code: async function build(file) {
    const { code, map, assets } = await ncc(file, options);
  
    if (Object.keys(assets).length)
      console.error("New unexpected assets are being emitted for", file);
  
    const name = basename(file, ".js");
    await mkdirp(resolve(DIST_DIR, name));
    write(resolve(DIST_DIR, name, "index.js"), code);
    write(resolve(DIST_DIR, name, "index.map.js"), map);
  }
docs: build file with its dependencies using ncc