Different cache id resolution per argument

[amaury1093]

My function has signature:

function myFunction(a: object, b: object): void;

const memoized = memoize(f);

If I understood well, when I memoize that, it memoizes by object reference:

memoize({ foo: 'bar' }, { bar: 'qux' });
memoize({ foo: 'bar' }, { bar: 'qux' }); // Cache NOT hit

I wish to memoize the 1st argument by its serialized version, and the 2nd argument by object reference. Namely, if:

const first = { foo: 'bar' };
const second = { bar: 'qux' };

The I want the 3 following tests to pass:

Test 1:

memoize(first, second);
memoize({ foo: 'bar' }, second); // Cache hit
memoize(first, second); // Cache hit

Test 2:

memoize(first, second);
memoize(first, { bar: 'qux' }); // Cache not hit
memoize({ foo: 'bar' }, { bar: 'qux' }); // Cache not hit

Test 3:

memoize({ foo: 'bar' }, second);
memoize({ foo: 'bar' }, second); // Cache hit
memoize(first, second); // Cache hit

Is that possible with the current version?

[medikoo]

Is that possible with the current version?

Yes it is, but you need to provide your own normalizer, which can work as e.g.:

const idCounter = 0;
const idMap = new WeakMap();
const getObjectId = obj => {
  if (idMap.has(obj)) return iMap.get(obj);
  const id = ++idCounter;
  idMap.set(obj, id);
  return id;
};

const memoized = memoize(f, {
  normalizer: ([a, b]) => `${getObjectId(b)},${JSON.stringify(a)}`
});

[medikoo]

Alternatively, if it would be the case where first argument is expected to be mapped by reference and second by serialized representation, it can be done more straightforward with weak mode:

const memoizeWeak = require("memoizee/weak");

const memoized = memoizeWeak(f, { normalizer: ([,b]) => JSON.stringify(b) });