Run results for: Immer vs shallow copy

Run details:

User agent: Mozilla/5.0 (Linux; arm; Android 6.0.1; Station Build/MOB30J; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/75.0.3770.100 YandexStation/2.3.3.15.550401165.20191118.USERDEBUG (YandexIO) Safari/537.36

Browser: Chrome 75

Operating system: Android 6.0.1

Device Platform: Desktop

Date tested: 4 years ago

Test name	Executions per second
immer	340.5 Ops/sec
shallow copy	1494.6 Ops/sec

HTML Preparation code:

<script src="https://unpkg.com/immer/dist/immer.umd.js"></script>

Script Preparation code:

var data = { items: {}, count: 0, keys: [] }

for (let index = 0; index < 100; index++) {
  data[index] = { id: index, name: `ITEM-${index}`, value: Math.random() }
  data.count++
  data.keys.push(index)
}

var NEW_ITEM_ID = data.count +1

var produce = immer.default

Tests:

immer
data = produce(data, draft => { draft.items[NEW_ITEM_ID] = { id: NEW_ITEM_ID, name: 'ITEM-NEW', value: 0 } draft.counter++ draft.keys.push(NEW_ITEM_ID) })
shallow copy
data = { ...data, items: { ...data.items, [NEW_ITEM_ID]: { id: NEW_ITEM_ID, name: 'ITEM-NEW', value: 0 } }, count: data.count +1, keys: [ ...data.keys, NEW_ITEM_ID] }