windycoys/js/navigation.spec.js

import Navigation from './navigation';

const navHtml = `<a href="/test">Test link</a>
<nav class="Nav">
  <button class="Menu">Menu</button>
  <div class="Nav-content">
    <h2 class="Nav-title">
      <a class="Nav-titleLink" href="/">WindyCOYS</a>
    </h2>
    <ul class="Nav-list">
      <li class="Nav-listItem">
        <a class="Nav-link" href="/">Home</a>
      </li>
      <li class="Nav-listItem">
        <a class="Nav-link" href="/about">About</a>
      </li>
    </ul>
  </div>
  <button class="Nav-close">close</button>
</nav>
<a href="/another-test">Another test link</a>`;

let nav;

beforeEach(() => {
  document.body.innerHTML = navHtml;
  // Mock Menu
  const menu = {
    container: document.querySelector('.Menu'),
    showMenu: jest.fn(),
    hideMenu: jest.fn(),
  };
  nav = new Navigation({
    container: document.querySelector('.Nav'),
    menu,
  });
});

describe('Navigation', () => {
  it('Should initialise', () => {
    nav.init();
    expect(nav).toMatchObject({});
  });

  it('Should fail to initialise if container is missing', () => {
    nav.init();
    expect((new Navigation()).state).toBeUndefined();
  });

  it('Should fail to initialise if the menu is not provided', () => {
    const noMenu = new Navigation({
      container: document.querySelector('.Nav'),
    });
    noMenu.init();
    expect(noMenu.state).toBeUndefined();
  });

  it('Should be hidden by default', () => {
    nav.init();
    expect(nav.container.classList.contains('is-open')).toBe(false);
  });

  it('Should close when the .Nav element is clicked', () => {
    nav.init();
    nav.openNav();
    const event = new Event('click');
    nav.container.dispatchEvent(event);
    expect(nav.state).toBe('hidden');
  });

  it('Should close when the user presses ESC', () => {
    nav.init();
    nav.openNav();
    const event = new Event('keydown');
    event.keyCode = 27;
    nav.container.dispatchEvent(event);
    expect(nav.state).toBe('hidden');
  });

  it('Should not close when the .Nav-content element is clicked', () => {
    nav.init();
    nav.openNav();
    const event = new Event('click');
    nav.container.querySelector('.Nav-content').dispatchEvent(event);
    expect(nav.state).toBe('visible');
  });

  it('Should have initial ARIA attributes', () => {
    nav.init();
    expect(nav.container.getAttribute('aria-hidden')).toBe('true');
  });

  it('Should update the ARIA attributes when visible', () => {
    nav.init();
    nav.openNav();
    expect(nav.container.getAttribute('aria-hidden')).toBe('false');
  });

  it('Should update the ARIA attributes when hidden', () => {
    nav.init();
    nav.openNav();
    nav.closeNav();
    expect(nav.container.getAttribute('aria-hidden')).toBe('true');
  });
});

describe('Navigation menu button', () => {
  it('Should open the Navigation when clicked', () => {
    nav.init();
    const event = new Event('click');
    nav.menu.container.dispatchEvent(event);
    expect(nav.state).toBe('visible');
  });
});

describe('Navigation close button', () => {
  it('Should close the Navigation when clicked', () => {
    nav.init();
    nav.openNav();
    const event = new Event('click');
    nav.container.querySelector('.Nav-close').dispatchEvent(event);
    expect(nav.state).toBe('hidden');
  });
});

describe('Navigation focus behaviour', () => {
  let first;
  let last;

  beforeEach(() => {
    nav.init();
    nav.openNav();
    first = nav.container.querySelector('.Nav-link');
    last = nav.container.querySelector('.Nav-close');
  });

  it('Should apply focus to .Nav-titleLink when opened', () => {
    const link = nav.container.querySelector('.Nav-titleLink');
    expect(document.activeElement).toBe(link);
  });

  test('Focus moves to first element when TAB pressed on last', () => {
    last.focus();
    const event = new Event('keydown');
    event.keyCode = 9;
    last.dispatchEvent(event);
    expect(document.activeElement).toBe(first);
  });

  test('Focus moves to last element when SHIFT + TAB pressed on first', () => {
    first.focus();
    const event = new Event('keydown');
    event.shiftKey = true;
    event.keyCode = 9;
    first.dispatchEvent(event);
    expect(document.activeElement).toBe(last);
  });
});