[TASK] Add property and return types to EventDispatcher

The object return on dispatch() is not a formal part of
the interface for BC reasons, but is required by the spec,
so thanks to LSP it's safe to add this way, and recommended.

Resolves: #97484
Releases: main
Change-Id: I01037753a0cc0cdb87c42900958edb2c1438233f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74440


Tested-by: core-ci <typo3@b13.com>
Tested-by: Benjamin Franzke <bfr@qbus.de>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Benjamin Franzke <bfr@qbus.de>
Reviewed-by: Benni Mack <benni@typo3.org>

typo3/sysext/adminpanel/Classes/Service/EventDispatcher.php

@@ -25,14 +25,14 @@ class EventDispatcher extends \TYPO3\CMS\Core\EventDispatcher\EventDispatcher
     /**
      * @var object[]
      */
-    protected $dispatchedEvents = [];
+    protected array $dispatchedEvents = [];
 
     public function getDispatchedEvents(): array
     {
         return $this->dispatchedEvents;
     }
 
-    public function dispatch(object $event)
+    public function dispatch(object $event): object
     {
         $this->dispatchedEvents[] = $event;
         return parent::dispatch($event);

typo3/sysext/core/Classes/EventDispatcher/EventDispatcher.php

@@ -28,17 +28,12 @@ use TYPO3\CMS\Core\SingletonInterface;
  */
 class EventDispatcher implements EventDispatcherInterface, SingletonInterface
 {
-    /**
-     * @var ListenerProviderInterface
-     */
-    protected $listenerProvider;
-
-    public function __construct(ListenerProviderInterface $listenerProvider)
-    {
-        $this->listenerProvider = $listenerProvider;
+    public function __construct(
+        protected readonly ListenerProviderInterface $listenerProvider
+    ) {
     }
 
-    public function dispatch(object $event)
+    public function dispatch(object $event): object
     {
         // If the event is already stopped, nothing to do here.
         if ($event instanceof StoppableEventInterface && $event->isPropagationStopped()) {