Preview twig email in controller during development

EmailViewController.php

<?php

namespace App\Controller;

use Symfony\Bridge\Twig\Mime\TemplatedEmail;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Mime\BodyRendererInterface;
use Symfony\Component\Routing\Attribute\Route;

class EmailViewController extends AbstractController
{
    public function __construct(
        private BodyRendererInterface $bodyRenderer
    )
    {
    }

    #[Route('/email/preview', name: 'email_view', condition: "'%kernel.environment%' === 'dev'")]
    public function __invoke(): Response
    {
        $email = new TemplatedEmail();

        $email->htmlTemplate('email/welcome.html.twig')
            ->context([
                'name' => 'John Doe',
            ])
            ->subject('Welcome to the Space Bar!');


        $this->bodyRenderer->render($email);
        $html = (string) $email->getHtmlBody();

        foreach ($email->getAttachments() as $attachment) {
            if($attachment->getDisposition() === 'inline') {
                $inlineMediaType = vsprintf('data:%s/%s;%s,', [
                    $attachment->getMediaType(),
                    $attachment->getMediaSubtype(),
                    $attachment->getPreparedHeaders()->get('Content-Transfer-Encoding')->getBody()
                ]);
                $html = str_replace(
                    'cid:'.$attachment->getName(),
                    $inlineMediaType.$attachment->bodyToString(),
                    $html
                );
            }
        }

        return new Response($html);
    }
}