule = composeTestRule,
  state = createState(),
  view = ::MyView,
) { ... }

but instead have to use like this:

intentTest<MyIntent, MyViewState>(
  composeTestRule = composeTestRule,
  state = createState(),
  view = { state, onIntent ->
    MyView(state, onIntent)
  }
) { ... }

Note that the compiler complains that it can't infer the types because there are multiple lambdas, but when I specify them like this it says that they can be inferred.

As my original description references, there is a youtrack issue but JetBrains rejected it. JetBrains said it was a 3rd party issue, and that's why I originally reported this here.

This should be implemented by the Compose compiler / runtime, but is not the highest priority since workarounds exists.

Triage notes: Needs investigation, might have a reasonable fix.