minor #31709 [EventDispatcher] Remove deprecation layer (derrabus)

This PR was merged into the 5.0-dev branch.

Discussion
----------

[EventDispatcher] Remove deprecation layer

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | yes
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | N/A
| License       | MIT
| Doc PR        | N/A

This PR removes all deprecations from the event dispatcher component.

Commits
-------

678e066aa8 [EventDispatcher] Remove deprecation layer.

src/Symfony/Component/EventDispatcher/CHANGELOG.md

@@ -1,6 +1,14 @@
 CHANGELOG
 =========
 
+5.0.0
+-----
+
+ * The signature of the `EventDispatcherInterface::dispatch()` method has been changed to `dispatch($event, string $eventName = null): object`.
+ * The `Event` class has been removed in favor of `Symfony\Contracts\EventDispatcher\Event`.
+ * The `TraceableEventDispatcherInterface` has been removed.
+ * The `WrappedListener` class is now final.
+
 4.3.0
 -----
 

src/Symfony/Component/EventDispatcher/Debug/TraceableEventDispatcher.php

@@ -14,14 +14,12 @@ namespace Symfony\Component\EventDispatcher\Debug;
 use Psr\EventDispatcher\StoppableEventInterface;
 use Psr\Log\LoggerInterface;
 use Symfony\Component\BrowserKit\Request;
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
-use Symfony\Component\EventDispatcher\LegacyEventDispatcherProxy;
-use Symfony\Component\EventDispatcher\LegacyEventProxy;
 use Symfony\Component\HttpFoundation\RequestStack;
 use Symfony\Component\Stopwatch\Stopwatch;
-use Symfony\Contracts\EventDispatcher\Event as ContractsEvent;
+use Symfony\Contracts\EventDispatcher\Event;
+use Symfony\Contracts\Service\ResetInterface;
 
 /**
  * Collects some data about event listeners.
@@ -30,7 +28,7 @@ use Symfony\Contracts\EventDispatcher\Event as ContractsEvent;
  *
  * @author Fabien Potencier <fabien@symfony.com>
  */
-class TraceableEventDispatcher implements TraceableEventDispatcherInterface
+class TraceableEventDispatcher implements EventDispatcherInterface, ResetInterface
 {
     protected $logger;
     protected $stopwatch;
@@ -44,7 +42,7 @@ class TraceableEventDispatcher implements TraceableEventDispatcherInterface
 
     public function __construct(EventDispatcherInterface $dispatcher, Stopwatch $stopwatch, LoggerInterface $logger = null, RequestStack $requestStack = null)
     {
-        $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+        $this->dispatcher = $dispatcher;
         $this->stopwatch = $stopwatch;
         $this->logger = $logger;
         $this->wrappedListeners = [];
@@ -130,32 +128,22 @@ class TraceableEventDispatcher implements TraceableEventDispatcherInterface
 
     /**
      * {@inheritdoc}
-     *
-     * @param string|null $eventName
      */
-    public function dispatch($event/*, string $eventName = null*/)
+    public function dispatch($event, string $eventName = null): object
     {
+        if (!\is_object($event)) {
+            throw new \TypeError(sprintf('Argument 1 passed to "%s::dispatch()" must be an object, %s given.', EventDispatcherInterface::class, \gettype($event)));
+        }
+
+        $eventName = $eventName ?? \get_class($event);
+
         if (null === $this->callStack) {
             $this->callStack = new \SplObjectStorage();
         }
 
         $currentRequestHash = $this->currentRequestHash = $this->requestStack && ($request = $this->requestStack->getCurrentRequest()) ? spl_object_hash($request) : '';
-        $eventName = 1 < \func_num_args() ? \func_get_arg(1) : null;
 
-        if (\is_object($event)) {
+        if (null !== $this->logger && ($event instanceof Event || $event instanceof StoppableEventInterface) && $event->isPropagationStopped()) {
-            $eventName = $eventName ?? \get_class($event);
-        } else {
-            @trigger_error(sprintf('Calling the "%s::dispatch()" method with the event name as first argument is deprecated since Symfony 4.3, pass it second and provide the event object first instead.', EventDispatcherInterface::class), E_USER_DEPRECATED);
-            $swap = $event;
-            $event = $eventName ?? new Event();
-            $eventName = $swap;
-
-            if (!$event instanceof Event) {
-                throw new \TypeError(sprintf('Argument 1 passed to "%s::dispatch()" must be an instance of %s, %s given.', EventDispatcherInterface::class, Event::class, \is_object($event) ? \get_class($event) : \gettype($event)));
-            }
-        }
-
-        if (null !== $this->logger && ($event instanceof Event || $event instanceof ContractsEvent || $event instanceof StoppableEventInterface) && $event->isPropagationStopped()) {
             $this->logger->debug(sprintf('The "%s" event is already stopped. No listeners have been called.', $eventName));
         }
 
@@ -291,35 +279,15 @@ class TraceableEventDispatcher implements TraceableEventDispatcherInterface
 
     /**
      * Called before dispatching the event.
-     *
-     * @param object $event
      */
-    protected function beforeDispatch(string $eventName, $event)
+    protected function beforeDispatch(string $eventName, object $event)
     {
-        $this->preDispatch($eventName, $event instanceof Event ? $event : new LegacyEventProxy($event));
     }
 
     /**
      * Called after dispatching the event.
-     *
-     * @param object $event
      */
-    protected function afterDispatch(string $eventName, $event)
+    protected function afterDispatch(string $eventName, object $event)
-    {
-        $this->postDispatch($eventName, $event instanceof Event ? $event : new LegacyEventProxy($event));
-    }
-
-    /**
-     * @deprecated since Symfony 4.3, will be removed in 5.0, use beforeDispatch instead
-     */
-    protected function preDispatch($eventName, Event $event)
-    {
-    }
-
-    /**
-     * @deprecated since Symfony 4.3, will be removed in 5.0, use afterDispatch instead
-     */
-    protected function postDispatch($eventName, Event $event)
     {
     }
 

src/Symfony/Component/EventDispatcher/Debug/TraceableEventDispatcherInterface.php

@@ -1,42 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\EventDispatcher\Debug;
-
-use Symfony\Component\EventDispatcher\EventDispatcherInterface;
-use Symfony\Component\HttpFoundation\Request;
-use Symfony\Contracts\Service\ResetInterface;
-
-/**
- * @deprecated since Symfony 4.1
- *
- * @author Fabien Potencier <fabien@symfony.com>
- */
-interface TraceableEventDispatcherInterface extends EventDispatcherInterface, ResetInterface
-{
-    /**
-     * Gets the called listeners.
-     *
-     * @param Request|null $request The request to get listeners for
-     *
-     * @return array An array of called listeners
-     */
-    public function getCalledListeners(/* Request $request = null */);
-
-    /**
-     * Gets the not called listeners.
-     *
-     * @param Request|null $request The request to get listeners for
-     *
-     * @return array An array of not called listeners
-     */
-    public function getNotCalledListeners(/* Request $request = null */);
-}

src/Symfony/Component/EventDispatcher/Debug/WrappedListener.php

@@ -12,19 +12,15 @@
 namespace Symfony\Component\EventDispatcher\Debug;
 
 use Psr\EventDispatcher\StoppableEventInterface;
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
-use Symfony\Component\EventDispatcher\LegacyEventProxy;
 use Symfony\Component\Stopwatch\Stopwatch;
 use Symfony\Component\VarDumper\Caster\ClassStub;
-use Symfony\Contracts\EventDispatcher\Event as ContractsEvent;
+use Symfony\Contracts\EventDispatcher\Event;
 
 /**
  * @author Fabien Potencier <fabien@symfony.com>
- *
- * @final since Symfony 4.3: the "Event" type-hint on __invoke() will be replaced by "object" in 5.0
  */
-class WrappedListener
+final class WrappedListener
 {
     private $listener;
     private $optimizedListener;
@@ -81,22 +77,22 @@ class WrappedListener
         return $this->listener;
     }
 
-    public function wasCalled()
+    public function wasCalled(): bool
     {
         return $this->called;
     }
 
-    public function stoppedPropagation()
+    public function stoppedPropagation(): bool
     {
         return $this->stoppedPropagation;
     }
 
-    public function getPretty()
+    public function getPretty(): string
     {
         return $this->pretty;
     }
 
-    public function getInfo($eventName)
+    public function getInfo(string $eventName): array
     {
         if (null === $this->stub) {
             $this->stub = self::$hasClassStub ? new ClassStub($this->pretty.'()', $this->listener) : $this->pretty.'()';
@@ -110,12 +106,8 @@ class WrappedListener
         ];
     }
 
-    public function __invoke(Event $event, $eventName, EventDispatcherInterface $dispatcher)
+    public function __invoke(object $event, string $eventName, EventDispatcherInterface $dispatcher): void
     {
-        if ($event instanceof LegacyEventProxy) {
-            $event = $event->getEvent();
-        }
-
         $dispatcher = $this->dispatcher ?: $dispatcher;
 
         $this->called = true;
@@ -129,7 +121,7 @@ class WrappedListener
             $e->stop();
         }
 
-        if (($event instanceof Event || $event instanceof ContractsEvent || $event instanceof StoppableEventInterface) && $event->isPropagationStopped()) {
+        if (($event instanceof Event || $event instanceof StoppableEventInterface) && $event->isPropagationStopped()) {
             $this->stoppedPropagation = true;
         }
     }

src/Symfony/Component/EventDispatcher/Event.php

@@ -1,38 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\EventDispatcher;
-
-/**
- * @deprecated since Symfony 4.3, use "Symfony\Contracts\EventDispatcher\Event" instead
- */
-class Event
-{
-    private $propagationStopped = false;
-
-    /**
-     * @return bool Whether propagation was already stopped for this event
-     *
-     * @deprecated since Symfony 4.3, use "Symfony\Contracts\EventDispatcher\Event" instead
-     */
-    public function isPropagationStopped()
-    {
-        return $this->propagationStopped;
-    }
-
-    /**
-     * @deprecated since Symfony 4.3, use "Symfony\Contracts\EventDispatcher\Event" instead
-     */
-    public function stopPropagation()
-    {
-        $this->propagationStopped = true;
-    }
-}

src/Symfony/Component/EventDispatcher/EventDispatcher.php

@@ -13,7 +13,7 @@ namespace Symfony\Component\EventDispatcher;
 
 use Psr\EventDispatcher\StoppableEventInterface;
 use Symfony\Component\EventDispatcher\Debug\WrappedListener;
-use Symfony\Contracts\EventDispatcher\Event as ContractsEvent;
+use Symfony\Contracts\EventDispatcher\Event;
 
 /**
  * The EventDispatcherInterface is the central point of Symfony's event listener system.
@@ -45,26 +45,15 @@ class EventDispatcher implements EventDispatcherInterface
 
     /**
      * {@inheritdoc}
-     *
-     * @param string|null $eventName
      */
-    public function dispatch($event/*, string $eventName = null*/)
+    public function dispatch($event, string $eventName = null): object
     {
-        $eventName = 1 < \func_num_args() ? \func_get_arg(1) : null;
+        if (!\is_object($event)) {
-
+            throw new \TypeError(sprintf('Argument 1 passed to "%s::dispatch()" must be an object, %s given.', EventDispatcherInterface::class, \gettype($event)));
-        if (\is_object($event)) {
-            $eventName = $eventName ?? \get_class($event);
-        } else {
-            @trigger_error(sprintf('Calling the "%s::dispatch()" method with the event name as first argument is deprecated since Symfony 4.3, pass it second and provide the event object first instead.', EventDispatcherInterface::class), E_USER_DEPRECATED);
-            $swap = $event;
-            $event = $eventName ?? new Event();
-            $eventName = $swap;
-
-            if (!$event instanceof Event) {
-                throw new \TypeError(sprintf('Argument 1 passed to "%s::dispatch()" must be an instance of %s, %s given.', EventDispatcherInterface::class, Event::class, \is_object($event) ? \get_class($event) : \gettype($event)));
-            }
         }
 
+        $eventName = $eventName ?? \get_class($event);
+
         if (null !== $this->optimized && null !== $eventName) {
             $listeners = $this->optimized[$eventName] ?? (empty($this->listeners[$eventName]) ? [] : $this->optimizeListeners($eventName));
         } else {
@@ -229,34 +218,14 @@ class EventDispatcher implements EventDispatcherInterface
      * @param string     $eventName The name of the event to dispatch
      * @param object     $event     The event object to pass to the event handlers/listeners
      */
-    protected function callListeners(iterable $listeners, string $eventName, $event)
+    protected function callListeners(iterable $listeners, string $eventName, object $event)
     {
-        if ($event instanceof Event) {
+        $stoppable = $event instanceof Event || $event instanceof StoppableEventInterface;
-            $this->doDispatch($listeners, $eventName, $event);
-
-            return;
-        }
-
-        $stoppable = $event instanceof ContractsEvent || $event instanceof StoppableEventInterface;
 
         foreach ($listeners as $listener) {
             if ($stoppable && $event->isPropagationStopped()) {
                 break;
             }
-            // @deprecated: the ternary operator is part of a BC layer and should be removed in 5.0
-            $listener($listener instanceof WrappedListener ? new LegacyEventProxy($event) : $event, $eventName, $this);
-        }
-    }
-
-    /**
-     * @deprecated since Symfony 4.3, use callListeners() instead
-     */
-    protected function doDispatch($listeners, $eventName, Event $event)
-    {
-        foreach ($listeners as $listener) {
-            if ($event->isPropagationStopped()) {
-                break;
-            }
             $listener($event, $eventName, $this);
         }
     }

src/Symfony/Component/EventDispatcher/EventDispatcherInterface.php

@@ -22,6 +22,11 @@ use Symfony\Contracts\EventDispatcher\EventDispatcherInterface as ContractsEvent
  */
 interface EventDispatcherInterface extends ContractsEventDispatcherInterface
 {
+    /**
+     * {@inheritdoc}
+     */
+    public function dispatch($event, string $eventName = null): object;
+
     /**
      * Adds an event listener that listens on the specified events.
      *

src/Symfony/Component/EventDispatcher/GenericEvent.php

@@ -11,6 +11,8 @@
 
 namespace Symfony\Component\EventDispatcher;
 
+use Symfony\Contracts\EventDispatcher\Event;
+
 /**
  * Event encapsulation class.
  *

src/Symfony/Component/EventDispatcher/ImmutableEventDispatcher.php

@@ -22,25 +22,14 @@ class ImmutableEventDispatcher implements EventDispatcherInterface
 
     public function __construct(EventDispatcherInterface $dispatcher)
     {
-        $this->dispatcher = LegacyEventDispatcherProxy::decorate($dispatcher);
+        $this->dispatcher = $dispatcher;
     }
 
     /**
      * {@inheritdoc}
-     *
-     * @param string|null $eventName
      */
-    public function dispatch($event/*, string $eventName = null*/)
+    public function dispatch($event, string $eventName = null): object
     {
-        $eventName = 1 < \func_num_args() ? \func_get_arg(1) : null;
-
-        if (\is_scalar($event)) {
-            // deprecated
-            $swap = $event;
-            $event = $eventName ?? new Event();
-            $eventName = $swap;
-        }
-
         return $this->dispatcher->dispatch($event, $eventName);
     }
 

src/Symfony/Component/EventDispatcher/LegacyEventDispatcherProxy.php

@@ -11,9 +11,7 @@
 
 namespace Symfony\Component\EventDispatcher;
 
-use Psr\EventDispatcher\StoppableEventInterface;
+use Symfony\Contracts\EventDispatcher\EventDispatcherInterface;
-use Symfony\Contracts\EventDispatcher\Event as ContractsEvent;
-use Symfony\Contracts\EventDispatcher\EventDispatcherInterface as ContractsEventDispatcherInterface;
 
 /**
  * An helper class to provide BC/FC with the legacy signature of EventDispatcherInterface::dispatch().
@@ -22,126 +20,10 @@ use Symfony\Contracts\EventDispatcher\EventDispatcherInterface as ContractsEvent
  *
  * @author Nicolas Grekas <p@tchwork.com>
  */
-final class LegacyEventDispatcherProxy implements EventDispatcherInterface
+final class LegacyEventDispatcherProxy
 {
-    private $dispatcher;
+    public static function decorate(?EventDispatcherInterface $dispatcher): ?EventDispatcherInterface
-
-    public static function decorate(?ContractsEventDispatcherInterface $dispatcher): ?ContractsEventDispatcherInterface
     {
-        if (null === $dispatcher) {
+        return $dispatcher;
-            return null;
-        }
-        $r = new \ReflectionMethod($dispatcher, 'dispatch');
-        $param2 = $r->getParameters()[1] ?? null;
-
-        if (!$param2 || !$param2->hasType() || $param2->getType()->isBuiltin()) {
-            return $dispatcher;
-        }
-
-        @trigger_error(sprintf('The signature of the "%s::dispatch()" method should be updated to "dispatch($event, string $eventName = null)", not doing so is deprecated since Symfony 4.3.', $r->class), E_USER_DEPRECATED);
-
-        $self = new self();
-        $self->dispatcher = $dispatcher;
-
-        return $self;
-    }
-
-    /**
-     * {@inheritdoc}
-     *
-     * @param string|null $eventName
-     */
-    public function dispatch($event/*, string $eventName = null*/)
-    {
-        $eventName = 1 < \func_num_args() ? \func_get_arg(1) : null;
-
-        if (\is_object($event)) {
-            $eventName = $eventName ?? \get_class($event);
-        } else {
-            @trigger_error(sprintf('Calling the "%s::dispatch()" method with the event name as first argument is deprecated since Symfony 4.3, pass it second and provide the event object first instead.', ContractsEventDispatcherInterface::class), E_USER_DEPRECATED);
-            $swap = $event;
-            $event = $eventName ?? new Event();
-            $eventName = $swap;
-
-            if (!$event instanceof Event) {
-                throw new \TypeError(sprintf('Argument 1 passed to "%s::dispatch()" must be an instance of %s, %s given.', ContractsEventDispatcherInterface::class, Event::class, \is_object($event) ? \get_class($event) : \gettype($event)));
-            }
-        }
-
-        $listeners = $this->getListeners($eventName);
-        $stoppable = $event instanceof Event || $event instanceof ContractsEvent || $event instanceof StoppableEventInterface;
-
-        foreach ($listeners as $listener) {
-            if ($stoppable && $event->isPropagationStopped()) {
-                break;
-            }
-            $listener($event, $eventName, $this);
-        }
-
-        return $event;
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function addListener($eventName, $listener, $priority = 0)
-    {
-        return $this->dispatcher->addListener($eventName, $listener, $priority);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function addSubscriber(EventSubscriberInterface $subscriber)
-    {
-        return $this->dispatcher->addSubscriber($subscriber);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function removeListener($eventName, $listener)
-    {
-        return $this->dispatcher->removeListener($eventName, $listener);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function removeSubscriber(EventSubscriberInterface $subscriber)
-    {
-        return $this->dispatcher->removeSubscriber($subscriber);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getListeners($eventName = null)
-    {
-        return $this->dispatcher->getListeners($eventName);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function getListenerPriority($eventName, $listener)
-    {
-        return $this->dispatcher->getListenerPriority($eventName, $listener);
-    }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function hasListeners($eventName = null)
-    {
-        return $this->dispatcher->hasListeners($eventName);
-    }
-
-    /**
-     * Proxies all method calls to the original event dispatcher.
-     */
-    public function __call($method, $arguments)
-    {
-        return $this->dispatcher->{$method}(...$arguments);
     }
 }

src/Symfony/Component/EventDispatcher/LegacyEventProxy.php

@@ -1,62 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\EventDispatcher;
-
-use Psr\EventDispatcher\StoppableEventInterface;
-use Symfony\Contracts\EventDispatcher\Event as ContractsEvent;
-
-/**
- * @internal to be removed in 5.0.
- */
-final class LegacyEventProxy extends Event
-{
-    private $event;
-
-    /**
-     * @param object $event
-     */
-    public function __construct($event)
-    {
-        $this->event = $event;
-    }
-
-    /**
-     * @return object $event
-     */
-    public function getEvent()
-    {
-        return $this->event;
-    }
-
-    public function isPropagationStopped()
-    {
-        if (!$this->event instanceof ContractsEvent && !$this->event instanceof StoppableEventInterface) {
-            return false;
-        }
-
-        return $this->event->isPropagationStopped();
-    }
-
-    public function stopPropagation()
-    {
-        if (!$this->event instanceof ContractsEvent) {
-            return;
-        }
-
-        $this->event->stopPropagation();
-    }
-
-    public function __call($name, $args)
-    {
-        return $this->event->{$name}(...$args);
-    }
-}

src/Symfony/Component/EventDispatcher/Tests/Debug/TraceableEventDispatcherTest.php

@@ -13,12 +13,11 @@ namespace Symfony\Component\EventDispatcher\Tests\Debug;
 
 use PHPUnit\Framework\TestCase;
 use Symfony\Component\EventDispatcher\Debug\TraceableEventDispatcher;
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 use Symfony\Component\EventDispatcher\EventDispatcherInterface;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 use Symfony\Component\Stopwatch\Stopwatch;
-use Symfony\Contracts\EventDispatcher\Event as ContractsEvent;
+use Symfony\Contracts\EventDispatcher\Event;
 
 class TraceableEventDispatcherTest extends TestCase
 {
@@ -140,19 +139,6 @@ class TraceableEventDispatcherTest extends TestCase
         $this->assertEquals([['event' => 'foo', 'pretty' => 'closure', 'priority' => 5]], $listeners);
     }
 
-    public function testDispatchContractsEvent()
-    {
-        $expectedEvent = new ContractsEvent();
-        $tdispatcher = new TraceableEventDispatcher(new EventDispatcher(), new Stopwatch());
-        $tdispatcher->addListener('foo', function ($event) use ($expectedEvent) {
-            $this->assertSame($event, $expectedEvent);
-        }, 5);
-        $tdispatcher->dispatch($expectedEvent, 'foo');
-
-        $listeners = $tdispatcher->getCalledListeners();
-        $this->assertArrayHasKey('stub', $listeners[0]);
-    }
-
     public function testDispatchAfterReset()
     {
         $tdispatcher = new TraceableEventDispatcher(new EventDispatcher(), new Stopwatch());

src/Symfony/Component/EventDispatcher/Tests/EventDispatcherTest.php

@@ -12,10 +12,9 @@
 namespace Symfony\Component\EventDispatcher\Tests;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
-use Symfony\Contracts\EventDispatcher\Event as ContractsEvent;
+use Symfony\Contracts\EventDispatcher\Event;
 
 class EventDispatcherTest extends TestCase
 {
@@ -135,22 +134,8 @@ class EventDispatcherTest extends TestCase
         $this->dispatcher->dispatch(new Event(), self::preFoo);
         $this->assertTrue($this->listener->preFooInvoked);
         $this->assertFalse($this->listener->postFooInvoked);
-        $this->assertInstanceOf('Symfony\Component\EventDispatcher\Event', $this->dispatcher->dispatch(new Event(), 'noevent'));
+        $this->assertInstanceOf('Symfony\Contracts\EventDispatcher\Event', $this->dispatcher->dispatch(new Event(), 'noevent'));
-        $this->assertInstanceOf('Symfony\Component\EventDispatcher\Event', $this->dispatcher->dispatch(new Event(), self::preFoo));
+        $this->assertInstanceOf('Symfony\Contracts\EventDispatcher\Event', $this->dispatcher->dispatch(new Event(), self::preFoo));
-        $event = new Event();
-        $return = $this->dispatcher->dispatch($event, self::preFoo);
-        $this->assertSame($event, $return);
-    }
-
-    public function testDispatchContractsEvent()
-    {
-        $this->dispatcher->addListener('pre.foo', [$this->listener, 'preFoo']);
-        $this->dispatcher->addListener('post.foo', [$this->listener, 'postFoo']);
-        $this->dispatcher->dispatch(new ContractsEvent(), self::preFoo);
-        $this->assertTrue($this->listener->preFooInvoked);
-        $this->assertFalse($this->listener->postFooInvoked);
-        $this->assertInstanceOf('Symfony\Component\EventDispatcher\Event', $this->dispatcher->dispatch(new Event(), 'noevent'));
-        $this->assertInstanceOf('Symfony\Component\EventDispatcher\Event', $this->dispatcher->dispatch(new Event(), self::preFoo));
         $event = new Event();
         $return = $this->dispatcher->dispatch($event, self::preFoo);
         $this->assertSame($event, $return);

src/Symfony/Component/EventDispatcher/Tests/EventTest.php

@@ -1,55 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\EventDispatcher\Tests;
-
-use PHPUnit\Framework\TestCase;
-use Symfony\Component\EventDispatcher\Event;
-
-/**
- * @group legacy
- */
-class EventTest extends TestCase
-{
-    /**
-     * @var \Symfony\Component\EventDispatcher\Event
-     */
-    protected $event;
-
-    /**
-     * Sets up the fixture, for example, opens a network connection.
-     * This method is called before a test is executed.
-     */
-    protected function setUp()
-    {
-        $this->event = new Event();
-    }
-
-    /**
-     * Tears down the fixture, for example, closes a network connection.
-     * This method is called after a test is executed.
-     */
-    protected function tearDown()
-    {
-        $this->event = null;
-    }
-
-    public function testIsPropagationStopped()
-    {
-        $this->assertFalse($this->event->isPropagationStopped());
-    }
-
-    public function testStopPropagationAndIsPropagationStopped()
-    {
-        $this->event->stopPropagation();
-        $this->assertTrue($this->event->isPropagationStopped());
-    }
-}

src/Symfony/Component/EventDispatcher/Tests/ImmutableEventDispatcherTest.php

@@ -12,8 +12,8 @@
 namespace Symfony\Component\EventDispatcher\Tests;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\EventDispatcher\ImmutableEventDispatcher;
+use Symfony\Contracts\EventDispatcher\Event;
 
 /**
  * @author Bernhard Schussek <bschussek@gmail.com>
@@ -39,13 +39,15 @@ class ImmutableEventDispatcherTest extends TestCase
     public function testDispatchDelegates()
     {
         $event = new Event();
+        $expectedResult = new class() {
+        };
 
         $this->innerDispatcher->expects($this->once())
             ->method('dispatch')
             ->with($event, 'event')
-            ->willReturn('result');
+            ->willReturn($expectedResult);
 
-        $this->assertSame('result', $this->dispatcher->dispatch($event, 'event'));
+        $this->assertSame($expectedResult, $this->dispatcher->dispatch($event, 'event'));
     }
 
     public function testGetListenersDelegates()

src/Symfony/Component/EventDispatcher/Tests/LegacyEventDispatcherTest.php

@@ -1,35 +0,0 @@
-<?php
-
-/*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
-
-namespace Symfony\Component\EventDispatcher\Tests;
-
-use Symfony\Component\EventDispatcher\Event;
-use Symfony\Component\EventDispatcher\EventDispatcher;
-use Symfony\Component\EventDispatcher\LegacyEventDispatcherProxy;
-
-/**
- * @group legacy
- */
-class LegacyEventDispatcherTest extends EventDispatcherTest
-{
-    protected function createEventDispatcher()
-    {
-        return LegacyEventDispatcherProxy::decorate(new TestLegacyEventDispatcher());
-    }
-}
-
-class TestLegacyEventDispatcher extends EventDispatcher
-{
-    public function dispatch($eventName, Event $event = null)
-    {
-        return parent::dispatch($event, $eventName);
-    }
-}

src/Symfony/Component/Form/FormEvent.php

@@ -11,7 +11,7 @@
 
 namespace Symfony\Component\Form;
 
-use Symfony\Component\EventDispatcher\Event;
+use Symfony\Contracts\EventDispatcher\Event;
 
 /**
  * @author Bernhard Schussek <bschussek@gmail.com>

src/Symfony/Component/HttpKernel/DataCollector/EventDataCollector.php

@@ -12,7 +12,6 @@
 namespace Symfony\Component\HttpKernel\DataCollector;
 
 use Symfony\Component\EventDispatcher\Debug\TraceableEventDispatcher;
-use Symfony\Component\EventDispatcher\Debug\TraceableEventDispatcherInterface;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\RequestStack;
 use Symfony\Component\HttpFoundation\Response;
@@ -60,12 +59,9 @@ class EventDataCollector extends DataCollector implements LateDataCollectorInter
 
     public function lateCollect()
     {
-        if ($this->dispatcher instanceof TraceableEventDispatcherInterface) {
+        if ($this->dispatcher instanceof TraceableEventDispatcher) {
             $this->setCalledListeners($this->dispatcher->getCalledListeners($this->currentRequest));
             $this->setNotCalledListeners($this->dispatcher->getNotCalledListeners($this->currentRequest));
-        }
-
-        if ($this->dispatcher instanceof TraceableEventDispatcher) {
             $this->setOrphanedEvents($this->dispatcher->getOrphanedEvents($this->currentRequest));
         }
 

src/Symfony/Component/HttpKernel/Event/KernelEvent.php

@@ -11,9 +11,9 @@
 
 namespace Symfony\Component\HttpKernel\Event;
 
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\HttpKernelInterface;
+use Symfony\Contracts\EventDispatcher\Event;
 
 /**
  * Base class for events thrown in the HttpKernel component.

src/Symfony/Component/HttpKernel/Tests/Debug/TraceableEventDispatcherTest.php

@@ -12,7 +12,6 @@
 namespace Symfony\Component\HttpKernel\Tests\Debug;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\EventDispatcher\EventDispatcher;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpFoundation\RequestStack;
@@ -20,6 +19,7 @@ use Symfony\Component\HttpFoundation\Response;
 use Symfony\Component\HttpKernel\Debug\TraceableEventDispatcher;
 use Symfony\Component\HttpKernel\HttpKernel;
 use Symfony\Component\Stopwatch\Stopwatch;
+use Symfony\Contracts\EventDispatcher\Event;
 
 class TraceableEventDispatcherTest extends TestCase
 {

src/Symfony/Component/Mailer/Event/MessageEvent.php

@@ -11,9 +11,9 @@
 
 namespace Symfony\Component\Mailer\Event;
 
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\Mailer\SmtpEnvelope;
 use Symfony\Component\Mime\RawMessage;
+use Symfony\Contracts\EventDispatcher\Event;
 
 /**
  * Allows the transformation of a Message.

src/Symfony/Component/Security/Core/Event/AuthenticationEvent.php

@@ -11,8 +11,8 @@
 
 namespace Symfony\Component\Security\Core\Event;
 
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
+use Symfony\Contracts\EventDispatcher\Event;
 
 /**
  * This is a general purpose authentication event.

src/Symfony/Component/Security/Core/Event/VoteEvent.php

@@ -11,8 +11,8 @@
 
 namespace Symfony\Component\Security\Core\Event;
 
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\Security\Core\Authorization\Voter\VoterInterface;
+use Symfony\Contracts\EventDispatcher\Event;
 
 /**
  * This event is dispatched on voter vote.

src/Symfony/Component/Security/Http/Event/InteractiveLoginEvent.php

@@ -11,9 +11,9 @@
 
 namespace Symfony\Component\Security\Http\Event;
 
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
+use Symfony\Contracts\EventDispatcher\Event;
 
 /**
  * @author Fabien Potencier <fabien@symfony.com>

src/Symfony/Component/Security/Http/Event/SwitchUserEvent.php

@@ -11,10 +11,10 @@
 
 namespace Symfony\Component\Security\Http\Event;
 
-use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\Security\Core\Authentication\Token\TokenInterface;
 use Symfony\Component\Security\Core\User\UserInterface;
+use Symfony\Contracts\EventDispatcher\Event;
 
 /**
  * SwitchUserEvent.

src/Symfony/Component/Workflow/Event/Event.php

@@ -11,10 +11,10 @@
 
 namespace Symfony\Component\Workflow\Event;
 
-use Symfony\Component\EventDispatcher\Event as BaseEvent;
 use Symfony\Component\Workflow\Marking;
 use Symfony\Component\Workflow\Transition;
 use Symfony\Component\Workflow\WorkflowInterface;
+use Symfony\Contracts\EventDispatcher\Event as BaseEvent;
 
 /**
  * @author Fabien Potencier <fabien@symfony.com>

src/Symfony/Component/Workflow/Tests/WorkflowTest.php

@@ -584,9 +584,11 @@ class EventDispatcherMock implements \Symfony\Component\EventDispatcher\EventDis
 {
     public $dispatchedEvents = [];
 
-    public function dispatch($event, string $eventName = null)
+    public function dispatch($event, string $eventName = null): object
     {
         $this->dispatchedEvents[] = $eventName;
+
+        return $event;
     }
 
     public function addListener($eventName, $listener, $priority = 0)