Is there a way to check if some value is of JsAny ...

# webassembly

[Pavel Kazlovich]

Is there a way to check if some value is of JsAny type? Naive is JsAny makes the compiler angry since it's an external type. My use case is writing a simple idempotent Any->JsAny converter which accepts primitives, iterables, maps and JsAny and gets me back JsAny or throws an error.

[Robert Jaros]

You can use mine: https://github.com/rjaros/kilua/blob/main/kilua/src/commonMain/kotlin/dev/kilua/utils/JavaScript.kt#L163

[Pavel Kazlovich]

@Robert Jaros very interesting, thank you. I have a question though: function's comment says that all unsupported values are converted to null on wasmJs, but as far as I see the else block uses cast(), which is just an unsafe this as T cast on wasmJs. How would it produce null if I use something like myDataClassInstance.toJsAny()?

[Robert Jaros]

The comment is wrong 🙂 It wasn't updated when it should have been.

[Pavel Kazlovich]

Ah, alright then 🙂
I guess it works the same as what I've ended up with. Anyway, thanks again, always interesting to see how people do utils for wasmJs.