Any examples using Wasm from JavaScript?

[liweijian]

There's hello-wasm sample, but it seems not work correctly.

Basically we can call Wasm from JavaScript via wrangler, so I did try to port this example to workerd.

I copy the simple.wasm generated by wat2wasm to the same folder of README project

wat2wasm src/simple.wat -o src/simple.wasm

And change the hello.js to:

import mod from "./simple.wasm";

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

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

addEventListener("fetch", (event) => {
  const retval = instance.exports.exported_func(42);
  event.respondWith(new Response(`Hello World! ${retval}`));
});

But got error when running:

❯ workerd serve my-config.capnp
service main: Uncaught SyntaxError: Cannot use import statement outside a module
  at main:1

[jihuayu]

What is you my-config.capnp?
If you use import mod from "./simple.wasm"; you need do like it

[SagarM21]

@jihuayu but I want to run the function using js code, is that possible, the code works with mjs file and wasm file.
I tried this below code and its not working

import mod from './index.wasm'; // Import WASM module
export default {
  async fetch(request, env, ctx) {
    try {
          const instance = await WebAssembly.instantiate(mod);
        
            const wasmModule = await instance.exports.msg();
       
          
            return new Response(`Success: ${wasmModule}`);
        } catch (error) {
            return new Response(`Error: ${error.message}`, { status: 500 });
        }
    }
}

using Workerd = import "/workerd/workerd.capnp";

const config :Workerd.Config = (
  services = [
    (name = "one", worker = .oneWorker),
  ],

  sockets = [
    (
      name = "one",
      http = (),
      service = "one",
      address = "*:30000",
    ),
  ]

);

const oneWorker :Workerd.Worker = (
  modules = [
    (name = "entry.js", esModule = embed "src/entry.js"),
    (name = "index.wasm", wasm = embed "src/index.wasm"),
  ],
  compatibilityDate = "2024-04-03",
  bindings = [
    
  ],
);