Service Worker and Cache Storage API: Coordinating asset updates during live migration

Direct answer

No. Invoking self.skipWaiting() followed by clients.claim() in the activate event does not guarantee that every open page immediately serves the new cache across Chrome, Firefox, and Safari.

Why the guarantee falls short

• Activation is asynchronous. The waiting worker becomes the active worker only after the current document finishes parsing; existing scripts keep running under the old worker.
• Claim changes the fetch handler. After clients.claim(), new network requests from that page are routed to the new worker, but the document’s in‑memory cache references and already‑loaded assets remain from the previous build.
• Browser‑specific update checks. Chrome checks for updates on navigation and after a short idle period; Firefox and Safari have different timelines, and some may defer script evaluation until the next navigation.

Recommended steps to avoid mixed‑version serving

1. Version the cache name (e.g., myapp-v1, myapp-v2). Store the build identifier in the service worker scope and use it for all caches.open() calls.
2. At install, precache the new asset set atomically with cache.addAll(); if any request fails, the whole step aborts, leaving the old cache untouched.
3. In activate, delete superseded caches after the new worker has taken control of all in‑scope clients, or use a controllerchange listener to delete them once no old pages remain.
4. Listen for the controllerchange event on navigator.serviceWorker. Once fired, issue a single location.reload() guarded by a flag so each page re‑fetches its document under the new worker.
5. Optionally, present a lightweight “update available” prompt that asks the user to reload if instant consistency is required without a full‑page flash.

Is a soft page reload sufficient?

A single location.reload() after controllerchange is the practical way to achieve consistency without perceiving downtime; the user sees a brief re‑render but no full‑reload loop. However, the reload is not instantaneous and depends on the browser’s update‑check cycle. If your requirement is sub‑second, zero‑notice transition, you must version the cache and delete old caches only after all clients have been claimed, then rely on the reload pattern described above.

Please confirm whether you are using a static cache name or a versioned one, so I can tailor the exact delete‑order and reload guard logic.