Function vendor_packages

cli/src/build.rs:151–175

For each imported name, resolve via the shared registry, fetch, and stash under dist/vendor/.

(
    manifest: &Manifest,
    imports: &BTreeSet<String>,
    out_dir: &Path,
)

/// For each imported name, resolve via the shared registry, fetch, and stash under dist/vendor/.
fn vendor_packages(
    manifest: &Manifest,
    imports: &BTreeSet<String>,
    out_dir: &Path,
) -> Result<(BTreeMap<String, String>, BTreeMap<String, String>)> {
    let mut std_local = BTreeMap::new();
    let mut host_local = BTreeMap::new();

    for name in imports {
        // Unknown names are project-local .py modules; let the runtime resolve them at run time.
        let Some((kind, url)) = pkg::resolve(name, manifest) else { continue };
        let bytes = fetch(&url).with_context(|| format!("fetching {url}"))?;
        let local = match kind {
            // std packages are .wasm, except pure-Python ones (test) served as .py; preserve the real extension.
            Kind::Std => format!("vendor/{name}.{}", if url.ends_with(".py") { "py" } else { "wasm" }),
            Kind::Host => format!("vendor/{name}/index.js"),
        };
        write_under(out_dir, &local, &bytes)?;
        match kind {
            Kind::Std => { std_local.insert(name.clone(), local); }
            Kind::Host => { host_local.insert(name.clone(), local); }
        }
    }
    Ok((std_local, host_local))
}

fn write_under(root: &Path, rel: &str, bytes: &[u8]) -> Result<()> {
    let path = root.join(rel);