class PlaceholderGeneratorTest

class PlaceholderGeneratorTest extends RendererTestBase {
  
  /**
   * The tested placeholder generator.
   *
   * @var \Drupal\Core\Render\PlaceholderGenerator
   */
  protected $placeholderGenerator;
  
  /**
   * @covers ::createPlaceholder
   * @dataProvider providerCreatePlaceholderGeneratesValidHtmlMarkup
   *
   * Ensure that the generated placeholder markup is valid. If it is not, then
   * simply using DOMDocument on HTML that contains placeholders may modify the
   * placeholders' markup, which would make it impossible to replace the
   * placeholders: the placeholder markup in #attached versus that in the HTML
   * processed by DOMDocument would no longer match.
   */
  public function testCreatePlaceholderGeneratesValidHtmlMarkup(array $element) {
    $build = $this->placeholderGenerator
      ->createPlaceholder($element);
    $original_placeholder_markup = (string) $build['#markup'];
    $processed_placeholder_markup = Html::serialize(Html::load($build['#markup']));
    $this->assertEquals($original_placeholder_markup, $processed_placeholder_markup);
  }
  
  /**
   * @return array
   */
  public function providerCreatePlaceholderGeneratesValidHtmlMarkup() {
    return [
      'multiple-arguments' => [
        [
          '#lazy_builder' => [
            'Drupal\\Tests\\Core\\Render\\PlaceholdersTest::callback',
            [
              'foo',
              'bar',
            ],
          ],
        ],
      ],
      'special-character-&' => [
        [
          '#lazy_builder' => [
            'Drupal\\Tests\\Core\\Render\\PlaceholdersTest::callback',
            [
              'foo&bar',
            ],
          ],
        ],
      ],
      'special-character-"' => [
        [
          '#lazy_builder' => [
            'Drupal\\Tests\\Core\\Render\\PlaceholdersTest::callback',
            [
              'foo"bar',
            ],
          ],
        ],
      ],
      'special-character-<' => [
        [
          '#lazy_builder' => [
            'Drupal\\Tests\\Core\\Render\\PlaceholdersTest::callback',
            [
              'foo<bar',
            ],
          ],
        ],
      ],
      'special-character->' => [
        [
          '#lazy_builder' => [
            'Drupal\\Tests\\Core\\Render\\PlaceholdersTest::callback',
            [
              'foo>bar',
            ],
          ],
        ],
      ],
    ];
  }

}