diff --git a/core/tests/Drupal/Tests/Component/Utility/XssTest.php b/core/tests/Drupal/Tests/Component/Utility/XssTest.php
index 0664f94..522db61 100644
--- a/core/tests/Drupal/Tests/Component/Utility/XssTest.php
+++ b/core/tests/Drupal/Tests/Component/Utility/XssTest.php
@@ -495,9 +495,14 @@ public function testAttribute($value, $expected, $message, $allowed_tags = NULL)
   }
 
   /**
-   * Data provider for testFilterXssAdminNotNormalized().
+   * Data provider for testAttributes().
    */
   public function providerTestAttributes() {
+    $token1 = '[something_looks:like:123:token]';
+    $token2 = '[another_token:with1:number]';
+    $token3 = '[yet_another:token:432]';
+    $token4 = '[running_out:of:token:id3as]';
+
     return [
       [
         '<img src="http://example.com/foo.jpg" title="Example: title" alt="Example: alt">',
@@ -529,6 +534,44 @@ public function providerTestAttributes() {
         'Link tag with numeric data attribute',
         ['a']
       ],
+      // Test attributes formatted like CSS and breakpoints.
+      [
+        '<section class="actions-menu-inner" ng-style="{ \'max-height\': maxPanelHeight }" ed-pretty-scrollbar ed-scroll-axis="y" ed-scroll-theme="light"></section>',
+        '<section class="actions-menu-inner" ng-style="{ \'max-height\': maxPanelHeight }" ed-pretty-scrollbar ed-scroll-axis="y" ed-scroll-theme="light"></section>',
+        'Section tag with ng- attribute',
+        ['section'],
+      ],
+      [
+        '<source srcset="image.jpg 1x" media="all and (min-width: 560px) and (max-width: 850px)" type="image/jpeg" />',
+        '<source srcset="image.jpg 1x" media="all and (min-width: 560px) and (max-width: 850px)" type="image/jpeg" />',
+        'Source with media containing breakpoints',
+        ['source'],
+      ],
+      // Test attributes formatted like tokens.
+      [
+        '<img src="' . $token1 . '" alt="' . $token2 . '" title="prefix ' . $token3 . ' suffix" />',
+        '<img src="' . $token1 . '" alt="' . $token2 . '" title="prefix ' . $token3 . ' suffix" />',
+        'Tokens in img tag attributes',
+        ['img'],
+      ],
+      [
+        '<p class="' . $token1 . '" id="' . $token2 . '">Paragraph with ' . $token3 . 'a token inside.</p>',
+        '<p class="' . $token1 . '" id="' . $token2 . '">Paragraph with ' . $token3 . 'a token inside.</p>',
+        'Tokens in p tag attributes and contents',
+        ['p'],
+      ],
+      [
+        '<a href="' . $token1 . '" title="prefix ' . $token2 . ' suffix" rel="' . $token3 . '">' . $token4 . ' plus more</a>',
+        '<a href="' . $token1 . '" title="prefix ' . $token2 . ' suffix" rel="' . $token3 . '">' . $token4 . ' plus more</a>',
+        'Tokens in a tag attributes and link text',
+        ['a'],
+      ],
+      [
+        '<unknown something="' . $token1 . '" another="prefix ' . $token2 . ' suffix">' . $token3 . '</unknown>',
+        '<unknown something="' . $token1 . '" another="prefix ' . $token2 . ' suffix">' . $token3 . '</unknown>',
+        'Tokens in made-up tag attributes',
+        ['unknown'],
+      ],
     ];
   }