import { RequestHandler } from "express";
/**
 * Wraps multer.single(fieldName) and normalizes every failure mode (oversized
 * file, wrong field name, rejected file type) into an ApiError before calling
 * next() -- errorHandler's isHttpLikeError() check only recognizes .statusCode
 * / .status, and multer.MulterError carries neither (just a .code string), so
 * letting it bubble unmapped would surface as a masked 500 instead of a 400.
 */
export declare function uploadSingleFile(fieldName: string): RequestHandler;