diff -u b/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php b/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php
--- b/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php
+++ b/core/modules/ckeditor/tests/src/FunctionalJavascript/CKEditorIntegrationTest.php
@@ -235,26 +235,30 @@
   }
 
   /**
-    * Tests if the CKEditor Inserts empty tags into DOM.
-    */
+   * Tests if the CKEditor Inserts empty tags into DOM.
+   */
   public function testDrupalEmptyInsert() {
-      $assert_session = $this->assertSession();
-      // navigate to the page
-      $this->drupalGet('node/add/page');
-      $this->waitForEditor();
-      // issue occurs on several clicks of the source button, when this happens the ckeditor text area increases
-      // so to check if the error has been fixed we toggle the source button and compare the first height to the last height
-      $this->pressEditorButton('source');
-      $this->assertNotEmpty($assert_session->waitForElement('css', '.cke__contents > textarea'));
-      $first_height =  $this->getSession()->evaluateScript('document.getElementById(cke_edit-body-0-value).clientHeight');
-      $this->pressEditorButton('source');
-      $this->assertNotEmpty($assert_session->waitForElement('css', '.cke__contents > span'));
-      $this->pressEditorButton('source');
-      $this->assertNotEmpty($assert_session->waitForElement('css', '.cke__contents > textarea'));
-      $last_height =  $this->getSession()->evaluateScript('document.getElementById(cke_edit-body-0-value).clientHeight');
-      // if the height is different then empty tag has been entered into the DOM
-      $this->assertEquals($first_height, $last_height);
+    $assert_session = $this->assertSession();
 
+    // Navigate to the page
+    $this->drupalGet('node/add/page');
+    $this->waitForEditor();
+
+    // Issue occurs on several clicks of the source button, when this happens
+    // the ckeditor text area increases.
+    // So to check if the error has been fixed we toggle the source button and
+    // compare the first height to the last height.
+    $this->pressEditorButton('source');
+    $this->assertNotEmpty($assert_session->waitForElement('css', '.cke__contents > textarea'));
+    $first_height = $this->getSession()->evaluateScript('document.getElementById(cke_edit-body-0-value).clientHeight');
+    $this->pressEditorButton('source');
+    $this->assertNotEmpty($assert_session->waitForElement('css', '.cke__contents > span'));
+    $this->pressEditorButton('source');
+    $this->assertNotEmpty($assert_session->waitForElement('css', '.cke__contents > textarea'));
+    $last_height = $this->getSession()->evaluateScript('document.getElementById(cke_edit-body-0-value).clientHeight');
+
+    // If the height is different then empty tag has been entered into the DOM.
+    $this->assertEquals($first_height, $last_height);
   }
 
 }