Are returns inside composable currently bugged (al...

# compose

[Yann Badoual]

Are returns inside composable currently bugged (alpha07)? I'm getting a lot of java.lang.IllegalStateException: Start/end imbalance when using them

Wrapping the whole follow code into a conditional block instead fixes the issue

[romainguy]

@Leland Richardson [G]

[Leland Richardson [G]]

We haven’t seen any issues - can you create a simple repro? This could be a runtime issue or a compiler issue

[Yann Badoual]

No problem, will try to do that this weekend

[Archie]

I also encountered this error as well..

I had a composable:

@Composable
fun MyComposable(
    myStateList: List<MyState>, 
    ...,
) {
    // ------- This here is causing the error
    val transformedMyState = myStateList.map {
        myTransformation(it)
    }
    // ------- Removing the code above, also removes the error
    LazyRowForIndexed(transformedMyState) {
        ...
    }
}

It was perfectly working on alpha06 and only encountered the error after migrating to alpha07 . So in the end I settled to:

@Composable
fun MyComposable(
    myStateList: List<MyState>, 
    ...,
) {
    LazyRowForIndexed(
        myStateList.map {
            myTransformation(it)
        }
    ) {
        ...
    }
}

I then no longer get the error... 🤔

[Leland Richardson [G]]

wow, that’s pretty curious

[Leland Richardson [G]]

can you file a big with the full code to repro?

[Leland Richardson [G]]

based on your observation it seems likely that there’s some compiler related issue here

[Archie]

Will try and recreate it... ill do after work and share the link here...

[Leland Richardson [G]]

thank you

[Archie]

Hi @Leland Richardson [G], I'm unsuccessful in recreating the error.. it seems that the error wasn't cause by the things I mentioned above... hmmm... I would try and backtrack my changes..

[Yann Badoual]

@Leland Richardson [G] Sorry for the delay, I managed to reproduce it with the following minified snippet:

@Composable
fun BuggedComposable(
) {
    Surface {
        Box(modifier = Modifier.fillMaxSize()) {
            val state = mutableStateOf<String?>(null)
            val title = state.value ?: return@Box
        }
    }
}

Removing the ?: return@Box fixes the crash.
Do you want me to file a bug with this?

(Using alpha07 and kotlin 1.4.0)

[Yann Badoual]

(Funny observation, removing the wrapping Box also avoids the crash, so I'm guessing a certain level of nesting is necessary before having the crash?)

[Leland Richardson [G]]

oh, nice. thanks so much for this repro

[Leland Richardson [G]]

if you could file a bug that would be great

[Leland Richardson [G]]

if not, i can file one on your behalf

[Yann Badoual]

will do

[Yann Badoual]

Done https://issuetracker.google.com/issues/173651155

[Leland Richardson [G]]

thank you!

[Yann Badoual]

Any news on this @Leland Richardson [G] ?

[Yann Badoual]

(Just FYI, still happening on alpha12)

[Paul Woitaschek]

Again happening on 1.4

[Paul Woitaschek]

Maybe the source is different: https://issuetracker.google.com/issues/264467571