Run results for: Object.assign vs SPREAD vs lodash assignIn

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36

Browser: Chrome 65

Operating system: Mac OS X 10.13.4

Device Platform: Other

Date tested: 6 years ago

Test name	Executions per second
Object.assign()	5706.6 Ops/sec
SPREAD operator	5620.9 Ops/sec
Lodash assignIn	11516.5 Ops/sec

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.js"></script>

Script Preparation code:

var foo = {}
for (var i=0;i<100;i++) {
    foo['foo'+i] = i;
    foo['bar'+i] = i;
    foo['foobar'+i] = i;
}

var bar = {}
for (var i=0;i<100;i++) {
    bar['bar'+i] = i;
    bar['foo'+i] = i;
    bar['barfoo'+i] = i;
}

Tests:

Object.assign()
Object.assign({}, foo, bar)
SPREAD operator
var a = {...foo, ...bar}
Lodash assignIn
_.assignIn({}, foo, bar)

Run results for: Object.assign vs SPREAD vs lodash assignIn

Object.assign()

SPREAD operator

Lodash assignIn