PHP built-in server shows index page instead of static file - php

Question

I created a project with Slim 3 and Twig using their simplest examples.
Folder structure is as follows:
- public
- index.php
- style.css
App code in index.php is as follows:
<?php
require 'vendor/autoload.php';
$app = new \Slim\App();
$container = $app->getContainer();
// Twig
$container['view'] = function ($container) {
$view = new \Slim\Views\Twig('src/views', [
'cache' => false // TODO
]);
// Instantiate and add Slim specific extension
$basePath = rtrim(str_ireplace('index.php', '', $container['request']->getUri()->getBasePath()), '/');
$view->addExtension(new Slim\Views\TwigExtension($container['router'], $basePath));
return $view;
};
$app->get('/', function ($request, $response, $args) {
return $this->view->render($response, 'index/index.html.twig');
})->setName('index');
$app->run();
Now, the problem is that trying to load /style.css shows the main page instead (index/index.html.twig). Why can I not access the style.css file?
The server I use it the PHP built-in development server, using the command:
php -S localhost:8000 -t public public/index.php
How can I load the assets? What's the issue here?

Answer 1

The cause was the PHP built-in development server being 'dumb'.
I had to include this check as the very first thing in the index.php file.
// To help the built-in PHP dev server, check if the request was actually for
// something which should probably be served as a static file
if (PHP_SAPI == 'cli-server') {
$url = parse_url($_SERVER['REQUEST_URI']);
$file = __DIR__ . $url['path'];
if (is_file($file)) return false;
}
Source: https://github.com/slimphp/Slim-Skeleton/blob/master/public/index.php

Answer 2

Another option I checked an works is run server inside public folder. You will not need that script:
cd public
php -S localhost:8000