Remote Requests Symfony - Render JS template asynchronously with Twig parameters

DemoController.php

<?php
    /**
     * @Route("/test.js", name="app.test")
     */
    public function test()
    {
        $optionalParams = array('foo'=>'bar');
        $renderedView = $this->renderView("test.js.twig");
        $resp = new Response($renderedView, $optionalParams);
        $resp->headers->set('Content-Type','text/javascript');
        return $resp; // this triggers the file test.js.twig with working JS out of it.
    }