const logger = require('./logger'); logger.info({ event: 'startup', msg: 'log rotation verification start' }); for (let i = 0; i < 5; i++) { logger.info({ event: 'heartbeat', idx: i, msg: `test log ${i}` }); } logger.error({ event: 'error-demo', code: 'E-DEMO', msg: 'demo error log' }); console.log('Wrote logs. Check logs directory.');