Implement Robust API Calls with Exponential Backoff and Retries in JavaScript

async function fetchDataWithRetry(url, options = {}, maxRetries = 5) {
  let retries = 0;
  while (retries < maxRetries) {
    try {
      const response = await fetch(url, options);
      if (!response.ok) {
        // Handle HTTP errors, e.g., 429 Too Many Requests, 5xx server errors
        if (response.status === 429 || response.status >= 500) {
          throw new Error(`API error: ${response.status} ${response.statusText}`);
        } else {
          // For other client errors (e.g., 400, 401, 403, 404), don't retry
          const errorData = await response.json().catch(() => ({ message: response.statusText }));
          console.error(`Non-retryable API error: ${response.status} ${errorData.message}`);
          throw new Error(`Non-retryable API error: ${response.status} ${errorData.message}`);
        }
      }
      return await response.json();
    } catch (error) {
      console.warn(`Attempt ${retries + 1} failed: ${error.message}`);
      retries++;
      if (retries < maxRetries) {
        const delay = Math.pow(2, retries) * 1000 + Math.random() * 1000; // Exponential backoff + jitter
        console.log(`Retrying in ${delay / 1000} seconds...`);
        await new Promise(resolve => setTimeout(resolve, delay));
      } else {
        console.error(`Max retries (${maxRetries}) reached. Failing request.`);
        throw error;
      }
    }
  }
}

// Example usage:
// fetchDataWithRetry('https://api.example.com/data', { method: 'GET' })
//   .then(data => console.log('Data fetched:', data))
//   .catch(err => console.error('Failed to fetch data after retries:', err));

// Example with a POST request
// fetchDataWithRetry('https://api.example.com/post-data', {
//   method: 'POST',
//   headers: { 'Content-Type': 'application/json' },
//   body: JSON.stringify({ key: 'value' })
// })
//   .then(result => console.log('POST result:', result))
//   .catch(err => console.error('Failed to post data after retries:', err));