Simple javascript memory leak tester

test-memory-leak.ts

// a quick memory leak tester

// TODO: actually verify and make it objectively testable

function getRandomInt(max: number) {
  return Math.floor(Math.random() * max);
}

const size = 2000 * 1000 as const; // whatever length to make the size big enough at each step

function malloc() {
  const arrInHeap = [...Array(size).keys()];

  return arrInHeap;
}

function randomCalc(arr: number[]) {
  // use randomness to prevent runtime/compiler to optimize which prevent the whole purpose of creating a big memory actually allocated
  const a = arr[getRandomInt(size)];
  const b = arr[getRandomInt(size)];
  return a + b;
}

// insert this into where the subject object that you think it might not release when its no longer referenced 
const m = malloc();

// insert these where the representation object's aliveness
const r = randomCalc(m); console.log(r);

const example = () => {
  const m = malloc();

  return () => {
    const r = randomCalc(m); console.log(r);
  }
}

const exampleNoLeak = example();
const aliveness = exampleNoLeak;

aliveness();
aliveness();
aliveness();
aliveness();

// should be released after this point - but strictly this is up to the runtime so might see the release only later;

const exampleLeak1 = example();
const exampleLeak2 = example();

exampleLeak2.arbitraryRef = exampleLeak1;
exampleLeak1.arbitraryRef = exampleLeak2;

exampleLeak2(); exampleLeak1();
exampleLeak2(); exampleLeak1();
exampleLeak2(); exampleLeak1();
exampleLeak2(); exampleLeak1();

// will be leaks even after here