Convert various source URLs (GitHub, npm, unpkg, WordPress) to jsDelivr CDN URLs.

jsdelivr.ts

/**
 * Convert various source URLs (GitHub, npm, unpkg, WordPress) to jsDelivr CDN URLs.
 * @param sourceUrl — the original file URL
 * @returns jsDelivr URL or null if the format is not recognized
 */
export function toJsDelivr(sourceUrl: string): string | null {
  const url = new URL(sourceUrl);
  const { hostname, pathname, searchParams } = url;

  // GitHub: handle both github.com/blob/... and raw.githubusercontent.com
  let match = pathname.match(
    /^\/([^/]+)\/([^/]+)\/(?:blob|raw)\/([^/]+)\/(.+)$/
  );
  if (hostname === 'github.com' && match) {
    const [, user, repo, version, filePath] = match;
    return `https://cdn.jsdelivr.net/gh/${user}/${repo}@${version}/${filePath}`;
  }
  match = pathname.match(
    /^\/([^/]+)\/([^/]+)\/([^/]+)\/(.+)$/
  );
  if (hostname === 'raw.githubusercontent.com' && match) {
    const [, user, repo, version, filePath] = match;
    return `https://cdn.jsdelivr.net/gh/${user}/${repo}@${version}/${filePath}`;
  }

  // npmjs.com: convert /package/<pkg>/v/<ver>?path=<file> to /npm/
  match = pathname.match(/^\/package\/([^/]+)(?:\/v\/([^/]+))?$/);
  if (hostname.endsWith('npmjs.com') && match) {
    const [, pkg, version] = match;
    const file = searchParams.get('path') ?? '';
    const verSegment = version ? `@${version}` : '';
    return `https://cdn.jsdelivr.net/npm/${pkg}${verSegment}/${file}`;
  }

  // unpkg.com: simply rebase to /npm/
  match = pathname.match(/^\/([^@/]+)@([^/]+)\/(.+)$/);
  if (hostname === 'unpkg.com' && match) {
    const [, pkg, version, filePath] = match;
    return `https://cdn.jsdelivr.net/npm/${pkg}@${version}/${filePath}`;
  }

  // WordPress plugins: /plugins/<proj>/(tags/<ver> | trunk)/<file>
  match = pathname.match(
    /^\/plugins\/([^/]+)\/(?:tags\/([^/]+)|trunk)\/(.+)$/
  );
  if (hostname === 'wordpress.org' && match) {
    const [, project, version, filePath] = match;
    const ref = version ? `tags/${version}` : 'trunk';
    return `https://cdn.jsdelivr.net/wp/plugins/${project}/${ref}/${filePath}`;
  }

  // WordPress themes: /themes/<proj>/<ver>/<file>
  match = pathname.match(/^\/themes\/([^/]+)\/([^/]+)\/(.+)$/);
  if (hostname === 'wordpress.org' && match) {
    const [, project, version, filePath] = match;
    return `https://cdn.jsdelivr.net/wp/themes/${project}/${version}/${filePath}`;
  }

  // Unknown format
  return null;
}