LocaleLibraryAlterTest.php

<?php

namespace Drupal\Tests\locale\Kernel;

use Drupal\Core\Asset\AttachedAssets;
use Drupal\KernelTests\KernelTestBase;

/**
 * Tests localization of the JavaScript libraries.
 *
 * Currently, only the jQuery datepicker is localized using Drupal translations.
 *
 * @group locale
 */
class LocaleLibraryAlterTest extends KernelTestBase {
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'locale',
    ];
    
    /**
     * Verifies that the datepicker can be localized.
     *
     * @see locale_library_alter()
     */
    public function testLibraryAlter() {
        $this->installSchema('locale', [
            'locales_location',
            'locales_source',
        ]);
        $assets = new AttachedAssets();
        $assets->setLibraries([
            'core/jquery.ui.datepicker',
        ]);
        $js_assets = $this->container
            ->get('asset.resolver')
            ->getJsAssets($assets, FALSE)[1];
        $this->assertArrayHasKey('core/modules/locale/locale.datepicker.js', $js_assets);
    }

}