If I define a method to return an exception, the t...

# javascript

[Grégory Lureau]

If I define a method to return an exception, the typescript exposes the actual implementation, like :

buildIllegalArgumentException(msg: string): kotlin.IllegalArgumentException;

But in VsCode it's handled as any , I suspect because the kotlin.XxxException are not exposed in the .d.ts.
Is there an option to make them defined/accessible for typescript?

[Grégory Lureau]

Manually, I was thinking about patching the problem by adding typescript definitions myself

export namespace kotlin {
    class Throwable {
        constructor()
        constructor(message: String)
        constructor(message: String, cause: Throwable)
        constructor(cause: Throwable)

        readonly name: string;
        readonly stack: string;
        readonly message: string;
    }

    class Exception extends Throwable{
        constructor()
        constructor(message: String) 
        constructor(message: String, cause: Throwable)
        constructor(cause: Throwable)
    }
    [...]

it works for name/stack/message but not enough to use instanceof ( ex instanceof kotlin.Exception )

TypeError: Cannot read properties of undefined (reading 'Exception')

Have you already try something similar? Why is it not provided by KotlinJs?

[turansky]

You can use browser Error instead

[Grégory Lureau]

I don't understand how. kotlin.Error is also defined in stdlib-js but not exposed in the generated typescript, so I expect the same issue.

[Grégory Lureau]

Just to be clear about my need, I want to expose a class (developed in Kotlin) that returns Exception, and on the typescript side be able to write

if (exception instanceof kotlin.IllegalArgumentException) doStuff()

[Grégory Lureau]

From what I tested I can use

if (exception.name == "IllegalArgumentException") doStuff()

But then I cannot check for inheritance 😞

[Grégory Lureau]

If I change my signature to Error , typescript exposes

buildIndexOutOfBoundsException(msg: string): kotlin.Error;

with kotlin.Error instead of Error. 😞

[turansky]

Looks like Throwable in Kotlin == Error in JS