Function saveDraft

packages/shared/draft.ts:94–116

(key: string, data: object)

 * Save a draft to disk.
 */
export function saveDraft(key: string, data: object): boolean {
  const draftGeneration = readGeneration((data as { draftGeneration?: unknown }).draftGeneration);
  const deletedGeneration = readTombstoneGeneration(key);
  if (draftGeneration !== null && deletedGeneration !== null && draftGeneration <= deletedGeneration) {
    return false;
  }
  const storedGeneration = readStoredDraftGeneration(key);
  if (draftGeneration !== null && storedGeneration !== null && draftGeneration < storedGeneration) {
    return false;
  }

  // Write-then-rename so a crash mid-write can't leave a truncated draft —
  // loadDraft would silently return null at exactly the recovery moment
  // drafts exist for. rename() is atomic within a directory.
  const finalPath = draftPath(key);
  const tmpPath = `${finalPath}.tmp`;
  writeFileSync(tmpPath, JSON.stringify(data), "utf-8");
  renameSync(tmpPath, finalPath);
  if (draftGeneration === null) {
    clearTombstone(key);
  }
  return true;
}

/**
 * Load a draft from disk. Returns null if not found.