diff --git a/core/modules/simpletest/simpletest.js b/core/modules/simpletest/simpletest.js
index c8aa11b..477b162 100644
--- a/core/modules/simpletest/simpletest.js
+++ b/core/modules/simpletest/simpletest.js
@@ -14,16 +14,10 @@
           .html(drupalSettings.simpleTest.images[0])
           .on('click', function () {
             var $tests = $group.nextUntil('.simpletest-group');
-            if ($group.hasClass('expanded')) {
-              $group.removeClass('expanded');
-              $tests.addClass('js-hide');
-              $image.html(drupalSettings.simpleTest.images[0]);
-            }
-            else {
-              $group.addClass('expanded');
-              $tests.removeClass('js-hide');
-              $image.html(drupalSettings.simpleTest.images[1]);
-            }
+            var expand = !$group.hasClass('expanded');
+            $group.toggleClass('expanded', expand);
+            $tests.toggleClass('js-hide', !expand);
+            $image.html(drupalSettings.simpleTest.images[+expand]);
           });
       });
     }