Handled aborts during retry backoff

Author: gkoos

src/client.ts

@@ -276,7 +276,8 @@ export function createClient<
           effectiveRetries,
           effectiveRetryDelay,
           shouldRetryWithHook,
-          request
+          request,
+          combinedSignal
         )
         if (effectiveHooks.transformResponse) {
           res = await effectiveHooks.transformResponse(res, request)

src/retry.ts

@@ -13,12 +13,40 @@ export const defaultDelay: RetryDelay = (ctx) => {
   return 2 ** ctx.attempt * 200 + Math.random() * 100
 }
 
+function waitForRetryDelay(ms: number, signal?: AbortSignal): Promise<void> {
+  if (ms <= 0) return Promise.resolve()
+  return new Promise((resolve) => {
+    if (!signal) {
+      setTimeout(resolve, ms)
+      return
+    }
+
+    if (signal.aborted) {
+      resolve()
+      return
+    }
+
+    const onAbort = () => {
+      clearTimeout(timer)
+      resolve()
+    }
+
+    const timer = setTimeout(() => {
+      signal.removeEventListener('abort', onAbort)
+      resolve()
+    }, ms)
+
+    signal.addEventListener('abort', onAbort, { once: true })
+  })
+}
+
 export async function retry(
   fn: () => Promise<Response>,
   retries: number,
   delay: RetryDelay,
   shouldRetry: (ctx: RetryContext) => boolean = () => true,
-  request: Request
+  request: Request,
+  signal?: AbortSignal
 ): Promise<Response> {
   let lastErr: unknown
   let lastRes: Response | undefined
@@ -36,7 +64,7 @@ export async function retry(
       ctx.error = undefined
       if (i < retries && shouldRetry(ctx)) {
         const wait = typeof delay === 'function' ? delay(ctx) : delay
-        await new Promise((r) => setTimeout(r, wait))
+        await waitForRetryDelay(wait, signal)
         continue
       }
       return lastRes
@@ -45,7 +73,7 @@ export async function retry(
       ctx.error = err
       if (i === retries || !shouldRetry(ctx)) throw err
       const wait = typeof delay === 'function' ? delay(ctx) : delay
-      await new Promise((r) => setTimeout(r, wait))
+      await waitForRetryDelay(wait, signal)
     }
   }
   throw lastErr

test/core/client.error.test.ts

@@ -293,11 +293,30 @@ describe('Advanced/Edge Cases: Custom Errors', () => {
         (err instanceof AbortError &&
           err.message === 'Request was aborted by user' &&
           err.cause === undefined) ||
-        (err instanceof TimeoutError && err.cause instanceof DOMException)
+        err instanceof TimeoutError
     )
     expect(abortFired).toBe(true)
   }, 1000)
 
+  it('AbortError: thrown when user aborts during retry backoff delay', async () => {
+    const fetchSpy = vi.fn().mockRejectedValue(new Error('first failure'))
+
+    global.fetch = fetchSpy
+    const controller = new AbortController()
+    const f = createClient({ retries: 1, retryDelay: 10_000 })
+
+    const promise = f('https://example.com', { signal: controller.signal })
+
+    setTimeout(() => controller.abort(), 5)
+
+    await expect(promise).rejects.toSatisfy(
+      (err) =>
+        err instanceof AbortError &&
+        err.message === 'Request was aborted by user'
+    )
+    expect(fetchSpy).toHaveBeenCalledTimes(1)
+  })
+
   it('NetworkError: thrown for different network error messages', async () => {
     const nativeErr = new TypeError('NetworkError: lost connection')
     global.fetch = vi.fn().mockRejectedValue(nativeErr)