import winston from "winston";
import type { LogEntry } from "../log-entry";
import type { LogLevel } from "../logger";
import { FileWriter } from "./file-writer";
export declare function renderAsJson(level: LogLevel, entry: LogEntry): string | null;
export declare class JsonFileWriter extends FileWriter {
    type: string;
    initFileLogger(): winston.Logger;
    render(entry: LogEntry): string | null;
    write(entry: LogEntry): void;
}