queryClient: retry certain 5xx codes automatically

src/queries/client.ts

@@ -1,12 +1,30 @@
 import { QueryClient } from '@tanstack/react-query';
 
+import { HTTPError } from 'soapbox/api/HTTPError';
+
+/** HTTP response codes to retry. */
+const RETRY_CODES = [502, 503, 504, 521, 522];
+
 const queryClient = new QueryClient({
   defaultOptions: {
     queries: {
       refetchOnWindowFocus: false,
       staleTime: 60000, // 1 minute
       gcTime: Infinity,
-      retry: false,
+      retry(failureCount: number, error: Error): boolean {
+        if (error instanceof HTTPError) {
+          const { response } = error;
+
+          // TODO: Implement Retry-After.
+          // const retryAfter = response.headers.get('Retry-After');
+
+          if (RETRY_CODES.includes(response.status)) {
+            return failureCount < 3;
+          }
+        }
+
+        return false;
+      },
     },
   },
 });