Run results for: Reduce vs. Find

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:104.0) Gecko/20100101 Firefox/104.0

Browser: Firefox 104

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: one year ago

Test name	Executions per second
With reduce	1795.2 Ops/sec
With find	65998.6 Ops/sec

Script Preparation code:

let length = 100;
const ids = Array.from(Array(length)).map(function (_, i) {
    return i;
})

function random(i) {
    return Math.ceil(Math.random() * i);
}

const data = ids.map(function (_, i) {
    const asset_id = random(100);
    if (asset_id <= 10) {
        return {brand_id: 20000 + i, asset_id};
    }
    return {brand_id: i, asset_id};
})

function withReduce() {
    const brandIdMap = data.reduce((acc, val) => {
            return {
                ...acc,
                [val.brand_id]: val.asset_id,
            };
        }, {});
    return ids.map((id) => {
        if (!brandIdMap[id]) return null;
        return {id: brandIdMap[id]};
    })
}
function withFind() {
    return ids.map((id) => {
        const value = data.find(({brand_id}) => brand_id === id);
        if (value) {
            return {id: value.asset_id};
        }
        return null;
    })
}

Tests:

With reduce
withReduce();
With find
withFind();

Run results for: Reduce vs. Find

With reduce

With find