logger.js

const { createLogger, format, transports } = require('winston');
const { combine, timestamp, label, printf } = format;

const myFormat = printf( ({ level, message, timestamp }) => {
  return `${timestamp} ${level}: ${message}`;
});

var filename = module.filename.split('/').slice(-1);

const logger = createLogger({
  level: 'debug',
  format: combine(
    label({ label: filename }),
    timestamp(),
    myFormat
  ),
  transports: [
    //
    // - Write to all logs with level `info` and below to `combined.log` 
    // - Write all logs error (and below) to `error.log`.
    //
    new transports.File({ filename: 'error.log', level: 'error' }),
    new transports.Console({level: 'verbose'}),
    new transports.File({ filename: 'combined.log' })
  ]
});

module.exports = logger;