Django ServiceWorker view

sw.js

// service worker
self.addEventListener("install", (event) => {
  event.waitUntil(
    caches.open("{{ cache_key }}").then((cache) =>
      cache.addAll([
        // {% for asset in assets %}
        "{{ asset }}",
        // {% endfor %}
      ])
    )
  );
});

self.addEventListener("activate", (event) => {
  event
    .waitUntil(
      caches
        .keys()
        .then((keys) =>
          Promise.all(
            keys
              .filter((key) => key !== "{{ cache_key }}")
              .map((key) => caches.delete(key))
          )
        )
    )
    .then(() => clients.claim());
});

self.addEventListener("fetch", (event) => {
  event.respondWith(
    caches
      .match(event.request)
      .then((response) => response || fetch(event.request))
  );
});

views.py

def serviceworker(request):
    """Dumb view that renders a service worker to cache static files."""
    staticfiles = [
        "css/dist/styles.css",
        "js/page.js",
        "img/icon1024-maskable.png",
    ]
    static_assets = list(map(staticfiles_storage.url, staticfiles))

    # Get the React bundle assets
    loader = get_loader("DEFAULT")
    bundle = _get_bundle(None, loader)
    static_assets += [f"{loader.asset_path}{asset}" for asset in bundle]

    # Calculate cache key from combined hashes
    re_hash = re.compile(r".*?\.([0-9a-f]{8,12})\.[a-z]{2,3}")
    hash_matches = map(re_hash.match, static_assets)
    cache_key = "".join([match.group(1) for match in hash_matches if match])

    return render(
        request,
        "sw.js",
        context={
            "assets": static_assets,
            "cache_key": cache_key,
        },
        content_type="application/javascript",
    )