Issue #3500564 by tom konda, catch: Remove the test-only jQuery key event polyfill

core/modules/system/tests/modules/jquery_key_event_polyfill_test/jquery_key_event_polyfill_test.info.yml

-name: 'jQuery key event polyfill test'
-type: module
-description: 'Polyfills the event.which property, needed for tests'
-package: Testing
-version: VERSION

core/modules/system/tests/modules/jquery_key_event_polyfill_test/jquery_key_event_polyfill_test.libraries.yml

-jquery.key_event.polyfill:
-  version: VERSION
-  js:
-    js/jquery.key_event.polyfill.js: { }

core/modules/system/tests/modules/jquery_key_event_polyfill_test/js/jquery.key_event.polyfill.js

-/**
- * @file
- * Adds a jQuery polyfill for event.which.
- *
- * In jQuery 3.6, the event.which polyfill was removed, which is not needed for
- * any supported browsers, but is still necessary to trigger keyboard events in
- * FunctionalJavaScript tests.
- *
- * @todo: This polyfill may be removed if MinkSelenium2Driver updates its use of
- * syn.js, https://github.com/minkphp/MinkSelenium2Driver/pull/333
- *
- * @see https://github.com/jquery/jquery/issues/4755
- * @see https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/which
- */
-
-(($) => {
-  // This is the polyfill implementation from jQuery 3.5.1, modified only to
-  // meet Drupal coding standards.
-  jQuery.event.addProp('which', function (event) {
-    const keyEventRegex = /^key/;
-    const mouseEventRegex = /^(?:mouse|pointer|contextmenu|drag|drop)|click/;
-    const button = event.button;
-
-    // Add which for key events
-    if (event.which == null && keyEventRegex.test(event.type)) {
-      return event.charCode != null ? event.charCode : event.keyCode;
-    }
-
-    // Add which for click: 1 === left; 2 === middle; 3 === right
-    if (
-      !event.which &&
-      button !== undefined &&
-      mouseEventRegex.test(event.type)
-    ) {
-      if (button && 1) {
-        return 1;
-      }
-
-      if (button && 2) {
-        return 3;
-      }
-
-      if (button && 4) {
-        return 2;
-      }
-
-      return 0;
-    }
-
-    return event.which;
-  });
-})(jQuery);

core/modules/system/tests/modules/jquery_keyevent_polyfill_test/src/Hook/JqueryKeyeventPolyfillTestHooks.php

-<?php
-
-declare(strict_types=1);
-
-namespace Drupal\jquery_keyevent_polyfill_test\Hook;
-
-use Drupal\Core\Hook\Attribute\Hook;
-
-/**
- * Hook implementations for jquery_keyevent_polyfill_test.
- */
-class JqueryKeyeventPolyfillTestHooks {
-
-  /**
-   * Implements hook_library_info_alter().
-   */
-  #[Hook('library_info_alter')]
-  public function libraryInfoAlter(&$libraries, $module): void {
-    if ($module == 'core' && isset($libraries['jquery'])) {
-      $libraries['jquery']['dependencies'][] = 'jquery_keyevent_polyfill_test/jquery.keyevent.polyfill';
-    }
-  }
-
-}

core/tests/Drupal/FunctionalJavascriptTests/WebDriverTestBase.php

@@ -75,7 +75,6 @@ protected function installModulesFromClassProperty(ContainerInterface $container
     self::$modules = [
       'js_testing_ajax_request_test',
       'js_testing_log_test',
-      'jquery_key_event_polyfill_test',
     ];
     if ($this->disableCssAnimations) {
       self::$modules[] = 'css_disable_transitions_test';