fix: improve stability and type-safety in FrontController

- Added assertion to ensure 'view' is an instance of Smarty to avoid potential type errors.
- Included plugin registration for 'filter_var' modifier to enhance view capabilities.
- Added a check for successful file_get_contents call to prevent potential errors when fetching thumbnails.
- Incorporated type assertion for 'projectDir' to enhance type safety and eliminate potential runtime errors.

classes/Controller/FrontController.php

@@ -13,6 +13,7 @@ use Alltube\Locale;
 use Alltube\Middleware\CspMiddleware;
 use Exception;
 use Graby\HttpClient\Plugin\ServerSideRequestForgeryProtection\Exception\InvalidURLException;
+use GrumPHP\Util\Str;
 use Slim\Http\StatusCode;
 use Slim\Http\Uri;
 use stdClass;
@@ -44,7 +45,12 @@ class FrontController extends BaseController
     {
         parent::__construct($container);
 
-        $this->view = $this->container->get('view');
+        $view = $this->container->get('view');
+        assert($view instanceof Smarty);
+        $this->view = $view;
+
+        // Plugins
+        $this->view->registerPlugin('modifier', 'filter_var', 'filter_var');
     }
 
     /**
@@ -226,6 +232,8 @@ class FrontController extends BaseController
         if (isset($this->video->thumbnail) && $this->video->thumbnail !== '') {
             /* Fetch the thumbnail */
             $thumbnailData = file_get_contents($this->video->thumbnail);
+
+            if ($thumbnailData !== false) {
                 $thumbnailData = base64_encode($thumbnailData);
                 /* Guess the mime type */
                 $thumbnailMime = 'image/jpeg';
@@ -240,6 +248,7 @@ class FrontController extends BaseController
 
                 $this->video->thumbnail = 'data:' . $thumbnailMime . ';base64,' . $thumbnailData;
             }
+        }
 
         $this->view->render(
             $response,
@@ -349,7 +358,11 @@ class FrontController extends BaseController
         $response = $cspMiddleware->applyHeader($response);
 
         if ($this->config->debug) {
-            $renderer = new HtmlErrorRenderer(true, null, null, $this->container->get('root_path'));
+            $projectDir = $this->container->get('root_path');
+
+            assert(is_string($projectDir) || is_null($projectDir));
+
+            $renderer = new HtmlErrorRenderer(true, null, null, $projectDir);
             $exception = $renderer->render($error);
 
             $response->getBody()->write($exception->getAsString());