/** Human-readable duration for console logs (e.g. 842ms, 2.1s). */
export function formatElapsedMs(elapsedMs: number): string {
  if (elapsedMs < 1000) {
    return `${Math.round(elapsedMs)}ms`;
  }
  return `${(elapsedMs / 1000).toFixed(1)}s`;
}

export function errorMessage(err: unknown): string {
  if (err instanceof Error && err.message.length > 0) {
    return err.message;
  }
  if (typeof err === "string" && err.length > 0) {
    return err;
  }
  return "Unknown error";
}