[DX] [Form] Add helper method to register form extensions during unit testing

src/Symfony/Component/Form/Test/FormIntegrationTestCase.php

@@ -29,6 +29,9 @@ abstract class FormIntegrationTestCase extends TestCase
     {
         $this->factory = Forms::createFormFactoryBuilder()
             ->addExtensions($this->getExtensions())
+            ->addTypeExtensions($this->getTypedExtensions())
+            ->addTypes($this->getTypes())
+            ->addTypeGuessers($this->getTypeGuessers())
             ->getFormFactory();
     }
 
@@ -36,4 +39,19 @@ abstract class FormIntegrationTestCase extends TestCase
     {
         return array();
     }
+
+    protected function getTypedExtensions()
+    {
+        return array();
+    }
+
+    protected function getTypes()
+    {
+        return array();
+    }
+
+    protected function getTypeGuessers()
+    {
+        return array();
+    }
 }