Unit Test for FormErrorSerializer in Symfony 4 - always valid form - forms

Question

I am trying to write a unit test for FormErrorSerializer that converts Symfony $form->getErrors() to a readable array.
My current approach is to create the form, give it data, and look for validation errors, but form is always valid. I don't get any errors no matter what data I provide to form.
In normal REST request/response it is working well and I am getting appropriate error message. I need help with getting the error messages in unit test.
namespace App\Tests\Unit;
use App\Form\UserType;
use App\Serializer\FormErrorSerializer;
use Symfony\Component\Form\Test\Traits\ValidatorExtensionTrait;
use Symfony\Component\Form\Test\TypeTestCase;
use Symfony\Component\Translation\Translator;
class FormErrorSerializerTest extends TypeTestCase
{
/**
* ValidatorExtensionTrait needed for invalid_options
* https://github.com/symfony/symfony/issues/22593
*/
use ValidatorExtensionTrait;
public function testConvertFormToArray(){
$form_data = [
'email' => 'test',
'plainPassword' => [
'pass' => '1',
'pass2' => '2'
]
];
$translator = new Translator('de');
$form = $this->factory->create(UserType::class);
$form->submit($form_data);
if( $form->isValid() ) {
echo "Form is valid"; exit;
}
$formErrorSerializer = new FormErrorSerializer($translator);
$errors = $formErrorSerializer->convertFormToArray($form);
print_r($errors); exit;
}
}
Find below the Serializer:
namespace App\Serializer;
use Symfony\Component\Form\FormError;
use Symfony\Component\Form\FormInterface;
use Symfony\Component\Translation\TranslatorInterface;
/**
* Serializes invalid Form instances.
*/
class FormErrorSerializer
{
private $translator;
public function __construct(TranslatorInterface $translator)
{
$this->translator = $translator;
}
public function convertFormToArray(FormInterface $data)
{
$form = $errors = [];
foreach ($data->getErrors() as $error) {
$errors[] = $this->getErrorMessage($error);
}
if ($errors) {
$form['errors'] = $errors;
}
$children = [];
foreach ($data->all() as $child) {
if ($child instanceof FormInterface) {
$children[$child->getName()] = $this->convertFormToArray($child);
}
}
if ($children) {
$form['children'] = $children;
}
return $form;
}
private function getErrorMessage(FormError $error)
{
if (null !== $error->getMessagePluralization()) {
return $this->translator->transChoice(
$error->getMessageTemplate(),
$error->getMessagePluralization(),
$error->getMessageParameters(),
'validators'
);
}
return $this->translator->trans($error->getMessageTemplate(), $error->getMessageParameters(), 'validators');
}
}

Answer 1

Ok, I was able to do this in 2 different ways.
First solution was to load the validator in getExtensions method. The factory in TypeTestCase doesn't bring the validator with it. So, not only you have to load the validator but you also have to explicitly specify the validations. You can specify validation using methods provided by symfony or you can directly point validator to the YAML or xml file if you are using one.
public function getExtensions()
{
$validator = (new ValidatorBuilder())
->addYamlMapping("path_to_validations.yaml")
->setConstraintValidatorFactory(new ConstraintValidatorFactory())
->getValidator();
$extensions[] = new CoreExtension();
$extensions[] = new ValidatorExtension($validator);
return $extensions;
}
However, I didn't use the above approach. I went with even better solution. Due to high complexity of my test case (as it needed multiple services), I went with a special container provided by Symfony's KernelTestCase. It provides private services in tests, and the factory it provides comes with validator and validations, just like you code in controller. You do not need to load validator explicitly. Find below my final test that extends KernelTestCase.
namespace App\Tests\Unit\Serializer;
use App\Entity\User;
use App\Form\UserType;
use App\Serializer\FormErrorSerializer;
use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
use Symfony\Component\Form\FormFactoryInterface;
use Symfony\Component\Form\FormInterface;
use Symfony\Component\Translation\TranslatorInterface;
class FormErrorSerializerTest extends KernelTestCase
{
/**
* {#inheritDoc}
*/
protected function setUp()
{
$kernel = self::bootKernel();
}
public function testConvertFormToArray_invalidData(){
$form_data = [
'email' => 'test',
'plainPassword' => [
'pass' => '1111',
'pass2' => ''
]
];
$user = new User();
$user->setEmail($form_data['email']);
$user->setPlainPassword($form_data['plainPassword']['pass']);
$factory = self::$container->get(FormFactoryInterface::class);
/**
* #var FormInterface $form
*/
$form = $factory->create(UserType::class, $user);
$form->submit($form_data);
$this->assertTrue($form->isSubmitted());
$this->assertFalse($form->isValid());
$translator = self::$container->get(TranslatorInterface::class);
$formErrorSerializer = new FormErrorSerializer($translator);
$errors = $formErrorSerializer->convertFormToArray($form);
$this->assertArrayHasKey('errors', $errors['children']['email']);
$this->assertArrayHasKey('errors', $errors['children']['plainPassword']['children']['pass']);
}
public function testConvertFormToArray_validData(){
$form_data = [
'email' => 'test#example.com',
'plainPassword' => [
'pass' => 'somepassword#slkd12',
'pass2' => 'somepassword#slkd12'
]
];
$user = new User();
$user->setEmail($form_data['email']);
$user->setPlainPassword($form_data['plainPassword']['pass']);
$factory = self::$container->get(FormFactoryInterface::class);
/**
* #var FormInterface $form
*/
$form = $factory->create(UserType::class, $user);
$form->submit($form_data);
$this->assertTrue($form->isSubmitted());
$this->assertTrue($form->isValid());
$translator = self::$container->get(TranslatorInterface::class);
$formErrorSerializer = new FormErrorSerializer($translator);
$errors = $formErrorSerializer->convertFormToArray($form);
$this->assertArrayNotHasKey('errors', $errors['children']['email']);
$this->assertArrayNotHasKey('errors', $errors['children']['plainPassword']['children']['pass']);
}
}
Please note that Symfony 4.1 has a special container that allows fetching private services.
self::$kernel->getContainer(); is not special container. It will not fetch private services.
However, self::$container; is special container that provides private services in testing.
More about this here.