Run results for: My reduce vs flatMap benchmark for collection

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Firefox/102.0

Browser: Firefox 102

Operating system: Windows

Device Platform: Desktop

Date tested: 2 years ago

Test name	Executions per second
flatMap	15177.9 Ops/sec
reduce	17209.0 Ops/sec

Script Preparation code:

var raw = new Array(250).fill({
    id: 'gid://something/Something/something',
    handle: 'something',
    name: 'Something',
    categories: ['SOMETHING'],
    lastViewedAt: '2022-03-18T21:30:18Z',
    isPinned: false,
});

AخA
 
var raw = new Array(250).fill({    id: 'gid://something/Something/something',    handle: 'something',    name: 'Something',    categories: ['SOMETHING'],    lastViewedAt: '2022-03-18T21:30:18Z',    isPinned: false,});

Tests:

flatMap

const flatMapped = raw.flatMap(({ id, categories, handle, name, lastViewedAt, isPinned }) => {
  if (categories.length === 0) {
    return [];
  }

  return {
    category: categories[0],
    handle,
    url: "https://google.com/",
    name,
    lastViewedAt: lastViewedAt == null ? null : new Date(lastViewedAt),
    author: "someone",
    isPinned,
    type: "something",
    gid: id,
  };
});

​x
 
const flatMapped = raw.flatMap(({ id, categories, handle, name, lastViewedAt, isPinned }) => {  if (categories.length === 0) {    return [];  }​  return {    category: categories[0],    handle,    url: "https://google.com/",    name,    lastViewedAt: lastViewedAt == null ? null : new Date(lastViewedAt),    author: "someone",    isPinned,    type: "something",    gid: id,  };});

reduce

const reduced = raw.reduce(function (array, { id, categories, handle, name, lastViewedAt, isPinned }) {
  if (categories.length === 0) {
    return array;
  }

  array.push({
    category: categories[0],
    handle,
    url: "https://google.com/",
    name,
    lastViewedAt: lastViewedAt == null ? null : new Date(lastViewedAt),
    author: "someone",
    isPinned,
    type: "something",
    gid: id,
  });
  return array;
}, []);

 
const reduced = raw.reduce(function (array, { id, categories, handle, name, lastViewedAt, isPinned }) {  if (categories.length === 0) {    return array;  }​  array.push({    category: categories[0],    handle,    url: "https://google.com/",    name,    lastViewedAt: lastViewedAt == null ? null : new Date(lastViewedAt),    author: "someone",    isPinned,    type: "something",    gid: id,  });  return array;}, []);