• Quick Start 🔥

  A lightweight, colorful, and feature-rich TypeScript logger with zero dependencies.

  • Setup

    install space first.

    # install
    space i @je-es/slog

    // import
    import { Logger } from '@je-es/slog';

  
  

  • Usage

    • Basic Logging

      // Create a logger instance
      const logger = new Logger('info', false);
      
      // Log at different levels
      logger.debug({ userId: 123 }, 'User lookup');
      logger.info({ status: 'ready' }, 'Server initialized');
      logger.warn({ memory: '85%' }, 'High memory usage');
      logger.error({ code: 'ECONNREFUSED' }, 'Database connection failed');
      logger.fatal({ error: 'OutOfMemory' }, 'Critical system error');
      
      // Output (JSON format):
      // {"timestamp":"2024-12-04T01:35:12.665Z","level":"INFO","message":"Server initialized","status":"ready"}

    
    

    • Pretty Mode (Human-Readable)

      // Enable pretty mode for colorful, readable logs
      const logger = new Logger('info', true);
      
      logger.info({ userId: 123 }, 'User authenticated');
      // Output: 01:35:12 ● User authenticated userId:123
      
      logger.warn({ disk: '90%' }, 'Low disk space');
      // Output: 01:35:12 ⚠ Low disk space disk:90%
      
      logger.error({ code: 500 }, 'Internal error');
      // Output: 01:35:12 ✖ Internal error code:500

    
    

    • HTTP Request Logging (Morgan-Style)

      const logger = new Logger('info', true);
      
      // Automatically formats HTTP request logs
      logger.info({
          method: 'GET',
          path: '/api/users',
          status: 200,
          duration: 45
      });
      // Output: 01:35:12 GET /api/users 200 45ms (colored)

    
    

    • Child Loggers with Prefixes

      const logger = new Logger('info', false);
      
      // Create namespaced loggers for different services
      const apiLogger = logger.child('API');
      const dbLogger = logger.child('Database');
      
      apiLogger.info({ endpoint: '/users' }, 'Request received');
      // Output: {"timestamp":"...","level":"INFO","message":"[API] Request received","endpoint":"/users"}
      
      // Nested child loggers
      const userService = apiLogger.child('Users');
      userService.info({ userId: 123 }, 'User created');
      // Output: {"timestamp":"...","level":"INFO","message":"[API:Users] User created","userId":123}

    
    

    • Log Levels & Filtering

      // Set minimum log level (debug < info < warn < error < fatal)
      const logger = new Logger('warn', false);
      
      logger.debug({ test: 1 }, 'Debug msg');  // ❌ Won't log
      logger.info({ test: 2 }, 'Info msg');    // ❌ Won't log
      logger.warn({ test: 3 }, 'Warning msg'); // ✅ Will log
      logger.error({ test: 4 }, 'Error msg');  // ✅ Will log
      logger.fatal({ test: 5 }, 'Fatal msg');  // ✅ Will log

    
    

    • Special Formatting (Pretty Mode)

      const logger = new Logger('info', true);
      
      // Route registration
      logger.info({ method: 'GET', path: '/api/users' }, 'Route added');
      // Output: 01:35:12 → GET    /api/users
      
      logger.info({ method: ['GET', 'POST'], path: '/api/auth' }, 'Route added');
      // Output: 01:35:12 → GET|POST /api/auth
      
      // Database connection
      logger.info({ name: 'PostgreSQL' }, '✔ Database connected');
      // Output: 01:35:12 ✓ Database connected (PostgreSQL)
      
      // Server startup
      logger.info({ url: 'http://localhost:3000' }, 'Server started');
      // Output: 01:35:12 ✓ Server started at http://localhost:3000

    
    

    • String Messages

      const logger = new Logger('info', false);
      
      // You can pass a string directly as the data parameter
      logger.info('Simple message');
      // Output: {"timestamp":"...","level":"INFO","message":"Simple message"}
      
      // Works in pretty mode too
      const prettyLogger = new Logger('info', true);
      prettyLogger.info('Application started');
      // Output: 01:35:12 ● Application started

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