🪵 Logger System

A beautiful, feature-rich logging system for TypeScript/JavaScript applications with colorized output, emoji icons, and flexible configuration options.

✨ Features

• 🎨 Colorized Output - Beautiful ANSI color codes for different log levels
• 🎯 Emoji Icons - Visual indicators for each log level
• ⏰ Timestamps - ISO 8601 formatted timestamps (configurable)
• 📊 Multiple Log Levels - Trace, Debug, Info, Success, Warn, Error, and Fatal
• 🔧 Flexible Configuration - Customize timestamp and colorization per log call
• 🚀 Zero Dependencies - Lightweight and fast
• 📦 TypeScript Support - Full type safety included

📦 Installation

npm install your-logger-package
# or
yarn add your-logger-package

🚀 Quick Start

import logger from './index';

// Simple logging
logger.info('Application started');
logger.success('Database connection established');
logger.warn('This is a warning');
logger.error('Something went wrong');

// With additional arguments
logger.debug('User data:', { id: 123, name: 'John' });
logger.error('Failed to connect:', error);

📚 API Reference

Log Levels

The logger supports seven log levels, each with its own color and emoji:

| Level | Emoji | Color | Use Case | |-------|-------|-------|----------| | trace | 🔍 | Gray | Very detailed tracing information | | debug | 🐛 | Cyan | Debug information for development | | info | ℹ️ | Green | General informational messages | | success | ✅ | Bright Green | Success messages and completed operations | | warn | ⚠️ | Yellow | Warning messages | | error | ❌ | Red | Error messages | | fatal | 💀 | Magenta | Critical errors that may cause termination |

Methods

logger.trace(message: string, ...args: any[]): void

Logs a trace-level message.

logger.trace('Entering function');

logger.debug(message: string, ...args: any[]): void

Logs a debug-level message.

logger.debug('Variable value:', variable);

logger.info(message: string, ...args: any[]): void

Logs an info-level message.

logger.info('Server listening on port 3000');

logger.success(message: string, ...args: any[]): void

Logs a success-level message. Perfect for indicating successful operations, completed tasks, or positive outcomes.

logger.success('User registration completed');
logger.success('Payment processed successfully', { transactionId: '12345' });

logger.warn(message: string, ...args: any[]): void

Logs a warning-level message.

logger.warn('Deprecated API used');

logger.error(message: string, ...args: any[]): void

Logs an error-level message.

logger.error('Failed to process request:', error);

logger.fatal(message: string, ...args: any[]): void

Logs a fatal-level message.

logger.fatal('Critical system failure');

logger.log(level: LogLevel, message: string, ...args: any[]): void

Generic log method that accepts a log level as the first parameter.

logger.log('info', 'Custom log level');

🎨 Output Format

The logger formats messages as follows:

[2024-01-15T10:30:45.123Z] ℹ️  INFO  Your message here

Format breakdown:

• [timestamp] - ISO 8601 formatted timestamp (optional)
• emoji - Visual indicator for the log level
• LEVEL - Uppercase log level name (padded to 5 characters)
• message - Your log message
• Color coding applied based on log level

💡 Examples

Basic Usage

import logger from './index';

// Different log levels
logger.trace('Detailed trace information');
logger.debug('Debugging information');
logger.info('Application started successfully');
logger.success('User logged in successfully');
logger.warn('This feature is deprecated');
logger.error('An error occurred');
logger.fatal('Critical failure');

With Additional Data

// Logging objects and arrays
logger.debug('User object:', { id: 1, name: 'Alice' });
logger.info('Processing items:', [1, 2, 3, 4, 5]);

// Logging errors
try {
    // some code
} catch (error) {
    logger.error('Exception caught:', error);
}

Dynamic Logging

const level = 'info';
logger.log(level, 'Dynamic log level');

🔧 Configuration

The logger uses sensible defaults but supports configuration through the LogOptions interface:

interface LogOptions {
    level?: LogLevel;
    timestamp?: boolean;  // Default: true
    colorize?: boolean;   // Default: true
}

Note: Currently, the logger applies default formatting to all messages. Future versions may support per-message configuration.

🎯 Use Cases

• Development - Use trace and debug for detailed development logs
• Production - Use info, warn, and error for production logging
• Monitoring - Use fatal for critical issues that require immediate attention
• Debugging - Use debug to track variable values and execution flow

🌟 Best Practices

1. Use appropriate log levels - Don't use error for warnings or info for debug messages
2. Include context - Add relevant data to help diagnose issues
3. Avoid logging sensitive data - Never log passwords, tokens, or personal information
4. Use structured logging - Pass objects as additional arguments for better parsing
5. Set log levels per environment - Consider filtering logs based on environment

📝 Example Output

[2024-01-15T10:30:45.123Z] 🔍 TRACE Entering authentication function
[2024-01-15T10:30:45.124Z] 🐛 DEBUG User ID: 12345
[2024-01-15T10:30:45.125Z] ℹ️  INFO  Processing authentication request
[2024-01-15T10:30:45.126Z] ✅ SUCCESS User authenticated successfully
[2024-01-15T10:30:45.127Z] ⚠️  WARN  Using deprecated authentication method
[2024-01-15T10:30:45.128Z] ❌ ERROR Failed to connect to database
[2024-01-15T10:30:45.129Z] 💀 FATAL Critical system failure detected

🤝 Contributing

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

📄 License

[Your License Here]

🙏 Acknowledgments

Built with ❤️ for the developer community.

Made with care | Simple, beautiful, and effective logging for your applications