Allow usage of message handler classes as message handler names

src/Message/MessageHandlerInterface.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Yiisoft\Queue\Message;
+
+interface MessageHandlerInterface
+{
+    public function handle(MessageInterface $message): void;
+}

src/Worker/Worker.php

@@ -15,6 +15,7 @@
 use Throwable;
 use Yiisoft\Injector\Injector;
 use Yiisoft\Queue\Exception\JobFailureException;
+use Yiisoft\Queue\Message\MessageHandlerInterface;
 use Yiisoft\Queue\Message\MessageInterface;
 use Yiisoft\Queue\Middleware\Consume\ConsumeFinalHandler;
 use Yiisoft\Queue\Middleware\Consume\ConsumeMiddlewareDispatcher;
@@ -77,6 +78,18 @@ public function process(MessageInterface $message, QueueInterface $queue): Messa
     private function getHandler(string $name): ?callable
     {
         if (!array_key_exists($name, $this->handlersCached)) {
+            $definition = $this->handlers[$name] ?? null;
+            if ($definition === null && $this->container->has($name)) {
+                $handler = $this->container->get($name);
+                if ($handler instanceof MessageHandlerInterface) {
+                    $this->handlersCached[$name] = [$handler, 'handle'];
+
+                    return $this->handlersCached[$name];
+                }
+
+                return null;
+            }
+
             $this->handlersCached[$name] = $this->prepare($this->handlers[$name] ?? null);
         }
 

tests/Integration/MessageConsumingTest.php

@@ -13,6 +13,7 @@
 use Yiisoft\Queue\Middleware\Consume\MiddlewareFactoryConsumeInterface;
 use Yiisoft\Queue\Middleware\FailureHandling\FailureMiddlewareDispatcher;
 use Yiisoft\Queue\Middleware\FailureHandling\MiddlewareFactoryFailureInterface;
+use Yiisoft\Queue\Tests\Integration\Support\TestHandler;
 use Yiisoft\Queue\Tests\TestCase;
 use Yiisoft\Queue\Worker\Worker;
 
@@ -41,4 +42,27 @@ public function testMessagesConsumed(): void
 
         $this->assertEquals($messages, $this->messagesProcessed);
     }
+
+    public function testMessagesConsumedByHandlerClass(): void
+    {
+        $handler = new TestHandler();
+        $container = $this->createMock(ContainerInterface::class);
+        $container->method('get')->with(TestHandler::class)->willReturn($handler);
+        $container->method('has')->with(TestHandler::class)->willReturn(true);
+        $worker = new Worker(
+            [],
+            new NullLogger(),
+            new Injector($container),
+            $container,
+            new ConsumeMiddlewareDispatcher($this->createMock(MiddlewareFactoryConsumeInterface::class)),
+            new FailureMiddlewareDispatcher($this->createMock(MiddlewareFactoryFailureInterface::class), [])
+        );
+
+        $messages = [1, 'foo', 'bar-baz'];
+        foreach ($messages as $message) {
+            $worker->process(new Message(TestHandler::class, $message), $this->getQueue());
+        }
+
+        $this->assertEquals($messages, $handler->messagesProcessed);
+    }
 }

tests/Integration/Support/TestHandler.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Yiisoft\Queue\Tests\Integration\Support;
+
+use Yiisoft\Queue\Message\MessageHandlerInterface;
+use Yiisoft\Queue\Message\MessageInterface;
+
+final class TestHandler implements MessageHandlerInterface
+{
+    public function __construct(public array $messagesProcessed = [])
+    {
+    }
+
+    public function handle(MessageInterface $message): void
+    {
+        $this->messagesProcessed[] = $message->getData();
+    }
+}