Magento2 router.php for php built-in Server

router.php

<?php

$debug = function($val){
    return;
    echo $val.PHP_EOL.'<br/>'.PHP_EOL;
};

/**
 * Caution, this is very experimental stuff
 * no garant for working result
 * has tons of potencial big security holes
 */

if (php_sapi_name() == 'cli-server') {
    /* route static assets and return false */


    $path = pathinfo($_SERVER["SCRIPT_FILENAME"]);
    /* 
    array(4) { 
    ["dirname"]=> string(25) "/work/cotya/mage_2/public" 
    ["basename"]=> string(9) "index.php" 
    ["extension"]=> string(3) "php" 
    ["filename"]=> string(5) "index" 
    } 
    */
    $url   = pathinfo(substr($_SERVER["REQUEST_URI"], 1));
    $route = parse_url(substr($_SERVER["REQUEST_URI"], 1))["path"];

    $debug($path['extension']);

    $outputFile = function($filePath) use ($url){
        $mapping = [
            'ico' => 'image/x-icon',
            'css' => 'text/css',
            'js'  => 'text/javascript',
        ];
        if (isset($mapping[$url['extension']])) {
            header("Content-Type: ".$mapping[$url['extension']]);
        }
        readfile($filePath);
        exit;
    };
    
    if(
        $path["basename"] == 'favicon.ico'
    ){
        $outputFile($_SERVER["SCRIPT_FILENAME"]);
    }
    
    $debug($route);
    $debug(strpos($route, 'errors/default/css/'));


    $magentoPackageDir = __DIR__.'/../vendor/magento/project-community-edition';
    
    if(strpos($route, 'pub/errors/default/') === 0){
        $route = preg_replace('#pub/errors/default/#', 'errors/default/', $route, 1);
    }


    $debug($route);
    
    
    if(
        strpos($route, 'media/') === 0 ||
        strpos($route, 'opt/') === 0 ||
        strpos($route, 'static/') === 0 ||
        strpos($route, 'errors/default/css/') === 0 ||
        strpos($route, 'errors/default/images/') === 0 ||
        false
    ){
        $magentoPackagePubDir = $magentoPackageDir.'/pub';

        $file = $magentoPackagePubDir.'/'.$route;
        $debug($file);
        if(file_exists($file)){
            $outputFile($file);
        }else{
            if(strpos($route, 'static/') === 0){
                $route = preg_replace('#static/#', '', $route, 1);
                $_GET['resource'] = $route;
                include($magentoPackagePubDir.'/static.php');
                exit;
            }elseif(strpos($route, 'media/') === 0){
                include($magentoPackagePubDir.'/get.php');
                exit;
            }
        }
    }

    if(strpos($route, 'pub/') === 0){

        $magentoPackageSetupDir = $magentoPackageDir.'/setup';
        $file = $magentoPackageSetupDir.'/'.$route;
        $debug($file);
        
        
        if(file_exists($file)){
            $outputFile($file);
        }
    }
    
    if(strpos($route, 'setup/') === 0){
        $magentoPackageSetupDir = $magentoPackageDir.'/setup';

        include($magentoPackageSetupDir.'/index.php');
        exit;
    }

}
/* go on with normal index.php operations */


include(__DIR__.'/index.php');