Run results for: group-by

Test name	Executions per second
✓ groupBy with two while	730,382 Ops/sec
groupBy with two filters	315,148 Ops/sec
groupBy with Set and filter	289,358 Ops/sec
groupBy with while and filter	169,359 Ops/sec

Script Preparation code:

 var collection = [
    {
      name: 'Fabver',
      type: 1,
      company: 'ADL',
    },
    {
      name: 'Fabian',
      type: 0,
      company: 'ADL',
    },
    {
      name: 'Andrés',
      type: 0,
      company: 'JWT',
    },
    {
      name: 'Andrew',
      type: 1,
      company: 'JWT',
    },
  ];

var index = Math.floor(Math.random() * 3);
var key = ['name', 'type', 'company'][index]

Tests:

groupBy with two while
if (!collection.length) return [collection]; const origin = [...collection]; const groups = []; while (origin.length) { const group = []; const obj = origin.shift(); if (obj) { group.push(obj); let i = 0; while (i < origin.length) { if (obj[key] === origin[i][key]) { group.push(origin.splice(i, 1)[0]); } i++; } } groups.push(group); } return groups;
groupBy with while and filter
if (!collection.length) return [collection]; const groups = []; let i = 0; let selected = {}; while (i < collection.length) { if (!selected || selected[key] !== collection[i][key]) { selected = collection[i]; groups.push(collection.filter((item) => item[key] === selected[key])); } i++; } return groups;
groupBy with Set and filter
if (!collection.length) return [collection]; const groups = []; const keyValues = collection.map((item) => item[key]); const uniqueValues = [...new Set(keyValues)]; uniqueValues.forEach((value) => groups.push(collection.filter((item) => item[key] === value))); return groups;
groupBy with two filters
if (!collection.length) return [collection]; const groups = []; const keyValues = collection.map((item) => item[key]); const uniqueValues = keyValues.filter((value, index, self) => self.indexOf(value) === index); uniqueValues.forEach((value) => groups.push(collection.filter((item) => item[key] === value))); return groups;

Group arrays by object key

groupBy with two while

groupBy with while and filter

groupBy with Set and filter

groupBy with two filters