diff --git a/core/modules/image/image.module b/core/modules/image/image.module
index 07f9fc3..12fa4fd 100644
--- a/core/modules/image/image.module
+++ b/core/modules/image/image.module
@@ -486,10 +486,10 @@ function image_field_config_delete(FieldConfigInterface $field) {
 }
 
 /**
- * Implements hook_form_FORM_ID_alter() for EditorImageDialog.
+ * Implements hook_form_FORM_ID_alter().
  *
  * Alters the image dialog form for text editor, to allow the user to select an
- * image style.
+ *   image style.
  *
  * @see \Drupal\editor\Form\EditorImageDialog::buildForm()
  */
@@ -512,6 +512,7 @@ function image_form_editor_image_dialog_alter(&$form, FormStateInterface $form_s
       '#default_value' => isset($image_element['data-image-style']) ? $image_element['data-image-style'] : NULL,
       '#options' => $image_style_options,
       '#required' => TRUE,
+      '#parents' => array('attributes', 'data-image-style'),
     );
 
     $form['actions']['save_modal']['#validate'][] = 'image_form_editor_image_dialog_validate';
@@ -538,17 +539,13 @@ function image_form_editor_image_dialog_validate(array &$form, FormStateInterfac
     /** @var \Drupal\file\FileInterface $file */
     $file = File::load($form_state->getValue('fid')[0]);
 
-    // Get the URI of the image from the file.
     $uri = $file->getFileUri();
 
-    // Transform absolute image URLs to relative image URLs: prevent problems
-    // on multisite set-ups and prevent mixed content errors.
-    $image_url = file_create_url($uri);
-    $image_url = file_url_transform_relative($image_url);
     // Set the 'src' attribute to the image style URL. FilterImageStyle will
     // look at the 'data-editor-file-uuid' attribute, not the 'src' attribute to
     // render the appropriate output.
-    $attributes['src'] = $image_style->buildUrl($image_url);
+    $image_url = $image_style->buildUrl($uri);
+    $attributes['src'] = file_url_transform_relative($image_url);
 
     /** @var \Drupal\Core\Image\ImageInterface $image */
     $image = \Drupal::service('image.factory')->get($uri);
@@ -557,7 +554,7 @@ function image_form_editor_image_dialog_validate(array &$form, FormStateInterfac
       // Get the original width and height of the image.
       $dimensions = array(
         'width' => $image->getWidth(),
-        'height' => $image->getHeight()
+        'height' => $image->getHeight(),
       );
 
       // Transform the 'width' and 'height' dimensions of the image based on the
diff --git a/core/modules/image/js/plugins/drupalimagestyle/plugin.js b/core/modules/image/js/plugins/drupalimagestyle/plugin.js
index bc7b7fa..ef8eae1 100644
--- a/core/modules/image/js/plugins/drupalimagestyle/plugin.js
+++ b/core/modules/image/js/plugins/drupalimagestyle/plugin.js
@@ -35,7 +35,7 @@
         var requiredContent = widgetDefinition.requiredContent.getDefinition();
         requiredContent.attributes['data-image-style'] = '';
         widgetDefinition.requiredContent = new CKEDITOR.style(requiredContent);
-        widgetDefinition.allowedContent.img.attributes += ',!data-image-style';
+        widgetDefinition.allowedContent.img.attributes['!data-image-style'] = true;
 
         // Decorate downcast().
         var originalDowncast = widgetDefinition.downcast;
diff --git a/core/modules/image/src/Plugin/CKEditorPlugin/DrupalImageStyle.php b/core/modules/image/src/Plugin/CKEditorPlugin/DrupalImageStyle.php
index 6689e30..d076508 100644
--- a/core/modules/image/src/Plugin/CKEditorPlugin/DrupalImageStyle.php
+++ b/core/modules/image/src/Plugin/CKEditorPlugin/DrupalImageStyle.php
@@ -63,12 +63,12 @@ public function isEnabled(Editor $editor) {
     }
 
     // Automatically enable this plugin if the text format associated with this
-    // text editor uses the filter_image_style filter and the drupalimagestyle
+    // text editor uses the filter_image_style filter and the DrupalImage
     // button is enabled.
     $format = $editor->getFilterFormat();
     if ($format->filters('filter_image_style')->status) {
       $toolbarButtons = CKEditorPluginManager::getEnabledButtons($editor);
-      return in_array('drupalimagestyle', $toolbarButtons);
+      return in_array('DrupalImage', $toolbarButtons);
     }
 
     return FALSE;
diff --git a/core/modules/image/src/Plugin/Filter/FilterImageStyle.php b/core/modules/image/src/Plugin/Filter/FilterImageStyle.php
index bb29180..328daed 100644
--- a/core/modules/image/src/Plugin/Filter/FilterImageStyle.php
+++ b/core/modules/image/src/Plugin/Filter/FilterImageStyle.php
@@ -93,16 +93,14 @@ public static function create(ContainerInterface $container, array $configuratio
    */
   public function process($text, $langcode) {
     if (stristr($text, 'data-image-style') !== FALSE) {
-      // Load all the image styles so each imgage found in the text can be
-      // checked to ensure it has a valid image style.
+      // Load all image styles so each image found in the text can be
+      // checked against a valid image style.
       $image_styles = $this->loadImageStyles();
 
-      // Load the text that is being processed into XML to find images.
       $dom = HTML::load($text);
       $xpath = new \DOMXPath($dom);
 
-      // Process each img element DOM element found with the necessary
-      // attributes.
+      // Process each img element found with the necessary attributes.
       /** @var \DOMElement $dom_element */
       foreach ($xpath->query('//*[@data-entity-type="file" and @data-entity-uuid and @data-image-style]') as $dom_element) {
         // Get the UUID and image style for the file.
@@ -116,23 +114,12 @@ public function process($text, $langcode) {
         }
 
         // Transform the HTML for the img element by applying an image style.
-        $altered_img = $this->getImageStyleHtml($file_uuid, $image_style_id, $dom_element);
-
-        // Load the altered HTML into a new DOMDocument and retrieve the element.
-        $updated_node = HTML::load($altered_img)->getElementsByTagName('body')
-          ->item(0)
-          ->childNodes
-          ->item(0);
-
-        // Import the updated node from the new DOMDocument into the original
-        // one, importing also the child nodes of the updated node.
-        $updated_node = $dom->importNode($updated_node, TRUE);
-
-        // Finally, replace the original image node with the new image node.
-        $dom_element->parentNode->replaceChild($updated_node, $dom_element);
+        $altered_img_markup = $this->getImageStyleHtml($file_uuid, $image_style_id, $dom_element);
+        $altered_img = $dom->createDocumentFragment();
+        $altered_img->appendXML($altered_img_markup);
+        $dom_element->parentNode->replaceChild($altered_img, $dom_element);
       }
 
-      // Process the filter with the newly updated DOM.
       return new FilterProcessResult(HTML::serialize($dom));
     }
 
@@ -141,9 +128,10 @@ public function process($text, $langcode) {
   }
 
   /**
-   * Loads the image styles.
+   * Loads the available image style names.
    *
    * @return string[]
+   *   Array keys of the available image styles.
    */
   protected function loadImageStyles() {
     return array_keys($this->entityTypeManager->getStorage('image_style')->loadMultiple());
@@ -159,7 +147,7 @@ protected function loadImageStyles() {
    *   The image information.
    */
   protected function getImageInfo($file_uuid) {
-    /** @var \Drupal\file\FileInterface $file; */
+    /** @var \Drupal\file\FileInterface $file */
     $file = $this->entityRepository->loadEntityByUuid('file', $file_uuid);
 
     // Determine uri, width and height of the source image.
@@ -174,7 +162,7 @@ protected function getImageInfo($file_uuid) {
     return [
       'uri' => $image_uri,
       'width' => $image_width,
-      'height' => $image_height
+      'height' => $image_height,
     ];
   }
 
@@ -185,7 +173,7 @@ protected function getImageInfo($file_uuid) {
    *   The DOM element for the img element.
    *
    * @return array
-   *  The attributes array.
+   *   The attributes array.
    */
   protected function prepareImageAttributes(\DOMElement $dom_element) {
     // Remove attributes that are no longer needed.
@@ -217,7 +205,7 @@ protected function prepareImageAttributes(\DOMElement $dom_element) {
    * @param string $image_style_id
    *   The ID for the image style.
    * @param \DOMElement $dom_element
-   *  The DOM element for the image element.
+   *   The DOM element for the image element.
    *
    * @return string
    *   The img element with the image style applied.
@@ -238,9 +226,11 @@ protected function getImageStyleHtml($file_uuid, $image_style_id, \DOMElement $d
       '#attributes' => $attributes,
     ];
 
-    $this->renderer->executeInRenderContext(new RenderContext(), function () use (&$image) {
+    $output = $this->renderer->executeInRenderContext(new RenderContext(), function () use (&$image) {
       return $this->renderer->render($image);
     });
+
+    return $output;
   }
 
   /**
@@ -256,5 +246,7 @@ public function tips($long = FALSE) {
     else {
       return t('You can display images using site-wide styles by adding a data-image-style attribute.');
     }
+
   }
+
 }
diff --git a/core/modules/image/tests/src/Functional/FilterImageStyleTest.php b/core/modules/image/tests/src/Functional/FilterImageStyleTest.php
new file mode 100644
index 0000000..63528cb
--- /dev/null
+++ b/core/modules/image/tests/src/Functional/FilterImageStyleTest.php
@@ -0,0 +1,121 @@
+<?php
+
+namespace Drupal\Tests\image\Functional;
+
+use Drupal\Tests\BrowserTestBase;
+use Drupal\filter\Entity\FilterFormat;
+use Drupal\file\Entity\File;
+use Drupal\Core\Url;
+
+/**
+ * @coversDefaultClass \Drupal\image\Plugin\Filter\FilterImageStyle
+ * @group image
+ */
+class FilterImageStyleTest extends BrowserTestBase {
+  /**
+   * Modules to enable.
+   *
+   * @var array
+   */
+  public static $modules = ['filter', 'file', 'editor', 'node', 'image'];
+
+  /**
+   * Text filter allowing images and has FilterImageStyle applied.
+   *
+   * @var \Drupal\Core\Entity\EntityInterface
+   */
+  protected $format;
+
+  /**
+   * Tasks common to all tests.
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $this->format = FilterFormat::create([
+      'format' => $this->randomMachineName(),
+      'name' => $this->randomString(),
+      'filters' => [
+        'filter_html' => [
+          'status' => 1,
+          'settings' => [
+            'allowed_html' => '<img src alt data-entity-type data-entity-uuid data-align data-caption data-image-style width height>',
+          ],
+        ],
+        'filter_image_style' => ['status' => 1],
+        'editor_file_reference' => ['status' => 1],
+      ],
+    ]);
+    $this->format->save();
+
+    $user = $this->drupalCreateUser(['access content', 'administer nodes']);
+    $this->drupalLogin($user);
+
+    $this->drupalCreateContentType(['type' => 'page', 'name' => 'Basic page']);
+  }
+
+  /**
+   * Helper function to create a test node with configurable image html.
+   */
+  protected function nodeHelper($image_html) {
+    $node = $this->drupalCreateNode([
+      'type' => 'page',
+      'title' => $this->randomString(),
+      'body' => [
+        [
+          'format' => $this->format->id(),
+          'value' => $image_html,
+        ],
+      ],
+    ]);
+    $node->save();
+
+    $this->drupalGet($node->toUrl());
+    $this->assertSession()->statusCodeEquals(200);
+  }
+
+  /**
+   * Tests that images not uploaded through media module are unmolested.
+   */
+  public function testImageNoStyle() {
+    $file_url = Url::fromUri('base:core/themes/bartik/screenshot.png')->toString();
+
+    $image_html = '<img src="' . $file_url . '" width="220">';
+    $this->nodeHelper($image_html);
+
+    /** @var \Behat\Mink\Element\NodeElement $img_element */
+    $image_element = $this->getSession()->getPage()->find('css', "img");
+    $this->assertFalse(empty($image_element));
+
+    $this->assertFalse($image_element->hasAttribute('class'));
+    $this->assertEquals($file_url, $image_element->getAttribute('src'));
+    $this->assertEquals('220', $image_element->getAttribute('width'));
+    $this->assertFalse($image_element->hasAttribute('height'));
+  }
+
+  /**
+   * Tests image style modification of images.
+   */
+  public function testImageStyle() {
+    $this->assertTrue(array_key_exists('medium', $this->container->get('entity_type.manager')->getStorage('image_style')->loadMultiple()));
+
+    $file = File::create(['uri' => 'core/themes/bartik/screenshot.png']);
+    $file->save();
+
+    $image_html = '<img src="' . file_url_transform_relative($file->url()) . '" data-entity-type="file" data-entity-uuid="' . $file->uuid() . '" data-image-style="medium" width="220">';
+    $this->nodeHelper($image_html);
+
+    /** @var \Behat\Mink\Element\NodeElement $img_element */
+    $image_element = $this->getSession()->getPage()->find('css', 'img.image-style-medium');
+    $this->assertFalse(empty($image_element));
+
+    $this->assertFalse($image_element->hasAttribute('data-entity-type'));
+    $this->assertFalse($image_element->hasAttribute('data-entity-uuid'));
+    $this->assertFalse($image_element->hasAttribute('data-image-style'));
+
+    $this->assertTrue(strpos($image_element->getAttribute('src'), 'medium'));
+    $this->assertEquals('220', $image_element->getAttribute('width'));
+    $this->assertEquals('164', $image_element->getAttribute('height'));
+  }
+
+}
diff --git a/core/modules/image/tests/src/FunctionalJavascript/AddImageTest.php b/core/modules/image/tests/src/FunctionalJavascript/AddImageTest.php
new file mode 100644
index 0000000..2b33a5b
--- /dev/null
+++ b/core/modules/image/tests/src/FunctionalJavascript/AddImageTest.php
@@ -0,0 +1,106 @@
+<?php
+
+namespace Drupal\Tests\image\FunctionalJavascript;
+
+use Drupal\filter\Entity\FilterFormat;
+use Drupal\FunctionalJavascriptTests\JavascriptTestBase;
+use Drupal\Tests\TestFileCreationTrait;
+use Drupal\editor\Entity\Editor;
+use Drupal\Core\Url;
+
+/**
+ * Tests the JavaScript functionality of the drupalimagestyle CKEditor plugin.
+ *
+ * @group image
+ */
+class AddImageTest extends JavascriptTestBase {
+
+  use TestFileCreationTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['filter', 'file', 'node', 'image', 'ckeditor'];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+
+    $format = FilterFormat::create([
+      'format' => 'filtered_html',
+      'name' => $this->randomString(),
+      'filters' => [
+        'filter_image_style' => ['status' => 1],
+      ],
+    ]);
+    $format->save();
+
+    $this->drupalCreateContentType(['type' => 'page', 'name' => 'Basic page']);
+
+    Editor::create([
+      'format' => 'filtered_html',
+      'editor' => 'ckeditor',
+    ])->save();
+
+    $user = $this->drupalCreateUser([
+      'access content',
+      'administer nodes',
+      'create page content',
+      'use text format filtered_html',
+    ]);
+    $this->drupalLogin($user);
+  }
+
+  /**
+   * Tests if an image can be placed inline with the data-image-style attribute.
+   */
+  public function testDataImageStyleElement() {
+    $image_url = Url::fromUri('base:core/themes/bartik/screenshot.png')->toString();
+
+    $this->drupalGet('node/add/page');
+    $this->assertSession()->statusCodeEquals(200);
+
+    $page = $this->getSession()->getPage();
+    // Wait for the ckeditor toolbar elements to appear (loading is done).
+    $image_button_selector = 'a.cke_button__drupalimage';
+    $this->assertJsCondition("jQuery('$image_button_selector').length > 0", 20000);
+    $this->assertSession()->assertWaitOnAjaxRequest();
+
+    $image_button = $page->find('css', $image_button_selector);
+    $this->assertNotEmpty($image_button);
+    $image_button->click();
+    // Wait for the modal form elements to appear (loading is done).
+    $this->assertJsCondition("jQuery('input[data-drupal-selector=\"edit-attributes-alt\"]').length > 0", 20000);
+
+    $url_input = $page->findField('attributes[src]');
+    $this->assertNotEmpty($url_input);
+    $url_input->setValue($image_url);
+
+    $alt_input = $page->findField('attributes[alt]');
+    $this->assertNotEmpty($alt_input);
+    $alt_input->setValue('asd');
+
+    $image_style_input_name = 'attributes[data-image-style]';
+    $this->assertNotEmpty($page->findField($image_style_input_name));
+    $page->selectFieldOption($image_style_input_name, 'thumbnail');
+
+    // To prevent 403s on save, we re-set our request (cookie) state.
+    $this->prepareRequest();
+
+    // Using NodeElement::click() on the button or NodeElement::submit() on the
+    // form generated phantomjs-internal exceptions. This was the only recourse.
+    $script = "jQuery('input[id^=\"edit-actions-save-modal\"]').click()";
+    $this->getSession()->executeScript($script);
+    $this->assertSession()->assertWaitOnAjaxRequest();
+
+    $source_button = $page->find('css', 'a.cke_button__source');
+    $this->assertNotEmpty($source_button);
+    $source_button->click();
+    $this->assertSession()->assertWaitOnAjaxRequest();
+
+    $this->assertContains('data-image-style="thumbnail"', $page->find('css', 'textarea.cke_source')->getValue());
+  }
+
+}
diff --git a/core/modules/image/tests/src/Kernel/EditorImageStyleDialogTest.php b/core/modules/image/tests/src/Kernel/EditorImageStyleDialogTest.php
index a062273..9282c32 100644
--- a/core/modules/image/tests/src/Kernel/EditorImageStyleDialogTest.php
+++ b/core/modules/image/tests/src/Kernel/EditorImageStyleDialogTest.php
@@ -39,7 +39,7 @@ class EditorImageStyleDialogTest extends EntityKernelTestBase {
     'image',
     'node',
     'system',
-    'user'
+    'user',
   ];
 
   /**
@@ -54,19 +54,40 @@ protected function setUp() {
     $this->installSchema('file', ['file_usage']);
     $this->installConfig(['node']);
 
-    // Add text formats.
+    // Install the image module config so we have the medium image style.
+    $this->installConfig('image');
+
+    // Create a node type for testing.
+    $type = NodeType::create(['type' => 'page', 'name' => 'page']);
+    $type->save();
+    node_add_body_field($type);
+    $this->installEntitySchema('user');
+    $this->container->get('router.builder')->rebuild();
+  }
+
+  /**
+   * Fixture to consolidate tasks while making filter status configurable.
+   *
+   * @param bool $enable_image_filter
+   *   Whether to activate filter_image_style in the text format.
+   *
+   * @return array|\Symfony\Component\HttpFoundation\Response
+   *   The submitted form.
+   */
+  protected function setUpForm($enable_image_filter) {
     $format = FilterFormat::create([
       'format' => $this->randomMachineName(),
       'name' => $this->randomString(),
       'weight' => 0,
       'filters' => [
-        'filter_image_style' => ['status' => TRUE]
+        'filter_image_style' => ['status' => $enable_image_filter],
       ],
     ]);
     $format->save();
 
     // Set up text editor.
-    $this->editor = Editor::create([
+    /** @var \Drupal\editor\EditorInterface $editor */
+    $editor = Editor::create([
       'format' => $format->id(),
       'editor' => 'ckeditor',
       'image_upload' => [
@@ -76,23 +97,8 @@ protected function setUp() {
         'status' => TRUE,
       ],
     ]);
-    $this->editor->save();
-
-    // Install the image module config so we have the medium image style.
-    $this->installConfig('image');
-
-    // Create a node type for testing.
-    $type = NodeType::create(['type' => 'page', 'name' => 'page']);
-    $type->save();
-    node_add_body_field($type);
-    $this->installEntitySchema('user');
-    $this->container->get('router.builder')->rebuild();
-  }
+    $editor->save();
 
-  /**
-   * Tests that editor image dialog works as expected.
-   */
-  public function testEditorImageStyleDialog() {
     /** @var \Drupal\file\FileInterface $file */
     $file = file_save_data(file_get_contents($this->root . '/core/modules/image/sample.png'), 'public://');
 
@@ -102,7 +108,6 @@ public function testEditorImageStyleDialog() {
         'alt' => 'Balloons floating above a field.',
         'data-entity-type' => 'file',
         'data-entity-uuid' => $file->uuid(),
-        'data-image-style' => 'medium',
       ],
       'dialogOptions' => [
         'title' => 'Edit Image',
@@ -116,10 +121,14 @@ public function testEditorImageStyleDialog() {
         'libraries' => '',
       ],
     ];
+    if ($enable_image_filter) {
+      $input['editor_object']['data-image-style'] = 'medium';
+    }
+
     $form_state = (new FormState())
       ->setRequestMethod('POST')
       ->setUserInput($input)
-      ->addBuildInfo('args', [$this->editor]);
+      ->addBuildInfo('args', [$editor]);
 
     /** @var \Drupal\Core\Form\FormBuilderInterface $form_builder */
     $form_builder = $this->container->get('form_builder');
@@ -129,14 +138,34 @@ public function testEditorImageStyleDialog() {
 
     /** @var \Drupal\Core\Render\RendererInterface $renderer */
     $renderer = \Drupal::service('renderer');
-    $renderer->executeInRenderContext(new RenderContext(), function() use (&$form, $form_builder, $form_id, $form_state) {
+    $renderer->executeInRenderContext(new RenderContext(), function () use (&$form, $form_builder, $form_id, $form_state) {
       $form = $form_builder->retrieveForm($form_id, $form_state);
       $form_builder->prepareForm($form_id, $form, $form_state);
       $form_builder->processForm($form_id, $form, $form_state);
     });
 
-    // Image style should be medium.
+    return $form;
+  }
+
+  /**
+   * Tests that style selection is hidden when filter_image_style is disabled.
+   */
+  public function testDialogNoStyles() {
+    $form = $this->setUpForm(FALSE);
+
+    $this->assertFalse(array_key_exists('image_style', $form));
+  }
+
+  /**
+   * Tests EditorImageDialog when filter_image_style is enabled.
+   */
+  public function testDialogStyles() {
+    $form = $this->setUpForm(TRUE);
+
+    $this->assertEquals(['large', 'medium', 'thumbnail'], array_keys($form['image_style']['selection']['#options']));
+
     $this->assertEquals('medium', $form['image_style']['selection']['#default_value']);
+    $this->assertEquals(TRUE, $form['image_style']['selection']['#required']);
   }
 
 }
diff --git a/core/modules/image/tests/src/Unit/FilterImageStyleTest.php b/core/modules/image/tests/src/Unit/FilterImageStyleTest.php
deleted file mode 100644
index ad1b047..0000000
--- a/core/modules/image/tests/src/Unit/FilterImageStyleTest.php
+++ /dev/null
@@ -1,106 +0,0 @@
-<?php
-
-namespace Drupal\Tests\image\Unit;
-
-use Drupal\Core\Entity\EntityRepository;
-use Drupal\Core\Entity\EntityStorageInterface;
-use Drupal\Core\Entity\EntityTypeManager;
-use Drupal\Core\Image\ImageFactory;
-use Drupal\Core\Render\Renderer;
-use Drupal\Tests\UnitTestCase;
-use Drupal\image\Plugin\Filter\FilterImageStyle;
-
-/**
- * @coversDefaultClass \Drupal\image\Plugin\Filter\FilterImageStyle
- * @group image
- */
-class FilterImageStyleTest extends UnitTestCase {
-
-  /**
-   * @var \Drupal\filter\Plugin\Filter\FilterHtml
-   */
-  protected $filter;
-
-  /**
-   * @var \Drupal\image\Plugin\Filter\FilterImageStyle
-   */
-  protected $filterImageStyle;
-
-  /**
-   * {@inheritdoc}
-   */
-  protected function setUp() {
-    parent::setUp();
-
-    $configuration = [];
-    $plugin_id = '';
-    $plugin_definition = ['provider' => 'image'];
-    $entityTypeManager = $this->prophesize(EntityTypeManager::class);
-    $entityRepository = $this->prophesize(EntityRepository::class);
-    $imageFactory = $this->prophesize(ImageFactory::class);
-    $renderer = $this->prophesize(Renderer::class);
-
-    $this->filterImageStyle = $this->getMockBuilder('Drupal\image\Plugin\Filter\FilterImageStyle')
-      ->setConstructorArgs([
-        $configuration,
-        $plugin_id,
-        $plugin_definition,
-        $entityTypeManager->reveal(),
-        $entityRepository->reveal(),
-        $imageFactory->reveal(),
-        $renderer->reveal()
-      ])
-      ->setMethods([
-        'loadImageStyles',
-        'getImageStyleHtml'
-      ])
-      ->getMock();
-  }
-
-  public function testProcessWithoutImage() {
-    $output = $this->filterImageStyle->process('<a></a>', 'en');
-    $this->assertEquals('<a></a>', $output);
-  }
-
-  /**
-   * @covers ::process
-   */
-  public function testProcessWithImage() {
-    $original_src = 'image.png';
-    $original_uuid = 'abcd-1234-ghij-5678';
-    $original_image_style = 'medium';
-    $original_width = '400';
-    $original_height = '300';
-    $original_alt = 'A wooly mammoth trumpets as a crevasse breaks open in the glacier.';
-
-    $original_img = '<img src="' . $original_src .'" width="' . $original_width .'" height="' . $original_height .'" alt="' . $original_alt .'" data-entity-uuid="' . $original_uuid . '" data-entity-type="file" data-image-style="' . $original_image_style . '" />';
-    $original_text = '<p>' . $original_img . '</p>';
-
-    $expected_src = 'styles/medium/public/inline-images/image.png';
-    $expected_width = '200';
-    $expected_height = '150';
-
-    $expected_img = '<img src="' . $expected_src .'" width="' . $expected_width .'" height="' . $expected_height .'" alt="' . $original_alt .'" />';
-    $expected_text = '<p>' . $expected_img . '</p>';
-
-    $this->filterImageStyle
-      ->method('loadImageStyles')
-      ->willReturn([
-        'thumbnail',
-        'medium',
-        'large'
-      ]);
-
-    $this->filterImageStyle
-      ->method('getImageStyleHtml')
-      ->with(
-        $this->equalTo($original_uuid),
-        $this->equalTo($original_image_style),
-        $this->anything()
-      )
-      ->willReturn($expected_img);
-
-    $output = $this->filterImageStyle->process($original_text, 'en');
-    $this->assertEquals($expected_text, $output);
-  }
-}