Run results for: assign after allocate object vs re-use object 2

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 11_2_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36

Browser: Chrome 89

Operating system: Mac OS X 11.2.3

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
allocate	543.0 Ops/sec
reuse	348.0 Ops/sec
without object.assign (allocate)	1120.8 Ops/sec
without object.assign (re-used)	427.0 Ops/sec

Script Preparation code:

var reused = {
	color: [1, 1, 1, 1],
  	position: [1, 1],
};

var map = new Map();
for (let i = 0; i < 1000000; i += 1) {
	map.set(`${i}`, {
	  color: [1, 1, 1, 1],
	  position: [1, 1],
      size: 99, // dummy key
	});  
}

Tests:

allocate
for (let i = 0; i < 10000; i += 1) { const target = map.get(`${i}`); Object.assign(target, { color: [i, i, i, i], position: [i, i], }); }
reuse
for (let i = 0; i < 10000; i += 1) { const target = map.get(`${i}`); reused = { color: [i, i, i, i], position: [i, i], }; Object.assign(target, reused); }
without object.assign (allocate)
for (let i = 0; i < 10000; i += 1) { const target = map.get(`${i}`); const newObj = { color: [i, i, i, i], position: [i, i], }; target.color = newObj.color; target.position = newObj.position; }
without object.assign (re-used)
for (let i = 0; i < 10000; i += 1) { const target = map.get(`${i}`); reused = { color: [i, i, i, i], position: [i, i], }; target.color = reused.color; target.position = reused.position; }

Run results for: assign after allocate object vs re-use object 2

allocate

reuse

without object.assign (allocate)

without object.assign (re-used)