Revert "fix: #3516264 CKEditor 5 loads all plugin translations on AJAX operations"

   */

  #[Hook('js_alter')]

  public function jsAlter(&$javascript, AttachedAssetsInterface $assets, LanguageInterface $language): void {

    $translations_library = 'core/ckeditor5.translations';

    // This file means CKEditor 5 translations are in use on the page.

    // @see locale_js_alter()

    $placeholder_file = 'core/assets/vendor/ckeditor5/translation.js';

    if (in_array($translations_library, $assets->getLibraries(), TRUE) || in_array($translations_library, $assets->getAlreadyLoadedLibraries(), TRUE)) {

      // This file is used to get a weight that will make it possible to

      // aggregate all translation files in a single aggregate.

    // This file is used to get a weight that will make it possible to aggregate

    // all translation files in a single aggregate.

    $ckeditor_dll_file = 'core/assets/vendor/ckeditor5/ckeditor5-dll/ckeditor5-dll.js';

    if (isset($javascript[$placeholder_file])) {

      // Use the placeholder file weight to set all the translations files

      // weights so they can be aggregated together as expected. Account for

      // requests where the library is not loaded such as when during an AJAX

      // request when it was already loaded via the main request. In these cases

      // it is unlikely that multiple JavaScript aggregates will be created

      // anyway since AJAX requests generally result in very few libraries being

      // loaded.

      $default_weight = $javascript[$placeholder_file]['weight'] ?? 0;

      // weights so they can be aggregated together as expected.

      $default_weight = $javascript[$placeholder_file]['weight'];

      if (isset($javascript[$ckeditor_dll_file])) {

        $default_weight = $javascript[$ckeditor_dll_file]['weight'];

      }

      // The placeholder file is not a real file, remove it from the list.

      unset($javascript[$placeholder_file]);

      // When the locale module isn't installed there are no translations.

      if (!\Drupal::moduleHandler()->moduleExists('locale')) {

        return;

        }

      }

    }

    // The placeholder file is not a real file, remove it from the list.

    unset($javascript[$placeholder_file]);

  }

  /**

namespace Drupal\Tests\ckeditor5\Unit;

use Drupal\ckeditor5\LanguageMapper;

use Drupal\ckeditor5\Hook\Ckeditor5Hooks;

use Drupal\ckeditor5\Plugin\Editor\CKEditor5;

use Drupal\Core\Asset\AttachedAssets;

use Drupal\Core\DependencyInjection\ContainerBuilder;

use Drupal\Core\Extension\ModuleHandlerInterface;

use Drupal\Core\Language\Language;

use Drupal\Tests\ckeditor5\Traits\PrivateMethodUnitTestTrait;

use Drupal\Tests\UnitTestCase;

use PHPUnit\Framework\Attributes\CoversClass;

    ];

  }

  /**

   * Test the js_alter hook alters when expected.

   *

   * @legacy-covers \Drupal\ckeditor5\Hook\Ckeditor5Hooks::jsAlter

   */

  public function testJsAlterHook(): void {

    $placeholder_file = 'core/assets/vendor/ckeditor5/translation.js';

    $language_mapper = $this->createMock(LanguageMapper::class);

    $language_mapper->expects($this->any())

      ->method('getMapping')

      ->willReturn('en');

    $hooks = new Ckeditor5Hooks($language_mapper);

    $assets = new AttachedAssets();

    $assets->setLibraries([

      'core/ckeditor5.translations',

      'core/ckeditor5.translations.en',

    ]);

    $language = new Language([

      'id' => 'en',

      'name' => 'English',

      'direction' => 'ltr',

    ]);

    $original_javascript = [

      'keep_this' => [

        'ckeditor5_langcode' => 'en',

      ],

      'remove_this' => [

        'ckeditor5_langcode' => 'sv',

      ],

      'keep_this_too' => [],

    ];

    $expected_javascript = [

      'keep_this' => [

        'ckeditor5_langcode' => 'en',

        'weight' => 5,

      ],

      'keep_this_too' => [],

    ];

    $container = new ContainerBuilder();

    $module_handler = $this->prophesize(ModuleHandlerInterface::class);

    $module_handler->moduleExists('locale')->willReturn(TRUE);

    $container->set('module_handler', $module_handler->reveal());

    \Drupal::setContainer($container);

    // First check that it filters when the placeholder script is present.

    $javascript = $original_javascript + [

      $placeholder_file => [

        'weight' => 5,

      ],

    ];

    $hooks->jsAlter($javascript, $assets, $language);

    $this->assertEquals($expected_javascript, $javascript);

    // Next check it still filters if the placeholder script has already been

    // loaded and is now excluded from the list, such as an AJAX operation

    // loading a new format which uses another set of plugins.

    $assets = new AttachedAssets();

    $assets->setLibraries([

      'core/ckeditor5.translations.en',

    ]);

    $assets->setAlreadyLoadedLibraries([

      'core/ckeditor5.translations',

    ]);

    $javascript = $original_javascript;

    $hooks->jsAlter($javascript, $assets, $language);

    // There was no placeholder to get the weight from.

    $expected_javascript['keep_this']['weight'] = 0;

    $this->assertEquals($expected_javascript, $javascript);

  }

}