fix(release): retry rate-limited HEADs in the download gate

Author: elkaix

scripts/release/cdn-consistency.mjs

@@ -137,8 +137,9 @@ export function collectReleaseDownloadUrls({ latestJson, releaseManifest, releas
 }
 
 /**
- * HEAD each URL and return the ones that do not answer 2xx. A transport error
- * or 5xx is retried `attempts` times in total; a 4xx is final at once.
+ * HEAD each URL and return the ones that do not answer 2xx. A transport error,
+ * 5xx, 403 or 429 (GitHub rate limiting) is retried `attempts` times in total;
+ * any other 4xx is final at once.
  */
 export async function findUnreachableUrls({ fetchImpl, sleep, urls, attempts = 3, retryDelayMs = 5_000 }) {
   const unreachable = [];
@@ -148,7 +149,7 @@ export async function findUnreachableUrls({ fetchImpl, sleep, urls, attempts = 3
       try {
         const response = await fetchImpl(url, { method: 'HEAD' });
         status = response.status;
-        if (response.ok || (status >= 400 && status < 500)) break;
+        if (response.ok || (status >= 400 && status < 500 && status !== 403 && status !== 429)) break;
       } catch (error) {
         status = error instanceof Error ? error.message : 'unreachable';
       }

scripts/release/cdn-consistency.test.mjs

@@ -86,3 +86,17 @@ void test('recovers when a retry succeeds', async () => {
   assert.deepEqual(unreachable, []);
   assert.equal(calls, 2);
 });
+
+void test('retries a rate-limited 429 instead of reporting it at once', async () => {
+  let calls = 0;
+  const unreachable = await findUnreachableUrls({
+    fetchImpl: async () => {
+      calls += 1;
+      return new Response(null, { status: calls === 1 ? 429 : 200 });
+    },
+    sleep: async () => {},
+    urls: ['a'],
+  });
+  assert.deepEqual(unreachable, []);
+  assert.equal(calls, 2);
+});