Stub implementation of the Web Storage API

stub-storage.ts

class StubStorage implements Storage {
  readonly items = new Map<string, string>();

  get itemsArray() {
    return Object.values(this.items);
  }

  get length(): number {
    return this.itemsArray.length;
  }

  clear(): void {
    this.items.clear();
  }

  getItem(key: string): string | null {
    return this.items.get(key) ?? null;
  }

  key(index: number): string | null {
    return this.itemsArray[index] ?? null;
  }

  removeItem(key: string): void {
    this.items.delete(key);
  }

  setItem(key: string, value: string): void {
    this.items.set(key, value);
  }
}