class CKEditorToolbarButtonTest

class CKEditorToolbarButtonTest extends BrowserTestBase {
    
    /**
     * Modules to enable for this test.
     *
     * @var array
     */
    protected static $modules = [
        'filter',
        'editor',
        'ckeditor',
        'locale',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * The admin user.
     *
     * @var \Drupal\user\Entity\User
     */
    protected $adminUser;
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        // Create a text format and associate this with CKEditor.
        FilterFormat::create([
            'format' => 'full_html',
            'name' => 'Full HTML',
            'weight' => 1,
            'filters' => [],
        ])->save();
        Editor::create([
            'format' => 'full_html',
            'editor' => 'ckeditor',
        ])->save();
        // Create a new user with admin rights.
        $this->adminUser = $this->drupalCreateUser([
            'administer languages',
            'access administration pages',
            'administer site configuration',
            'administer filters',
        ]);
    }
    
    /**
     * Method tests CKEditor image buttons.
     */
    public function testImageButtonDisplay() {
        $this->drupalLogin($this->adminUser);
        // Install the Arabic language (which is RTL) and configure as the default.
        $edit = [];
        $edit['predefined_langcode'] = 'ar';
        $this->drupalGet('admin/config/regional/language/add');
        $this->submitForm($edit, 'Add language');
        $edit = [
            'site_default_language' => 'ar',
        ];
        $this->drupalGet('admin/config/regional/language');
        $this->submitForm($edit, 'Save configuration');
        // Once the default language is changed, go to the tested text format
        // configuration page.
        $this->drupalGet('admin/config/content/formats/manage/full_html');
        // Check if any image button is loaded in CKEditor json.
        $json_encode = function ($html) {
            return trim(Json::encode($html), '"');
        };
        
        /** @var \Drupal\Core\File\FileUrlGeneratorInterface $file_url_generator */
        $file_url_generator = \Drupal::service('file_url_generator');
        $markup = $json_encode($file_url_generator->generateString('core/modules/ckeditor/js/plugins/drupalimage/icons/drupalimage.png'));
        $this->assertSession()
            ->responseContains($markup);
    }

}