Example winston configuration with file rotation

logger.ts

import 'winston-daily-rotate-file'

import stringify from 'json-stringify-safe'
import path from 'path'
import winston from 'winston'

import config from '@/config'

const dailyRotateTransport = new winston.transports.DailyRotateFile({
  filename: path.join(config.logBase, `${config.appName}-%DATE%.log`),
  datePattern: 'YYYY-MM-DD-HH',
  zippedArchive: true,
  maxSize: '30m',
  maxFiles: '30d',
})

const prettyJson = winston.format.printf((info) => {
  if (typeof info.message === 'object') {
    info.message = stringify(info.message, null, 4)
  }
  return `[${config.appName}] [${info.timestamp}] ${info.level}: ${info.message}`
})

export const logger = winston.createLogger({
  transports: [
    new winston.transports.File({
      level: 'info',
      filename: path.join(config.logBase, `${config.appName}.log`),
      handleExceptions: true,
      maxsize: 10485760,
      maxFiles: 1,
    }),
    new winston.transports.Console({
      level: 'debug',
      handleExceptions: true,
    }),
    dailyRotateTransport,
  ],
  format: winston.format.combine(
    winston.format.colorize(),
    winston.format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }),
    winston.format.prettyPrint(),
    winston.format.splat(),
    winston.format.simple(),
    winston.format.json(),
    prettyJson,
  ),
  exitOnError: false,
})