Symfony: Service auto registration

AppExtension.php

<?php

namespace App\DependencyInjection;

use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\HttpKernel\DependencyInjection\Extension;
use Symfony\Component\Finder\Finder;

class AppExtension extends Extension
{
    public function load(array $configs, ContainerBuilder $container)
    {
        $this->registerServicesIn([
            __DIR__ . '/../Http/Transformer'
        ]);
    }
    
    private function registerServicesIn(array $paths)
    {
        $files = $this->collectServiceDefinitions($paths);

        $unregisteredClasses = $this->getUnregisteredClasses($container);
        $services = array_intersect_key($unregisteredClasses, array_flip($files));

        $this->registerServices($services, $container);
    }

    private function registerServices(array $services, ContainerBuilder $container)
    {
        foreach ($services as $className) {
            if ($container->has($className)) {
                continue;
            }

            $container
                ->register($className, $className)
                ->setAutowired(true);
        }
    }

    private function collectServiceDefinitions(array $paths)
    {
        $finder = new Finder();
        $finder->files()->in($paths)->files()->name('*.php');

        $files = [];
        foreach ($finder as $file) {
            $file = realpath($file);

            require_once $file;

            $files[] = $file;
        }

        return $files;
    }

    /**
     * @param ContainerBuilder $container
     * @return \ReflectionClass[]
     */
    private function getUnregisteredClasses(ContainerBuilder $container)
    {
        $definitions = $container->getDefinitions();

        $registeredClasses = [];
        foreach ($definitions as $id => $definition) {
            $registeredClasses[] = $definition->getClass();
        }

        $declaredClasses = get_declared_classes();
        $unregisteredClasses = array_diff($declaredClasses, $registeredClasses);

        $keys = array_map(function ($className) {
            return (new \ReflectionClass($className))->getFileName();
        }, $unregisteredClasses);

        return array_combine($keys, $unregisteredClasses);
    }
}

TODO:

• Register all classes defined by given paths as services + autowring
• Skip if there is any services with given class name of resolved classes
• Skip Exceptions?
• Configurable list of excluded paths.