Convert respec-worker as an ES module

[saschanaz]

As part of #1640:

A worker script can be a module if we construct it by new Worker(url, { type: "module" }). I think this will ultimately benefit #1469 where we can load it as a module that can also work in Node.js.

• Wait until browsers support it

[marcoscaceres]

That be very cool. Do you have any details about {type: "module"} support?

[saschanaz]

MDN: https://developer.mozilla.org/en-US/docs/Web/API/Worker/Worker
Spec: https://html.spec.whatwg.org/multipage/workers.html#dedicated-workers-and-the-worker-interface
Chromium: https://bugs.chromium.org/p/chromium/issues/detail?id=680046
Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1247687
Safari: https://bugs.webkit.org/show_bug.cgi?id=164860

An interesting support indicator: https://aremodulesready.com/

It seems it currently lacks any browser support.

[marcoscaceres]

Seems it’s now supported across all browsers. So, might be time 😎

[marcoscaceres]

Oh wait… firefox not done yet.