EyJsLogger

An extensible logging system that combines debug for debugging with keys and pino for structured logging and server transmission.

✨ Features

• 🔍 Debug with keys: Uses the debug library for filtering logs by specific keys
• 📊 Structured logging: Uses pino for structured logging with context
• 🚀 Server transmission: Configuration for sending logs to remote servers
• 🎯 Strongly typed: Fully typed with TypeScript
• 🔧 Extensible: Easy to extend with new log types
• 🎨 Consistent API: logger.method format for all logs
• 🌈 Colorized output: Different colors for different log levels
• ⚡ High performance: Minimal overhead in production

📦 Installation

npm install eyjslogger
# or
yarn add eyjslogger
# or
bun add eyjslogger

🚀 Quick Start

import { logger, createLogger } from 'eyjslogger'

// Use default logger
logger.info('Application started')
logger.warn('This is a warning')
logger.error('Something went wrong')

// Create custom logger
const customLogger = createLogger({
  level: 'debug',
  enableDebug: true,
  debugKeys: ['my-app:database', 'my-app:api'],
  serviceName: 'my-service'
})

📖 Usage

Basic Logging

import { logger } from 'eyjslogger'

// Basic logs
logger.info('User logged in')
logger.warn('Performance degradation detected')
logger.error('Database connection failed')
logger.trace('Detailed trace information')

Logs with Context

logger.info('User login attempt', { 
  userId: 'user123', 
  ip: '192.168.1.1', 
  userAgent: 'Mozilla/5.0...' 
})

logger.error('Database connection failed', { 
  error: 'Connection timeout',
  retryCount: 3,
  lastAttempt: new Date().toISOString()
})

Specific Log Types

// User actions
logger.userAction('purchase', 'user456', { 
  amount: 99.99, 
  currency: 'USD' 
})

// System information
logger.systemInfo('Cache cleared successfully', { 
  cacheSize: '2.5MB',
  itemsRemoved: 150
})

// Business logic
logger.businessLogic('Order processing completed', { 
  orderId: 'order-789',
  processingTime: '2.3s'
})

// Warnings
logger.deprecatedFeature('old-api', 'new-api')
logger.performanceWarning('Slow query detected', { duration: '2.5s' })
logger.securityWarning('Multiple failed login attempts', { attempts: 5 })

// Errors
logger.validationError('Invalid email format', 'email', 'invalid-email')
logger.databaseError('Connection timeout', 'SELECT * FROM users WHERE id = ?')
logger.apiError('Rate limit exceeded', '/api/users', 429)
logger.authenticationError('Invalid credentials', 'user123')
logger.systemError('Memory limit exceeded', 'cache-service')
logger.businessError('Insufficient funds', 'payment-processing')

Debug with Keys

import { logger, DEBUG_KEYS, databaseDebug, apiDebug } from 'eyjslogger'

// Debug with specific keys
logger.debug(DEBUG_KEYS.DATABASE, 'Executing query', { 
  query: 'SELECT * FROM users',
  duration: '45ms'
})

logger.debug(DEBUG_KEYS.API, 'Request received', { 
  method: 'GET',
  url: '/api/users'
})

// Use predefined debug loggers
databaseDebug('Connection pool status: healthy')
apiDebug('Response sent successfully', { statusCode: 200 })

Environment Configuration

# Enable debug for specific keys
DEBUG=my-app:database,my-app:api node app.js

# Enable all debug logs
DEBUG=* node app.js

# Use wildcards
DEBUG=my-app:* node app.js

Programmatic Configuration

import { createLogger, debugUtils } from 'eyjslogger'

const logger = createLogger({
  level: 'debug',                    // Log level (trace, debug, info, warn, error)
  enableDebug: true,                 // Enable debug system
  debugKeys: ['app:db', 'app:api'],  // Enabled debug keys
  serverUrl: 'https://logs.com/api', // Remote log server URL
  serviceName: 'my-service'          // Service name
})

// Enable/disable debug keys dynamically
debugUtils.enableDebugKeys('app:auth', 'app:cache')
debugUtils.disableDebugKeys('app:db')

🎨 Color Scheme

• 🔍 TRACE - Gray - Very detailed information
• 🐛 DEBUG - Cyan - Debugging information
• ℹ️ INFO - Green - General information
• ⚠️ WARN - Yellow - Warnings
• ❌ ERROR - Red - Errors
• 💀 FATAL - Magenta - Critical errors

🔧 Configuration Options

| Option | Type | Default | Description | |--------|------|---------|-------------| | level | string | 'info' | Log level (trace, debug, info, warn, error) | | enableDebug | boolean | true | Enable debug system | | debugKeys | string[] | [] | Enabled debug keys | | serverUrl | string | undefined | Remote log server URL | | serviceName | string | 'eyjslogger' | Service name |

📚 API Reference

Logger Methods

Basic Methods

• logger.info(message, context?)
• logger.warn(message, context?)
• logger.error(message, context?)
• logger.debug(key, message, context?)
• logger.trace(message, context?)

Specific Info Methods

• logger.userAction(action, userId?, context?)
• logger.systemInfo(message, context?)
• logger.businessLogic(message, context?)

Specific Warning Methods

• logger.deprecatedFeature(feature, alternative?, context?)
• logger.performanceWarning(message, metrics?)
• logger.securityWarning(message, context?)
• logger.configurationWarning(message, context?)

Specific Error Methods

• logger.validationError(message, field?, value?, context?)
• logger.databaseError(message, query?, context?)
• logger.apiError(message, endpoint?, statusCode?, context?)
• logger.authenticationError(message, userId?, context?)
• logger.systemError(message, component?, context?)
• logger.businessError(message, operation?, context?)

Debug Keys

import { DEBUG_KEYS } from 'eyjslogger'

DEBUG_KEYS.DATABASE    // 'eyjslogger:database'
DEBUG_KEYS.API         // 'eyjslogger:api'
DEBUG_KEYS.AUTH        // 'eyjslogger:auth'
DEBUG_KEYS.CACHE       // 'eyjslogger:cache'
DEBUG_KEYS.VALIDATION  // 'eyjslogger:validation'
DEBUG_KEYS.PERFORMANCE // 'eyjslogger:performance'

Predefined Debug Loggers

import { 
  databaseDebug, 
  apiDebug, 
  authDebug, 
  cacheDebug, 
  validationDebug, 
  performanceDebug 
} from 'eyjslogger'

🧪 Testing

# Run tests
npm test

# Run tests in watch mode
npm run test:watch

# Type checking
npm run type-check

📄 License

MIT © Your Name

🤝 Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

📞 Support

If you have any questions or need help, please open an issue on GitHub.

Made with ❤️ by Your Name