Run results for: immer push vs spread

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/133.0.0.0 Safari/537.36

Browser: Chrome 133

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: one year ago

spread

14.4M/s

immer

168K/s

View exact numbers

Test name	Executions per second
✓ spread	14,399,329 Ops/sec
immer	167,752 Ops/sec

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/npm/immer@9.0.13/dist/immer.umd.production.min.js"></script>

Script Preparation code:

const createList = () => 
  Array.from({ length: 100 }, (_, i) => ({ id: i, value: `Item ${i}` }));

const list = createList();
const nextItem = { id: "x", value: "I'm next" };

Tests:

immer
const updatedList = immer.produce(list, (draft) => { draft.push(nextItem); });
spread
const updatedList = [...list, nextItem];