/src/lib.rs:

#[wasm_bindgen(module = "/www/utils.js")]
extern "C" {
  fn random(max: usize) -> usize;
}

/www/utils.js:

export function random(max) {
  return Math.round(Math.random() * max)
}

wasm-pack builds correctly:

But in package.json, it is not inclueded:

I found similar issues: #663, #557, #881. But all of them were not resloved. So I create this.