class BlockHtmlTest

class BlockHtmlTest extends BrowserTestBase {
  
  /**
   * Modules to install.
   *
   * @var array
   */
  protected static $modules = [
    'block',
    'block_test',
  ];
  
  /**
   * {@inheritdoc}
   */
  protected $defaultTheme = 'stark';
  
  /**
   * {@inheritdoc}
   */
  protected function setUp() : void {
    parent::setUp();
    $this->drupalLogin($this->rootUser);
    // Enable the test_html block, to test HTML ID and attributes.
    \Drupal::state()->set('block_test.attributes', [
      'data-custom-attribute' => 'foo',
    ]);
    \Drupal::state()->set('block_test.content', $this->randomMachineName());
    $this->drupalPlaceBlock('test_html', [
      'id' => 'test_html_block',
    ]);
    // Enable a menu block, to test more complicated HTML.
    $this->drupalPlaceBlock('system_menu_block:admin', [
      'id' => 'test_menu_block',
    ]);
  }
  
  /**
   * Tests for valid HTML for a block.
   */
  public function testHtml() {
    $this->drupalGet('');
    // Ensure that a block's ID is converted to an HTML valid ID, and that
    // block-specific attributes are added to the same DOM element.
    $this->assertSession()
      ->elementExists('xpath', '//div[@id="block-test-html-block" and @data-custom-attribute="foo"]');
    // Ensure expected markup for a menu block.
    $this->assertSession()
      ->elementExists('xpath', '//nav[@id="block-test-menu-block"]/ul/li');
  }

}