Cuihua Error Handler

Prompts

🛡️ AI-powered error handling assistant that transforms fragile code into resilient systems. Automatically generate comprehensive error handling, recovery strategies, and graceful degradation. Because every production system deserves bulletproof error handling.

Install

openclaw skills install cuihua-error-handler

cuihua-error-handler - Bulletproof Your Code 🛡️

Turn fragile code into production-ready, resilient systems.

An intelligent error handling assistant that automatically:

🔍 Detects missing error handling
✨ Generates comprehensive try/catch blocks
🔄 Implements recovery strategies (retry, fallback, circuit breaker)
📊 Reports error handling coverage
🛡️ Prevents silent failures and crashes

🎯 Why cuihua-error-handler?

The harsh reality:

❌ 80% of production issues come from poor error handling
❌ Silent failures waste hours of debugging
❌ Unhandled rejections crash Node.js servers
❌ Generic try/catch blocks hide the real problems

cuihua-error-handler fixes all of this.

🚀 Quick Start

Analyze error handling

Tell your OpenClaw agent:

"Check error handling coverage in src/"

The agent will:

Scan all async functions
Detect missing try/catch blocks
Identify swallowed errors
Report error handling coverage

Add error handling

"Add error handling to getUserById in api/users.js"

The agent will:

Analyze failure points
Generate specific error types
Add retry logic for network errors
Add fallback for missing data
Add structured logging

Generate recovery strategies

"Add circuit breaker to payment service"

The agent will:

Implement circuit breaker pattern
Add failure rate monitoring
Generate fallback responses
Add automatic recovery

🎨 Features

1. Smart Error Detection 🔍

Automatically finds missing error handling:

// ❌ BEFORE - Fragile code
async function getUserById(id) {
  const res = await fetch(`/api/users/${id}`);
  return res.json();
}

// 🔍 DETECTED ISSUES:
// - No error handling for network failures
// - No handling for non-200 responses
// - No handling for invalid JSON
// - No logging for debugging

2. Comprehensive Error Handling ✨

Generates production-ready error handling:

// ✅ AFTER - Bulletproof code
class UserServiceError extends Error {
  constructor(message, options = {}) {
    super(message);
    this.name = 'UserServiceError';
    this.statusCode = options.statusCode;
    this.originalError = options.cause;
  }
}

async function getUserById(id) {
  try {
    // Validation
    if (!id || typeof id !== 'string') {
      throw new UserServiceError('Invalid user ID', { statusCode: 400 });
    }

    // Network request with timeout
    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), 5000);
    
    const res = await fetch(`/api/users/${id}`, {
      signal: controller.signal
    });
    
    clearTimeout(timeout);

    // HTTP error handling
    if (!res.ok) {
      if (res.status === 404) {
        throw new UserServiceError(`User ${id} not found`, { statusCode: 404 });
      }
      if (res.status >= 500) {
        throw new UserServiceError('Server error, please retry', { statusCode: 502 });
      }
      throw new UserServiceError(`HTTP ${res.status}`, { statusCode: res.status });
    }

    // JSON parsing with error handling
    let data;
    try {
      data = await res.json();
    } catch (parseError) {
      throw new UserServiceError('Invalid response format', {
        statusCode: 502,
        cause: parseError
      });
    }

    return data;

  } catch (error) {
    // Network errors (timeout, connection refused)
    if (error.name === 'AbortError') {
      logger.error('getUserById timeout', { id, timeout: 5000 });
      throw new UserServiceError('Request timeout', {
        statusCode: 504,
        cause: error
      });
    }

    if (error.message.includes('fetch failed')) {
      logger.error('getUserById network error', { id, error: error.message });
      throw new UserServiceError('Network error', {
        statusCode: 503,
        cause: error
      });
    }

    // Re-throw UserServiceError
    if (error instanceof UserServiceError) {
      logger.error('getUserById failed', { id, error: error.message });
      throw error;
    }

    // Unexpected errors
    logger.error('getUserById unexpected error', { id, error });
    throw new UserServiceError('Internal error', {
      statusCode: 500,
      cause: error
    });
  }
}

3. Retry Strategies 🔄

Smart retry with exponential backoff:

async function retryWithBackoff(fn, options = {}) {
  const {
    maxRetries = 3,
    initialDelay = 1000,
    maxDelay = 10000,
    backoffFactor = 2,
    shouldRetry = (error) => true
  } = options;

  let lastError;
  let delay = initialDelay;

  for (let attempt = 0; attempt <= maxRetries; attempt++) {
    try {
      return await fn();
    } catch (error) {
      lastError = error;

      // Check if we should retry
      if (attempt === maxRetries || !shouldRetry(error)) {
        throw error;
      }

      // Wait before retry
      logger.warn(`Retry attempt ${attempt + 1}/${maxRetries} after ${delay}ms`, {
        error: error.message
      });

      await new Promise(resolve => setTimeout(resolve, delay));

      // Exponential backoff
      delay = Math.min(delay * backoffFactor, maxDelay);
    }
  }

  throw lastError;
}

// Usage
async function fetchUserWithRetry(id) {
  return retryWithBackoff(
    () => getUserById(id),
    {
      maxRetries: 3,
      shouldRetry: (error) => {
        // Retry on network errors and 5xx
        return error.statusCode >= 500 || error.name === 'NetworkError';
      }
    }
  );
}

4. Circuit Breaker Pattern ⚡

Prevent cascading failures:

class CircuitBreaker {
  constructor(fn, options = {}) {
    this.fn = fn;
    this.failureThreshold = options.failureThreshold || 5;
    this.resetTimeout = options.resetTimeout || 60000;
    this.state = 'CLOSED'; // CLOSED, OPEN, HALF_OPEN
    this.failureCount = 0;
    this.nextAttempt = Date.now();
  }

  async execute(...args) {
    if (this.state === 'OPEN') {
      if (Date.now() < this.nextAttempt) {
        throw new Error('Circuit breaker is OPEN');
      }
      // Try to recover
      this.state = 'HALF_OPEN';
    }

    try {
      const result = await this.fn(...args);
      this.onSuccess();
      return result;
    } catch (error) {
      this.onFailure();
      throw error;
    }
  }

  onSuccess() {
    this.failureCount = 0;
    if (this.state === 'HALF_OPEN') {
      this.state = 'CLOSED';
      logger.info('Circuit breaker recovered');
    }
  }

  onFailure() {
    this.failureCount++;
    if (this.failureCount >= this.failureThreshold) {
      this.state = 'OPEN';
      this.nextAttempt = Date.now() + this.resetTimeout;
      logger.error('Circuit breaker opened', {
        failureCount: this.failureCount,
        resetTimeout: this.resetTimeout
      });
    }
  }
}

// Usage
const getUserBreaker = new CircuitBreaker(getUserById, {
  failureThreshold: 5,
  resetTimeout: 60000
});

async function fetchUserSafely(id) {
  try {
    return await getUserBreaker.execute(id);
  } catch (error) {
    if (error.message === 'Circuit breaker is OPEN') {
      // Return cached data or default
      return getCachedUser(id) || { id, name: 'Unknown', error: true };
    }
    throw error;
  }
}

5. Graceful Degradation 🎯

Fallback to cached/default data:

async function getUserWithFallback(id) {
  try {
    // Try primary source
    return await getUserById(id);
  } catch (error) {
    logger.warn('Primary source failed, trying fallback', { id, error: error.message });

    try {
      // Try cache
      const cached = await cache.get(`user:${id}`);
      if (cached) {
        logger.info('Returned cached user', { id });
        return { ...cached, _cached: true };
      }
    } catch (cacheError) {
      logger.error('Cache also failed', { id, error: cacheError.message });
    }

    // Return default user
    logger.warn('Returning default user', { id });
    return {
      id,
      name: 'Guest User',
      _default: true,
      _error: error.message
    };
  }
}

6. Error Coverage Analysis 📊

Comprehensive coverage reporting:

🛡️ Error Handling Coverage Report
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

📁 Files analyzed: 42
🔍 Functions analyzed: 156
  - Async functions: 89
  - Sync functions: 67

📊 Overall coverage: 68%

❌ Missing error handling (28 functions):

Critical (needs immediate attention):
  1. api/payment.js:45 - processPayment()
     Risk: High - Financial transaction
     Recommendation: Add try/catch + transaction rollback

  2. api/auth.js:23 - verifyToken()
     Risk: High - Security critical
     Recommendation: Add error handling + logging

  3. db/users.js:78 - updateUserProfile()
     Risk: Medium - Data mutation
     Recommendation: Add validation + rollback

⚠️  Weak error handling (12 functions):

  1. api/users.js:12 - getUserById()
     Issue: Generic catch block without specific handling
     Recommendation: Add error type differentiation

  2. services/email.js:34 - sendWelcomeEmail()
     Issue: Swallowed errors (empty catch block)
     Recommendation: Add logging + alerting

💡 Recommendations:
  - Add error handling to 28 unprotected functions
  - Improve 12 weak error handlers
  - Target coverage: 90%+ for production readiness

📋 Usage Examples

Example 1: Protect API Route

User: "Add error handling to POST /api/orders"

Agent:

// ✅ Generated comprehensive error handling

app.post('/api/orders', async (req, res) => {
  try {
    // Validation
    const { userId, items, paymentMethod } = req.body;
    
    if (!userId || !items || !paymentMethod) {
      return res.status(400).json({
        error: 'Missing required fields',
        required: ['userId', 'items', 'paymentMethod']
      });
    }

    if (!Array.isArray(items) || items.length === 0) {
      return res.status(400).json({
        error: 'Items must be a non-empty array'
      });
    }

    // Create order with error handling
    let order;
    try {
      order = await createOrder({ userId, items, paymentMethod });
    } catch (error) {
      if (error.code === 'INSUFFICIENT_STOCK') {
        return res.status(409).json({
          error: 'Some items are out of stock',
          unavailable: error.items
        });
      }
      throw error; // Re-throw for outer handler
    }

    // Process payment with retry
    let payment;
    try {
      payment = await retryWithBackoff(
        () => processPayment(order.id, paymentMethod),
        { maxRetries: 3 }
      );
    } catch (error) {
      // Rollback order
      await cancelOrder(order.id);
      
      if (error.code === 'PAYMENT_DECLINED') {
        return res.status(402).json({
          error: 'Payment declined',
          reason: error.reason
        });
      }
      throw error;
    }

    // Success
    res.status(201).json({
      orderId: order.id,
      paymentId: payment.id,
      status: 'confirmed'
    });

  } catch (error) {
    logger.error('Order creation failed', {
      body: req.body,
      error: error.message,
      stack: error.stack
    });

    res.status(500).json({
      error: 'Failed to create order',
      message: process.env.NODE_ENV === 'development'
        ? error.message
        : 'Please try again later'
    });
  }
});

Example 2: Database Operations

User: "Add error handling to database queries"

Agent:

class UserRepository {
  async findById(id) {
    try {
      const user = await db.query(
        'SELECT * FROM users WHERE id = $1',
        [id]
      );
      
      if (!user) {
        throw new NotFoundError(`User ${id} not found`);
      }
      
      return user;
    } catch (error) {
      if (error instanceof NotFoundError) {
        throw error;
      }
      
      logger.error('Database query failed', {
        method: 'findById',
        id,
        error: error.message
      });
      
      throw new DatabaseError('Failed to fetch user', { cause: error });
    }
  }

  async update(id, data) {
    const client = await db.getClient();
    
    try {
      await client.query('BEGIN');
      
      const result = await client.query(
        'UPDATE users SET name = $1, email = $2 WHERE id = $3 RETURNING *',
        [data.name, data.email, id]
      );
      
      if (result.rowCount === 0) {
        throw new NotFoundError(`User ${id} not found`);
      }
      
      await client.query('COMMIT');
      return result.rows[0];
      
    } catch (error) {
      await client.query('ROLLBACK');
      
      if (error.code === '23505') { // Unique violation
        throw new ConflictError('Email already exists');
      }
      
      if (error instanceof NotFoundError) {
        throw error;
      }
      
      logger.error('User update failed', { id, data, error: error.message });
      throw new DatabaseError('Failed to update user', { cause: error });
      
    } finally {
      client.release();
    }
  }
}

Example 3: External API Calls

User: "Add resilience to third-party API calls"

Agent:

class WeatherAPI {
  constructor() {
    this.breaker = new CircuitBreaker(this._fetch.bind(this), {
      failureThreshold: 5,
      resetTimeout: 60000
    });
    this.cache = new Map();
  }

  async getWeather(city) {
    // Try cache first
    const cached = this.cache.get(city);
    if (cached && Date.now() - cached.timestamp < 300000) { // 5 min cache
      logger.info('Returning cached weather', { city });
      return cached.data;
    }

    try {
      // Call with circuit breaker
      const data = await this.breaker.execute(city);
      
      // Update cache
      this.cache.set(city, {
        data,
        timestamp: Date.now()
      });
      
      return data;
      
    } catch (error) {
      logger.error('Weather API failed', { city, error: error.message });
      
      // Return stale cache if available
      if (cached) {
        logger.warn('Returning stale cached data', { city });
        return { ...cached.data, _stale: true };
      }
      
      // Return default
      return {
        city,
        temperature: null,
        condition: 'Unknown',
        _error: error.message
      };
    }
  }

  async _fetch(city) {
    const response = await retryWithBackoff(
      () => fetch(`https://api.weather.com/v1/${city}`),
      {
        maxRetries: 3,
        shouldRetry: (error) => {
          // Don't retry client errors
          return !error.statusCode || error.statusCode >= 500;
        }
      }
    );

    if (!response.ok) {
      throw new Error(`Weather API error: ${response.status}`);
    }

    return response.json();
  }
}

⚙️ Configuration

Create .errorhandlerrc.json:

{
  "coverage": {
    "minimum": 80,
    "target": 95,
    "failOnBelow": true
  },
  "patterns": {
    "enableRetry": true,
    "enableCircuitBreaker": true,
    "enableFallback": true,
    "maxRetries": 3,
    "retryDelay": 1000
  },
  "logging": {
    "logLevel": "error",
    "includeStack": true,
    "structuredLogging": true
  },
  "customErrors": {
    "baseClass": "AppError",
    "errorTypes": [
      "ValidationError",
      "NotFoundError",
      "UnauthorizedError",
      "ForbiddenError"
    ]
  }
}

🔒 Error Types

Built-in Error Types

// Base error class
class AppError extends Error {
  constructor(message, options = {}) {
    super(message);
    this.name = this.constructor.name;
    this.statusCode = options.statusCode || 500;
    this.code = options.code;
    this.originalError = options.cause;
  }
}

// Domain-specific errors
class ValidationError extends AppError {
  constructor(message, fields) {
    super(message, { statusCode: 400 });
    this.fields = fields;
  }
}

class NotFoundError extends AppError {
  constructor(resource) {
    super(`${resource} not found`, { statusCode: 404 });
    this.resource = resource;
  }
}

class UnauthorizedError extends AppError {
  constructor(message = 'Unauthorized') {
    super(message, { statusCode: 401 });
  }
}

class ConflictError extends AppError {
  constructor(message) {
    super(message, { statusCode: 409 });
  }
}

class ServiceUnavailableError extends AppError {
  constructor(service) {
    super(`${service} is temporarily unavailable`, { statusCode: 503 });
    this.service = service;
  }
}

💰 Pricing

Free Tier

✅ Error coverage analysis
✅ Basic try/catch generation
✅ Up to 10 files per project

Pro ($10/month)

✅ Unlimited files
✅ Advanced patterns (retry, circuit breaker)
✅ Custom error types
✅ CI/CD integration
✅ Priority support

Enterprise ($79/month)

✅ Everything in Pro
✅ Team error handling policies
✅ Error monitoring integration
✅ Custom recovery strategies
✅ SLA support

📚 Resources

📜 License

MIT License - see LICENSE for details.

🙏 Acknowledgments

Built with 🌸 by 翠花 (Cuihua) for the OpenClaw community.

Because production systems deserve bulletproof error handling.

Made with 🌸 | Cuihua Series | ClawHub Pioneer

Transform fragile code into resilient systems.

Cuihua Error Handler

Install

cuihua-error-handler - Bulletproof Your Code 🛡️

🎯 Why cuihua-error-handler?

🚀 Quick Start

Analyze error handling

Add error handling

Generate recovery strategies

🎨 Features

1. Smart Error Detection 🔍

2. Comprehensive Error Handling ✨

3. Retry Strategies 🔄

4. Circuit Breaker Pattern ⚡

5. Graceful Degradation 🎯

6. Error Coverage Analysis 📊

📋 Usage Examples

Example 1: Protect API Route

Example 2: Database Operations

Example 3: External API Calls

⚙️ Configuration

🔒 Error Types

Built-in Error Types

💰 Pricing

Free Tier

Pro ($10/month)

Enterprise ($79/month)

📚 Resources

📜 License

🙏 Acknowledgments

Related skills