import LogLevel from "./levels.js";
import { FieldsObject } from "./logger.js";
/**
 * A log hook is a function which is called with the log object, the log level, and the message
 * just before the log is written to the output.
 *
 * The logObject is the full JSON object which will be emitted, however for convenience the
 * level and message are also passed in.
 *
 * A hook is allowed to modify the log object as required.
 */
export type LogHook = (logObject: FieldsObject, level: LogLevel, msg: string) => void;
export declare function WithCaller(dropFrames?: number): LogHook;