lodash/test/shuffle.spec.ts

import assert from 'node:assert';
import lodashStable from 'lodash';
import shuffle from '../src/shuffle';

describe('shuffle', () => {
    const array = [1, 2, 3],
        object = { a: 1, b: 2, c: 3 };

    it('should return a new array', () => {
        assert.notStrictEqual(shuffle(array), array);
    });

    it('should contain the same elements after a collection is shuffled', () => {
        assert.deepStrictEqual(shuffle(array).sort(), array);
        assert.deepStrictEqual(shuffle(object).sort(), array);
    });

    it('should shuffle small collections', () => {
        const actual = lodashStable.times(1000, () => shuffle([1, 2]));

        assert.deepStrictEqual(lodashStable.sortBy(lodashStable.uniqBy(actual, String), '0'), [
            [1, 2],
            [2, 1],
        ]);
    });

    it('should treat number values for `collection` as empty', () => {
        assert.deepStrictEqual(shuffle(1), []);
    });
});