Run results for: structuredClone vs spread vs Object.assign vs copy + more

Note!: none of these tests actually do the same thing, and the data in the example is simple. consider also using arrays: those are nice. Some of these are shallow, some of these are deep-ish. Data is lost through JSON serialization and back, and more data would be lost in JSON and other methods depending on the data stored.

Go to the benchmark

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:139.0) Gecko/20100101 Firefox/139.0

Browser: Firefox 139

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: one year ago

Cursed Proxy

35.6M/s

Object.assign

28.2M/s

Copy

8.2M/s

spread syntax

8.0M/s

Object.fromEntries

1.8M/s

JSON

1.2M/s

structuredClone()

796K/s

View exact numbers

Test name	Executions per second
✓ Cursed Proxy	35,649,600 Ops/sec
Object.assign	28,211,466 Ops/sec
Copy	8,243,931 Ops/sec
spread syntax	7,955,542 Ops/sec
Object.fromEntries	1,771,491 Ops/sec
JSON	1,242,840 Ops/sec
structuredClone()	795,630 Ops/sec

Script Preparation code:

var voucher = {
    "single": false,
    "applyOverTaxes": false,
    "discountType": "1",
    "value": 100,
    "minimumAmount": 0,
    "quantity": 1,
    "suffixLength": 8,
    "code": "IF5R0AFX",
    "vertical": true,
    "allowedPaymentMethods": null,
    "allowedBanks": null,
    "types": undefined,
    "partners": "Many",
    "startDate": "2020-10-21T00:00:00.000Z",
    "endDate": "2020-10-21T00:00:00.000Z",
    "applyed": false
}

function copy(toCopy)
{
	if(typeof toCopy !== 'object' || toCopy === null)
	{
		return toCopy;
	}
	else if(Array.isArray(toCopy))
	{
		let len = toCopy.length;
		let result = new Array(len);

		for(let i = 0; i < len; i++)
		{
			let _toCopy = toCopy[i];
			result[i] = typeof _toCopy !== 'object' || _toCopy === null ? _toCopy : copy(_toCopy);
		}

		return result;
	}
	else
	{
		let result = {};

		for(let i in toCopy)
		{
			let _toCopy = toCopy[i];
			result[i] = typeof _toCopy !== 'object' || _toCopy === null ? _toCopy : copy(_toCopy);
		}

		return result;
	}
}

Tests:

structuredClone()
var newObj = structuredClone(voucher)
spread syntax
var newObj = {...voucher}
Object.assign
var newObj = Object.assign({}, voucher)
Object.fromEntries
var newObj = Object.fromEntries(Object.entries(voucher))
JSON
// loses the "types" property var newObj = JSON.parse(JSON.stringify(voucher))
Cursed Proxy
// this registers as surprisingly performant for some reason, but keep in mind i didn't benchmark // usage, only creation, so in reality this could potentially not be performant when setting/getting. // either way this is really scuffed so you probably shouldn't take this approach var newObject = new Proxy({}, { get (o, p) { return p in o ? o[p] : o[p] ??= voucher[p] }, set (o, p, v) { o[p] = v; return true } })
Copy
var newObj = copy(voucher)