What are some examples of using Winston for logging in Node.js?

What are some examples of using Winston for logging in Node.js?

Winston is a versatile logging library for Node.js. Here are a few examples:

1. Basic Logging:

   const winston = require('winston');
   const logger = winston.createLogger({
       level: 'info',
       format: winston.format.json(),
       transports: [
           new winston.transports.Console(),
           new winston.transports.File({ filename: 'combined.log' })
       ]
   });
   logger.info('Hello, this is an info message!');
   

2. Logging with Different Levels:

   logger.error('This is an error message!');
   logger.warn('This is a warning message!');
   

3. Custom Formats:

   const logger = winston.createLogger({
       format: winston.format.combine(
           winston.format.timestamp(),
           winston.format.printf(({ timestamp, level, message }) => {
               return `${timestamp} ${level}: ${message}`;
           })
       ),
       transports: [new winston.transports.Console()]
   });
   logger.info('Custom formatted log message.');
   

These examples should help you get started with Winston!

Can I log to multiple transports at once?

Yes, you can log to multiple transports simultaneously in Winston. You just need to specify multiple transport instances in the transports array when creating the logger. For example:

const logger = winston.createLogger({
    level: 'info',
    format: winston.format.json(),
    transports: [
        new winston.transports.Console(),
        new winston.transports.File({ filename: 'error.log', level: 'error' }),
        new winston.transports.File({ filename: 'combined.log' })
    ]
});
logger.info('This will log to both console and combined.log');
logger.error('This will log to console and error.log');