shuffles an array in place

shuffle.ts

const swap = <T>(t: T[], i: number, j: number) => {
	[t[i], t[j]] = [t[j], t[i]];
};

export const shuffle = <T>(t: T[]) => {
	for (let i = t.length - 1; i > 0; i -= 1) {
		const j = Math.floor(Math.random() * (i + 1));
		swap(t, i, j);
	}
};

usage.ts

import { shuffle } from 'shuffle';

const pokemon = [
  'squirtle',
  'snorlax',
  'haunter',
  'mankey',
  'mewtwo',
];

shuffle(pokemon);

console.log(pokemon); // some new arrangement