title: winston logger to show line number and file name
body: <p>I have tried to show filename using winston logger in nodejs app, but it is always showing the index.js file as the filename.
  And I can't find any way to show the line number correctly:</p>
  
  <pre><code>const path = require('path');
  
  const logLevel = 'debug';
  const {
      createLogger,
      format,
      transports,
      config,
  } = require('winston');
  
  const customTransports = [];
  
  const transportOptions = {};
  if (config.env === 'development') {
      transportOptions.format = format.combine(
          format.cli(),
          format.errors({ stack: true }),
          format.splat(),
          format.simple(),
      );
  }
  
  customTransports.push(new transports.Console(transportOptions));
  
  const defaultConfig = {
      level: logLevel,
      levels: config.npm.levels,
      format: format.combine(
          format.label({ label: path.basename(process.mainModule.filename) }),
          format.colorize(),
          format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }),
          format.printf(
              ({
                  level, message, label, timestamp,
              }) =&gt; `${timestamp} ${level} [${label}]: ${message}`,
          ),
      ),
      transports: customTransports,
      exitOnError: false,
  };
  
  const logger = createLogger(defaultConfig);
  
  module.exports = logger;
  </code></pre>
  
  <p>I am using this version <code>"winston": "^3.2.1"</code></p>
  
  <p>could you help me show the line number and filename of the log?</p>