class EntityReferenceWidgetTest

class EntityReferenceWidgetTest extends MediaLibraryTestBase {
    use SortableTestTrait;
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'field_ui',
    ];
    
    /**
     * The theme to install as the default for testing.
     *
     * @var string
     */
    protected $defaultTheme = 'starterkit_theme';
    
    /**
     * Test media items.
     *
     * @var \Drupal\media\MediaInterface[]
     */
    protected $mediaItems = [];
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        // Create a few example media items for use in selection.
        $this->mediaItems = $this->createMediaItems([
            'type_one' => [
                'Horse',
                'Bear',
                'Cat',
                'Dog',
            ],
            'type_two' => [
                'Crocodile',
                'Lizard',
                'Snake',
                'Turtle',
            ],
        ]);
        // Create a user who can use the Media library.
        $user = $this->drupalCreateUser([
            'access content',
            'create basic_page content',
            'edit own basic_page content',
            'view media',
            'create media',
            'administer node form display',
        ]);
        $this->drupalLogin($user);
    }
    
    /**
     * Tests that disabled media items don't capture focus on page load.
     */
    public function testFocusNotAppliedWithoutSelectionChange() : void {
        // Create a node with the maximum number of values for the field_twin_media
        // field.
        $node = $this->drupalCreateNode([
            'type' => 'basic_page',
            'field_twin_media' => [
                $this->mediaItems['Horse'],
                $this->mediaItems['Bear'],
            ],
        ]);
        $this->drupalGet($node->toUrl('edit-form'));
        $open_button = $this->assertElementExistsAfterWait('css', '.js-media-library-open-button[name^="field_twin_media"]');
        // The open button should be disabled, but not have the
        // 'data-disabled-focus' attribute.
        $this->assertFalse($open_button->hasAttribute('data-disabled-focus'));
        $this->assertTrue($open_button->hasAttribute('disabled'));
        // The button should be disabled.
        $this->assertJsCondition('jQuery("#field_twin_media-media-library-wrapper .js-media-library-open-button").is(":disabled")');
        // The button should not have focus.
        $this->assertJsCondition('jQuery("#field_twin_media-media-library-wrapper .js-media-library-open-button").not(":focus")');
    }
    
    /**
     * Tests that the Media library's widget works as expected.
     */
    public function testWidget() : void {
        $assert_session = $this->assertSession();
        $page = $this->getSession()
            ->getPage();
        // Visit a node create page.
        $this->drupalGet('node/add/basic_page');
        // Assert that media widget instances are present.
        $assert_session->pageTextContains('Unlimited media');
        $assert_session->pageTextContains('Twin media');
        $assert_session->pageTextContains('Single media type');
        $assert_session->pageTextContains('Empty types media');
        // Assert generic media library elements.
        $this->openMediaLibraryForField('field_unlimited_media');
        $assert_session->elementExists('css', '.ui-dialog-titlebar-close')
            ->click();
        // Assert that the media type menu is available when more than 1 type is
        // configured for the field.
        $menu = $this->openMediaLibraryForField('field_unlimited_media');
        $this->assertTrue($menu->hasLink('Show Type One media (selected)'));
        $this->assertFalse($menu->hasLink('Type Two'));
        $this->assertTrue($menu->hasLink('Type Three'));
        $this->assertFalse($menu->hasLink('Type Four'));
        $this->switchToMediaType('Three');
        // Assert the active tab is set correctly.
        $this->assertFalse($menu->hasLink('Show Type One media (selected)'));
        $this->assertTrue($menu->hasLink('Show Type Three media (selected)'));
        // Assert the focus is set to the first tabbable element when a vertical tab
        // is clicked.
        $this->assertJsCondition('jQuery(tabbable.tabbable(document.getElementById("media-library-content"))[0]).is(":focus")');
        $assert_session->elementExists('css', '.ui-dialog-titlebar-close')
            ->click();
        // Assert that there are no links in the media library view.
        $this->openMediaLibraryForField('field_unlimited_media');
        $assert_session->elementNotExists('css', '.media-library-item__name a');
        $assert_session->elementNotExists('css', '.view-media-library .media-library-item__edit');
        $assert_session->elementNotExists('css', '.view-media-library .media-library-item__remove');
        $assert_session->elementExists('css', '.ui-dialog-titlebar-close')
            ->click();
        // Assert that the media type menu is available when the target_bundles
        // setting for the entity reference field is null. All types should be
        // allowed in this case.
        $menu = $this->openMediaLibraryForField('field_null_types_media');
        // Assert that the button to open the media library does not submit the
        // parent form. We can do this by checking if the validation of the parent
        // form is not triggered.
        $assert_session->pageTextNotContains('Title field is required.');
        $this->assertTrue($menu->hasLink('Type One'));
        $this->assertTrue($menu->hasLink('Type Two'));
        $this->assertTrue($menu->hasLink('Type Three'));
        $this->assertTrue($menu->hasLink('Type Four'));
        $this->assertTrue($menu->hasLink('Type Five'));
        // Insert media to test validation with null target_bundles.
        $this->switchToMediaType('One');
        $this->assertAnnounceContains('Showing Type One media.');
        $this->selectMediaItem(0);
        $this->pressInsertSelected('Added one media item.');
        // Assert that the media type menu is not available when only 1 type is
        // configured for the field.
        $this->openMediaLibraryForField('field_single_media_type', '#media-library-wrapper');
        $this->waitForElementTextContains('.media-library-selected-count', '0 of 1 item selected');
        // Select a media item, assert the hidden selection field contains the ID of
        // the selected item.
        $this->selectMediaItem(0);
        $assert_session->hiddenFieldValueEquals('media-library-modal-selection', '4');
        $this->assertSelectedMediaCount('1 of 1 item selected');
        $assert_session->elementNotExists('css', '.js-media-library-menu');
        $assert_session->elementExists('css', '.ui-dialog-titlebar-close')
            ->click();
        // Assert the menu links can be sorted through the widget configuration.
        $this->openMediaLibraryForField('field_twin_media');
        $links = $this->getTypesMenu()
            ->findAll('css', 'a');
        $link_titles = [];
        foreach ($links as $link) {
            $link_titles[] = $link->getText();
        }
        $expected_link_titles = [
            'Show Type Three media (selected)',
            'Show Type One media',
            'Show Type Two media',
            'Show Type Four media',
        ];
        $this->assertSame($link_titles, $expected_link_titles);
        $this->drupalGet('admin/structure/types/manage/basic_page/form-display');
        // Ensure that the widget settings form is not displayed when only
        // one media type is allowed.
        $assert_session->pageTextContains('Single media type');
        $assert_session->buttonNotExists('field_single_media_type_settings_edit');
        $assert_session->buttonExists('field_twin_media_settings_edit')
            ->press();
        $this->assertElementExistsAfterWait('css', '#field-twin-media .tabledrag-toggle-weight')
            ->press();
        $assert_session->fieldExists('fields[field_twin_media][settings_edit_form][settings][media_types][type_one][weight]')
            ->selectOption('0');
        $assert_session->fieldExists('fields[field_twin_media][settings_edit_form][settings][media_types][type_three][weight]')
            ->selectOption('1');
        $assert_session->fieldExists('fields[field_twin_media][settings_edit_form][settings][media_types][type_four][weight]')
            ->selectOption('2');
        $assert_session->fieldExists('fields[field_twin_media][settings_edit_form][settings][media_types][type_two][weight]')
            ->selectOption('3');
        $assert_session->buttonExists('Save')
            ->press();
        $this->drupalGet('node/add/basic_page');
        $this->openMediaLibraryForField('field_twin_media');
        $link_titles = array_map(function ($link) {
            return $link->getText();
        }, $links);
        $this->assertSame($link_titles, [
            'Show Type One media (selected)',
            'Show Type Three media',
            'Show Type Four media',
            'Show Type Two media',
        ]);
        $assert_session->elementExists('css', '.ui-dialog-titlebar-close')
            ->click();
        // Assert the announcements for media type navigation in the media library.
        $this->openMediaLibraryForField('field_unlimited_media');
        $this->switchToMediaType('Three');
        $this->assertAnnounceContains('Showing Type Three media.');
        $this->switchToMediaType('One');
        $this->assertAnnounceContains('Showing Type One media.');
        // Assert the links can be triggered by via the space bar.
        $assert_session->elementExists('named', [
            'link',
            'Type Three',
        ])
            ->keyPress(32);
        $this->assertAnnounceContains('Showing Type Three media.');
        $assert_session->elementExists('css', '.ui-dialog-titlebar-close')
            ->click();
        // Assert media is only visible on the tab for the related media type.
        $this->openMediaLibraryForField('field_unlimited_media');
        $assert_session->pageTextContains('Dog');
        $assert_session->pageTextContains('Bear');
        $assert_session->pageTextNotContains('Turtle');
        $this->switchToMediaType('Three');
        $this->assertAnnounceContains('Showing Type Three media.');
        $assert_session->elementExists('named', [
            'link',
            'Show Type Three media (selected)',
        ]);
        $assert_session->pageTextNotContains('Dog');
        $assert_session->pageTextNotContains('Bear');
        $assert_session->pageTextNotContains('Turtle');
        $assert_session->elementExists('css', '.ui-dialog-titlebar-close')
            ->click();
        // Assert the exposed name filter of the view.
        $this->openMediaLibraryForField('field_unlimited_media');
        $session = $this->getSession();
        $session->getPage()
            ->fillField('Name', 'Dog');
        $session->getPage()
            ->pressButton('Apply filters');
        $this->waitForText('Dog');
        $this->waitForNoText('Bear');
        $session->getPage()
            ->fillField('Name', '');
        $session->getPage()
            ->pressButton('Apply filters');
        $this->waitForText('Dog');
        $this->waitForText('Bear');
        $assert_session->elementExists('css', '.ui-dialog-titlebar-close')
            ->click();
        // Assert adding a single media item and removing it.
        $this->openMediaLibraryForField('field_twin_media');
        $this->selectMediaItem(0);
        $this->pressInsertSelected('Added one media item.');
        // Assert the focus is set back on the open button of the media field.
        $this->assertJsCondition('jQuery("#field_twin_media-media-library-wrapper .js-media-library-open-button").is(":focus")');
        // The toggle for weight inputs' visibility should not be available when the
        // field contains a single item.
        $wrapper = $assert_session->elementExists('css', '.field--name-field-twin-media');
        $assert_session->elementNotExists('named', [
            'button',
            'Show media item weights',
        ], $wrapper);
        // Remove the selected item.
        $button = $assert_session->buttonExists('Remove', $wrapper);
        $this->assertSame('Remove Dog', $button->getAttribute('aria-label'));
        $button->press();
        $this->waitForText('Dog has been removed.');
        // Assert the focus is set back on the open button of the media field.
        $this->assertJsCondition('jQuery("#field_twin_media-media-library-wrapper .js-media-library-open-button").is(":focus")');
        // Assert we can select the same media item twice.
        $this->openMediaLibraryForField('field_twin_media');
        $page->checkField('Select Dog');
        $this->pressInsertSelected('Added one media item.');
        $this->openMediaLibraryForField('field_twin_media');
        $page->checkField('Select Dog');
        $this->pressInsertSelected('Added one media item.');
        $this->waitForElementsCount('css', '.field--name-field-twin-media [data-media-library-item-delta]', 2);
        // Assert that we can toggle the visibility of the weight inputs when the
        // field contains more than one item.
        $wrapper = $assert_session->elementExists('css', '.field--name-field-twin-media');
        $wrapper->pressButton('Show media item weights');
        // Ensure that the styling doesn't accidentally render the weight field
        // unusable.
        $assert_session->fieldExists('Weight', $wrapper)
            ->click();
        $wrapper->pressButton('Hide media item weights');
        // Assert the same has been added twice and remove the items again.
        $this->waitForElementsCount('css', '.field--name-field-twin-media [data-media-library-item-delta]', 2);
        $assert_session->hiddenFieldValueEquals('field_twin_media[selection][0][target_id]', '4');
        $assert_session->hiddenFieldValueEquals('field_twin_media[selection][1][target_id]', '4');
        $wrapper->pressButton('Remove');
        $this->waitForText('Dog has been removed.');
        $wrapper->pressButton('Remove');
        $this->waitForText('Dog has been removed.');
        $result = $wrapper->waitFor(10, function ($wrapper) {
            
            /** @var \Behat\Mink\Element\NodeElement $wrapper */
            return $wrapper->findButton('Remove') == NULL;
        });
        $this->assertTrue($result);
        // Assert the selection is persistent in the media library modal, and
        // the number of selected items is displayed correctly.
        $this->openMediaLibraryForField('field_twin_media');
        // Assert the number of selected items is displayed correctly.
        $this->assertSelectedMediaCount('0 of 2 items selected');
        // Select a media item, assert the hidden selection field contains the ID of
        // the selected item.
        $checkboxes = $this->getCheckboxes();
        $this->assertCount(4, $checkboxes);
        $this->selectMediaItem(0, '1 of 2 items selected');
        $assert_session->hiddenFieldValueEquals('media-library-modal-selection', '4');
        // Select another item and assert the number of selected items is updated.
        $this->selectMediaItem(1, '2 of 2 items selected');
        $assert_session->hiddenFieldValueEquals('media-library-modal-selection', '4,3');
        // Assert unselected items are disabled when the maximum allowed items are
        // selected (cardinality for this field is 2).
        $this->assertTrue($checkboxes[2]->hasAttribute('disabled'));
        $this->assertTrue($checkboxes[3]->hasAttribute('disabled'));
        // Assert the selected items are updated when deselecting an item.
        $checkboxes[0]->click();
        $this->assertSelectedMediaCount('1 of 2 items selected');
        $assert_session->hiddenFieldValueEquals('media-library-modal-selection', '3');
        // Assert deselected items are available again.
        $this->assertFalse($checkboxes[2]->hasAttribute('disabled'));
        $this->assertFalse($checkboxes[3]->hasAttribute('disabled'));
        // The selection should be persisted when navigating to other media types in
        // the modal.
        $this->switchToMediaType('Three');
        $this->switchToMediaType('One');
        $selected_checkboxes = [];
        foreach ($this->getCheckboxes() as $checkbox) {
            if ($checkbox->isChecked()) {
                $selected_checkboxes[] = $checkbox->getValue();
            }
        }
        $this->assertCount(1, $selected_checkboxes);
        $assert_session->hiddenFieldValueEquals('media-library-modal-selection', implode(',', $selected_checkboxes));
        $this->assertSelectedMediaCount('1 of 2 items selected');
        // Add to selection from another type.
        $this->switchToMediaType('Two');
        $checkboxes = $this->getCheckboxes();
        $this->assertCount(4, $checkboxes);
        $this->selectMediaItem(0, '2 of 2 items selected');
        $assert_session->hiddenFieldValueEquals('media-library-modal-selection', '3,8');
        // Assert unselected items are disabled when the maximum allowed items are
        // selected (cardinality for this field is 2).
        $this->assertFalse($checkboxes[0]->hasAttribute('disabled'));
        $this->assertTrue($checkboxes[1]->hasAttribute('disabled'));
        $this->assertTrue($checkboxes[2]->hasAttribute('disabled'));
        $this->assertTrue($checkboxes[3]->hasAttribute('disabled'));
        // Assert the checkboxes are also disabled on other pages.
        $this->switchToMediaType('One');
        $this->assertTrue($checkboxes[0]->hasAttribute('disabled'));
        $this->assertFalse($checkboxes[1]->hasAttribute('disabled'));
        $this->assertTrue($checkboxes[2]->hasAttribute('disabled'));
        $this->assertTrue($checkboxes[3]->hasAttribute('disabled'));
        // Select the items.
        $this->pressInsertSelected('Added 2 media items.');
        // Assert the open button is disabled.
        $open_button = $this->assertElementExistsAfterWait('css', '.js-media-library-open-button[name^="field_twin_media"]');
        $this->assertTrue($open_button->hasAttribute('data-disabled-focus'));
        $this->assertTrue($open_button->hasAttribute('disabled'));
        $this->assertJsCondition('jQuery("#field_twin_media-media-library-wrapper .js-media-library-open-button").is(":disabled")');
        // Ensure that the selection completed successfully.
        $assert_session->pageTextNotContains('Add or select media');
        $assert_session->elementTextNotContains('css', '#field_twin_media-media-library-wrapper', 'Dog');
        $assert_session->elementTextContains('css', '#field_twin_media-media-library-wrapper', 'Cat');
        $assert_session->elementTextContains('css', '#field_twin_media-media-library-wrapper', 'Turtle');
        $assert_session->elementTextNotContains('css', '#field_twin_media-media-library-wrapper', 'Snake');
        // Remove "Cat" (happens to be the first remove button on the page).
        $button = $assert_session->buttonExists('Remove', $wrapper);
        $this->assertSame('Remove Cat', $button->getAttribute('aria-label'));
        $button->press();
        $this->waitForText('Cat has been removed.');
        // Assert the focus is set to the wrapper of the other selected item.
        $this->assertJsCondition('jQuery("#field_twin_media-media-library-wrapper [data-media-library-item-delta]").is(":focus")');
        $assert_session->elementTextNotContains('css', '#field_twin_media-media-library-wrapper', 'Cat');
        $assert_session->elementTextContains('css', '#field_twin_media-media-library-wrapper', 'Turtle');
        // Assert the open button is no longer disabled.
        $open_button = $assert_session->elementExists('css', '.js-media-library-open-button[name^="field_twin_media"]');
        $this->assertFalse($open_button->hasAttribute('data-disabled-focus'));
        $this->assertFalse($open_button->hasAttribute('disabled'));
        $this->assertJsCondition('jQuery("#field_twin_media-media-library-wrapper .js-media-library-open-button").is(":not(:disabled)")');
        // Open the media library again and select another item.
        $this->openMediaLibraryForField('field_twin_media');
        $this->selectMediaItem(0);
        $this->pressInsertSelected('Added one media item.');
        $this->waitForElementTextContains('#field_twin_media-media-library-wrapper', 'Dog');
        $assert_session->elementTextNotContains('css', '#field_twin_media-media-library-wrapper', 'Cat');
        $assert_session->elementTextContains('css', '#field_twin_media-media-library-wrapper', 'Turtle');
        $assert_session->elementTextNotContains('css', '#field_twin_media-media-library-wrapper', 'Snake');
        // Assert the open button is disabled.
        $this->assertTrue($assert_session->elementExists('css', '.js-media-library-open-button[name^="field_twin_media"]')
            ->hasAttribute('data-disabled-focus'));
        $this->assertTrue($assert_session->elementExists('css', '.js-media-library-open-button[name^="field_twin_media"]')
            ->hasAttribute('disabled'));
        $this->assertJsCondition('jQuery("#field_twin_media-media-library-wrapper .js-media-library-open-button").is(":disabled")');
        // Assert the selection is cleared when the modal is closed.
        $this->openMediaLibraryForField('field_unlimited_media');
        $checkboxes = $this->getCheckboxes();
        $this->assertGreaterThanOrEqual(4, count($checkboxes));
        // Nothing is selected yet.
        $this->assertFalse($checkboxes[0]->isChecked());
        $this->assertFalse($checkboxes[1]->isChecked());
        $this->assertFalse($checkboxes[2]->isChecked());
        $this->assertFalse($checkboxes[3]->isChecked());
        $this->assertSelectedMediaCount('0 items selected');
        // Select the first 2 items.
        $checkboxes[0]->click();
        $this->assertSelectedMediaCount('1 item selected');
        $checkboxes[1]->click();
        $this->assertSelectedMediaCount('2 items selected');
        $this->assertTrue($checkboxes[0]->isChecked());
        $this->assertTrue($checkboxes[1]->isChecked());
        $this->assertFalse($checkboxes[2]->isChecked());
        $this->assertFalse($checkboxes[3]->isChecked());
        // Close the dialog, reopen it and assert not is selected again.
        $assert_session->elementExists('css', '.ui-dialog-titlebar-close')
            ->click();
        $this->openMediaLibraryForField('field_unlimited_media');
        $checkboxes = $this->getCheckboxes();
        $this->assertGreaterThanOrEqual(4, count($checkboxes));
        $this->assertFalse($checkboxes[0]->isChecked());
        $this->assertFalse($checkboxes[1]->isChecked());
        $this->assertFalse($checkboxes[2]->isChecked());
        $this->assertFalse($checkboxes[3]->isChecked());
        $assert_session->elementExists('css', '.ui-dialog-titlebar-close')
            ->click();
        // Finally, save the form.
        $assert_session->elementExists('css', '.js-media-library-widget-toggle-weight')
            ->click();
        $this->submitForm([
            'title[0][value]' => 'My page',
            'field_twin_media[selection][0][weight]' => '3',
        ], 'Save');
        $assert_session->pageTextContains('Basic Page My page has been created');
        // We removed this item earlier.
        $assert_session->pageTextNotContains('Cat');
        // This item was never selected.
        $assert_session->pageTextNotContains('Snake');
        // "Turtle" should come after "Dog", since we changed the weight.
        $assert_session->elementExists('css', '.field--name-field-twin-media > .field__items > .field__item:last-child:contains("Turtle")');
        // Make sure everything that was selected shows up.
        $assert_session->pageTextContains('Dog');
        $assert_session->pageTextContains('Turtle');
        // Re-edit the content and make a new selection.
        $this->drupalGet('node/1/edit');
        $assert_session->pageTextContains('Dog');
        $assert_session->pageTextNotContains('Cat');
        $assert_session->pageTextNotContains('Bear');
        $assert_session->pageTextNotContains('Horse');
        $assert_session->pageTextContains('Turtle');
        $assert_session->pageTextNotContains('Snake');
        $this->openMediaLibraryForField('field_unlimited_media');
        // Select all media items of type one (should also contain Dog, again).
        $this->selectMediaItem(0);
        $this->selectMediaItem(1);
        $this->selectMediaItem(2);
        $this->selectMediaItem(3);
        $this->pressInsertSelected('Added 4 media items.');
        $this->waitForText('Dog');
        $assert_session->pageTextContains('Cat');
        $assert_session->pageTextContains('Bear');
        $assert_session->pageTextContains('Horse');
        $assert_session->pageTextContains('Turtle');
        $assert_session->pageTextNotContains('Snake');
        $this->submitForm([], 'Save');
        $assert_session->pageTextContains('Dog');
        $assert_session->pageTextContains('Cat');
        $assert_session->pageTextContains('Bear');
        $assert_session->pageTextContains('Horse');
        $assert_session->pageTextContains('Turtle');
        $assert_session->pageTextNotContains('Snake');
    }
    
    /**
     * Tests saving a required media library field.
     */
    public function testRequiredMediaField() : void {
        $assert_session = $this->assertSession();
        $page = $this->getSession()
            ->getPage();
        // Make field_unlimited_media required.
        $field_config = FieldConfig::loadByName('node', 'basic_page', 'field_unlimited_media');
        $field_config->setRequired(TRUE)
            ->save();
        $this->drupalGet('node/add/basic_page');
        $page->fillField('Title', 'My page');
        $page->pressButton('Save');
        // Check that a clear error message is shown.
        $assert_session->pageTextNotContains('This value should not be null.');
        $assert_session->pageTextContains(sprintf('%s field is required.', $field_config->label()));
        // Open the media library, select an item and save the node.
        $this->openMediaLibraryForField('field_unlimited_media');
        $this->selectMediaItem(0);
        $this->pressInsertSelected('Added one media item.');
        $page->pressButton('Save');
        // Confirm that the node was created.
        $this->assertSession()
            ->pageTextContains('Basic page My page has been created.');
    }
    
    /**
     * Tests that changed order is maintained after removing a selection.
     */
    public function testRemoveAfterReordering() : void {
        $assert_session = $this->assertSession();
        $page = $this->getSession()
            ->getPage();
        $this->drupalGet('node/add/basic_page');
        $page->fillField('Title', 'My page');
        $this->openMediaLibraryForField('field_unlimited_media');
        $page->checkField('Select Dog');
        $page->checkField('Select Cat');
        $page->checkField('Select Bear');
        // Order: Dog - Cat - Bear.
        $this->pressInsertSelected('Added 3 media items.');
        // Move first item (Dog) to the end.
        // Order: Cat - Bear - Dog.
        $this->sortableAfter('[data-media-library-item-delta="0"]', '[data-media-library-item-delta="2"]', '.js-media-library-selection');
        $wrapper = $assert_session->elementExists('css', '.field--name-field-unlimited-media');
        // Remove second item (Bear).
        // Order: Cat - Dog.
        $wrapper->find('css', "[aria-label='Remove Bear']")
            ->press();
        $this->waitForText('Bear has been removed.');
        $page->pressButton('Save');
        $assert_session->elementTextContains('css', '.field--name-field-unlimited-media > .field__items > .field__item:last-child', 'Dog');
    }
    
    /**
     * Tests that order is correct after re-order and adding another item.
     */
    public function testAddAfterReordering() : void {
        $assert_session = $this->assertSession();
        $page = $this->getSession()
            ->getPage();
        $this->drupalGet('node/add/basic_page');
        $page->fillField('Title', 'My page');
        $this->openMediaLibraryForField('field_unlimited_media');
        $page->checkField('Select Dog');
        $page->checkField('Select Cat');
        // Order: Dog - Cat.
        $this->pressInsertSelected('Added 2 media items.');
        // Change positions.
        // Order: Cat - Dog.
        $this->sortableAfter('[data-media-library-item-delta="0"]', '[data-media-library-item-delta="1"]', '.js-media-library-selection');
        $this->openMediaLibraryForField('field_unlimited_media');
        $this->selectMediaItem(2);
        // Order: Cat - Dog - Bear.
        $this->pressInsertSelected('Added one media item.');
        $page->pressButton('Save');
        $assert_session->elementTextContains('css', '.field--name-field-unlimited-media > .field__items > .field__item:first-child', 'Cat');
        $assert_session->elementTextContains('css', '.field--name-field-unlimited-media > .field__items > .field__item:last-child', 'Bear');
    }
    
    /**
     * Checks for inclusion of text in #drupal-live-announce.
     *
     * @param string $expected_message
     *   The text that is expected to be present in the #drupal-live-announce element.
     *
     * @internal
     */
    protected function assertAnnounceContains(string $expected_message) : void {
        $assert_session = $this->assertSession();
        $this->assertNotEmpty($assert_session->waitForElement('css', "#drupal-live-announce:contains('{$expected_message}')"));
    }
    
    /**
     * {@inheritdoc}
     */
    protected function sortableUpdate($item, $from, $to = NULL) {
        // See core/modules/media_library/js/media_library.widget.js.
        $script = <<<JS
(function (\$) {
    var selection = document.querySelectorAll('.js-media-library-selection');
    selection.forEach(function (widget) {
        \$(widget).children().each(function (index, child) {
            \$(child).find('.js-media-library-item-weight').val(index);
        });
    });
})(jQuery)

JS;
        $this->getSession()
            ->executeScript($script);
    }
    
    /**
     * Tests the preview displayed by the field widget.
     */
    public function testWidgetPreview() : void {
        $assert_session = $this->assertSession();
        $page = $this->getSession()
            ->getPage();
        $node = $this->drupalCreateNode([
            'type' => 'basic_page',
            'field_unlimited_media' => [
                $this->mediaItems['Horse'],
            ],
        ]);
        $media_id = $this->mediaItems['Horse']
            ->id();
        // Assert that preview is present for current user, who can view media.
        $this->drupalGet($node->toUrl('edit-form'));
        $assert_session->elementTextContains('css', '[data-drupal-selector="edit-field-unlimited-media-selection-0"]', 'Horse');
        $remove_button = $page->find('css', '[data-drupal-selector="edit-field-unlimited-media-selection-0-remove-button"]');
        $this->assertSame('Remove Horse', $remove_button->getAttribute('aria-label'));
        $assert_session->pageTextNotContains('You do not have permission to view media item');
        $remove_button->press();
        $this->waitForText("Removing Horse.");
        $this->waitForText("Horse has been removed.");
        // Logout without saving.
        $this->drupalLogout();
        // Create a user who can edit content but not view media.
        // Must remove permission from authenticated role first, otherwise the new
        // user will inherit that permission.
        $role = Role::load(RoleInterface::AUTHENTICATED_ID);
        $role->revokePermission('view media');
        $role->save();
        $non_media_editor = $this->drupalCreateUser([
            'access content',
            'create basic_page content',
            'edit any basic_page content',
        ]);
        $this->drupalLogin($non_media_editor);
        // Assert that preview does not reveal media name.
        $this->drupalGet($node->toUrl('edit-form'));
        // There should be no preview name.
        $assert_session->elementTextNotContains('css', '[data-drupal-selector="edit-field-unlimited-media-selection-0"]', 'Horse');
        // The remove button should have a generic message.
        $remove_button = $page->find('css', '[data-drupal-selector="edit-field-unlimited-media-selection-0-remove-button"]');
        $this->assertSame('Remove media', $remove_button->getAttribute('aria-label'));
        $assert_session->pageTextContains("You do not have permission to view media item {$media_id}.");
        // Confirm ajax text does not reveal media name.
        $remove_button->press();
        $this->waitForText("Removing media.");
        $this->waitForText("Media has been removed.");
    }

}