handle optional MessageSubscriberInterface if exist

src/Symfony/MessageMapFactory.php

@@ -7,6 +7,7 @@
 use Symfony\Component\Messenger\Handler\MessageSubscriberInterface;
 use function class_exists;
 use function count;
+use function interface_exists;
 use function is_array;
 use function is_int;
 use function is_string;
@@ -91,7 +92,7 @@ public function create(): MessageMap
 	/** @return iterable<string, array<string, string>> */
 	private function guessHandledMessages(ClassReflection $reflectionClass): iterable
 	{
-		if ($reflectionClass->implementsInterface(MessageSubscriberInterface::class)) {
+		if (interface_exists(MessageSubscriberInterface::class) && $reflectionClass->implementsInterface(MessageSubscriberInterface::class)) {
 			$className = $reflectionClass->getName();
 
 			foreach ($className::getHandledMessages() as $index => $value) {

tests/Type/Symfony/ExtensionTest.php

@@ -6,6 +6,7 @@
 use ReflectionMethod;
 use Symfony\Component\HttpFoundation\Request;
 use function class_exists;
+use function interface_exists;
 use function strpos;
 
 class ExtensionTest extends TypeInferenceTestCase
@@ -15,6 +16,11 @@ class ExtensionTest extends TypeInferenceTestCase
 	public function dataFileAsserts(): iterable
 	{
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/messenger_handle_trait.php');
+
+		if (interface_exists('Symfony\Component\Messenger\Handler\MessageSubscriberInterface')) {
+			yield from $this->gatherAssertTypes(__DIR__ . '/data/messenger_handle_trait_with_subscriber.php');
+		}
+
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/envelope_all.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/header_bag_get.php');
 		yield from $this->gatherAssertTypes(__DIR__ . '/data/response_header_bag_get_cookies.php');

tests/Type/Symfony/data/messenger_handle_trait.php

@@ -2,7 +2,6 @@
 
 namespace MessengerHandleTrait;
 
-use Symfony\Component\Messenger\Handler\MessageSubscriberInterface;
 use Symfony\Component\Messenger\HandleTrait;
 use function PHPStan\Testing\assertType;
 
@@ -16,41 +15,6 @@ public function __invoke(RegularQuery $query): RegularQueryResult
     }
 }
 
-class BooleanQuery {}
-class StringQuery {}
-class IntQuery {}
-class FloatQuery {}
-class MultiQueryHandler implements MessageSubscriberInterface
-{
-    public static function getHandledMessages(): iterable
-    {
-        yield BooleanQuery::class;
-        yield IntQuery::class => ['method' => 'handleInt'];
-        yield FloatQuery::class => ['method' => 'handleFloat'];
-        yield StringQuery::class => ['method' => 'handleString'];
-    }
-
-    public function __invoke(BooleanQuery $query): bool
-    {
-        return true;
-    }
-
-    public function handleInt(IntQuery $query): int
-    {
-        return 0;
-    }
-
-    public function handleFloat(FloatQuery $query): float
-    {
-        return 0.0;
-    }
-
-    public function handleString(StringQuery $query): string
-    {
-        return 'string result';
-    }
-}
-
 class TaggedQuery {}
 class TaggedResult {}
 class TaggedHandler
@@ -61,21 +25,6 @@ public function handle(TaggedQuery $query): TaggedResult
     }
 }
 
-class MultiHandlesForInTheSameHandlerQuery {}
-class MultiHandlesForInTheSameHandler implements MessageSubscriberInterface
-{
-    public static function getHandledMessages(): iterable
-    {
-        yield MultiHandlesForInTheSameHandlerQuery::class;
-        yield MultiHandlesForInTheSameHandlerQuery::class => ['priority' => '0'];
-    }
-
-    public function __invoke(MultiHandlesForInTheSameHandlerQuery $query): bool
-    {
-        return true;
-    }
-}
-
 class MultiHandlersForTheSameMessageQuery {}
 class MultiHandlersForTheSameMessageHandler1
 {
@@ -99,15 +48,9 @@ public function __invoke()
     {
         assertType(RegularQueryResult::class, $this->handle(new RegularQuery()));
 
-        assertType('bool', $this->handle(new BooleanQuery()));
-        assertType('int', $this->handle(new IntQuery()));
-        assertType('float', $this->handle(new FloatQuery()));
-        assertType('string', $this->handle(new StringQuery()));
-
         assertType(TaggedResult::class, $this->handle(new TaggedQuery()));
 
         // HandleTrait will throw exception in fact due to multiple handle methods/handlers per single query
-        assertType('mixed', $this->handle(new MultiHandlesForInTheSameHandlerQuery()));
         assertType('mixed', $this->handle(new MultiHandlersForTheSameMessageQuery()));
     }
 }

tests/Type/Symfony/data/messenger_handle_trait_with_subscriber.php

@@ -0,0 +1,72 @@
+<?php declare(strict_types = 1);
+
+namespace MessengerHandleTrait;
+
+use Symfony\Component\Messenger\Handler\MessageSubscriberInterface;
+use Symfony\Component\Messenger\HandleTrait;
+use function PHPStan\Testing\assertType;
+
+class BooleanQuery {}
+class StringQuery {}
+class IntQuery {}
+class FloatQuery {}
+class MultiQueryHandler implements MessageSubscriberInterface
+{
+    public static function getHandledMessages(): iterable
+    {
+        yield BooleanQuery::class;
+        yield IntQuery::class => ['method' => 'handleInt'];
+        yield FloatQuery::class => ['method' => 'handleFloat'];
+        yield StringQuery::class => ['method' => 'handleString'];
+    }
+
+    public function __invoke(BooleanQuery $query): bool
+    {
+        return true;
+    }
+
+    public function handleInt(IntQuery $query): int
+    {
+        return 0;
+    }
+
+    public function handleFloat(FloatQuery $query): float
+    {
+        return 0.0;
+    }
+
+    public function handleString(StringQuery $query): string
+    {
+        return 'string result';
+    }
+}
+
+class MultiHandlesForInTheSameHandlerQuery {}
+class MultiHandlesForInTheSameHandler implements MessageSubscriberInterface
+{
+    public static function getHandledMessages(): iterable
+    {
+        yield MultiHandlesForInTheSameHandlerQuery::class;
+        yield MultiHandlesForInTheSameHandlerQuery::class => ['priority' => '0'];
+    }
+
+    public function __invoke(MultiHandlesForInTheSameHandlerQuery $query): bool
+    {
+        return true;
+    }
+}
+
+class HandleTraitClass {
+    use HandleTrait;
+
+    public function __invoke()
+    {
+        assertType('bool', $this->handle(new BooleanQuery()));
+        assertType('int', $this->handle(new IntQuery()));
+        assertType('float', $this->handle(new FloatQuery()));
+        assertType('string', $this->handle(new StringQuery()));
+
+        // HandleTrait will throw exception in fact due to multiple handle methods/handlers per single query
+        assertType('mixed', $this->handle(new MultiHandlesForInTheSameHandlerQuery()));
+    }
+}