Run results for: Immer vs Spread Reducer With Filled State

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/131.0.0.0 Safari/537.36

Browser: Chrome 131

Operating system: Windows

Device Platform: Desktop

Date tested: one month ago

Test name	Executions per second
immer	1391.8 Ops/sec
Mutate	43561092.0 Ops/sec
Spread	3678.0 Ops/sec
immer pull up	1644691.0 Ops/sec

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/npm/immer@3.1.3/dist/immer.umd.min.js"></script>
<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

function getItems(count) {
  let id = 1;
  return _.times(count, () => ({
    name: "city" + id++,
    visited: true
  }))
}


data = getItems(1000).reduce((acc, curr) => ({ ...acc, [curr.name]: curr.visited }), {})

Tests:

immer
const reducer = (state, curr) => { return immer.produce(state, draft => { draft[curr] = curr }) }; reducer(data, 'yolo')
Mutate
const reducer = (draft, curr) => { draft[curr] = curr; return draft; }; reducer(data, 'yolo')
Spread
const reducer = (draft, curr) => ({ ...draft, [curr]: curr }); reducer(data, 'yolo')
immer pull up
const reducer = immer.produce((draft, curr) => { draft[curr] = curr; }); reducer(data, 'yolo')

Run results for: Immer vs Spread Reducer With Filled State

immer

Mutate

Spread

immer pull up