test.js

import test from 'ava';
import Immutable from 'immutable';

import shuffle from './index';

test('not equal after shuffle', t => {
  const list = Immutable.fromJS([...Array(10).keys()]);
  for (let i = 1000; i >= 0; i--) {
    const result = shuffle(list);
    t.false(Immutable.is(list, result));
  }
});

test('huge list', t => {
  const list = Immutable.fromJS([...Array(999999).keys()]);
  const result = shuffle(list);
  t.false(Immutable.is(list, result));
});

test('empty list', t => {
  const list = Immutable.fromJS([]);
  t.notThrows(() => {
    const result = shuffle(list);
    t.true(Immutable.is(list, result));
  });
});

test('single element list', t => {
  const list = Immutable.fromJS(['1']);
  t.notThrows(() => {
    const result = shuffle(list);
    t.true(Immutable.is(list, result));
  });
});