Node.js: How do you implement a custom HTTP client with retry logic in Node.js?

1async function fetchWithRetry(url, options = {}, retries = 3) {
2    const { delay = 1000, backoff = 2, ...fetchOptions } = options;
3
4    for (let attempt = 0; attempt <= retries; attempt++) {
5        try {
6            const response = await fetch(url, fetchOptions);
7
8            if (response.ok) return response;
9
10            // Do not retry on client errors (4xx)
11            if (response.status >= 400 && response.status < 500) {
12                throw new Error(`Client error: ${response.status}`);
13            }
14
15            // Server error — retry
16            throw new Error(`Server error: ${response.status}`);
17        } catch (err) {
18            if (attempt === retries) throw err;
19
20            const waitTime = delay * Math.pow(backoff, attempt);
21            console.log(`Attempt ${attempt + 1} failed, retrying in ${waitTime}ms`);
22            await new Promise(r => setTimeout(r, waitTime));
23        }
24    }
25}
26
27// Usage
28const response = await fetchWithRetry("https://api.example.com/data", {
29    retries: 3,
30    delay: 1000,
31    headers: { Authorization: "Bearer token" },
32});