Function parseBookFolderName

packages/core/src/sync/sync-naming.ts:61–67

(folderName: string)

 * Returns null when the trailing 36 chars do not match a UUID-v4-shaped string.
 */
export function parseBookFolderName(folderName: string): string | null {
  if (folderName.length < 37) return null;
  const candidateId = folderName.slice(-36);
  if (!UUID_RE.test(candidateId)) return null;
  if (folderName[folderName.length - 37] !== "-") return null;
  return candidateId;
}

/** Heuristic: file is a cover if its extension is a known image format. */
export function isCoverFileName(fileName: string): boolean {