Run results for: 100 elems: Spread operator vs. Array.map and lodash.set vs spread v2

Run details:

User agent: Mozilla/5.0 (Linux; Android 10; Mi 9T) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.115 Mobile Safari/537.36

Browser: Chrome Mobile 92

Operating system: Android

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
Spread operator	176347.9 Ops/sec
Spread operator v2	193288.3 Ops/sec
map	780254.8 Ops/sec
spread v3	330339.7 Ops/sec

HTML Preparation code:


<script src='https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.5/lodash.min.js'></script>

Script Preparation code:

permutations = new Array(20).map(() => ({ pagination: 'blah blah blah' }));
function updatePagination(action, prev) {
  return action;
}
action = 'something else';
state = { data: { permutations: [] } };
index = 5;

Tests:

Spread operator
const updated = Object.assign([...permutations], { [index]: Object.assign({}, permutations[index], { pagination: updatePagination(action, permutations[index]) }) }) return { ...state, data: { ...state.data, permutations: updated } };
Spread operator v2
const updated = Object.assign([...permutations], { [index]: { ...permutations[index], pagination: updatePagination(action, permutations[index]) } }) return { ...state, data: { ...state.data, permutations: updated } };
map
const updated = permutations.map((p, i) => { if (i === index) { return {...p, pagination: updatePagination(action, p)}; } return p; }); return { ...state, data: { ...state.data, permutations: updated } };
spread v3
let updated = [...permutations]; updated[index] = { ...updated[index], pagination: updatePagination(action, updated[index]) }; return { ...state, data: { ...state.data, permutations: updated } };

Run results for: 100 elems: Spread operator vs. Array.map and lodash.set vs spread v2

A comparison of the performance of the spread operator, [ ...array ], vs. Array.map(i => ...) and

Spread operator

Spread operator v2

map

spread v3