Run results for: lodash flatten vs reduce

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/94.0.4606.54 Safari/537.36

Browser: Chrome 94

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
flatten	3566785.0 Ops/sec
reduce	385361.3 Ops/sec

HTML Preparation code:

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

Script Preparation code:

window.obj = {};

for (var i = 0, len = 10; i < len; i++) {
  var arr = []
  obj['key' + i] = arr
  for (var n = 0, len = 10; n < len; n++) {
    arr.push({ ['key' + n]: n });
  }
}

Tests:

flatten
_.flatten(obj, (acc, val, key) => { acc[key] = val.map(d => ({ label: key, value: val })); return acc; }, {})
reduce
Object.entries(obj).reduce((acc, [key, val]) => { acc[key] = val.map(d => ({ label: key, value: val })); return acc; }, {})