feature #28399 [Messenger] Add a SenderLocator decoupled from Contain…

…erInterface (fabpot)

This PR was merged into the 4.2-dev branch.

Discussion
----------

[Messenger] Add a SenderLocator decoupled from ContainerInterface

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

For handler locators, we have a generic `HandlerLocator` class that takes a simple mapping instead of a service locator. The same did not exist for sender locators. So, this PR adds this possibility as well. That allows for something like this:

```php
new MessageBus([
    new SendMessageMiddleware(new SenderLocator([
        Message::class => new AmqpTransport($encoderDecoder, $encoderDecoder, $connection),
    ])),
    new HandleMessageMiddleware(new HandlerLocator([
        Message::class => new MessageHandler(),
    ])),
]);
```

Commits
-------

e658e15 [Messenger] added a SenderLocator decoupled from ContainerInterface

src/Symfony/Bundle/FrameworkBundle/Resources/config/messenger.xml

@@ -8,7 +8,7 @@
         <defaults public="false" />
 
         <!-- Asynchronous -->
-        <service id="messenger.asynchronous.routing.sender_locator" class="Symfony\Component\Messenger\Asynchronous\Routing\SenderLocator">
+        <service id="messenger.asynchronous.routing.sender_locator" class="Symfony\Component\Messenger\Asynchronous\Routing\ContainerSenderLocator">
             <argument type="service" id="messenger.sender_locator" />
             <argument type="collection" /> <!-- Message to sender ID mapping -->
         </service>

src/Symfony/Component/Messenger/Asynchronous/Middleware/SendMessageMiddleware.php

@@ -11,7 +11,7 @@
 
 namespace Symfony\Component\Messenger\Asynchronous\Middleware;
 
-use Symfony\Component\Messenger\Asynchronous\Routing\SenderLocator;
+use Symfony\Component\Messenger\Asynchronous\Routing\AbstractSenderLocator;
 use Symfony\Component\Messenger\Asynchronous\Routing\SenderLocatorInterface;
 use Symfony\Component\Messenger\Asynchronous\Transport\ReceivedMessage;
 use Symfony\Component\Messenger\Envelope;
@@ -60,6 +60,6 @@ public function handle($envelope, callable $next)
 
     private function mustSendAndHandle($message): bool
     {
-        return (bool) SenderLocator::getValueFromMessageRouting($this->messagesToSendAndHandleMapping, $message);
+        return (bool) AbstractSenderLocator::getValueFromMessageRouting($this->messagesToSendAndHandleMapping, $message);
     }
 }

src/Symfony/Component/Messenger/Asynchronous/Routing/AbstractSenderLocator.php

@@ -0,0 +1,38 @@
+<?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\Messenger\Asynchronous\Routing;
+
+/**
+ * @author Samuel Roze <samuel.roze@gmail.com>
+ *
+ * @internal
+ */
+abstract class AbstractSenderLocator implements SenderLocatorInterface
+{
+    public static function getValueFromMessageRouting(array $mapping, $message)
+    {
+        if (isset($mapping[\get_class($message)])) {
+            return $mapping[\get_class($message)];
+        }
+        if ($parentsMapping = array_intersect_key($mapping, class_parents($message))) {
+            return current($parentsMapping);
+        }
+        if ($interfaceMapping = array_intersect_key($mapping, class_implements($message))) {
+            return current($interfaceMapping);
+        }
+        if (isset($mapping['*'])) {
+            return $mapping['*'];
+        }
+
+        return null;
+    }
+}

src/Symfony/Component/Messenger/Asynchronous/Routing/ContainerSenderLocator.php

@@ -0,0 +1,40 @@
+<?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\Messenger\Asynchronous\Routing;
+
+use Psr\Container\ContainerInterface;
+use Symfony\Component\Messenger\Transport\SenderInterface;
+
+/**
+ * @author Samuel Roze <samuel.roze@gmail.com>
+ */
+class ContainerSenderLocator extends AbstractSenderLocator
+{
+    private $senderServiceLocator;
+    private $messageToSenderIdMapping;
+
+    public function __construct(ContainerInterface $senderServiceLocator, array $messageToSenderIdMapping)
+    {
+        $this->senderServiceLocator = $senderServiceLocator;
+        $this->messageToSenderIdMapping = $messageToSenderIdMapping;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getSenderForMessage($message): ?SenderInterface
+    {
+        $senderId = self::getValueFromMessageRouting($this->messageToSenderIdMapping, $message);
+
+        return $senderId ? $this->senderServiceLocator->get($senderId) : null;
+    }
+}

src/Symfony/Component/Messenger/Asynchronous/Routing/SenderLocator.php

@@ -11,56 +11,35 @@
 
 namespace Symfony\Component\Messenger\Asynchronous\Routing;
 
-use Psr\Container\ContainerInterface;
+use Symfony\Component\Messenger\Exception\RuntimeException;
 use Symfony\Component\Messenger\Transport\SenderInterface;
 
 /**
- * @author Samuel Roze <samuel.roze@gmail.com>
+ * @author Fabien Potencier <fabien@symfony.com>
  */
-class SenderLocator implements SenderLocatorInterface
+class SenderLocator extends AbstractSenderLocator
 {
-    private $senderServiceLocator;
-    private $messageToSenderIdMapping;
+    private $messageToSenderMapping;
 
-    public function __construct(ContainerInterface $senderServiceLocator, array $messageToSenderIdMapping)
+    public function __construct(array $messageToSenderMapping)
     {
-        $this->senderServiceLocator = $senderServiceLocator;
-        $this->messageToSenderIdMapping = $messageToSenderIdMapping;
+        $this->messageToSenderMapping = $messageToSenderMapping;
     }
 
     /**
      * {@inheritdoc}
      */
     public function getSenderForMessage($message): ?SenderInterface
     {
-        $senderId = $this->getSenderId($message);
-
-        return $senderId ? $this->senderServiceLocator->get($senderId) : null;
-    }
-
-    private function getSenderId($message): ?string
-    {
-        return self::getValueFromMessageRouting($this->messageToSenderIdMapping, $message);
-    }
-
-    /**
-     * @internal
-     */
-    public static function getValueFromMessageRouting(array $mapping, $message)
-    {
-        if (isset($mapping[\get_class($message)])) {
-            return $mapping[\get_class($message)];
+        $sender = self::getValueFromMessageRouting($this->messageToSenderMapping, $message);
+        if (null === $sender) {
+            return null;
         }
-        if ($parentsMapping = array_intersect_key($mapping, class_parents($message))) {
-            return current($parentsMapping);
-        }
-        if ($interfaceMapping = array_intersect_key($mapping, class_implements($message))) {
-            return current($interfaceMapping);
-        }
-        if (isset($mapping['*'])) {
-            return $mapping['*'];
+
+        if (!$sender instanceof SenderInterface) {
+            throw new RuntimeException(sprintf('The sender instance provided for message "%s" should be of type "%s" but got "%s".', \get_class($message), SenderInterface::class, \is_object($sender) ? \get_class($sender) : \gettype($sender)));
         }
 
-        return null;
+        return $sender;
     }
 }

src/Symfony/Component/Messenger/CHANGELOG.md

@@ -4,6 +4,9 @@ CHANGELOG
 4.2.0
 -----
 
+ * [BC BREAK] `SenderLocator` has been renamed to `ContainerSenderLocator`
+   Be careful as there is still a `SenderLocator` class, but it does not rely on a `ContainerInterface` to find senders.
+   Instead, it accepts the sender instance itself instead of its identifier in the container.
  * [BC BREAK] `MessageSubscriberInterface::getHandledMessages()` return value has changed. The value of an array item
    needs to be an associative array or the method name. 
  * `ValidationMiddleware::handle()` and `SendMessageMiddleware::handle()` now require an `Envelope` object

src/Symfony/Component/Messenger/Exception/RuntimeException.php

@@ -0,0 +1,19 @@
+<?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\Messenger\Exception;
+
+/**
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class RuntimeException extends \RuntimeException implements ExceptionInterface
+{
+}

src/Symfony/Component/Messenger/Tests/Asynchronous/Routing/ContainerSenderLocatorTest.php

@@ -0,0 +1,91 @@
+<?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\Messenger\Tests\Asynchronous\Routing;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\DependencyInjection\Container;
+use Symfony\Component\Messenger\Asynchronous\Routing\ContainerSenderLocator;
+use Symfony\Component\Messenger\Tests\Fixtures\ChildDummyMessage;
+use Symfony\Component\Messenger\Tests\Fixtures\DummyMessage;
+use Symfony\Component\Messenger\Tests\Fixtures\DummyMessageInterface;
+use Symfony\Component\Messenger\Tests\Fixtures\SecondMessage;
+use Symfony\Component\Messenger\Transport\SenderInterface;
+
+class ContainerSenderLocatorTest extends TestCase
+{
+    public function testItReturnsTheSenderBasedOnTheMessageClass()
+    {
+        $sender = $this->getMockBuilder(SenderInterface::class)->getMock();
+        $container = new Container();
+        $container->set('my_amqp_sender', $sender);
+
+        $locator = new ContainerSenderLocator($container, array(
+            DummyMessage::class => 'my_amqp_sender',
+        ));
+
+        $this->assertSame($sender, $locator->getSenderForMessage(new DummyMessage('Hello')));
+        $this->assertNull($locator->getSenderForMessage(new SecondMessage()));
+    }
+
+    public function testItReturnsTheSenderBasedOnTheMessageParentClass()
+    {
+        $container = new Container();
+
+        $sender = $this->getMockBuilder(SenderInterface::class)->getMock();
+        $container->set('my_amqp_sender', $sender);
+
+        $apiSender = $this->getMockBuilder(SenderInterface::class)->getMock();
+        $container->set('my_api_sender', $apiSender);
+
+        $locator = new ContainerSenderLocator($container, array(
+            DummyMessageInterface::class => 'my_api_sender',
+            DummyMessage::class => 'my_amqp_sender',
+        ));
+
+        $this->assertSame($sender, $locator->getSenderForMessage(new ChildDummyMessage('Hello')));
+        $this->assertNull($locator->getSenderForMessage(new SecondMessage()));
+    }
+
+    public function testItReturnsTheSenderBasedOnTheMessageInterface()
+    {
+        $container = new Container();
+
+        $sender = $this->getMockBuilder(SenderInterface::class)->getMock();
+        $container->set('my_amqp_sender', $sender);
+
+        $locator = new ContainerSenderLocator($container, array(
+            DummyMessageInterface::class => 'my_amqp_sender',
+        ));
+
+        $this->assertSame($sender, $locator->getSenderForMessage(new DummyMessage('Hello')));
+        $this->assertNull($locator->getSenderForMessage(new SecondMessage()));
+    }
+
+    public function testItSupportsAWildcardInsteadOfTheMessageClass()
+    {
+        $container = new Container();
+
+        $sender = $this->getMockBuilder(SenderInterface::class)->getMock();
+        $container->set('my_amqp_sender', $sender);
+
+        $apiSender = $this->getMockBuilder(SenderInterface::class)->getMock();
+        $container->set('my_api_sender', $apiSender);
+
+        $locator = new ContainerSenderLocator($container, array(
+            DummyMessage::class => 'my_amqp_sender',
+            '*' => 'my_api_sender',
+        ));
+
+        $this->assertSame($sender, $locator->getSenderForMessage(new DummyMessage('Hello')));
+        $this->assertSame($apiSender, $locator->getSenderForMessage(new SecondMessage()));
+    }
+}

src/Symfony/Component/Messenger/Tests/Asynchronous/Routing/SenderLocatorTest.php

@@ -12,11 +12,9 @@
 namespace Symfony\Component\Messenger\Tests\Asynchronous\Routing;
 
 use PHPUnit\Framework\TestCase;
-use Symfony\Component\DependencyInjection\Container;
 use Symfony\Component\Messenger\Asynchronous\Routing\SenderLocator;
-use Symfony\Component\Messenger\Tests\Fixtures\ChildDummyMessage;
+use Symfony\Component\Messenger\Exception\RuntimeException;
 use Symfony\Component\Messenger\Tests\Fixtures\DummyMessage;
-use Symfony\Component\Messenger\Tests\Fixtures\DummyMessageInterface;
 use Symfony\Component\Messenger\Tests\Fixtures\SecondMessage;
 use Symfony\Component\Messenger\Transport\SenderInterface;
 
@@ -25,67 +23,21 @@ class SenderLocatorTest extends TestCase
     public function testItReturnsTheSenderBasedOnTheMessageClass()
     {
         $sender = $this->getMockBuilder(SenderInterface::class)->getMock();
-        $container = new Container();
-        $container->set('my_amqp_sender', $sender);
-
-        $locator = new SenderLocator($container, array(
-            DummyMessage::class => 'my_amqp_sender',
-        ));
-
-        $this->assertSame($sender, $locator->getSenderForMessage(new DummyMessage('Hello')));
-        $this->assertNull($locator->getSenderForMessage(new SecondMessage()));
-    }
-
-    public function testItReturnsTheSenderBasedOnTheMessageParentClass()
-    {
-        $container = new Container();
-
-        $sender = $this->getMockBuilder(SenderInterface::class)->getMock();
-        $container->set('my_amqp_sender', $sender);
-
-        $apiSender = $this->getMockBuilder(SenderInterface::class)->getMock();
-        $container->set('my_api_sender', $apiSender);
-
-        $locator = new SenderLocator($container, array(
-            DummyMessageInterface::class => 'my_api_sender',
-            DummyMessage::class => 'my_amqp_sender',
-        ));
-
-        $this->assertSame($sender, $locator->getSenderForMessage(new ChildDummyMessage('Hello')));
-        $this->assertNull($locator->getSenderForMessage(new SecondMessage()));
-    }
-
-    public function testItReturnsTheSenderBasedOnTheMessageInterface()
-    {
-        $container = new Container();
-
-        $sender = $this->getMockBuilder(SenderInterface::class)->getMock();
-        $container->set('my_amqp_sender', $sender);
-
-        $locator = new SenderLocator($container, array(
-            DummyMessageInterface::class => 'my_amqp_sender',
+        $locator = new SenderLocator(array(
+            DummyMessage::class => $sender,
         ));
 
         $this->assertSame($sender, $locator->getSenderForMessage(new DummyMessage('Hello')));
         $this->assertNull($locator->getSenderForMessage(new SecondMessage()));
     }
 
-    public function testItSupportsAWildcardInsteadOfTheMessageClass()
+    public function testItThrowsExceptionIfConfigurationIsWrong()
     {
-        $container = new Container();
-
-        $sender = $this->getMockBuilder(SenderInterface::class)->getMock();
-        $container->set('my_amqp_sender', $sender);
-
-        $apiSender = $this->getMockBuilder(SenderInterface::class)->getMock();
-        $container->set('my_api_sender', $apiSender);
-
-        $locator = new SenderLocator($container, array(
-            DummyMessage::class => 'my_amqp_sender',
-            '*' => 'my_api_sender',
+        $locator = new SenderLocator(array(
+            DummyMessage::class => 'amqp',
         ));
 
-        $this->assertSame($sender, $locator->getSenderForMessage(new DummyMessage('Hello')));
-        $this->assertSame($apiSender, $locator->getSenderForMessage(new SecondMessage()));
+        $this->expectException(RuntimeException::class);
+        $locator->getSenderForMessage(new DummyMessage('Hello'));
     }
 }