@yyberi/logger

A lightweight wrapper around pino for structured, level-based logging in both development and production environments.

Installation

npm install @yyberi/logger

Features

• Root & child loggers keyed by service or module name
• Automatic environment detection (NODE_ENV) for console pretty-printing in development and file-based logging in production
• Customizable log levels via the LogLevel enum
• ISO timestamps in production logs
• Configurable log directory via the LOG_DIR environment variable

Usage

import getLogger, { LogLevel } from '@yyberi/logger';

// Root logger (defaults to service name '@yyberi/logger')
const logger = getLogger();

// Optionally set a specific service name:
const customLogger = getLogger('my-service');

// Set global log level
logger.setLogLevel(LogLevel.INFO);

logger.info('Application started');

// Create a module-specific child logger
const authLogger = logger.child({ name: 'auth' });
authLogger.debug('Checking user credentials');

Configuration

• NODE_ENV=production

  • Logs to file at $LOG_DIR/app.log (defaults to ./logs/app.log) with level info and above
  • Outputs JSON with fields: timestamp, env, version, service, plus the log message

• NODE_ENV not set or anything else

  • Logs to console with colors and single-line pretty printing
  • Ignores service and module fields in pretty output (shown as prefix)

API Reference

| Method | Description | | --------------------------------------------- | ----------------------------------- | | getLogger(serviceName?) | Get or create a root logger | | logger.child(bindings) | Create a child logger with metadata | | logger.setLogLevel(lvl) | Dynamically adjust log level | | logger.fatal(...), error, warn, info, debug | Log at the specified level |

Environment Variables

• LOG_DIR — Directory where app.log will be stored (defaults to ./logs)
• NODE_ENV — Determines production vs development behavior
• npm_package_version — Automatically picked up from your package.json for metadata

Tips & Caveats

• The logs directory will be created automatically if it does not exist.
• Production logs are written asynchronously; buffered logs may be lost if the process exits abruptly.
• The timestamp override yields ISO-formatted strings; no further configuration needed.

Keywords

log, logging, logger, pino, pino-pretty

License

This project is licensed under the MIT License. Feel free to use and modify as needed.