rater/tests/Integration/Auth/LoginTest.php

<?php

namespace App\Tests\Integration\Auth;

use App\Repository\UserRepository;
use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;

class LoginTest extends WebTestCase
{
    public function testAddingNewSubject(): void
    {
        $client = static::createClient();

        $faker = \Zenstruck\Foundry\faker();
        $email = $faker->email();
        $plainPwd = $faker->password(8, 12);

        $client->request('GET', '/account/register');

        $client->submitForm('form_register', [
            'form[email]' => $email,
            'form[password]' => $plainPwd,
            'form[password_again]' => $plainPwd,
        ]);

        $this->assertResponseRedirects();

        $subject = static::getContainer()
            ->get(UserRepository::class)
            ->findOneBy(['email' => $email]);

        $this->assertNotNull($subject);
    }
}