/** Read ordered rows in bounded pages, including children of batched IDs.
 * Callers must supply a stable order and preserve their authorization filters.
 */
export async function readPages<T>(
  load: (from: number, to: number) => PromiseLike<readonly T[]>,
  pageSize = 500,
): Promise<T[]> {
  if (!Number.isInteger(pageSize) || pageSize < 1) throw new Error("Invalid page size");
  const rows: T[] = [];
  for (let from = 0; ; from += pageSize) {
    const page = await load(from, from + pageSize - 1);
    rows.push(...page);
    if (page.length < pageSize) return rows;
  }
}