Run results for: JavaScript spread operator vs Object.assign performance - modify object

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/116.0.0.0 Safari/537.36

Browser: Chrome 116

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
Using the spread operator	54793840.0 Ops/sec
Using Object.assign	7636371.0 Ops/sec

Tests:

Using the spread operator

const firstObject = {
  attempts: 1,
  created_at: 1694778031091,
  expires_at: 1694778091091,
  source: {
    externalId: "831f76fc-5a9d-49bc-8d4b-114010cedb73",
    name: "Tengen Uzui",
    type: "phone",
  },
  type: "phone",
  value: "411273",
};
const finalObject = {
  ...firstObject,
  attempts: firstObject.attempts + 1,
};

​x
 
const firstObject = {  attempts: 1,  created_at: 1694778031091,  expires_at: 1694778091091,  source: {    externalId: "831f76fc-5a9d-49bc-8d4b-114010cedb73",    name: "Tengen Uzui",    type: "phone",  },  type: "phone",  value: "411273",};const finalObject = {  ...firstObject,  attempts: firstObject.attempts + 1,};​

Using Object.assign

const firstObject = {
  attempts: 1,
  created_at: 1694778031091,
  expires_at: 1694778091091,
  source: {
    externalId: "831f76fc-5a9d-49bc-8d4b-114010cedb73",
    name: "Tengen Uzui",
    type: "phone",
  },
  type: "phone",
  value: "411273",
};

const finalObject = Object.assign({}, firstObject, {
  attempts: firstObject.attempts + 1,
});

 
const firstObject = {  attempts: 1,  created_at: 1694778031091,  expires_at: 1694778091091,  source: {    externalId: "831f76fc-5a9d-49bc-8d4b-114010cedb73",    name: "Tengen Uzui",    type: "phone",  },  type: "phone",  value: "411273",};​const finalObject = Object.assign({}, firstObject, {  attempts: firstObject.attempts + 1,});​