Added error handling for loading config files from installed packages (#262)

[TASK] Throw Exception if config files from installed packages cannot be loaded

Author: RKlingler

packages/fractor/src/DependencyInjection/ContainerContainerBuilder.php

@@ -4,6 +4,7 @@
 
 namespace a9f\Fractor\DependencyInjection;
 
+use a9f\Fractor\Exception\ShouldNotHappenException;
 use a9f\FractorExtensionInstaller\Generated\InstalledPackages;
 use Symfony\Component\Config\FileLocator;
 use Symfony\Component\Console\DependencyInjection\AddConsoleCommandPass;
@@ -60,7 +61,16 @@ private function collectConfigFilesFromExtensions(): array
         }
 
         foreach (InstalledPackages::PACKAGES as $package) {
-            $collectedConfigFiles[] = $package['path'] . '/config/application.php';
+            $configPath = $package['path'] . '/config/application.php';
+
+            if (! is_readable($configPath)) {
+                throw new ShouldNotHappenException(sprintf(
+                    'Config file "%s" is not readable or does not exist.',
+                    $configPath
+                ));
+            }
+
+            $collectedConfigFiles[] = $configPath;
         }
 
         return $collectedConfigFiles;