#map — 10LOC

Node.jsadvanced

A zero-dependency LRU cache built on Map's insertion order

export const createLRUCache = <K, V>(capacity: number) => {
  const cache = new Map<K, V>();

  const get = (key: K) => {
    if (!cache.has(key)) return undefined;

A Map already tracks insertion order — re-inserting on access is enough to get real LRU eviction for free, no library needed.