export declare function errorMessage(err: unknown): string;
export declare function toArgs(body: unknown): Record<string, unknown>;
/** The request's JSON body. Rejects a body over `maxBytes`, which is
 *  10 MB unless the caller serves a route that takes more.
 *
 *  `drainBytes` says what happens to the rest of a body that is too large.
 *  With 0, the request is destroyed at once, and a client that is still
 *  sending sees a dropped connection. With more, up to that many further
 *  bytes are read and thrown away, so the client can finish sending and
 *  read the caller's reply. Past that, the request is destroyed. */
export declare function parseJsonBody(req: {
    on: (event: string, cb: (...args: any[]) => void) => void;
    destroy?: () => void;
}, maxBytes?: number, drainBytes?: number): Promise<unknown>;