diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/StringTextareaWidget.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/StringTextareaWidget.php
index 8658dd0..44af9df 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/StringTextareaWidget.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/StringTextareaWidget.php
@@ -78,7 +78,7 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
       '#default_value' => $items[$delta]->value,
       '#rows' => $this->getSetting('rows'),
       '#placeholder' => $this->getSetting('placeholder'),
-      '#attributes' => array('class' => array('text-full')),
+      '#attributes' => array('class' => array('js-text-full', 'text-full')),
     );
 
     return $element;
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/StringTextfieldWidget.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/StringTextfieldWidget.php
index 0ed4239..79bc044 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/StringTextfieldWidget.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/StringTextfieldWidget.php
@@ -79,7 +79,7 @@ public function formElement(FieldItemListInterface $items, $delta, array $elemen
       '#size' => $this->getSetting('size'),
       '#placeholder' => $this->getSetting('placeholder'),
       '#maxlength' => $this->getFieldSetting('max_length'),
-      '#attributes' => array('class' => array('text-full')),
+      '#attributes' => array('class' => array('js-text-full', 'text-full')),
     );
 
     return $element;
diff --git a/core/modules/filter/templates/text-format-wrapper.html.twig b/core/modules/filter/templates/text-format-wrapper.html.twig
index ce3ba55..367de09 100644
--- a/core/modules/filter/templates/text-format-wrapper.html.twig
+++ b/core/modules/filter/templates/text-format-wrapper.html.twig
@@ -15,7 +15,7 @@
  * @ingroup themeable
  */
 #}
-<div>
+<div class="js-text-format-wrapper">
   {{ children }}
   {% if description %}
     <div{{ attributes }}>{{ description }}</div>
diff --git a/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWithSummaryWidget.php b/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWithSummaryWidget.php
index ba8c875..c6bef4f 100644
--- a/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWithSummaryWidget.php
+++ b/core/modules/text/src/Plugin/Field/FieldWidget/TextareaWithSummaryWidget.php
@@ -78,8 +78,8 @@ function formElement(FieldItemListInterface $items, $delta, array $element, arra
       '#attached' => array(
         'library' => array('text/drupal.text'),
       ),
-      '#attributes' => array('class' => array('text-summary')),
-      '#prefix' => '<div class="text-summary-wrapper">',
+      '#attributes' => array('class' => array('js-text-summary', 'text-summary')),
+      '#prefix' => '<div class="js-text-summary-wrapper text-summary-wrapper">',
       '#suffix' => '</div>',
       '#weight' => -10,
     );
diff --git a/core/modules/text/text.js b/core/modules/text/text.js
index 2ab1d0a..c03b85e 100644
--- a/core/modules/text/text.js
+++ b/core/modules/text/text.js
@@ -7,12 +7,12 @@
    */
   Drupal.behaviors.textSummary = {
     attach: function (context, settings) {
-      $(context).find('.text-summary').once('text-summary').each(function () {
-        var $widget = $(this).closest('.text-format-wrapper');
+      $(context).find('.js-text-summary').once('text-summary').each(function () {
+        var $widget = $(this).closest('.js-text-format-wrapper');
 
-        var $summary = $widget.find('.text-summary-wrapper');
+        var $summary = $widget.find('.js-text-summary-wrapper');
         var $summaryLabel = $summary.find('label').eq(0);
-        var $full = $widget.find('.text-full').closest('.form-item');
+        var $full = $widget.find('.js-text-full').closest('.form-item');
         var $fullLabel = $full.find('label').eq(0);
 
         // Create a placeholder label when the field cardinality is greater
diff --git a/core/themes/classy/templates/content-edit/text-format-wrapper.html.twig b/core/themes/classy/templates/content-edit/text-format-wrapper.html.twig
index b8e0250..4bd1566 100644
--- a/core/themes/classy/templates/content-edit/text-format-wrapper.html.twig
+++ b/core/themes/classy/templates/content-edit/text-format-wrapper.html.twig
@@ -13,7 +13,7 @@
  * @see template_preprocess_text_format_wrapper()
  */
 #}
-<div class="text-format-wrapper form-item">
+<div class="js-text-format-wrapper text-format-wrapper form-item">
   {{ children }}
   {% if description %}
     {%