From 805bbaead993beaf4670586d98fac8aec6939171 Mon Sep 17 00:00:00 2001
From: William Valentin <william.valentin.info@gmail.com>
Date: Wed, 18 Feb 2026 12:22:01 -0800
Subject: [PATCH] fix(gateway-ui): refresh service worker and static cache
 headers

---
 src/gateway/server.test.ts | 11 +++++++++++
 src/gateway/static.ts      |  8 +++++++-
 src/gateway/ui/lib/pwa.js  |  5 ++++-
 src/gateway/ui/sw.js       | 39 +++++++++++++++++++++++++++++---------
 4 files changed, 52 insertions(+), 11 deletions(-)

diff --git a/src/gateway/server.test.ts b/src/gateway/server.test.ts
index fd00408..d37a885 100644
--- a/src/gateway/server.test.ts
+++ b/src/gateway/server.test.ts
@@ -295,6 +295,7 @@ describe('GatewayServer integration', () => {
     const res = await fetch(`http://127.0.0.1:${TEST_PORT}/`);
     expect(res.status).toBe(200);
     expect(res.headers.get('content-type')).toBe('text/html');
+    expect(res.headers.get('cache-control')).toBe('no-cache');
     const body = await res.text();
     expect(body).toContain('Flynn');
   });
@@ -308,6 +309,16 @@ describe('GatewayServer integration', () => {
     expect(res.headers.get('content-type')).toBe('text/css');
   });
 
+  it('serves sw.js with no-store cache policy', async () => {
+    if (!LISTEN_ALLOWED) {
+      return;
+    }
+    const res = await fetch(`http://127.0.0.1:${TEST_PORT}/sw.js`);
+    expect(res.status).toBe(200);
+    expect(res.headers.get('content-type')).toBe('application/javascript');
+    expect(res.headers.get('cache-control')).toBe('no-store');
+  });
+
   it('returns 404 for unknown HTTP path', async () => {
     if (!LISTEN_ALLOWED) {
       return;
diff --git a/src/gateway/static.ts b/src/gateway/static.ts
index 4c91058..2bd0b4d 100644
--- a/src/gateway/static.ts
+++ b/src/gateway/static.ts
@@ -71,7 +71,13 @@ export async function serveStatic(
   // Try to read and serve the file
   try {
     const content = await readFile(filePath);
-    res.writeHead(200, { 'Content-Type': contentType });
+    const headers: Record<string, string> = { 'Content-Type': contentType };
+    if (pathname === '/sw.js') {
+      headers['Cache-Control'] = 'no-store';
+    } else if (pathname === '/index.html') {
+      headers['Cache-Control'] = 'no-cache';
+    }
+    res.writeHead(200, headers);
     res.end(content);
     return true;
   } catch {
diff --git a/src/gateway/ui/lib/pwa.js b/src/gateway/ui/lib/pwa.js
index c3309a1..9f4197d 100644
--- a/src/gateway/ui/lib/pwa.js
+++ b/src/gateway/ui/lib/pwa.js
@@ -60,7 +60,10 @@ export async function registerPwaServiceWorker() {
   if (!('serviceWorker' in navigator)) {
     return null;
   }
-  return navigator.serviceWorker.register(withToken('/sw.js'));
+  const registration = await navigator.serviceWorker.register(withToken('/sw.js'));
+  // Ask the browser to check for a newer worker on app load.
+  void registration.update().catch(() => undefined);
+  return registration;
 }
 
 export async function getPushStatus() {
diff --git a/src/gateway/ui/sw.js b/src/gateway/ui/sw.js
index 542807e..e9c9dfe 100644
--- a/src/gateway/ui/sw.js
+++ b/src/gateway/ui/sw.js
@@ -1,4 +1,4 @@
-const CACHE_NAME = 'flynn-webchat-v1';
+const CACHE_NAME = 'flynn-webchat-v2';
 const token = new URL(self.location.href).searchParams.get('token');
 const withToken = (path) => {
   if (!token) {
@@ -34,17 +34,38 @@ self.addEventListener('fetch', (event) => {
     return;
   }
 
-  event.respondWith((async () => {
-    const cached = await caches.match(event.request, { ignoreSearch: true });
-    if (cached) {
-      return cached;
-    }
+  const requestUrl = new URL(event.request.url);
+  const isNavigation = event.request.mode === 'navigate';
+  const isStaticAsset = requestUrl.origin === self.location.origin
+    && (requestUrl.pathname.startsWith('/lib/')
+      || requestUrl.pathname.startsWith('/pages/')
+      || requestUrl.pathname === '/app.js'
+      || requestUrl.pathname === '/style.css'
+      || requestUrl.pathname === '/index.html'
+      || requestUrl.pathname === '/manifest.webmanifest');
 
+  event.respondWith((async () => {
     try {
-      return await fetch(event.request);
+      const networkResponse = await fetch(event.request);
+      if (isNavigation || isStaticAsset) {
+        const cache = await caches.open(CACHE_NAME);
+        await cache.put(event.request, networkResponse.clone());
+      }
+      return networkResponse;
     } catch {
-      const fallback = await caches.match('/index.html', { ignoreSearch: true });
-      return fallback || new Response('Offline', { status: 503 });
+      const cached = await caches.match(event.request, { ignoreSearch: true });
+      if (cached) {
+        return cached;
+      }
+
+      if (isNavigation) {
+        const fallback = await caches.match('/index.html', { ignoreSearch: true });
+        if (fallback) {
+          return fallback;
+        }
+      }
+
+      return new Response('Offline', { status: 503 });
     }
   })());
 });