Test if a joined regexp is faster than a simple array lookup

regexp-vs-array-speed-comparison.js

// needs node >= 8.5
const { PerformanceObserver, performance } = require('perf_hooks');

const URL = '/api/v1/admin/dashboard';
const ROUTES_ARRAY = [
  '/api/v1/admin/dashboard',
  '/api/v1/user/private',
  '/api/v1/user/public',
  '/api/v1/webhook'
];
const ROUTE_EXEMPTIONS = new RegExp('^(' + ROUTES_ARRAY.join('|') + ')', 'i');

const obs = new PerformanceObserver((items) => {
  console.log(items.getEntries()[0].duration);
  console.log(items.getEntries());
  performance.clearMarks();
});
obs.observe({ entryTypes: ['measure'] });

performance.mark('A');
regexplookup(() => {
  performance.mark('B');
  performance.measure('A to B', 'A', 'B');
});

performance.mark('C');
arraylookup(() => {
  performance.mark('D');
  performance.measure('C to D', 'C', 'D');
});

function regexplookup(callback) {
  for (i=0;i<1000000;i++) {
    ROUTE_EXEMPTIONS.test(URL);
  }
  callback();
}

function arraylookup(callback) {
  for (i=0;i<1000000;i++) {
    ROUTES_ARRAY.forEach((route) => {
     URL.indexOf(route);
    });
  }
  callback();
}

Regexp Lookup:

53.835653
[ PerformanceEntry {
    duration: 53.835653,
    startTime: 439669652.471017,
    entryType: 'measure',
    name: 'A to B' } ]

Array Lookup:

284.145556
[ PerformanceEntry {
    duration: 284.145556,
    startTime: 439669711.964357,
    entryType: 'measure',
    name: 'C to D' } ]