import { LRUCache } from '@/utils/lru-cache';
describe('LRUCache', () => {
const realNow = Date.now;
afterEach(() => {
// Restore Date.now after time-based tests
Date.now = realNow;
});
it('gets and sets values; has/delete/clear/size/keys work', () => {
const cache = new LRUCache<string>({ maxSize: 3, ttl: 60_000 });
expect(cache.size()).toBe(0);
expect(cache.get('a')).toBeNull();
expect(cache.has('a')).toBe(false);
cache.set('a', '1');
cache.set('b', '2');
cache.set('c', '3');
expect(cache.size()).toBe(3);
expect(cache.has('a')).toBe(true);
expect(cache.get('a')).toBe('1');
// keys() iteration
const keys = Array.from(cache.keys());
expect(keys.length).toBe(3);
// delete
expect(cache.delete('b')).toBe(true);
expect(cache.has('b')).toBe(false);
expect(cache.size()).toBe(2);
// clear
cache.clear();
expect(cache.size()).toBe(0);
});
it('evicts least recently used when exceeding maxSize', () => {
const cache = new LRUCache<string>({ maxSize: 2, ttl: 60_000 });
cache.set('a', '1');
cache.set('b', '2');
// Access 'a' to make it most recently used
expect(cache.get('a')).toBe('1');
// Add 'c' -> should evict least recently used (which is 'b')
cache.set('c', '3');
expect(cache.has('a')).toBe(true);
expect(cache.has('b')).toBe(false);
expect(cache.has('c')).toBe(true);
});
it('expires entries by ttl via get/has and evictExpired()', () => {
const start = 1_000_000_000_000; // arbitrary epoch
Date.now = jest.fn(() => start);
const cache = new LRUCache<string>({ maxSize: 5, ttl: 10_000 });
cache.set('x', 'val');
// Advance time within TTL
(Date.now as unknown as jest.Mock).mockReturnValue(start + 9_000);
expect(cache.has('x')).toBe(true);
expect(cache.get('x')).toBe('val');
// Advance beyond TTL
(Date.now as unknown as jest.Mock).mockReturnValue(start + 11_000);
expect(cache.has('x')).toBe(false);
expect(cache.get('x')).toBeNull();
// Re-add and then evictExpired
(Date.now as unknown as jest.Mock).mockReturnValue(start + 12_000);
cache.set('y', 'val2');
(Date.now as unknown as jest.Mock).mockReturnValue(start + 23_000);
cache.evictExpired();
expect(cache.has('y')).toBe(false);
});
});
