Retrying Failed API Requests with Exponential Backoff

async function fetchWithRetry(url, options = {}, retries = 3, delay = 1000, exponentialBase = 2) {
  for (let i = 0; i < retries; i++) {
    try {
      const response = await fetch(url, options);

      if (response.ok) {
        return response;
      } else if (response.status >= 400 && response.status < 500 && response.status !== 429) {
        // Don't retry client-side errors (except 429 Too Many Requests)
        console.error(`Client error encountered (Status: ${response.status}). Not retrying.`);
        throw new Error(`Client Error: ${response.status} ${response.statusText}`);
      } else {
        // Retry server errors or 429
        console.warn(`Attempt ${i + 1} failed (Status: ${response.status}). Retrying...`);
        const backoffDelay = delay * (exponentialBase ** i);
        await new Promise(res => setTimeout(res, backoffDelay));
      }
    } catch (error) {
      if (i < retries - 1) {
        console.warn(`Network or unknown error on attempt ${i + 1}: ${error.message}. Retrying...`);
        const backoffDelay = delay * (exponentialBase ** i);
        await new Promise(res => setTimeout(res, backoffDelay));
      } else {
        console.error(`Max retries reached. Final error: ${error.message}`);
        throw error;
      }
    }
  }
  throw new Error('Failed to fetch after multiple retries.');
}

// Example usage:
// async function getData() {
//   const apiUrl = 'https://api.example.com/unstable-service';
//   try {
//     const response = await fetchWithRetry(apiUrl, { method: 'GET' }, 5, 500); // 5 retries, starting with 500ms delay
//     const data = await response.json();
//     console.log('Successfully fetched data:', data);
//   } catch (error) {
//     console.error('Failed to get data after retries:', error);
//   }
// }
// getData();