Run results for: Reduce Destructuring vs Assertion

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.106 YaBrowser/21.6.0.1108 Yowser/2.5 Safari/537.36

Browser: Yandex Browser 21

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
{ ...acc, [x]: true }	806.7 Ops/sec
acc[x] = true;	5856.7 Ops/sec

Script Preparation code:

var arr = Array(10_000).fill(0);

Tests:

{ ...acc, [x]: true }
arr.reduce((acc, x) => ({ ...acc, [x]: true }), {})
acc[x] = true;
arr.reduce((acc, x) => { acc[x] = true; return acc; }, {})

Run results for: Reduce Destructuring vs Assertion

{ ...acc, [x]: true }

acc[x] = true;