Added note about using the Validator TypeTestCase in form unit testing

form/unit_testing.rst

@@ -124,7 +124,7 @@ To create your form correctly, you need to make the type available to the
 form factory in your test. The easiest way is to register it manually
 before creating the parent form using the ``PreloadedExtension`` class::
 
-    // src/AppBundle/Tests/Form/Type/TestedTypeTests.php
+    // src/AppBundle/Tests/Form/Type/TestedTypeTest.php
     namespace AppBundle\Tests\Form\Type;
 
     use AppBundle\Form\Type\TestedType;
@@ -161,43 +161,34 @@ Adding Custom Extensions
 ------------------------
 
 It often happens that you use some options that are added by
-:doc:`form extensions </form/create_form_type_extension>`. One of the
-cases may be the ``ValidatorExtension`` with its ``invalid_message`` option.
+:doc:`form extensions </form/create_form_type_extension>`.
 The ``TypeTestCase`` only loads the core form extension, which means an
 :class:`Symfony\\Component\\OptionsResolver\\Exception\\InvalidOptionsException`
 will be raised if you try to test a class that depends on other extensions.
 The :method:`Symfony\\Component\\Form\\Test\\TypeTestCase::getExtensions` method
 allows you to return a list of extensions to register::
 
-    // src/AppBundle/Tests/Form/Type/TestedTypeTests.php
+    // src/AppBundle/Tests/Form/Type/TestedTypeTest.php
     namespace AppBundle\Tests\Form\Type;
 
     use AppBundle\Form\Type\TestedType;
-    use Symfony\Component\Form\Extension\Validator\ValidatorExtension;
     use Symfony\Component\Form\Form;
     use Symfony\Component\Form\Forms;
     use Symfony\Component\Form\FormBuilder;
     use Symfony\Component\Form\Test\TypeTestCase;
-    use Symfony\Component\Validator\ConstraintViolationList;
     use Symfony\Component\Validator\Mapping\ClassMetadata;
-    use Symfony\Component\Validator\Validator\ValidatorInterface;
 
     class TestedTypeTest extends TypeTestCase
     {
         protected function getExtensions()
         {
-            $validator = $this->createMock(ValidatorInterface::class);
             // use getMock() on PHPUnit 5.3 or below
             // $validator = $this->getMock(ValidatorInterface::class);
-            $validator
-                ->method('validate')
-                ->will($this->returnValue(new ConstraintViolationList()));
             $validator
                 ->method('getMetadataFor')
                 ->will($this->returnValue(new ClassMetadata(Form::class)));
-
             return array(
-                new ValidatorExtension($validator),
+                new MyFormExtension(),
             );
         }
 
@@ -210,7 +201,7 @@ Testing against Different Sets of Data
 If you are not familiar yet with PHPUnit's `data providers`_, this might be
 a good opportunity to use them::
 
-    // src/AppBundle/Tests/Form/Type/TestedTypeTests.php
+    // src/AppBundle/Tests/Form/Type/TestedTypeTest.php
     namespace AppBundle\Tests\Form\Type;
 
     use AppBundle\Form\Type\TestedType;