chaos-injector/middlewares/randomFailure.js

Chaos engineering middleware for testing API resilience

// ChaosInjector/middlewares/randomFailure.js

function randomFailure(options = {}) {
  const { failureRate = 0.0, errorTypes = ['500'] } = options;

  return function(req, res, next) {
    const randomStatus = Math.random();

    if (randomStatus < failureRate) {
      const errorType = errorTypes[Math.floor(Math.random() * errorTypes.length)];

      switch (errorType) {
        case '400':
          return res.status(400).json({ error: 'Bad Request' });
        case '401':
          return res.status(401).json({ error: 'Unauthorized' });
        case '403':
          return res.status(403).json({ error: 'Forbidden' });
        case '404':
          return res.status(404).json({ error: 'Not Found' });
        case '405':
          return res.status(405).json({ error: 'Method Not Allowed' });
        case '409':
          return res.status(409).json({ error: 'Conflict' });
        case '429':
          return res.status(429).json({ error: 'Too Many Requests' });
        case '500':
          return res.status(500).json({ error: 'Internal Server Error' });
        case '502':
          return res.status(502).json({ error: 'Bad Gateway' });
        case '503':
          return res.status(503).json({ error: 'Service Unavailable' });
        case '504':
          return res.status(504).json({ error: 'Gateway Timeout' });
        case 'empty':
          return res.status(500).send(); // Sending empty response with 500 status
        default:
          return next(new Error(`Unsupported error type: ${errorType}`));
      }
    }
    next();
  };
}

module.exports = randomFailure;