Chore: proper retry with undici

Build/lib/fetch-retry.ts

@@ -28,9 +28,7 @@ if (!fs.existsSync(CACHE_DIR)) {
 
 const agent = new Agent({
   allowH2: true
-});
-
-agent.compose(
+}).compose(
   interceptors.dns({
     // disable IPv6
     dualStack: false,
@@ -42,6 +40,11 @@ agent.compose(
     minTimeout: 500, // The initial retry delay in milliseconds
     maxTimeout: 10 * 1000, // The maximum retry delay in milliseconds
 
+    // Undici still uses `statusCodes` as the first gate for HTTP response retries.
+    // Our custom `retry()` callback only runs after a response status is admitted here,
+    // so we must list our status codes here before we can read it in our retry callback.
+    statusCodes: [404, 429, 500, 502, 503, 504],
+
     // TODO: this part of code is only for allow more errors to be retried by default
     // This should be removed once https://github.com/nodejs/undici/issues/3728 is implemented
     retry(err, { state, opts }, cb) {
@@ -68,13 +71,22 @@ agent.compose(
         && (
           statusCode === 401 // Unauthorized, should check credentials instead of retrying
           || statusCode === 403 // Forbidden, should check permissions instead of retrying
-          || statusCode === 404 // Not Found, should check URL instead of retrying
+          // || statusCode === 404 // Not Found, should check URL instead of retrying
           || statusCode === 405 // Method Not Allowed, should check method instead of retrying
         )
       ) {
         return cb(err);
       }
 
+      const origin = opts.origin?.toString();
+      if (statusCode === 404) {
+        if (origin?.includes('cdn.jsdelivr.net')) {
+          // continue retry anyway, jsDelivr has recently broken and return HTTP 404 for bad origin
+        } else {
+          return cb(err);
+        }
+      }
+
       // if (errorCode === 'UND_ERR_REQ_RETRY') {
       //   return cb(err);
       // }