Promise.race illustrated with sourceforge mirrors

promise-race.js

const fetch = require('node-fetch');

const mirrors = ['astuteinternet', 'ayera', 'cfhcable', 'cytranet', 'datapacket', 'excellmedia', 'freefr', 'gigenet', 'iweb', 'jaist', 'kent', 'liquidtelecom', 'managedway', 'nchc', 'netcologne', 'netix', 'newcontinuum', 'phoenixnap', 'pilotfiber', 'razaoinfo', 'superb-dca2', 'superb-sea2', 'svwh', 'tenet', 'ufpr', 'versaweb'];
const url = 'https://sourceforge.net/projects/filezilla/files/FileZilla_Client/3.31.0/FileZilla_3.31.0_win64-setup.exe/download';

// Find the fastest Sourceforge mirror manually
// The usual use case would for Promise.race would be
// when calling images from multiple servers
// (imagine different AWS S3 storage) to get the fastest one
var p = Promise.race(
  mirrors.map((mirror, index) => {
      return fetch(`${url}?use_mirror=${mirror}`);
  })
);

p.then(response => console.log(response.url));