bartender/middlewares/CorsControl.php

<?php

namespace Middlewares;

use Psr\Http\Message\ServerRequestInterface;
use React\Http\Message\Response;

class CorsControl
{
    public function __invoke(ServerRequestInterface $request, $next)
    {
        if ($request->getMethod() === 'OPTIONS') {
            return new Response(204);
        }

        if (is_string($next) && class_exists($next)) {
            $instance = new $next();
            if (is_callable($instance)) {
                $next = $instance;
            } else {
                throw new \RuntimeException("Controller “{$next}” não é callable");
            }
        }

        return $next($request);
    }
}