Merge pull request 'fix(pwa): network-first navigation so a new deploy loads online immediately' (#200) from feature/sw-fresh-online into development

gateway/internal/webui/webui.go

@@ -71,6 +71,11 @@ func handlerFor(content fs.FS, stripPrefix, indexName string) http.Handler {
 		// app (notably a relaunched Telegram Mini App) is a cache hit, not a re-download.
 		if strings.HasPrefix(name, "assets/") {
 			w.Header().Set("Cache-Control", "public, max-age=31536000, immutable")
+		} else if name == "sw.js" {
+			// The service worker must be revalidated on every load so a new deploy's worker (and its
+			// fresh precache manifest) is picked up promptly; a cached sw.js would strand clients on
+			// the old build. The worker's network-first navigation then serves the fresh shell online.
+			w.Header().Set("Cache-Control", "no-cache")
 		}
 		files.ServeHTTP(w, r)
 	})

gateway/internal/webui/webui_test.go

@@ -94,6 +94,10 @@ func TestHandlerServesServiceWorkerAsJavaScript(t *testing.T) {
 	if ct := resp.Header.Get("Content-Type"); !strings.HasPrefix(ct, "text/javascript") {
 		t.Errorf("Content-Type = %q, want text/javascript", ct)
 	}
+	// Revalidated on every load so a new deploy's worker (and its fresh precache) is picked up.
+	if cc := resp.Header.Get("Cache-Control"); cc != "no-cache" {
+		t.Errorf("sw.js Cache-Control = %q, want no-cache", cc)
+	}
 }
 
 // TestHandlerFallsBackToShellForUnknownManifestPath guards the trap: a manifest/sw path NOT emitted

ui/src/sw.ts

@@ -8,7 +8,7 @@
 // served stale. Registration stays manual and web-only (pwa.svelte.ts): skipped in the mock build
 // and inside a Telegram/VK Mini App.
 import { clientsClaim } from 'workbox-core';
-import { cleanupOutdatedCaches, createHandlerBoundToURL, precacheAndRoute } from 'workbox-precaching';
+import { cleanupOutdatedCaches, matchPrecache, precacheAndRoute } from 'workbox-precaching';
 import { NavigationRoute, registerRoute } from 'workbox-routing';
 
 // The injectManifest build replaces self.__WB_MANIFEST with the precache list; the DOM lib knows
@@ -28,10 +28,25 @@ cleanupOutdatedCaches();
 // needs. The landing page and the old-engine polyfill bundle are excluded via the build globs.
 precacheAndRoute(self.__WB_MANIFEST);
 
-// Serve the precached shell for any in-scope top-level navigation. Deny-list the RPC path and the
+// Navigations are network-first so a new deploy loads immediately when online: fetch the fresh
+// (no-cache) shell from the server — it references the new hashed assets, which are then fetched
+// fresh — and only fall back to the precached shell when the network is unreachable or too slow (a
+// short timeout). This keeps the app up to date online while still cold-launching offline. Only the
+// tiny HTML is re-fetched; the immutable hashed assets stay cache-first (precacheAndRoute above) and
+// re-download only when their hash — i.e. the version — changes. Deny-list the RPC path and the
 // admin console so those are never resolved to the app shell.
-registerRoute(
+const NAV_TIMEOUT_MS = 3000;
-  new NavigationRoute(createHandlerBoundToURL('index.html'), {
+async function freshShell({ request }: { request: Request }): Promise<Response> {
-    denylist: [/^\/scrabble\.edge\.v1\.Gateway/, /^\/_gm\//],
+  const ctrl = new AbortController();
-  }),
+  const timer = setTimeout(() => ctrl.abort(), NAV_TIMEOUT_MS);
-);
+  try {
+    const res = await fetch(request, { signal: ctrl.signal });
+    if (res.ok) return res;
+  } catch {
+    /* offline or too slow — serve the precached shell below */
+  } finally {
+    clearTimeout(timer);
+  }
+  return (await matchPrecache('index.html')) ?? Response.error();
+}
+registerRoute(new NavigationRoute(freshShell, { denylist: [/^\/scrabble\.edge\.v1\.Gateway/, /^\/_gm\//] }));