Update to Drupal 8.0.0-beta15. For more information, see: https://www.drupal.org/node/2563023

core/modules/simpletest/simpletest.js

@@ -11,6 +11,9 @@
    * Collapses table rows followed by group rows on the test listing page.
    *
    * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   *   Attach collapse behavior on the test listing page.
    */
   Drupal.behaviors.simpleTestGroupCollapse = {
     attach: function (context) {
@@ -34,6 +37,9 @@
    * Toggles test checkboxes to match the group checkbox.
    *
    * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   *   Attaches behavior for selecting all tests in a group.
    */
   Drupal.behaviors.simpleTestSelectAll = {
     attach: function (context) {
@@ -75,6 +81,9 @@
    * Source text:       .table-filter-text-source
    *
    * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   *   Attaches the filter behavior the the text input element.
    */
   Drupal.behaviors.simpletestTableFilterByText = {
     attach: function (context) {
@@ -95,8 +104,8 @@
 
         // Filter if the length of the query is at least 3 characters.
         if (query.length >= 3) {
-          // Indicate that a search has been performed, and hide the "select all"
-          // checkbox.
+          // Indicate that a search has been performed, and hide the
+          // "select all" checkbox.
           searched = true;
           $('#simpletest-form-table thead th.select-all input').hide();