Added LRU support to cache

tests/cache.spec.ts

@@ -3,14 +3,16 @@ import { Cache } from '../src';
 describe('Cache', () => {
 	type TestItem = { id: string; value: string };
 
-	let cache: Cache<string, TestItem>;
+	let cache: Cache<string | symbol, TestItem>;
 	let storageMock: Storage;
 	let storageGetItemSpy: jest.SpyInstance;
 	let storageSetItemSpy: jest.SpyInstance;
 
 	beforeEach(() => {
+		jest.useFakeTimers();
+
 		storageMock = {
-			constructor: {name: 'Storage' as any},
+			constructor: { name: 'Storage' as any },
 			getItem: jest.fn(),
 			setItem: jest.fn(),
 			removeItem: jest.fn(),
@@ -23,11 +25,15 @@ describe('Cache', () => {
 		storageGetItemSpy = jest.spyOn(storageMock, 'getItem');
 		storageSetItemSpy = jest.spyOn(storageMock, 'setItem');
 
-		cache = new Cache<string, TestItem>('id', {
+		cache = new Cache<string | symbol, TestItem>('id', {
 			persistentStorage: { storage: storageMock, key: 'cache' },
 		});
+
 		jest.clearAllMocks();
-		jest.useFakeTimers();
+	});
+
+	afterEach(() => {
+		jest.useRealTimers();
 	});
 
 	it('adds and gets an item', () => {
@@ -58,10 +64,12 @@ describe('Cache', () => {
 		expect(storageSetItemSpy).toHaveBeenCalled();
 	});
 
-	it('clears the cache', () => {
-		cache.add({ id: '1', value: 'test' });
+	it('clears the cache & cancels TTL timers', () => {
+		cache.set('1', { id: '1', value: 'x' }, 1);
 		cache.clear();
-		expect(cache.get('1')).toBeNull();
+		// Even after timers advance, nothing should appear or throw
+		jest.advanceTimersByTime(1500);
+		expect(cache.get('1', true)).toBeNull();
 		expect(cache.complete).toBe(false);
 	});
 
@@ -75,7 +83,7 @@ describe('Cache', () => {
 		expect(cache.complete).toBe(true);
 	});
 
-	it('returns correct keys, entries, and map', () => {
+	it('returns correct keys, entries, map, and values()', () => {
 		cache.add({ id: 'x', value: 'foo' });
 		cache.add({ id: 'y', value: 'bar' });
 		expect(cache.keys().sort()).toEqual(['x', 'y']);
@@ -83,6 +91,8 @@ describe('Cache', () => {
 		const m = cache.map();
 		expect(Object.keys(m)).toEqual(expect.arrayContaining(['x', 'y']));
 		expect(m['x'].value).toBe('foo');
+		// CHANGE: values() was a snapshot field before; now it’s a method
+		expect(cache.values().map(v => v.id).sort()).toEqual(['x', 'y']);
 	});
 
 	it('persists and restores from storage', () => {
@@ -93,6 +103,8 @@ describe('Cache', () => {
 			persistentStorage: { storage: storageMock, key: 'cache' },
 		});
 		expect(c.get('z')).toEqual({ id: 'z', value: 'from-storage' });
+		// ensure it used the right storage key
+		expect(storageGetItemSpy).toHaveBeenCalledWith('cache');
 	});
 
 	it('expiryPolicy "delete" removes expired items completely', () => {
@@ -112,20 +124,71 @@ describe('Cache', () => {
 		expect(val && val._expired).toBe(true);
 	});
 
-	// Uncomment and adapt this test if TTL/expiry timers are supported by your implementation
-	// it('expires and deletes items after TTL', () => {
-	//   jest.useFakeTimers();
-	//   cache = new Cache<string, TestItem>('id', { ttl: 0.01 });
-	//   cache.add({ id: 'ttl1', value: 'temp' });
-	//   jest.advanceTimersByTime(100);
-	//   expect(cache.get('ttl1')).toBeNull();
-	// });
+	it('TTL expiration deletes by default', () => {
+		cache.add({ id: 'ttl1', value: 'tick' }, 1);
+		jest.advanceTimersByTime(999);
+		expect(cache.get('ttl1')).toEqual({ id: 'ttl1', value: 'tick' });
+		jest.advanceTimersByTime(2);
+		expect(cache.get('ttl1')).toBeNull();
+	});
 
-	// Edge: add error handling test
-	it('throws if instantiating with invalid key property', () => {
-		expect(() => {
-			const invalid = new Cache<'string', TestItem>('id');
-			// try invalid.add({id: 'z', value: 'fail'}) if needed
-		}).not.toThrow();
+	it('TTL overwrite cancels previous timer', () => {
+		cache.add({ id: 'ow', value: 'v1' }, 1);
+		jest.advanceTimersByTime(500);
+		cache.add({ id: 'ow', value: 'v2' }, 1);
+		jest.advanceTimersByTime(600);
+		expect(cache.get('ow')).toEqual({ id: 'ow', value: 'v2' });
+		jest.advanceTimersByTime(500);
+		expect(cache.get('ow')).toBeNull();
+	});
+
+	it('find() returns first match respecting expired flag', () => {
+		cache.options.expiryPolicy = 'keep';
+		cache.add({ id: 'f1', value: 'hello' });
+		cache.add({ id: 'f2', value: 'world' });
+		cache.expire('f1');
+		expect(cache.find({ value: 'hello' })).toBeUndefined();
+		expect(cache.find({ value: 'hello' }, true)).toEqual({ id: 'f1', value: 'hello', _expired: true });
+	});
+
+	it('symbol keys are supported when using set/get directly', () => {
+		const s = Symbol('k');
+		// NOTE: can’t use add() without a primary key; set works fine
+		cache.set(s, { id: 'sym', value: 'ok' });
+		expect(cache.get(s as any)).toEqual({ id: 'sym', value: 'ok' });
+		// ensure keys() includes the symbol
+		const keys = cache.keys(true);
+		expect(keys.includes(s as any)).toBe(true);
+	});
+
+	it('LRU: evicts least-recently-used when over capacity', () => {
+		const lruCache = new Cache<string, TestItem>('id', {
+			sizeLimit: 2,
+			persistentStorage: { storage: storageMock, key: 'cache' },
+		});
+
+		lruCache.add({ id: 'A', value: '1' });
+		lruCache.add({ id: 'B', value: '2' });
+		// touch A to make it MRU
+		expect(lruCache.get('A')).toEqual({ id: 'A', value: '1' });
+		// add C → should evict least-recently-used (B)
+		lruCache.add({ id: 'C', value: '3' });
+
+		expect(lruCache.get('B')).toBeNull();
+		expect(lruCache.get('A')).toEqual({ id: 'A', value: '1' });
+		expect(lruCache.get('C')).toEqual({ id: 'C', value: '3' });
+	});
+
+	it('delete() removes from LRU and cancels timer', () => {
+		const lruCache = new Cache<string, TestItem>('id', { sizeLimit: 2 });
+		lruCache.set('A', { id: 'A', value: '1' }, 1);
+		lruCache.delete('A');
+		jest.advanceTimersByTime(1200);
+		expect(lruCache.get('A', true)).toBeNull();
+	});
+
+	it('throws when adding item missing the primary key', () => {
+		const c = new Cache<'id', any>('id');
+		expect(() => c.add({ nope: 'missing' } as any)).toThrow(/Doesn't exist/);
 	});
 });