Run results for: Reduce with spread operator vs without on a small array

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:120.0) Gecko/20100101 Firefox/120.0

Browser: Firefox 120

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
reduce with spread	332709.1 Ops/sec
reduce without spread	690814.9 Ops/sec

Script Preparation code:

var array = new Array(10).fill(1)

function withSpread(acc, item, index) {
    return {
        ...acc,
        [index]: {
            id: index,
            timestamp: new Date(new Date().getTime() + (index * 1000)),
            isOdd: index % 2 === 0,
            isEven: index % 2 !== 0
        }
    };
}

function withOutSpread(acc, item, index) {
    acc[index] = {
        id: index,
        timestamp: new Date(new Date().getTime() + (index * 1000)),
        isOdd: index % 2 === 0,
        isEven: index % 2 !== 0
    }
    return acc;
}

Tests:

reduce with spread
array.reduce(withSpread, {})
reduce without spread
array.reduce(withOutSpread, {})

Run results for: Reduce with spread operator vs without on a small array

Reduce with spread operator vs without on a small array

reduce with spread

reduce without spread