DiscordTransport example

$scheme = $dsn->getScheme();

        if ('discord' !== $scheme) {
            throw new UnsupportedSchemeException($dsn, 'discord', $this->getSupportedSchemes());
        }

        $token = $this->getUser($dsn);
        $webhookId = $dsn->getRequiredOption('webhook_id');
        $host = 'default' === $dsn->getHost() ? null : $dsn->getHost();
        $port = $dsn->getPort();

        return (new DiscordTransport($token, $webhookId, $this->client, $this->dispatcher))->setHost($host)->setPort($port);
    }

    protected function getSupportedSchemes(): array
    {
        return ['discord'];
    }
}

use Symfony\Component\Notifier\Message\ChatMessage;
use Symfony\Component\Notifier\Message\SmsMessage;
use Symfony\Component\Notifier\Test\TransportTestCase;
use Symfony\Component\Notifier\Tests\Transport\DummyMessage;
use Symfony\Contracts\HttpClient\HttpClientInterface;
use Symfony\Contracts\HttpClient\ResponseInterface;

final class DiscordTransportTest extends TransportTestCase
{
    public static function createTransport(HttpClientInterface $client = null): DiscordTransport
    {
        return (new DiscordTransport('testToken', 'testWebhookId', $client ?? new MockHttpClient()))->setHost('host.test');
    }

    public static function toStringProvider(): iterable
    {
        yield ['discord://host.test?webhook_id=testWebhookId', self::createTransport()];
    }

    public static function supportedMessagesProvider(): iterable
    {
        yield [new ChatMessage('Hello!')];
    }