Hi folks, Compose 1.1.0 can’t seem to handle ?: with null values, doesn’t generate text on null input. It works fine in 1.0.5 with Kotlin 1.5.31

@Composable
fun Greeting(name: String?) {
    name?.let { Text(text = "Hello $name!") } ?: Text(text = "Hello!")
}

Is this the same as https://issuetracker.google.com/issues/198511576 ?

That's a weird way to use let and ?:

It’s still a valid expression , @Alexander Maryanovsky although a if/else would be more readable in this case

It is, but it’s not clear whether the behavior a bug. What’s the result of the expression

name?.let { Text(text = "Hello $name!") }

if

name

is

null

? On the face of it, it’s

null

, but actually it’s

Unit

. Not sure why, but there’s probably a good explanation.

yes, because the elvis operator on the

name

and not the result of

let

Yeah, looks like the compose compiler is inserting some additional code there which causes the result to be

Unit

Ah, that’s what you mean. Okay!

But I’m seeing the same behavior with Compose 1.0.1 and Kotlin 1.5.31

The observed behaviour may be a bug but would this code

@Composable
fun Greeting(name: String?) {
    Text(if (name != null) "Hello $name!" else "Hello!")
}

not be several times more readable and also less error prone (for the developer and the compiler)?

This usage of ?: was just for minimum steps, the actual usage in app involves additional logic within those blocks.

@Sam It doesn’t matter what additional logic is inside those blocks. Just replace them with an

if … else …

Yeah using as a workaround for now, but seems to be regression for sure

Even if there was no compose bug here, you’re relying on the last statement in the

let

not returning

null

Wonder if there are any other tricky usage around nullable types that might fail at runtime