feature #26648 [Messenger] Added a middleware that validates messages (Nyholm)

This PR was squashed before being merged into the 4.1-dev branch (closes #26648).

Discussion
----------

[Messenger] Added a middleware that validates messages

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

This is inspired by [Fervo](https://github.com/fervo/ValidatedMessage).  It runs the validator over messages implementing the `ValidatedMessageInterface`.

Commits
-------

43a51714d4 [Messenger] Added a middleware that validates messages

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php

@@ -1005,10 +1005,14 @@ class Configuration implements ConfigurationInterface
                         ->arrayNode('middlewares')
                             ->addDefaultsIfNotSet()
                             ->children()
-                            ->arrayNode('doctrine_transaction')
-                                ->canBeEnabled()
-                                ->children()
-                                    ->scalarNode('entity_manager_name')->info('The name of the entity manager to use')->defaultNull()->end()
+                                ->arrayNode('doctrine_transaction')
+                                    ->canBeEnabled()
+                                    ->children()
+                                        ->scalarNode('entity_manager_name')->info('The name of the entity manager to use')->defaultNull()->end()
+                                    ->end()
+                                ->end()
+                                ->arrayNode('validation')
+                                    ->{!class_exists(FullStack::class) && class_exists(Validation::class) ? 'canBeDisabled' : 'canBeEnabled'}()
                                 ->end()
                             ->end()
                         ->end()

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/FrameworkExtension.php

@@ -1459,6 +1459,14 @@ class FrameworkExtension extends Extension
         } else {
             $container->removeDefinition('messenger.middleware.doctrine_transaction');
         }
+
+        if ($config['middlewares']['validation']['enabled']) {
+            if (!$container->has('validator')) {
+                throw new LogicException('The Validation middleware is only available when the Validator component is installed and enabled. Try running "composer require symfony/validator".');
+            }
+        } else {
+            $container->removeDefinition('messenger.middleware.validator');
+        }
     }
 
     private function registerCacheConfiguration(array $config, ContainerBuilder $container)

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

@@ -25,6 +25,12 @@
             <tag name="message_bus_middleware" priority="-10" />
         </service>
 
+        <service id="messenger.middleware.validator" class="Symfony\Component\Messenger\Middleware\ValidationMiddleware">
+            <argument type="service" id="validator" />
+
+            <tag name="message_bus_middleware" priority="100" />
+        </service>
+
         <service id="messenger.middleware.doctrine_transaction" class="Symfony\Bridge\Doctrine\Messenger\DoctrineTransactionMiddleware">
             <argument type="service" id="doctrine" />
             <argument /> <!-- Entity manager name -->

src/Symfony/Bundle/FrameworkBundle/Resources/config/schema/symfony-1.0.xsd

@@ -371,6 +371,7 @@
     <xsd:complexType name="messenger_middleware">
         <xsd:sequence>
             <xsd:element name="doctrine-transaction" type="messenger_doctrine_transaction" minOccurs="0" maxOccurs="1" />
+            <xsd:element name="validation" type="messenger_validation" minOccurs="0" maxOccurs="1" />
         </xsd:sequence>
     </xsd:complexType>
 
@@ -378,4 +379,8 @@
         <xsd:attribute name="entity-manager-name" type="xsd:string" />
         <xsd:attribute name="enabled" type="xsd:boolean" />
     </xsd:complexType>
+
+    <xsd:complexType name="messenger_validation">
+        <xsd:attribute name="enabled" type="xsd:boolean" />
+    </xsd:complexType>
 </xsd:schema>

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/ConfigurationTest.php

@@ -258,6 +258,9 @@ class ConfigurationTest extends TestCase
                         'enabled' => false,
                         'entity_manager_name' => null,
                     ),
+                    'validation' => array(
+                        'enabled' => false,
+                    ),
                 ),
             ),
         );

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/php/messenger_validation.php

@@ -0,0 +1,11 @@
+<?php
+
+$container->loadFromExtension('framework', array(
+    'messenger' => array(
+        'middlewares' => array(
+            'validation' => array(
+                'enabled' => false,
+            ),
+        ),
+    ),
+));

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/xml/messenger_validation.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<container xmlns="http://symfony.com/schema/dic/services"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns:framework="http://symfony.com/schema/dic/symfony"
+    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd
+        http://symfony.com/schema/dic/symfony http://symfony.com/schema/dic/symfony/symfony-1.0.xsd">
+
+    <framework:config>
+        <framework:messenger>
+            <framework:middlewares>
+                <framework:validation enabled="false"/>
+            </framework:middlewares>
+        </framework:messenger>
+    </framework:config>
+</container>

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/Fixtures/yml/messenger_validation.yml

@@ -0,0 +1,5 @@
+framework:
+    messenger:
+        middlewares:
+            validation:
+                enabled: false

src/Symfony/Bundle/FrameworkBundle/Tests/DependencyInjection/FrameworkExtensionTest.php

@@ -45,6 +45,7 @@ use Symfony\Component\Serializer\Normalizer\DateTimeNormalizer;
 use Symfony\Component\Serializer\Normalizer\JsonSerializableNormalizer;
 use Symfony\Component\Translation\DependencyInjection\TranslatorPass;
 use Symfony\Component\Validator\DependencyInjection\AddConstraintValidatorsPass;
+use Symfony\Component\Validator\Validation;
 use Symfony\Component\Workflow;
 
 abstract class FrameworkExtensionTest extends TestCase
@@ -532,6 +533,16 @@ abstract class FrameworkExtensionTest extends TestCase
         $this->assertEquals('foobar', $def->getArgument(1));
     }
 
+    public function testMessengerValidationDisabled()
+    {
+        if (!class_exists(Validation::class)) {
+            self::markTestSkipped('Skipping tests since Validator component is not installed');
+        }
+
+        $container = $this->createContainerFromFile('messenger_validation');
+        $this->assertFalse($container->hasDefinition('messenger.middleware.validator'));
+    }
+
     public function testTranslator()
     {
         $container = $this->createContainerFromFile('full');

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

@@ -0,0 +1,44 @@
+<?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;
+
+use Symfony\Component\Validator\ConstraintViolationListInterface;
+
+/**
+ * @author Tobias Nyholm <tobias.nyholm@gmail.com>
+ */
+class ValidationFailedException extends \RuntimeException implements ExceptionInterface
+{
+    private $violations;
+    private $violatingMessage;
+
+    /**
+     * @param object $violatingMessage
+     */
+    public function __construct($violatingMessage, ConstraintViolationListInterface $violations)
+    {
+        $this->violatingMessage = $violatingMessage;
+        $this->violations = $violations;
+
+        parent::__construct(sprintf('Message of type "%s" failed validation.', get_class($this->violatingMessage)));
+    }
+
+    public function getViolatingMessage()
+    {
+        return $this->violatingMessage;
+    }
+
+    public function getViolations(): ConstraintViolationListInterface
+    {
+        return $this->violations;
+    }
+}

src/Symfony/Component/Messenger/Middleware/ValidationMiddleware.php

@@ -0,0 +1,39 @@
+<?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\Middleware;
+
+use Symfony\Component\Messenger\Exception\ValidationFailedException;
+use Symfony\Component\Messenger\MiddlewareInterface;
+use Symfony\Component\Validator\Validator\ValidatorInterface;
+
+/**
+ * @author Tobias Nyholm <tobias.nyholm@gmail.com>
+ */
+class ValidationMiddleware implements MiddlewareInterface
+{
+    private $validator;
+
+    public function __construct(ValidatorInterface $validator)
+    {
+        $this->validator = $validator;
+    }
+
+    public function handle($message, callable $next)
+    {
+        $violations = $this->validator->validate($message);
+        if (count($violations)) {
+            throw new ValidationFailedException($message, $violations);
+        }
+
+        return $next($message);
+    }
+}