JSON logs

JSON logs are a simple way to log structured data for further processing.

By default, @neodx/log uses Pretty logs for development and JSON logs for production.

If you want to reproduce this behavior, you can use the following code:

import { createLogger, json, pretty } from '@neodx/log/node';

const logger = createLogger({
  target: process.env.NODE_ENV === 'production' ? json() : pretty()
});

logger.info('Hello World!');

The output will be:

{"level": 30,"time": 1696791460010,"msg": "Hello World!","pid": 87438,"hostname": "my-hostname"}

Levels

Log levels will be converted to their numeric value.

logger.error('error');
logger.warn('warn');
logger.info('info');
logger.done('done');
logger.debug('debug');

{"level": 10,"time": 1696791460010,"msg": "error","pid": 87438,"hostname": "my-hostname"}
{"level": 20,"time": 1696791460010,"msg": "warn","pid": 87438,"hostname": "my-hostname"}
{"level": 30,"time": 1696791460010,"msg": "info","pid": 87438,"hostname": "my-hostname"}
{"level": 40,"time": 1696791460010,"msg": "done","pid": 87438,"hostname": "my-hostname"}
{"level": 50,"time": 1696791460010,"msg": "debug","pid": 87438,"hostname": "my-hostname"}

Extend JSON

Any additional metadata will be added to the JSON output.

logger.info({ foo: 'bar' }, 'Hello World!');

{"level": 30,"time": 1696791460010,"msg": "Hello World!","pid": 87438,"hostname": "my-hostname","foo": "bar"}

Related

• Pretty logs