Leverage trigger_deprecation() from symfony/deprecation-contracts

Author: nicolas-grekas

LegacyEventDispatcherProxy.php

@@ -13,7 +13,7 @@
 
 use Symfony\Contracts\EventDispatcher\EventDispatcherInterface;
 
-@trigger_error(sprintf('%s is deprecated since Symfony 5.1, use the event dispatcher without the proxy.', LegacyEventDispatcherProxy::class), E_USER_DEPRECATED);
+trigger_deprecation('symfony/event-dispatcher', '5.1', '%s is deprecated, use the event dispatcher without the proxy.', LegacyEventDispatcherProxy::class);
 
 /**
  * A helper class to provide BC/FC with the legacy signature of EventDispatcherInterface::dispatch().

composer.json

@@ -17,6 +17,7 @@
     ],
     "require": {
         "php": "^7.2.5",
+        "symfony/deprecation-contracts": "^2.1",
         "symfony/event-dispatcher-contracts": "^2"
     },
     "require-dev": {