import type { ParsingOptions, WorkBook } from 'xlsx';
/**
 * Parses a workbook away from the UI thread when a dedicated Worker can be
 * created. A null result asks the caller to use the synchronous fallback.
 */
export declare function readSpreadsheetWorkbookInWorker(bytes: ArrayBuffer, options: ParsingOptions, signal?: AbortSignal): Promise<WorkBook | null>;