import swap from '../../utils/swap'; describe('swap', () => { it('should swap value positions', () => { const test1 = [1, 2, 3, 4]; swap(test1, 1, 2); expect(test1).toEqual([1, 3, 2, 4]); const test2 = [ { firstName: '1', lastName: 'Luo', id: '75309979-e340-49eb-8016-5f67bfb56c1c', }, { firstName: '2', lastName: 'Luo', id: '75309979-e340-49eb-8016-5f67bfb56c1c', }, { firstName: '3', lastName: 'Luo', id: '75309979-e340-49eb-8016-5f67bfb56c1c', }, ]; swap(test2, 0, 2); expect(test2).toEqual([ { firstName: '3', lastName: 'Luo', id: '75309979-e340-49eb-8016-5f67bfb56c1c', }, { firstName: '2', lastName: 'Luo', id: '75309979-e340-49eb-8016-5f67bfb56c1c', }, { firstName: '1', lastName: 'Luo', id: '75309979-e340-49eb-8016-5f67bfb56c1c', }, ]); }); it('should swap undefined position when index is not exists', () => { const test1 = [1, 2, 3, 4]; swap(test1, 0, 4); expect(test1).toEqual([undefined, 2, 3, 4, 1]); const test2 = [1, 2, 3, 4]; swap(test2, 2, 6); expect(test2).toEqual([1, 2, undefined, 4, undefined, undefined, 3]); }); });