/**
* LRUCache Tests
*/
import { describe, it, expect } from 'vitest';
import { LRUCache, DEFAULT_CACHE_OPTIONS } from './cache.js';
describe('LRUCache', () => {
describe('basic operations', () => {
it('should store and retrieve values', () => {
const cache = new LRUCache<string, number>();
cache.set('a', 1);
cache.set('b', 2);
expect(cache.get('a')).toBe(1);
expect(cache.get('b')).toBe(2);
});
it('should return undefined for non-existent keys', () => {
const cache = new LRUCache<string, number>();
expect(cache.get('missing')).toBeUndefined();
});
it('should check if key exists with has()', () => {
const cache = new LRUCache<string, number>();
cache.set('exists', 1);
expect(cache.has('exists')).toBe(true);
expect(cache.has('missing')).toBe(false);
});
it('should delete entries', () => {
const cache = new LRUCache<string, number>();
cache.set('a', 1);
expect(cache.has('a')).toBe(true);
const deleted = cache.delete('a');
expect(deleted).toBe(true);
expect(cache.has('a')).toBe(false);
// Deleting non-existent key returns false
expect(cache.delete('missing')).toBe(false);
});
it('should clear all entries', () => {
const cache = new LRUCache<string, number>();
cache.set('a', 1);
cache.set('b', 2);
cache.set('c', 3);
expect(cache.size).toBe(3);
cache.clear();
expect(cache.size).toBe(0);
expect(cache.has('a')).toBe(false);
});
it('should report correct size', () => {
const cache = new LRUCache<string, number>();
expect(cache.size).toBe(0);
cache.set('a', 1);
expect(cache.size).toBe(1);
cache.set('b', 2);
expect(cache.size).toBe(2);
cache.delete('a');
expect(cache.size).toBe(1);
});
});
describe('LRU eviction', () => {
it('should evict oldest entry when maxSize exceeded', () => {
const cache = new LRUCache<number, string>({ maxSize: 2 });
cache.set(1, 'a');
cache.set(2, 'b');
cache.set(3, 'c'); // Should evict key 1
expect(cache.has(1)).toBe(false);
expect(cache.has(2)).toBe(true);
expect(cache.has(3)).toBe(true);
expect(cache.size).toBe(2);
});
it('should update access order on get()', () => {
const cache = new LRUCache<number, string>({ maxSize: 2 });
cache.set(1, 'a');
cache.set(2, 'b');
cache.get(1); // Access key 1, making it most recently used
cache.set(3, 'c'); // Should evict key 2 (oldest)
expect(cache.has(1)).toBe(true);
expect(cache.has(2)).toBe(false);
expect(cache.has(3)).toBe(true);
});
it('should update position when setting existing key', () => {
const cache = new LRUCache<number, string>({ maxSize: 2 });
cache.set(1, 'a');
cache.set(2, 'b');
cache.set(1, 'a-updated'); // Re-set key 1, making it most recently used
cache.set(3, 'c'); // Should evict key 2 (oldest)
expect(cache.has(1)).toBe(true);
expect(cache.get(1)).toBe('a-updated');
expect(cache.has(2)).toBe(false);
expect(cache.has(3)).toBe(true);
});
it('should work with maxSize of 1', () => {
const cache = new LRUCache<string, number>({ maxSize: 1 });
cache.set('a', 1);
expect(cache.get('a')).toBe(1);
cache.set('b', 2);
expect(cache.has('a')).toBe(false);
expect(cache.get('b')).toBe(2);
});
});
describe('stats()', () => {
it('should return correct statistics', () => {
const cache = new LRUCache<string, number>({ maxSize: 10 });
cache.set('a', 1);
cache.set('b', 2);
cache.set('c', 3);
const stats = cache.stats();
expect(stats.size).toBe(3);
expect(stats.maxSize).toBe(10);
expect(stats.keys).toEqual(['a', 'b', 'c']);
});
it('should return empty keys array for empty cache', () => {
const cache = new LRUCache<string, number>();
const stats = cache.stats();
expect(stats.size).toBe(0);
expect(stats.keys).toEqual([]);
});
});
describe('constructor options', () => {
it('should use default maxSize of 50', () => {
const cache = new LRUCache<number, string>();
const stats = cache.stats();
expect(stats.maxSize).toBe(50);
});
it('should accept custom maxSize', () => {
const cache = new LRUCache<number, string>({ maxSize: 100 });
const stats = cache.stats();
expect(stats.maxSize).toBe(100);
});
it('should work with different key/value types', () => {
// Number keys
const numCache = new LRUCache<number, string>();
numCache.set(1, 'one');
expect(numCache.get(1)).toBe('one');
// Object values
interface User {
name: string;
}
const objCache = new LRUCache<string, User>();
objCache.set('user1', { name: 'Alice' });
expect(objCache.get('user1')).toEqual({ name: 'Alice' });
});
});
describe('DEFAULT_CACHE_OPTIONS', () => {
it('should have expected default values', () => {
expect(DEFAULT_CACHE_OPTIONS).toEqual({
maxSize: 50,
debug: false,
name: 'RFCCache',
});
});
});
});
