Using runtime.onInstalled.addListener

[flosse]

Adding a event listener with

let closure: Closure<dyn Fn(JsValue)> = Closure::new(move |js: JsValue| {
  let reason = js.as_string().expect("reason string"); 
  // ...
});
web_extensions_sys::chrome
  .runtime()
  .on_installed()
  .add_listener(closure.as_ref().unchecked_ref());
closure.forget();

but the event is never fired because the JS API runtime.onInstalled.addListener has to be called synchronously in the background script. And because WASM is asynchronously loaded, the execution of the web-extensions-sys wrapper is called too late

import init from './pkg/background.js';
// here we have to call runtime.onInstalled.addListener
init()
  .then(() => {
    // but it's called by the WASM module here
  })
  .catch(console.error)

There is a method that can init the module synchronously but the fetch is still asynchronous:

fetch("./pkg/background_bg.wasm")
   .then((response) => response.arrayBuffer())
   .then((bytes) => {
     wasm.initSync(bytes);
   })
   .catch(console.error);

So does anybody have an idea how to solve this problem?

[hut8]

https://groups.google.com/a/chromium.org/g/chromium-extensions/c/HbavKaHwEXU

// in service worker
var promise = WebAssembly.instantiateStreaming(......);
async function onInstall() {
  let obj = await promise;
  // use obj 
}
chrome.runtime.onInstalled.addListener(onInstall);

That makes it seem like the answer is "you can't do it", and it can really only be improved slightly from where we are now.