feat: implement retry delay

README.md

@@ -103,7 +103,8 @@ await ofetch('/url', { ignoreResponseError: true })
 
 ```ts
 await ofetch('http://google.com/404', {
-  retry: 3
+  retry: 3,
+  retryDelay: 500, //ms, default to 100
 })
 ```
 

src/fetch.ts

@@ -45,7 +45,10 @@ export interface FetchOptions<R extends ResponseType = ResponseType>
   responseType?: R;
   response?: boolean;
   retry?: number | false;
-
+  /**
+   * Delay between retries in milliseconds.
+   */
+  retryDelay?: number;
   onRequest?(context: FetchContext): Promise<void> | void;
   onRequestError?(
     context: FetchContext & { error: Error }
@@ -86,14 +89,15 @@ const retryStatusCodes = new Set([
 export function createFetch(globalOptions: CreateFetchOptions): $Fetch {
   const { fetch, Headers } = globalOptions;
 
-  function onError(context: FetchContext): Promise<FetchResponse<any>> {
+  async function onError(context: FetchContext): Promise<FetchResponse<any>> {
     // Is Abort
     // If it is an active abort, it will not retry automatically.
     // https://developer.mozilla.org/en-US/docs/Web/API/DOMException#error_names
     const isAbort =
       (context.error && context.error.name === "AbortError") || false;
     // Retry
     if (context.options.retry !== false && !isAbort) {
+      const retryDelay = context.options.retryDelay || 100;
       let retries;
       if (typeof context.options.retry === "number") {
         retries = context.options.retry;
@@ -103,6 +107,7 @@ export function createFetch(globalOptions: CreateFetchOptions): $Fetch {
 
       const responseCode = (context.response && context.response.status) || 500;
       if (retries > 0 && retryStatusCodes.has(responseCode)) {
+        await new Promise((resolve) => setTimeout(resolve, retryDelay));
         return $fetchRaw(context.request, {
           ...context.options,
           retry: retries - 1,

test/index.test.ts

@@ -135,7 +135,7 @@ describe("ofetch", () => {
       const { headers } = await $fetch(getURL("post"), {
         method: "POST",
         body: { num: 42 },
-        headers: sentHeaders,
+        headers: sentHeaders as HeadersInit,
       });
       expect(headers).to.include({ "x-header": "1" });
       expect(headers).to.include({ accept: "application/json" });
@@ -196,6 +196,19 @@ describe("ofetch", () => {
     expect(error.request).to.equal(getURL("404"));
   });
 
+  it("retry with delay", async () => {
+    const fast = $fetch<string>(getURL("404"), {
+      retry: 2,
+      retryDelay: 1,
+    }).catch(() => "fast");
+    const slow = $fetch<string>(getURL("404"), {
+      retry: 2,
+      retryDelay: 100,
+    }).catch(() => "slow");
+    const race = await Promise.race([slow, fast]);
+    expect(race).to.equal("fast");
+  });
+
   it("abort with retry", () => {
     const controller = new AbortController();
     async function abortHandle() {