The worst thing ever

sleepsort.js

const sleepsort = (arr, callback) => {
    for (var a in arr) {
        setTimeout((i) => callback(i), a, a);
    }
}

let test = [39, 9, 34, 26, 3, 30, 31, 18, 21, 3, 38, 7, 13, 16, 27, 21, 18, 8, 8, 38, 2, 11, 29, 11, 22, 28, 22, 9, 12, 0, 18, 2, 30, 29, 14, 23, 27, 38, 22, 22]

sleepsort(test, i => console.log(i));