WASM_WORKERS and ES6 exports

[tzvetelin-vassilev]

Version of emscripten/emsdk: 3.1.13

options: -s MODULARIZE=1 -s EXPORT_ES6=1 -s WASM_WORKERS

wasm_worker.js should be slightly different with ES6 exported Module
Worker constructor needs option type = module
importScripts(d.js) is not working in this mode, in classic mode also is not working because ES6 export
importScripts should be replaced with dynamic import

[sbc100]

At the very least we should error out if don't currently support this setup. Someone else was also ran into this issue in #19007.

[dr-matt]

Is it likely that fixing this is a matter of modifying wasm_worker.js to behave differently using #if EXPORT_ES6 ? I tinkered around with that file a bit and was able to get further, but I'm not familiar enough with all the js interactions to know exactly what modifications are needed and where.

[pca006132]

it seems that pthread worker also has this problem: https://github.com/emscripten-core/emscripten/blob/main/src/worker.js

[RReverser]

Is it likely that fixing this is a matter of modifying wasm_worker.js to behave differently using #if EXPORT_ES6

That seems about right, but @juj is probably the one who could help more here.

it seems that pthread worker also has this problem: main/src/worker.js

No, pthread workers support ESM, we have tests for that too.

[pca006132]

No, pthread workers support ESM, we have tests for that too.

But when pthread workers are run inside nodejs and treated as a module, it will error with require is not defined in ES module scope.

I think the current way of handling this is to add

  const {createRequire: createRequire} = await import('module');
  var require = createRequire(import.meta.url);

[maorcc]

Is there now any workaround for using WASM_WORKERS with ES6?