DOMUtilities.test.ts

// Copyright (c) 2022 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import {renderElementIntoDOM} from '../../testing/DOMHelpers.js';

import * as Platform from './platform.js';

describe('DOMUtilities', () => {
  describe('deepActiveElement', () => {
    it('returns the active element if there is no shadow root', () => {
      const btn = document.createElement('button');
      btn.innerText = 'Click me!';
      renderElementIntoDOM(btn);
      btn.focus();
      const activeElement = Platform.DOMUtilities.deepActiveElement(document);
      assert.strictEqual(activeElement, btn);
    });

    it('dives through the shadow root and finds the right active element', () => {
      class TestComponent extends HTMLElement {
        shadow = this.attachShadow({mode: 'open'});
        button = document.createElement('button');

        connectedCallback(): void {
          this.button.innerText = 'Click me from the shadow root!';
          this.shadow.appendChild(this.button);
          this.button.focus();
        }
      }
      customElements.define('dom-utilities-test-component', TestComponent);

      const component = new TestComponent();
      renderElementIntoDOM(component);
      const activeElement = Platform.DOMUtilities.deepActiveElement(document);
      assert.strictEqual(activeElement, component.button);
    });
  });

  describe('getEnclosingShadowRootForNode', () => {
    it('returns null if no shadow root is found up the tree', () => {
      const parent = document.createElement('div');
      const child = document.createElement('p');
      parent.appendChild(child);
      renderElementIntoDOM(parent);
      assert.isNull(Platform.DOMUtilities.getEnclosingShadowRootForNode(child));
    });

    it('returns the shadow root in the tree', () => {
      const div = document.createElement('div');

      class TestComponent extends HTMLElement {
        readonly #shadow = this.attachShadow({mode: 'open'});

        connectedCallback() {
          this.#shadow.appendChild(div);
        }
      }
      customElements.define('shadow-root-test', TestComponent);
      const component = new TestComponent();
      renderElementIntoDOM(component);
      assert.strictEqual(Platform.DOMUtilities.getEnclosingShadowRootForNode(div), component.shadowRoot);
    });
  });
});