CORS middleware for Lumen and PSR-7

app.php

<?php

/*
some code on bootstrap/app.php...
*/

$app->middleware([
    App\Http\Middleware\CorsMiddleware::class
    /* maybe, antother middlewares... */
]);

/*
some code...
*/

CorsMiddleware.php

<?php

namespace App\Http\Middleware;

use Closure;

class CorsMiddleware
{
    /**
     * Handle an incoming request.
     *
     * @param  $request
     * @param  \Closure  $next
     * @return mixed
     */
    public function handle($request, Closure $next)
    {
		//Intercepts OPTIONS requests
		if($request->isMethod('OPTIONS')) {
			$response = response('', 200);
		} else {
			// Pass the request to the next middleware
			$response = $next($request);
		}
        
		// Adds headers to the response
		$response->headers->set('Access-Control-Allow-Methods', 'HEAD, GET, POST, PUT, PATCH, DELETE');
		$response->headers->set('Access-Control-Allow-Headers', $request->header('Access-Control-Request-Headers'));
		$response->headers->set('Access-Control-Allow-Origin', '*');

		// Sends it
		return $response;
	}
}