Run results for: object spread vs immutable-js set vs immer 2

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.0.1 Safari/605.1.15

Browser: Safari 26

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 6 months ago

Test name	Executions per second
object spread	65.4 Ops/sec
immutable-js	3531.2 Ops/sec
immer	7.4 Ops/sec

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/immutable/3.8.2/immutable.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/immutability-helper@2.7.0/index.min.js"></script>
<script src="https://unpkg.com/immer@6.0.3/dist/immer.umd.production.min.js"></script>

Tests:

object spread
let obj = {}; for(i=0;i<1000;i++){ const key = 'key'+i const value = 'value'+i obj = {...obj, [key]: {key, value}} }
immutable-js
let obj = Immutable.Map(); for(i=0;i<1000;i++){ const key = 'key'+i const value = 'value'+i obj = obj.set(key, {key, value}) }
immer
let obj = {}; for(i=0;i<1000;i++){ obj = immer.produce(obj, draft => { const key = 'key'+i const value = 'value'+i draft[key] = {key, value} }) }