Error Codes

{
  "code": "SUBSCRIPTION_FAILED",
  "message": "Minimum importance must be between 0-10",
  "details": {
    "field": "minImportance",
    "value": 15,
    "allowedRange": "0-10"
  },
  "timestamp": "2024-01-15T10:30:00Z"
}

socket.on('news:error', (error) => {
  console.error(`[${error.code}] ${error.message}`);
  
  switch (error.code) {
    case 'AUTHENTICATION_FAILED':
      handleAuthFailed(error);
      break;
    case 'NOT_AUTHENTICATED':
      handleNotAuthenticated(error);
      break;
    case 'SUBSCRIPTION_FAILED':
      handleSubscriptionFailed(error);
      break;
    case 'WEBSOCKET_NOT_SUPPORTED':
      handleWebSocketNotSupported(error);
      break;
    default:
      handleUnknownError(error);
  }
});

function handleAuthFailed(error) {
  console.error('Authentication failed:', error.message);
  
  // Check API key format
  if (!byul_api_key?.startsWith('byul_v2_')) {
    console.error('Invalid API key format. Must start with byul_v2_');
  }
  
  // Disconnect and require re-authentication
  socket.disconnect();
}

function handleNotAuthenticated(error) {
  console.warn('Authentication lost:', error.message);
  
  // Attempt reconnection with authentication
  socket.disconnect();
  
  setTimeout(() => {
    socket.connect();
  }, 2000);
}

class SubscriptionValidator {
  static validate(params) {
    const errors = [];
    
    if (params.minImportance && (params.minImportance < 0 || params.minImportance > 10)) {
      errors.push('minImportance must be between 0 and 10');
    }
    
    if (params.limit && (params.limit < 1 || params.limit > 100)) {
      errors.push('limit must be between 1 and 100');
    }
    
    return errors;
  }
}

// Usage
const params = { minImportance: 7, limit: 20 };
const validationErrors = SubscriptionValidator.validate(params);

if (validationErrors.length === 0) {
  socket.emit('news:subscribe', params);
} else {
  console.error('Validation failed:', validationErrors);
}