Controller not found: service "AppBundle/Controller/TestController.php" does not exist - php

Question

I get the error Controller not found: service "AppBundle / Controller / TestController.php" does not exist
but i don't know how to debug it. Can someone please help me !?
Is it possible that the error comes from the routing or it is something else !?
I just want to clarify that I use Symfony 3.4.
Here is the extract from the TestController.php code
<?php
namespace AppBundle\Controller;
use AppBundle\Entity\Task;
use AppBundle\Form\TaskType;
use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing\Annotation\Route;
/**
* #Route("test/form-test")
*/
class TestController extends Controller
{
/**
* #Route("/", name="test")
*/
public function newAction(Request $request)
{
// creates a task and gives it some dummy data for this example
$task = new Task();
$task->setTask('Write a blog post');
$task->setDueDate(new \DateTime('tomorrow'));
$form = $this->get('form.factory')->createNamed('addTask', TaskType::class, $task);
$form->handleRequest($request);
$validator = $this->get('validator');
$errors = $validator->validate($form);
if (count($editErrors) > 0) {
$errorsString = (string)$editErrors;
return new Response($errorsString);
}
echo('------------------------------------------------------------------------' . $form->isSubmitted() . ' && ' . $form->isValid());
if ($form->isSubmitted() && $form->isValid()) {
// $form->getData() holds the submitted values
// but, the original `$task` variable has also been updated
$task = $form->getData();
// ... perform some action, such as saving the task to the database
// for example, if Task is a Doctrine entity, save it!
// $entityManager = $this->getDoctrine()->getManager();
// $entityManager->persist($task);
// $entityManager->flush();
return new Response('<h1>-----------------------------------------------------------------------------------OK</h1>');
}
return $this->render('default/index.html.twig', [
'form' => $form->createView(),
'errors' => $errors,
]);
}
}
thank you in advance