<?php

declare(strict_types=1);

namespace App\Controller\Portal;

use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpKernel\Attribute\AsController;
use Symfony\Component\Routing\Attribute\Route;
use Symfony\Contracts\HttpClient\HttpClientInterface;

#[AsController]
final class TestController
{
    #[Route('/test')]
    public function index(HttpClientInterface $client): Response
    {
        return new Response($client->request('GET', 'https://www.google.com')->getContent());
    }
}

<?php

declare(strict_types=1);

namespace Functional;

use Symfony\Bundle\FrameworkBundle\Test\WebTestCase;
use Symfony\Component\HttpClient\MockHttpClient;
use Symfony\Component\HttpClient\Response\MockResponse;
use Symfony\Contracts\HttpClient\HttpClientInterface;

final class TestControllerTest extends WebTestCase
{
    public function testResponseMocking(): void
    {
        $client = self::createClient();
        $cannedResponse = 'Request Mocked successfully!';
        self::getContainer()->set(HttpClientInterface::class, new MockHttpClient(new MockResponse($cannedResponse)));

        $client->request('GET', 'http://127.0.0.1/test');
        self::assertSame($cannedResponse, $client->getResponse()->getContent());
    }
}