cuihua-logger - Production-Ready Logging 📝

Debug faster with intelligent, structured logging.

An AI-powered logging assistant that automatically:

• 📝 Generates structured logs with proper context
• 🎯 Selects appropriate log levels (debug, info, warn, error)
• 📊 Adds performance metrics and timing
• 🔍 Detects missing logs in critical paths
• ⚡ Optimizes log output for production

🎯 Why cuihua-logger?

The problem:

• ❌ Too many console.log() everywhere
• ❌ No structure, hard to search
• ❌ Wrong log levels (everything is "info")
• ❌ Missing context (what user? what request?)
• ❌ Performance overhead in production

cuihua-logger solves all of this.

🚀 Quick Start

Analyze logging coverage

"Check logging coverage in src/"

Add structured logging

"Add logging to getUserById function"

Generate performance logs

"Add performance logging to API endpoints"

🎨 Features

1. Structured Logging ✨

// ❌ BEFORE - Unstructured
async function getUserById(id) {
  console.log('Getting user:', id);
  const user = await db.query('SELECT * FROM users WHERE id = $1', [id]);
  console.log('User found:', user);
  return user;
}

// ✅ AFTER - Structured
async function getUserById(id) {
  logger.info('Fetching user', { 
    userId: id,
    operation: 'getUserById'
  });
  
  const startTime = Date.now();
  const user = await db.query('SELECT * FROM users WHERE id = $1', [id]);
  const duration = Date.now() - startTime;
  
  logger.info('User fetched successfully', {
    userId: id,
    operation: 'getUserById',
    duration,
    found: !!user
  });
  
  return user;
}

2. Smart Log Levels 🎯

// Automatic level selection based on context

logger.debug('Cache hit', { key, ttl }); // Development only

logger.info('User logged in', { userId, ip }); // Important events

logger.warn('Rate limit approaching', { 
  userId, 
  current: 95, 
  limit: 100 
}); // Potential issues

logger.error('Payment failed', { 
  orderId, 
  error: error.message,
  stack: error.stack 
}); // Critical errors

3. Performance Logging ⚡

async function fetchData() {
  const timer = logger.startTimer();
  
  const data = await expensiveOperation();
  
  timer.done({ level: 'info', message: 'Operation complete' });
  
  return data;
}

// Output: "Operation complete" duration=1234ms

4. Request Tracking 🔍

app.use((req, res, next) => {
  req.requestId = generateId();
  req.logger = logger.child({ 
    requestId: req.requestId,
    method: req.method,
    path: req.path 
  });
  
  req.logger.info('Request started');
  
  res.on('finish', () => {
    req.logger.info('Request completed', {
      statusCode: res.statusCode,
      duration: Date.now() - req.startTime
    });
  });
  
  next();
});

📋 Usage Examples

Example 1: Add Logging to Function

User: "Add logging to processOrder function"

Generated:

async function processOrder(orderId, items) {
  logger.info('Processing order', { orderId, itemCount: items.length });
  
  try {
    // Validate
    if (!orderId || !items.length) {
      logger.warn('Invalid order data', { orderId, items });
      throw new ValidationError('Invalid order');
    }
    
    // Create order
    const order = await createOrder(orderId, items);
    logger.info('Order created', { orderId, orderNumber: order.number });
    
    // Process payment
    const payment = await processPayment(order);
    logger.info('Payment processed', { 
      orderId, 
      paymentId: payment.id,
      amount: payment.amount 
    });
    
    return order;
    
  } catch (error) {
    logger.error('Order processing failed', {
      orderId,
      error: error.message,
      stack: error.stack
    });
    throw error;
  }
}

Example 2: API Endpoint Logging

app.post('/api/users', async (req, res) => {
  const { logger } = req;
  
  logger.info('Creating user', { email: req.body.email });
  
  try {
    const user = await userService.create(req.body);
    
    logger.info('User created successfully', {
      userId: user.id,
      email: user.email
    });
    
    res.status(201).json(user);
    
  } catch (error) {
    logger.error('User creation failed', {
      email: req.body.email,
      error: error.message
    });
    
    res.status(500).json({ error: 'Failed to create user' });
  }
});

⚙️ Logger Configuration

Winston

import winston from 'winston';

const logger = winston.createLogger({
  level: process.env.LOG_LEVEL || 'info',
  format: winston.format.combine(
    winston.format.timestamp(),
    winston.format.errors({ stack: true }),
    winston.format.json()
  ),
  transports: [
    new winston.transports.File({ filename: 'error.log', level: 'error' }),
    new winston.transports.File({ filename: 'combined.log' })
  ]
});

Pino (fastest)

import pino from 'pino';

const logger = pino({
  level: process.env.LOG_LEVEL || 'info',
  timestamp: pino.stdTimeFunctions.isoTime,
  formatters: {
    level: (label) => ({ level: label })
  }
});

📊 Log Levels

💰 Pricing

Free

• ✅ Basic log generation
• ✅ Up to 10 files

Pro ($8/month)

• ✅ Unlimited files
• ✅ Performance logging
• ✅ Request tracking
• ✅ CI/CD integration

Enterprise ($59/month)

• ✅ Team policies
• ✅ Log aggregation setup
• ✅ Custom formatters

📚 Best Practices

1. Always log errors with context
2. Use structured logging (objects, not strings)
3. Include request IDs for tracing
4. Don't log sensitive data (passwords, tokens)
5. Use appropriate log levels

📜 License

MIT

🙏 Acknowledgments

Built with 🌸 by 翠花 (Cuihua)

Made with 🌸 | Cuihua Series | ClawHub Pioneer