Validate the extended type for lazy-loaded type extensions

UPGRADE-2.8.md

@@ -231,6 +231,10 @@ Form
    $form = $this->createForm(MyType::class);
    ```
 
+ * Registering type extensions as a service with an alias which does not
+   match the type returned by `getExtendedType` is now forbidden. Fix your
+   implementation to define the right type.
+
 Translator
 ----------
 

src/Symfony/Component/Form/CHANGELOG.md

@@ -9,6 +9,7 @@ CHANGELOG
  * deprecated the "cascade_validation" option in favor of setting "constraints"
    with the Valid constraint
  * moved data trimming logic of TrimListener into StringUtil
+ * [BC BREAK] When registering a type extension through the DI extension, the tag alias has to match the actual extended type.
 
 2.7.0
 -----

src/Symfony/Component/Form/Extension/DependencyInjection/DependencyInjectionExtension.php

@@ -68,7 +68,18 @@ class DependencyInjectionExtension implements FormExtensionInterface
 
         if (isset($this->typeExtensionServiceIds[$name])) {
             foreach ($this->typeExtensionServiceIds[$name] as $serviceId) {
-                $extensions[] = $this->container->get($serviceId);
+                $extensions[] = $extension = $this->container->get($serviceId);
+
+                // validate result of getExtendedType() to ensure it is consistent with the service definition
+                if ($extension->getExtendedType() !== $name) {
+                    throw new InvalidArgumentException(
+                        sprintf('The extended type specified for the service "%s" does not match the actual extended type. Expected "%s", given "%s".',
+                            $serviceId,
+                            $name,
+                            $extension->getExtendedType()
+                        )
+                    );
+                }
             }
         }
 

src/Symfony/Component/Form/Tests/Extension/DependencyInjection/DependencyInjectionExtensionTest.php

@@ -0,0 +1,80 @@
+<?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\Form\Tests\Extension\DependencyInjection;
+
+use Symfony\Component\DependencyInjection\Exception\ServiceNotFoundException;
+use Symfony\Component\Form\Extension\DependencyInjection\DependencyInjectionExtension;
+
+class DependencyInjectionExtensionTest extends \PHPUnit_Framework_TestCase
+{
+    public function testGetTypeExtensions()
+    {
+        $container = $this->getMock('Symfony\Component\DependencyInjection\ContainerInterface');
+
+        $typeExtension1 = $this->getMock('Symfony\Component\Form\FormTypeExtensionInterface');
+        $typeExtension1->expects($this->any())
+            ->method('getExtendedType')
+            ->willReturn('test');
+        $typeExtension2 = $this->getMock('Symfony\Component\Form\FormTypeExtensionInterface');
+        $typeExtension2->expects($this->any())
+            ->method('getExtendedType')
+            ->willReturn('test');
+        $typeExtension3 = $this->getMock('Symfony\Component\Form\FormTypeExtensionInterface');
+        $typeExtension3->expects($this->any())
+            ->method('getExtendedType')
+            ->willReturn('other');
+
+        $services = array(
+            'extension1' => $typeExtension1,
+            'extension2' => $typeExtension2,
+            'extension3' => $typeExtension3,
+        );
+
+        $container->expects($this->any())
+            ->method('get')
+            ->willReturnCallback(function ($id) use ($services) {
+                if (isset($services[$id])) {
+                    return $services[$id];
+                }
+
+                throw new ServiceNotFoundException($id);
+            });
+
+        $extension = new DependencyInjectionExtension($container, array(), array('test' => array('extension1', 'extension2'), 'other' => array('extension3')), array());
+
+        $this->assertTrue($extension->hasTypeExtensions('test'));
+        $this->assertFalse($extension->hasTypeExtensions('unknown'));
+        $this->assertSame(array($typeExtension1, $typeExtension2), $extension->getTypeExtensions('test'));
+    }
+
+    /**
+     * @expectedException \Symfony\Component\Form\Exception\InvalidArgumentException
+     */
+    public function testThrowExceptionForInvalidExtendedType()
+    {
+        $container = $this->getMock('Symfony\Component\DependencyInjection\ContainerInterface');
+
+        $typeExtension = $this->getMock('Symfony\Component\Form\FormTypeExtensionInterface');
+        $typeExtension->expects($this->any())
+            ->method('getExtendedType')
+            ->willReturn('unmatched');
+
+        $container->expects($this->any())
+            ->method('get')
+            ->with('extension')
+            ->willReturn($typeExtension);
+
+        $extension = new DependencyInjectionExtension($container, array(), array('test' => array('extension')), array());
+
+        $extension->getTypeExtensions('test');
+    }
+}

src/Symfony/Component/Form/composer.json

@@ -26,6 +26,7 @@
         "symfony/phpunit-bridge": "~2.7|~3.0.0",
         "doctrine/collections": "~1.0",
         "symfony/validator": "~2.8|~3.0.0",
+        "symfony/dependency-injection": "~2.3|~3.0.0",
         "symfony/http-foundation": "~2.2|~3.0.0",
         "symfony/http-kernel": "~2.4|~3.0.0",
         "symfony/security-csrf": "~2.4|~3.0.0",