My build appears to be creating a corrupted WASM. The browser is reporting `wasm validation error: ...

# webassembly

[Darryl Miles]

My build appears to be creating a corrupted WASM. The browser is reporting wasm validation error: at offset 43269: duplicate export
I have tried to use wasm2wat on it from wabt but that also reports error 000008f: error: expected valid result type (got -0xf)
Project is using Kotlin 1.9.24

[Svyatoslav Kuzmich [JB]]

Exports (@JsExport, @WasmExport) need to have a unique name, but Kotlin/Wasm currently doesn’t check for duplicate exports.

Wabt doesn’t seem to support GC types. I prefer https://github.com/bytecodealliance/wasm-tools parse print command instead.

[Darryl Miles]

Thanks for this testing with FireFox again now (otherwise I'd be trying to chase wasm2wat working)

[Darryl Miles]

I think the issue is (but still confirming now):

@OptIn(ExperimentalJsExport::class)
@JsExport
fun myFunction(event: Event, ele: HTMLElement) {
  // this works
}

///// then I changed to
@OptIn(ExperimentalJsExport::class)
@JsExport
fun myFunction(event: Event, ele: HTMLElement? = null) {
  // this is a problem
  // I think the default param must create an extra non-unique symbol 
}

[Svyatoslav Kuzmich [JB]]

Indeed: https://pl.kotl.in/ZcN7NRVaT

[Darryl Miles]

Does this need to be reported or a known matter ?

[Svyatoslav Kuzmich [JB]]

I’ll file a ticket, thanks!

[Svyatoslav Kuzmich [JB]]

https://youtrack.jetbrains.com/issue/KT-69570/K-Wasm-JsExport-with-default-parameter-value-compiles-to-invalid-Wasm