import winston from 'winston';
const { combine, timestamp, errors, json, printf, colorize } = winston.format;
// Custom format for development (colored and pretty)
const devFormat = printf(({ level, message, timestamp, ...meta }) => {
const metaStr = Object.keys(meta).length ? ` ${JSON.stringify(meta)}` : '';
return `${timestamp} ${level}: ${message}${metaStr}`;
});
// Create the logger
const logger = winston.createLogger({
level: process.env.LOG_LEVEL || 'info',
format: combine(
errors({ stack: true }),
timestamp({ format: 'YYYY-MM-DD HH:mm:ss.SSS' })
),
transports: [
// File transport for all logs
new winston.transports.File({
filename: 'logs/combined.log',
format: json()
}),
// File transport for errors only
new winston.transports.File({
filename: 'logs/error.log',
level: 'error',
format: json()
})
],
// Handle uncaught exceptions only (rejections handled separately to avoid conflicts)
exceptionHandlers: [
new winston.transports.File({ filename: 'logs/exceptions.log' })
]
});
// Add console transport with pretty formatting for non-production
if (process.env.NODE_ENV !== 'production') {
logger.add(new winston.transports.Console({
format: combine(
colorize({ all: true }),
timestamp({ format: 'HH:mm:ss.SSS' }),
devFormat
)
}));
} else {
// Production console output (structured JSON)
logger.add(new winston.transports.Console({
format: combine(
timestamp(),
json()
)
}));
}
// Handle unhandled promise rejections with ResponseAborted filtering
// This is the single, authoritative rejection handler
process.on('unhandledRejection', (reason: unknown) => {
// Skip ResponseAborted errors - they're normal when SSE connections close
if (reason && typeof reason === 'object' && reason.constructor && reason.constructor.name === 'ResponseAborted') {
return;
}
// Log other unhandled rejections to file
logger.error('Unhandled Promise Rejection', {
rejection: true,
error: reason,
stack: reason instanceof Error ? reason.stack : undefined
});
});
export default logger;
