@nullvoxpopuli/ember-composable-helpers/src/helpers/shuffle.ts

Composable helpers for Ember

import { helper } from '@ember/component/helper';
import { isArray as isEmberArray } from '@ember/array';
import { typeOf } from '@ember/utils';

export function shuffle<T>(array: T[], randomizer?: () => number) {
  array = array.slice(0);
  let count = array.length;
  let rand, temp;
  randomizer = (typeOf(randomizer) === 'function' && randomizer) || Math.random;

  while (count > 1) {
    rand = Math.floor(randomizer() * count--);

    temp = array[count];
    array[count] = array[rand]!;
    array[rand] = temp!;
  }
  return array;
}

export default helper(function <T>([randomizer, array]: [
  (() => number) | T[] | undefined,
  T[]?,
]) {
  if (array === undefined) {
    array = randomizer as T[];
    randomizer = undefined;
  }

  if (!isEmberArray(array)) {
    return [array];
  }

  return shuffle(array, randomizer as () => number);
});