[EventDispatcher] Better error reporting when arguments to dispatch() are swapped

Author: Rimas Kudelis

EventDispatcher.php

@@ -54,7 +54,7 @@ public function dispatch($event/*, string $eventName = null*/)
 
         if (\is_object($event)) {
             $eventName = $eventName ?? \get_class($event);
-        } elseif (\is_string($event) && (null === $eventName || $eventName instanceof Event)) {
+        } elseif (\is_string($event) && (null === $eventName || $eventName instanceof ContractsEvent || $eventName instanceof Event)) {
             @trigger_error(sprintf('Calling the "%s::dispatch()" method with the event name as the first argument is deprecated since Symfony 4.3, pass it as the second argument and provide the event object as the first argument instead.', EventDispatcherInterface::class), E_USER_DEPRECATED);
             $swap = $event;
             $event = $eventName ?? new Event();

LegacyEventDispatcherProxy.php

@@ -59,7 +59,7 @@ public function dispatch($event/*, string $eventName = null*/)
 
         if (\is_object($event)) {
             $eventName = $eventName ?? \get_class($event);
-        } elseif (\is_string($event) && (null === $eventName || $eventName instanceof Event)) {
+        } elseif (\is_string($event) && (null === $eventName || $eventName instanceof ContractsEvent || $eventName instanceof Event)) {
             @trigger_error(sprintf('Calling the "%s::dispatch()" method with the event name as the first argument is deprecated since Symfony 4.3, pass it as the second argument and provide the event object as the first argument instead.', ContractsEventDispatcherInterface::class), E_USER_DEPRECATED);
             $swap = $event;
             $event = $eventName ?? new Event();