Issue #3317938 by catch, Lendude, nod_, quietone: views_ui LibraryCachIngTest is failing randomly

<?php

namespace Drupal\Tests\views_ui\FunctionalJavascript;

use Drupal\FunctionalJavascriptTests\WebDriverTestBase;

/**

 * Tests the JavaScript library caching on consecutive requests.

 *

 * @group views_ui

 */

class LibraryCachingTest extends WebDriverTestBase {

  /**

   * {@inheritdoc}

   */

  protected static $modules = ['node', 'views', 'views_ui'];

  /**

   * {@inheritdoc}

   */

  protected $defaultTheme = 'stark';

  /**

   * Tests if the Views UI dialogs open on consecutive requests.

   */

  public function testConsecutiveDialogRequests() {

    $admin_user = $this->drupalCreateUser([

      'administer site configuration',

      'administer views',

      'administer nodes',

      'access content overview',

    ]);

    // Disable automatic live preview to make the sequence of calls clearer.

    \Drupal::configFactory()->getEditable('views.settings')->set('ui.always_live_preview', FALSE)->save();

    $this->drupalLogin($admin_user);

    $this->drupalGet('admin/structure/views/view/content');

    $page = $this->getSession()->getPage();

    // Use the 'Add' link for fields to open a dialog. This will load the proper

    // dialog libraries.

    $add_link = $page->findById('views-add-field');

    $this->assertTrue($add_link->isVisible(), 'Add fields button found.');

    $add_link->click();

    $this->assertJsCondition("jQuery('.ui-dialog-titlebar').length > 0");

    // Close the dialog and open it again. No no libraries will be loaded, but a

    // cache entry will be made for not loading any libraries.

    $page->pressButton('Close');

    $add_link->click();

    $this->assertJsCondition("jQuery('.ui-dialog-titlebar').length > 0");

    $page->pressButton('Close');

    // Reload the page.

    $this->drupalGet('admin/structure/views/view/content');

    $page = $this->getSession()->getPage();

    // Now use the 'Update preview' button to load libraries.

    $preview = $page->findById('preview-submit');

    // The first click will load all the libraries.

    $preview->click();

    $this->assertJsCondition("jQuery('.ajax-progress').length === 0");

    // The second click will not load any new libraries.

    $preview->click();

    $this->assertJsCondition("jQuery('.ajax-progress').length === 0");

    // Check to see if the dialogs still open.

    $add_link = $page->findById('views-add-field');

    $add_link->click();

    $this->assertJsCondition("jQuery('.ui-dialog-titlebar').length > 0");

    $page->pressButton('Close');

  }

}