Add a messenger middleware to enforce null results

symfony · polc · Oct 7, 2018 · Oct 7, 2018 · Oct 7, 2018 · Oct 7, 2018
commit d89ffd3ef24a62923438bec360676e1cce8d36f0
diff --git a/src/Symfony/Component/Messenger/Exception/NonNullResultException.php b/src/Symfony/Component/Messenger/Exception/NonNullResultException.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 Paul Le Corre <paul@lecorre.me>
+ */
+    class NonNullResultException extends \LogicException implements ExceptionInterface
+{
+}
diff --git a/src/Symfony/Component/Messenger/Middleware/EnforceNullResultMiddleware.php b/src/Symfony/Component/Messenger/Middleware/EnforceNullResultMiddleware.php
@@ -0,0 +1,30 @@
+<?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\NonNullResultException;
+
+/**
+ * @author Paul Le Corre <paul@lecorre.me>
+ */
+class EnforceNullResultMiddleware implements MiddlewareInterface
+{
+    public function handle($message, callable $next)
+    {
+        $result = $next($message);
+        if (null !== $result) {
+            throw new NonNullResultException(sprintf('Non null result for message %s.', \get_class($message)));
+        }
+
+        return $result;
+    }
+}
diff --git a/src/Symfony/Component/Messenger/Tests/Middleware/EnforceNullResultMiddlewareTest.php b/src/Symfony/Component/Messenger/Tests/Middleware/EnforceNullResultMiddlewareTest.php
@@ -0,0 +1,43 @@
+<?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\Middleware;
+
+use PHPUnit\Framework\TestCase;
+use Symfony\Component\Messenger\Middleware\EnforceNullResultMiddleware;
+use Symfony\Component\Messenger\Tests\Fixtures\DummyMessage;
+
+class EnforceNullResultMiddlewareTest extends TestCase
+{
+    public function testItCallsNextMiddleware()
+    {
+        $message = new DummyMessage('Hey');
+
+        $next = $this->createPartialMock(\stdClass::class, array('__invoke'));
+        $next->expects($this->once())->method('__invoke')->with($message);
+
+        $middleware = new EnforceNullResultMiddleware();
+        $middleware->handle($message, $next);
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Messenger\Exception\NonNullResultException
+     * @expectedExceptionMessage Non null result for message Symfony\Component\Messenger\Tests\Fixtures\DummyMessage.
+     */
+    public function testItThrowExceptionOnNonNullResult()
+    {
+        $next = $this->createPartialMock(\stdClass::class, array('__invoke'));
+        $next->expects($this->once())->method('__invoke')->will($this->returnValue('Non null value'));
+
+        $middleware = new EnforceNullResultMiddleware();
+        $middleware->handle(new DummyMessage('Hey'), $next);
+    }
+}