Run results for: object copy bench

Test name	Executions per second
✓ Object assign	8,810,644 Ops/sec
Spread syntax	3,055,664 Ops/sec
babyClone	817,323 Ops/sec
window.structuredClone	234,350 Ops/sec

Script Preparation code:

var voucher = {
    "single": false,
    "applyOverTaxes": false,
    "discountType": "1",
    "value": 100,
    "minimumAmount": 0,
    "quantity": 1,
    "suffixLength": 8,
    "code": "IF5R0AFX",
    "vertical": [],
    "allowedPaymentMethods": [],
    "allowedBanks": [],
    "types": [],
    "partners": [],
    "startDate": "2020-10-21T00:00:00.000Z",
    "endDate": "2020-10-21T00:00:00.000Z",
    "applyed": false
}

function babyClone(obj) {
  switch (typeof obj) {
    case 'string':
    case 'number':
    case 'bigint':
    case 'boolean':
    case 'symbol':
    case 'undefined':
      return obj;
    case 'object':
      if (!obj) return null;
      if (Array.isArray(obj)) {
        return Array.prototype.map.call(obj, babyClone);
      }
	  if (Object.getPrototypeOf(obj) !== Object.getPrototypeOf({})) {
	    // this won't catch Proxy
	    throw 'trying to copy a class instance';
	  }
      let copy = {};
      for (let sym of Object.getOwnPropertySymbols(obj)) {
        copy[sym] = babyClone(obj[sym]);
      }
      for (let key in obj) {
        copy[key] = babyClone(obj[key]);
      }
      return copy;
    case 'function':
      throw 'no copying things with functions in them';
    default:
      throw 'what new nonsense have they added to js';
  }
}

Tests:

window.structuredClone
const copy = window.structuredClone(voucher);
Spread syntax
const copy = { ...voucher };
Object assign
const copy = {}; Object.assign(copy, voucher);
babyClone
const copy = babyClone(voucher);

Run results for: object copy bench

window.structuredClone

Spread syntax

Object assign

babyClone