Winston does not log errors

[Slyke]

Please tell us about your environment:

• winston version?
  • winston@2
  • winston@3
• node -v outputs: v13.1.0
• Operating System? (Windows, macOS, or Linux) Linux
• Language? (all | TypeScript X.X | ES6/7 | ES5 | Dart) ES6

What is the problem?

Winston does not log errors, nor catch exceptions.

What do you expect to happen instead?

Winston to catch and log errors and exceptions

Other information

Here's my Winston setup:

  const setupLogger = () => {
    try {
      const logger = require('winston');
      const path = require('path');
      const logPath = path.normalize(`${__dirname}/logs/`);
      console.log(`Log path ${logPath}`);

      const formatMessage = (theLog) => {
        if (theLog instanceof Error) {
          return `${theLog.timestamp} ${theLog.level}: ${theLog.message} - StackTrace: ${theLog.stack}`;
        } else {
          return `${theLog.timestamp} ${theLog.level}: ${theLog.message}`;
        }
      };

      const transportDefaults = {
        handleExceptions: true,
        exitOnError: false
      };

      const loggerInstance = logger.createLogger({
        level: 'info',
        format: logger.format.combine(
          logger.format.printf((theLog) => `${theLog.timestamp} ${theLog.level}: ${theLog.message}`),
          logger.format.timestamp(),
          logger.format.json()
        ),
        transports: [
          new logger.transports.File({ filename: `${logPath}combined.log`, ...transportDefaults }),
          new logger.transports.File({ filename: `${logPath}error.log`, level: 'error', ...transportDefaults }),
          new logger.transports.File({ filename: `${logPath}warn.log`, level: 'warn', ...transportDefaults }),
          new logger.transports.File({ filename: `${logPath}info.log`, level: 'info', ...transportDefaults }),
          new logger.transports.File({ filename: `${logPath}debug.log`, level: 'debug', ...transportDefaults })
        ],
        exceptionHandlers: [
          new logger.transports.File({ filename: `${logPath}exceptions.log`, ...transportDefaults })
        ]
      });
    
      if (process.env.NODE_ENV !== 'production') {
        loggerInstance.add(new logger.transports.Console({
          handleExceptions: true,
          exitOnError: false,
          format: logger.format.combine(
            logger.format.errors({ stack: true }),
            logger.format.colorize(),
            logger.format.align(),
            logger.format.printf((theLog) => formatMessage(theLog)),
          )
        }));
        console.log('Logging to console');
      }

      return loggerInstance;
    
    } catch (err) {
      console.log("Error setting up logger: ", err);
      process.exit(5);
    }
  };

If an exception happens, nothing is saved to any file, nor is it printed to console. It's as if everything is fine and nothing erred.

If I Logger.error(err) in an exception block, then this is printed to file:

{"level":"error","timestamp":"2020-02-02T06:56:07.973Z"}

And this is printed to console:

2020-02-02T06:56:07.973Z error:         undefined

[c-vetter]

Thanks to #1771 (comment), I found that you need to add the errors formatter to the logger itself. It does not work on the transport.

So, instead of this:

const log = winston.createLogger({
	transports: [new winston.transports.Console({
		format: combine(
			errors(),
			stringify(),
			cli(),
		),
	})],
})

This is necessary:

const log = winston.createLogger({
	format: errors(),
	transports: [new winston.transports.Console({
		format: combine(
			stringify(),
			cli(),
		),
	})],
})