useMemo — recomputes only on dep change

What does this output?

let computeCount = 0;

function useMemo(factory, deps) {
  let cached = null;
  return function get(newDeps) {
    if (cached && newDeps.every((d, i) => d === cached.deps[i])) {
      return cached.value;
    }
    computeCount++;
    cached = { value: factory(...newDeps), deps: newDeps };
    return cached.value;
  };
}

const getFiltered = useMemo(
  (items, query) => items.filter(x => x.includes(query)),
  []
);

const items = ['apple', 'banana', 'apricot'];

const r1 = getFiltered([items, 'ap']);
const r2 = getFiltered([items, 'ap']);  // same deps
const r3 = getFiltered([items, 'ban']); // query changed

console.log(computeCount);
console.log(r1.join(','));
console.log(r2.join(','));
console.log(r3.join(','));

Correct Output

2
apple,apricot
apple,apricot
banana

Why this output?