Retry a request with backoff

Arguments

task() => Promise<T>

An async function to invoke. Called afresh on each attempt.

options.attemptsnumber

Maximum number of calls to task before giving up. Defaults to 3.

options.baseDelaynumber

Milliseconds to wait after the first failure. Doubles after each subsequent failure. Defaults to 100.

Returns

Promise<T> — Resolves with the first successful value from task. Rejects with the last error if every attempt fails.

Examples

let calls = 0;
const value = await retry(async () => {
  calls++;
  if (calls < 3) throw new Error("flaky");
  return "ok";
}, { attempts: 5, baseDelay: 10 });
// value === "ok", calls === 3

try {
  await retry(async () => { throw new Error("down"); }, { attempts: 2, baseDelay: 10 });
} catch (err) {
  // err.message === "down" — the last error surfaces
}

What it has to do

• Resolve as soon as any attempt succeeds.
• Reject with the last error once attempts are exhausted.
• Double the delay after each failure, starting at baseDelay.

Notes

• Don't sleep after the final failed attempt — rejecting immediately feels snappier and matches what callers expect.
• In production you'd typically add jitter to the delay so retrying clients don't all pile back on at the same instant.