Run results for: JavaScript spread operator vs Object.assign performance vs Elm builtin update

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0 Safari/605.1.15

Browser: Safari 14

Operating system: Mac OS X 10.15.6

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
Using the spread operator	1726785.2 Ops/sec
Using Object.assign	4081463.5 Ops/sec
Current Elm Update	4353432.5 Ops/sec
Inline copying	286700768.0 Ops/sec

Script Preparation code:


function _Utils_update(oldRecord, updatedFields)
{
	var newRecord = {};

	for (var key in oldRecord)
	{
		newRecord[key] = oldRecord[key];
	}

	for (var key in updatedFields)
	{
		newRecord[key] = updatedFields[key];
	}

	return newRecord;
}

Tests:

Using the spread operator
const firstObject = { sampleData: 'Hello world', moreData: 'foo bar' } const secondObject = { moreData: 'foo bar' } const finalObject = { ...firstObject, ...secondObject };
Using Object.assign
const firstObject = { sampleData: 'Hello world', moreData: 'foo bar' } const secondObject = { moreData: 'foo bar' } const finalObject = Object.assign({}, firstObject, secondObject);
Current Elm Update
const firstObject = { sampleData: 'Hello world', moreData: 'foo bar' } const secondObject = { moreData: 'foo bar' } const finalObject = _Utils_update(firstObject, secondObject);
Inline copying
const firstObject = { sampleData: 'Hello world', moreData: 'foo bar' } const secondObject = { moreData: 'foo bar' } const finalObject = {sampleData: firstObject.sampleData, moreData: secondObject.moreData }

Run results for: JavaScript spread operator vs Object.assign performance vs Elm builtin update

Using the spread operator

Using Object.assign

Current Elm Update

Inline copying