array-shuffle.js based on https://stackoverflow.com/a/12646864/173630

array-shuffle.js

const shuffleArray = function(array) {
    const a = array.slice();

    for (let i = a.length - 1; i > 0; i--) {
        const j = Math.floor(Math.random() * (i + 1));
        [a[i], a[j]] = [a[j], a[i]];
    }

    return a;
};