Run results for: Reduce Destructuring vs Assertion

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.135 YaBrowser/21.6.2.867 Yowser/2.5 Safari/537.36

Browser: Yandex Browser 21

Operating system: Mac OS X 10.15.6

Device Platform: Desktop

Date tested: 3 years ago

Test name	Executions per second
{ ...acc, [x]: true }	815.2 Ops/sec
acc[x] = true;	6550.3 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;