Emit WASM

[Quafadas]

Seeks to address #3837

I have some outstanding questions;

1. As I'm altering the scalaJSModule public API, a double check here would be welcomed. In particular, I've just called the module property emitWasm. sjrd pretty clearly called the linker API withExperimentalUseWebAssembly. However, if at some point it became non-experimental, I assume that's a compatibility problem. Advice welcomed - I've gone with the simplest name possible - emitWasm.
2. CI will fail, because node is < 22. The runnable test does work locally for me. Does mill require, assume or otherwise advertise compatibility with any particular node version? If not, I'll simply push the node version forward in the GHA definitions. OItherwise, I'd welcome advice - I'm not clear what the best way to manage the CI would be.

Those are the two points where I'd welcome advice. I think this is the path to victory;

• public API check?
• node version
• documentation
• CI green

[lihaoyi]

Thanks @Quafadas!

1. Updating the ScalaJSModule public API is fine. Let's prefix the name scalaJSEmitWasm, since it's a Scalajs specific task.
2. Mill does not advertise any required node version, so you can require whatever version you want, just make sure to document it (e.g. in def scalaJSEmitWasm)
3. Let's also include an example/scalalib/web/ example test with a short illustrative example and some english prose explaining what is going on

[Quafadas]

The documentation has been written somewhat blindly - I can't seem to get past this locally.

simon@Simons-Mac-mini mill-1 % mill docs.localPages
[0753/1698] docs.oldDocSources
[0753] Cloning into '/Users/simon/Code/mill-1/out/docs/oldDocSources.dest/0.11.12'...
[0753] done.
[0753] error: pathspec '0.11.12' did not match any file(s) known to git
[1698/1698] ============================================================================================================================================================================================== docs.localPages ================================================================================================================================================================================================== 1s
1 tasks failed
docs.oldDocSources os.SubprocessException: Result of git…: 1

    os.proc.call(ProcessOps.scala:230)
    build_.docs.package_.$anonfun$oldDocSources$4(package.mill:247)
    scala.collection.immutable.List.map(List.scala:247)
    scala.collection.immutable.List.map(List.scala:79)
    build_.docs.package_.$anonfun$oldDocSources$3(package.mill:244)

[lefou]

@Quafadas Could be you have a sparse git checkout. You can use mill docs.fastPages which should skip the older versions.

[Quafadas]

@lefou Thankyou! I think the docs works as I expect...

[Quafadas]

Pending further feedback and making CI happy, I believe this now to be mergeable.

[lihaoyi]

Looks good to me, thanks @Quafadas! Email me your international bank transfer details and I will close out the bounty

[Quafadas]

@lihaoyi r.e. bounty I'd say don't worry about it I get plenty out of mill so let's keep that resource inside the project.

You can either add it to the scala 3 migration slush fund, or if you ever get the chance to have dinner with Tobias and/or Lorenzo - make it a nice one.

[lihaoyi]

@Quafadas got it! In that case I'll pass the bounty to the scala center then to support their work