[wasm] drop cjs follow-up

[pavelsavara]

• move -s EXPORT_ES6=1 to compilation or defaults .rsp
• rename samples like console-v8-es6 to console-v8
• rename or remove folder runtime\es6
• use v8 --module to
  • get rid of src\mono\sample\wasm\console-v8-es6\v8shim.cjs
  • make test-main.js ES6
  • src\mono\wasm\host\JSEngineHost.cs
• remove imports.isGlobal from exports.ts

https://bugzilla.mozilla.org/show_bug.cgi?id=1247687

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Issue Details

---

• move -s EXPORT_ES6=1 to compilation or defaults .rsp
• rename samples like console-v8-es6 to console-v8
• rename or remove folder runtime\es6
• use v8 --module to
  • get rid of src\mono\sample\wasm\console-v8-es6\v8shim.cjs
  • make test-main.js ES6
  • src\mono\wasm\host\JSEngineHost.cs

Author:	pavelsavara
Assignees:	pavelsavara
Labels:	arch-wasm, area-System.Runtime.InteropServices.JavaScript
Milestone:	7.0.0

[firasdib]

Hi,

Unsure if this is a good issue to comment on, but the change of always compiling to ES6 seems to break my build. I can't use import.meta.url and would like to stick to the old behavior, but from my search, I have not found a way to revert back to the old behavior.

Could you please advise?

Thank you.

[pavelsavara]

@firasdib we are not going back to CommonJS. I would like to learn more about your problem with import.meta.url so that I could try to advise you or to address the issue. Thank you.

[firasdib]

I am trying to run some compiled code in the browser, and it says I cannot use import.meta.url outside of a module. It also contains export statements which aren't understood by the browser, either.

Specifically I am trying to use this in a web worker.

[pavelsavara]

Web workers in FF don't support ES6 yet and I think we don't support running dotnet on worker either.
The message maybe means that you loaded the file as plain JS not as module. Maybe via script tag ?

[firasdib]

It works fine with the older preview build (currently whats running on regex101), but I am unable to update due to this limitation.

The only way to load scripts in the worker is through importScripts(), not script tags.

Why can't you keep ES6 for your internal functions, but allow it to be compiled to cjs through a flag? ES6 was opt in before, but now its removed, making it not usable for me, which is extremely unfortunate.

[pavelsavara]

Why can't you keep ES6 for your internal functions, but allow it to be compiled to cjs through a flag? ES6 was opt in before, but now its removed, making it not usable for me, which is extremely unfortunate.

• Because it doubles our test surface.
• It brings lot of additional complexity in detecting scriptDirectory on various JS engines
• We are also planning further modularization of the runtime. With CJS we would have to bring our own RequireJS on the web.

[firasdib]

Can it not be transpiled to any version of ES?

Not sure what scriptDirectory is, should be fairly simple to specify manually if necessary where the wasm file is?

I will try to find a manual way of managing this, otherwise I'm stumped at how to keep supporting .NET on regex101...

[pavelsavara]

Can it not be transpiled to any version of ES?

Could you take dotnet.js and transpile it on your end? It would be good to figure out if it could be done.