Show the update banner only when the running build differs from the server and make Refresh UI land the new shell on flaky links

frontend/sw.test.js

@@ -27,8 +27,9 @@ const SW_SOURCE = fs.readFileSync(path.join(__dirname, 'sw.js'), 'utf8');
 
 // Builds a fresh sandboxed SW environment with the given starting cache keys
 // and returns handles to drive/inspect it.
-function loadSw(initialCacheKeys) {
+function loadSw(initialCacheKeys, { fetchImpl } = {}) {
   const cacheStore = new Set(initialCacheKeys);
+  const puts = [];
   const deleted = [];
   const clientMessages = [];
 
@@ -50,14 +51,15 @@ function loadSw(initialCacheKeys) {
     async delete(key) { deleted.push(key); return cacheStore.delete(key); },
     async open(key) {
       cacheStore.add(key);
-      return { addAll: async () => {}, match: async () => undefined, put: async () => {} };
+      return { addAll: async () => {}, match: async () => undefined, put: async (url) => { puts.push(url); } };
     },
   };
 
   const sandbox = {
     self: self_,
     caches: caches_,
-    fetch: async () => { throw new Error('fetch not mocked'); },
+    fetch: fetchImpl || (async () => { throw new Error('fetch not mocked'); }),
+    Request: class { constructor(url, init) { this.url = url; Object.assign(this, init); } },
     Response: class { constructor(body, init) { this.body = body; Object.assign(this, init); } },
     URL,
     console,
@@ -72,7 +74,14 @@ function loadSw(initialCacheKeys) {
     await waitPromise;
   }
 
-  return { triggerActivate, deleted, clientMessages, cacheStoreRemaining: () => Array.from(cacheStore) };
+  async function triggerInstall() {
+    let waitPromise = Promise.resolve();
+    const event = { waitUntil: (p) => { waitPromise = p; } };
+    for (const fn of listeners.install || []) fn(event);
+    await waitPromise;
+  }
+
+  return { triggerActivate, triggerInstall, deleted, puts, clientMessages, cacheStoreRemaining: () => Array.from(cacheStore) };
 }
 
 test('activate does NOT broadcast on a fresh install (only the current-version cache exists)', async () => {
@@ -115,3 +124,29 @@ test('activate reports an update and still preserves utility caches together', a
     ['ytplayer-fonts', 'ytplayer-thumbs', 'ytplayer-v1.0.4'].sort()
   );
 });
+
+test('install fetches every shell file past the HTTP cache and retries dropped requests', async () => {
+  const seen = {};
+  const sw = loadSw([], {
+    fetchImpl: async (req) => {
+      seen[req.url] = (seen[req.url] || 0) + 1;
+      assert.strictEqual(req.cache, 'reload', 'must bypass the browser HTTP cache');
+      // The homelab link drops the first request for app.js.
+      if (req.url === '/app.js' && seen[req.url] === 1) throw new TypeError('network error');
+      return { ok: true, status: 200 };
+    },
+  });
+  await sw.triggerInstall();
+  assert.strictEqual(seen['/app.js'], 2, 'a dropped request is retried');
+  assert.ok(sw.puts.includes('/app.js') && sw.puts.includes('/'), 'shell files cached');
+  assert.deepStrictEqual(sw.deleted, []);
+});
+
+test('a failed install deletes its partial cache so activate never mistakes it for an old deploy', async () => {
+  const sw = loadSw([], {
+    fetchImpl: async (req) => (req.url === '/styles.css' ? { ok: false, status: 504 } : { ok: true, status: 200 }),
+  });
+  await assert.rejects(sw.triggerInstall(), /styles\.css/);
+  assert.deepStrictEqual(sw.deleted, ['ytplayer-v1.0.4'], 'partial cache removed');
+  assert.deepStrictEqual(sw.cacheStoreRemaining(), []);
+});