// In Shoal the viewer runs in a frame with scripts only (no same origin), where touching localStorage or
// sessionStorage throws. The upstream UI reads both (onboarding, the identity reveal, sound settings), some of it
// without a try, so the page gets in-memory stand-ins before any of it loads.
for (const name of ['localStorage', 'sessionStorage'] as const) {
  try {
    void window[name].length;
  } catch {
    const data = new Map<string, string>();
    const memory: Storage = {
      get length() {
        return data.size;
      },
      clear: () => data.clear(),
      getItem: (k) => data.get(k) ?? null,
      key: (i) => [...data.keys()][i] ?? null,
      removeItem: (k) => void data.delete(k),
      setItem: (k, v) => void data.set(k, String(v)),
    };
    try {
      Object.defineProperty(window, name, { value: memory, configurable: true });
    } catch {
      // nothing more to do: the upstream code that guards its storage keeps working
    }
  }
}