string-compare-bench.js

import { group, run, bench } from 'mitata';

// Do warmup
for (let i = 0; i < 10; i++) bench('noop', () => { });

group('Set vs array vs literal', () => {
  // Do checks with arrays
  const arr = ['hi', 'there', 'nagna', 'randomlongstring', 'small'];
  const arrInclude = (item) => arr.includes(item);

  // Do checks with set
  const set = new Set(arr);
  const setHas = (item) => set.has(item);

  // Do checks with objects
  const obj = {};
  for (let i = 0, l = arr.length; i < l; ++i) obj[arr[i]] = null;
  const objHas = (item) => obj[item] === null;
  const objHas2 = (item) => item in obj;

  // Generate a function which compares the input string to all strings in the list
  const rawHas = Function(`return (i)=>${arr.map((str) => 'i===' + JSON.stringify(str)).join('||')};`)();
  
  // Generate strings
  const newArr = [];
  for (let i = 0; i < 100000; i++)
    newArr.push(Math.random() < 0.5 ? `${Math.random()}` : arr[Math.round(Math.random() * 4)]);

  bench('Array', () => newArr.map(arrInclude));
  bench('Set', () => newArr.map(setHas));
  bench('Object', () => newArr.map(objHas));
  bench('Object 2', () => newArr.map(objHas2));
  bench('Raw', () => newArr.map(rawHas));
});

run();

// The raw method is faster because static string comparisons can be 
// optimized to ptr-to-ptr comparison