Shuffling an array in Javascript

ArrayShuffleExtension.js

Array.prototype.shuffle = function () {
    return this.map(item => {
        return {
            index: Math.random(),
            value: item
        }
    })
        .sort((item1, item2) => item1.index - item2.index)
        .map(item => item.value)
}

let arr = [
    { x:1, y:1 },
    { x:2, y:2 },
    { x:3, y:3 },
    { x:4, y:4 },
    { x:5, y:5 },
];

let shuffleArr = arr.shuffle();