fix: refresh cached app shell after deployments

backend/main.py

@@ -783,6 +783,9 @@ if static_dir.exists():
     async def spa(path: str):
         root = static_dir.resolve()
         target = (root / path).resolve()
+        headers = {"Cache-Control": "no-cache, no-store, must-revalidate, max-age=0"}
         if target.is_file() and target.is_relative_to(root):
+            if target.name == "sw.js":
+                return FileResponse(target, headers=headers)
             return FileResponse(target)
-        return FileResponse(root / "index.html")
+        return FileResponse(root / "index.html", headers=headers)

frontend/public/sw.js

@@ -1,5 +1,5 @@
-const CACHE = 'dodo-shell-v2'
-const SHELL = ['/', '/manifest.json', '/icon-192.png', '/icon-512.png', '/apple-touch-icon.png']
+const CACHE = 'dodo-shell-v3'
+const SHELL = ['/manifest.json', '/icon-192.png', '/icon-512.png', '/apple-touch-icon.png']
 self.addEventListener('install', (event) => {
   self.skipWaiting()
   event.waitUntil(caches.open(CACHE).then((cache) => cache.addAll(SHELL)))
@@ -11,11 +11,16 @@ self.addEventListener('fetch', (event) => {
   const url = new URL(event.request.url)
   if (url.pathname.startsWith('/api/')) return
   if (event.request.method !== 'GET') return
+  const isNavigation = event.request.mode === 'navigate'
+  if (isNavigation) {
+    event.respondWith(fetch(event.request).catch(() => caches.match('/offline.html')))
+    return
+  }
   event.respondWith(
     caches.match(event.request).then((cached) => cached || fetch(event.request).then((response) => {
       const copy = response.clone()
       caches.open(CACHE).then((cache) => cache.put(event.request, copy))
       return response
-    }).catch(() => caches.match('/'))),
+    })),
   )
 })