I'm trying to import a javascript function from Wasm. For the

worker.ts

, I defined a function `consoleLog`:

ts
import mod from '../build/out.wasm';

const importObject = {
  imports: {
    consoleLog: (arg: number) => {
      console.log(`Hello from JavaScript: ${arg}`);
    },
  },
};

const instance = await WebAssembly.instantiate(mod, importObject);

export default {
  async fetch() {
    const retval = instance.exports.add100(2, 5);
    return new Response(`Success: ${retval}`);
  },
};

And I'm using AssemblyScript for the Wasm side:

ts
declare function consoleLog(arg0: i32): void;

export function add100(a: i32, b: i32): i32 {  
  // consoleLog(100);
  return a + b + 100;
}

Since I commented the

//consoleLog(100);

out, it works well after compile:

sh
asc assembly/index.ts --outFile build/out.wasm --optimize

However, when I un-commented it as:

ts
declare function consoleLog(arg0: i32): void;

export function add100(a: i32, b: i32): i32 {  
  consoleLog(100);
  return a + b + 100;
}

I got an error after `asc`:

shell
service core:user:wasm102: Uncaught Error: No such module "bea1e1adde3b4c3c5cbc0842c823a3c93a930163-out.wasm".
  imported from "worker.js"
✘ [ERROR] MiniflareCoreError [ERR_RUNTIME_FAILURE]: The Workers runtime failed to start. There is likely additional logging output above.

Just wondering what's the appropriate way to import javascript function from Wasm?

it looks correct to me, I am not familiar with using assemblyscript, but what you probably need some way of telling it to look for the

consoleLog

function in the object you call

imports

. In emscripten, for example, the default import object that it looks for is called

env

, and if you want to import a function from a different object you have to give use a macro to tell the compiler the name of the object you want to import from.