cards.test.js

import React from 'react';
import { shallow } from 'enzyme';
import { useGlobal } from 'reactn';
import Cards from './cards';

jest.mock('reactn');

it('should render a Card component for each global state card', () => {
  const cards = ['Q', 'J', 'K', 'A', '2'];
  useGlobal.mockReturnValueOnce([cards]);
  
  const wrapper = shallow(<Cards />);
  expect(wrapper).toMatchSnapshot();
});

it('should tell no card is selected if cards are empty', () => {
  const cards = [];
  useGlobal.mockReturnValueOnce([cards]);
  
  const wrapper = shallow(<Cards />);
  expect(wrapper).toMatchSnapshot();
});