Symfony version(s) affected

6.0.4

Description

AnnotationDirectoryLoader::load() has a return type RouteCollection, but it may return null in some situations

Because it calls parent::load(), which is AnnotationFileLoader::load(), which has return type ?RouteCollection

How to reproduce

1. have an abstract class that extends \Symfony\Bundle\FrameworkBundle\Controller\AbstractController (e.g. abstract class AdminController extends AbstractController)
2. have config/routes/annotations.yaml similar to:

controllers:
    resource: '../../src/**/*Controller.php'
    type: annotation

kernel:
    resource: ../../src/Kernel.php
    type: annotation

3. upgrade from 5.4.4 to 6.0.4
4. Symfony\Component\Routing\Loader\AnnotationDirectoryLoader::load(): Return value must be of type Symfony\Component\Routing\RouteCollection, null returned

Possible Solution

Change the return type of AnnotationDirectoryLoader::load() to ?RouteCollection

Additional Context

No response