My js export classes started throwing exceptions, ...

# webassembly

[Rok Oblak]

My js export classes started throwing exceptions, after updating from Kotlin 2.1.10 to 2.1.20.

But my question is - am I doing something wrong or is this the current state of the debugging experience? This is a nightmare to try to figure out what went wrong.

[Rok Oblak]

I am using export interfaces for Google Maps web:

This piece of code suddenly started crashing:

@JsName("google.maps.Map")
external class GMap(element: Element) {

}

It it directly caused by upgrading Kotlin from 2.1.10 to 2.1.20

[Artem Kobzar]

@bashor @Ilya Goncharov [JB] ^^

[bashor]

@Rok Oblak could you please file an issue?

[bashor]

Could you please navigate to location on the top of stack (composeApp.uninstantiated.mjs:5084) and share what is there?

[Rok Oblak]

Yep will file an issue, thank you! here is the 5084th line:

[Rok Oblak]

Filed a ticket:

CMP-8258 External class crashes with Kotlin version upgrade

edit: I see it is filed under CMP, but that may not be the right place, let me know...

[bashor]

Thanks for the report, I think the issue should be moved to Kotlin project.

[bashor]

Using CoroutineExceptionHandler may help you to get a proper exception, so you can put a breakpoint there or print a stacktrace, like below:

val handler = CoroutineExceptionHandler { _, exception ->
    println("CoroutineExceptionHandler got ${exception.stackTraceToString()}")
}

[Rok Oblak]

Thanks Zalim, unfortunately no useful info is given - I tried adding these handlers in all my scopes but it did not catch the exception (it happens inside the composable, so I am not sure where to put it in that case.
However I did put a try/catch inside the actual instance contruction of this javascript object (Gmap(element)) and that does successfully catch the exception, however it is non-informative:

console.js:36 JsException: Exception was thrown while running JavaScript code

[bashor]

@Rok Oblak thanks for the update, you can find one more trick to try in the issue

[Rok Oblak]

Thank you Zalim! I managed to resolve it after your suggestions. I had to use the file-level JsQualifier, and move the js(...) functions in a separate file.