I have a simple wasmjs demo app, which was working fine until i upgraded to latest kotlinx-coroutine...

# webassembly

[suresh]

I have a simple wasmjs demo app, which was working fine until i upgraded to latest kotlinx-coroutine 1.8.0. After that, it throws the following error.

[suresh]

Uncaught (in promise) TypeError: Failed to execute 'compile' on 'WebAssembly': Incorrect response MIME type. Expected 'application/wasm'.

[suresh]

The application is being served from a ktor app using static resource directory. Any idea how to debug/fix this issue ?

[suresh]

Things were working fine until 1.8.0-RC release of kotlinx-coroutine. I am still not 100% sure the coroutine update causing this error.

[Artem Kobzar]

What server do you use for serving static files?

[suresh]

ktor, the wasm module compiled output will get copied to backend module resources/app directory and will get served as static resources

fun Route.webApp() {
  webApp("/app", "app")
}

fun Route.webApp(remotePath: String, basePackage: String) {
  staticResources(remotePath, basePackage) {
    exclude { it.path.endsWith(".log") }
    default("index.html")
    modify { url, call ->
      when (call.request.path()) {
        remotePath -> call.respondRedirect("$remotePath/")
      }
    }
  }
}

[suresh]

The same issue when hosting the wasmJsBrowserDistribution on github pages also.

[Artem Kobzar]

Could you check what is Content-Type of the response with the `wasm`file?

[suresh]

hmm..somehow it shows as Content-Type: text/html; charset=UTF-8

[suresh]

what should be actual content type for wasm files?

[suresh]

by thw way, the typs is fetch for this wasm file as it’s loaded by the wrapper script.

[Artem Kobzar]

Should be application/wasm

[Artem Kobzar]

Could you make something like this:

if (call.requrest.path().endsWith(".wasm")) {
   call.response.header(HttpHeaders.ContentType, "application/wasm")
}

[suresh]

ok..let me check that

[suresh]

Seems like the issue is something different… Any idea why .wasm files not getting copied to dist directory ? I am running wasmJsBrowserDistribution

[suresh]

seems like a regression on 2.0.0-Beta4

[suresh]

Can be easily reproduce by running

$ git clone <https://github.com/Kotlin/kotlin-wasm-examples>
$ cd browser-example 
// change the plugin version to 2.0.0-Beta4
$ ./gradlew wasmJsBrowserDistribution

[suresh]

https://youtrack.jetbrains.com/issue/KT-65889

[Artem Kobzar]

@Ilya Goncharov [JB] ^^