Run results for: Object.assign vs Immer vs Spread Reducer With Filled State

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Firefox/102.0

Browser: Firefox 102

Operating system: Mac OS X 10.15

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
Object.assign	27170068.0 Ops/sec
Mutate	857568512.0 Ops/sec
Spread	25621.2 Ops/sec
immer pull up	1164741.5 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:

Object.assign
const reducer = (state, curr) => { return Object.assign(state, {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: Object.assign vs Immer vs Spread Reducer With Filled State

Object.assign

Mutate

Spread

immer pull up