Run results for: reduce-vs-uniqBy

Run details:

User agent: Mozilla/5.0 (iPhone; CPU iPhone OS 14_4_1 like Mac OS X) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/14.0.3 Mobile/15E148 Safari/604.1

Browser: Mobile Safari 14

Operating system: iOS 14.4.1

Device Platform: Mobile

Date tested: 3 years ago

Test name	Executions per second
Array.prototype.reduce()	280981.4 Ops/sec
_.uniqBy	164791.7 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:

var workOrders = _.range(_.random(100)).map(x => ({
  assignee: {
    id: _.random(1, 10),
  },
}));

Tests:

Array.prototype.reduce()
workOrders.reduce((accumulator, workOrder) => { if (workOrder.assignee === null) { return accumulator; } const assigneeExists = accumulator.some(assignee => assignee.id === workOrder.assignee.id); return assigneeExists === true ? accumulator : [...accumulator, workOrder.assignee]; }, []);
_.uniqBy
_(workOrders).map('assignee').filter().uniqBy('id').value();

Run results for: reduce-vs-uniqBy

Compare different ways of extracting unique items

Array.prototype.reduce()

_.uniqBy