xtask/Add rustwasm task

[Luni-4]

Pull Request Template

Checklist

• Confirmed that run-checks all script has been executed.
• Made sure the book is up to date with changes in this PR.

Related Issues/PRs

Provide links to relevant issues and dependent PRs.

Changes

This PR fixes #851

Testing

Describe how these changes have been tested.

[Luni-4]

@antimora

I need your help because I think I'm doing something wrong. I get the following error running cargo xtask dist

[2023-11-28T10:06:50Z INFO  xtask::runwasm] Generating package...
[2023-11-28T10:06:50Z INFO  xtask::runchecks] rustup target add wasm32-unknown-unknown


info: component 'rust-std' for target 'wasm32-unknown-unknown' is up to date
[2023-11-28T10:06:50Z INFO  xtask::runwasm] Building Non-SIMD version of wasm for web...
Error: failed to parse manifest: /home/burn/Cargo.toml
Caused by: failed to parse manifest: /home/burn/Cargo.toml
Caused by: TOML parse error at line 1, column 1
  |
1 | [workspace]
  | ^
missing field `package`

Error: cargo command failed

Is it related to xtask-wasm?

[AlexErrant]

Burn is setup as a workspace, and you're using wasm-pack, which led me to this possibly relevant issue.

[Luni-4]

@AlexErrant

I've used wasm-pack because of this script https://github.com/Tracel-AI/burn/blob/main/examples/image-classification-web/build-for-web.sh
I do not know which command I should use to build the package otherwise

[AlexErrant]

Suggested change

	let mut command = Command::new("wasm-pack");
	let mut command = Command::new("wasm-pack");
	command.current_dir("./examples/image-classification-web");

I think adding current_dir is important, since that in turn sets which Cargo.toml to use. If you add

    let exit = build_command
        .spawn()
        .unwrap()
        .wait()
        .unwrap();
    log::info!("build's spawn's exit: {}", exit);

to dist below you'll observe that it runs successfully with exit code 0. Unfortunately, this doesn't solve the larger issue with arg.base.build_command(build_command). If you don't set current_dir, you'll observe that build_command.spawn() exits with the same error output as arg.base.build_command(build_command). This makes me think that arg.base.build_command(build_command) isn't respecting command.current_dir.

Grepping xtask-wasm for current_dir yields only one hit, so I think it's an upstream problem.

[antimora]

I've reviewed the work in progress and believe it will require additional time to be properly fixed.

I'm not sure if you have considered integrating xtask directly under example/image-classifier-web, which, in my opinion, seems to be the most appropriate approach. For the task at hand, I suggest relying on xtask-wasm. The xtask under each example would essentially serve as a driver, a thin wrapper, instead of incorporating the logic into the root's xtask. This approach would ensure each example remains self-contained, primarily leveraging the logic from xtask-wasm.

[Luni-4]

@antimora

My initial idea was to create a script which could be used for all our examples, but more generally, for wasm applications. That would also provide a general-purpose mechanism, that is why I've discarded the integration of xtask-wasm in each example. That could also lead to a bunch of duplicated code and difficulties in maintaining these examples if new code is added.

[antimora]

I'll close it for now since the approach will be different a little bit. I'll try to reuse code from it.

[Luni-4]

Yes, sorry for giving up this PR, busy times. You can reuse my code without any problem!