Function isNotARepositoryCause

packages/computer/src/git/errors.ts:101–130

(cause: unknown)

 * internal shape.
 */
export function isNotARepositoryCause(cause: unknown): boolean {
  if (!(cause instanceof Error)) return false;
  // isomorphic-git's NotFoundError shows up in three flavours
  // depending on how deep we got before the failure:
  //
  //   - VFS-level ENOENT on the gitdir itself: message contains
  //     `.git` plus an ENOENT-shaped phrase.
  //   - HEAD lookup before any other read: a NotFoundError whose
  //     message reads "Could not find HEAD." / "Could not find
  //     refs/heads/main."
  //   - Object-store lookup: a NotFoundError on a SHA or pack.
  //
  // For the not-a-repo signal we want the first two: missing
  // .git or missing HEAD. Object-store misses are a different
  // failure mode and should not collapse to NotARepositoryError.
  const code = (cause as { code?: unknown }).code;
  const name = cause.name;
  const message = cause.message;
  if (
    (name === "NotFoundError" || code === "NotFoundError") &&
    /Could not find (HEAD|refs\/)/.test(message)
  ) {
    return true;
  }
  const m = message.toLowerCase();
  return (
    m.includes(".git") &&
    (m.includes("enoent") || m.includes("could not find") || m.includes("does not exist"))
  );
}