import '@testing-library/jest-dom/vitest'; // Node 25 ships a partial localStorage global that lacks getItem/setItem/clear // unless launched with --localstorage-file. jsdom sees Node's global and skips // installing its own. Replace with an in-memory Storage-compatible polyfill so // tests (and browser-only code under test) see a working localStorage. class MemoryStorage implements Storage { private store = new Map(); get length() { return this.store.size; } clear(): void { this.store.clear(); } getItem(key: string): string | null { return this.store.get(key) ?? null; } key(i: number): string | null { return Array.from(this.store.keys())[i] ?? null; } removeItem(key: string): void { this.store.delete(key); } setItem(key: string, value: string): void { this.store.set(key, String(value)); } } const memLocal = new MemoryStorage(); const memSession = new MemoryStorage(); Object.defineProperty(globalThis, 'localStorage', { configurable: true, value: memLocal }); Object.defineProperty(globalThis, 'sessionStorage', { configurable: true, value: memSession }); if (typeof window !== 'undefined') { Object.defineProperty(window, 'localStorage', { configurable: true, value: memLocal }); Object.defineProperty(window, 'sessionStorage', { configurable: true, value: memSession }); }