winst-logger.js

winst-logger.js

const path = require('path');
const util = require('util');
const { createLogger, format, transports } = require('winston');
const { combine, timestamp, label, printf } = format;
const myFormat = printf(info => {
  info.label = info.label.padStart(5,' ');
  info.level.padStart(7,' ');
  let re = /[\r\n]+/;
  
  if(typeof info.message === "object")
    info.message = util.inspect(info.message);

  let splitMessages = typeof info.message==="string"
    ?info.message.split(re)
    :[""];
  
  if(splitMessages.length>1){
    let reducer = (a,msg)=> a+(a.length>0?`\r\n`:'')+`${info.timestamp} [${info.label}] ${info.level}: ${msg}`;
    return splitMessages.reduce(reducer,'');
  }else{
    return `${info.timestamp} [${info.label.padStart(5,' ')}] ${info.level.padStart(5,' ')}: ${info.message}`;
  }
});

const winstLogger = function(loggerLabel){
  let logger = createLogger({
    format: combine(
      label({ label: loggerLabel }),
      timestamp(),
      myFormat
    ),
    transports: [
      new transports.File({ 
        filename: path.join(__dirname,'logs/',`${loggerLabel}.error.log`),
        json:false, 
        maxsize:'10485760', 
        maxFiles:'10',
        level:'error'
      }),
      new transports.File({
        filename: path.join(__dirname,'logs/',`${loggerLabel}.log`), 
        json:false, 
        maxsize:'10485760', 
        maxFiles:'10', 
        level:'silly'
      })
    ]
  });
  if (['production','testing'].indexOf(process.env.NODE_ENV)===-1) {
    logger.add(new transports.Console({
      format: combine(
        format.colorize(),
        label({ label: loggerLabel }),
        timestamp(),
        myFormat
      ),
      level:'debug',
      prettyPrint:true
    }));
  }
  return logger;
};

exports.winstLogger=winstLogger;