Issue #3273017: Create a validator service for Extension update to confirm they were installed via Composer

automatic_updates_extensions/src/Validator/InstalledPackagesValidator.php

@@ -11,7 +11,7 @@ use Drupal\package_manager\Event\PreOperationStageEvent;
 use Symfony\Component\EventDispatcher\EventSubscriberInterface;
 
 /**
- *
+ * Validates packages installed through Automatic updates extensions.
  */
 class InstalledPackagesValidator implements EventSubscriberInterface {
 
@@ -46,6 +46,7 @@ class InstalledPackagesValidator implements EventSubscriberInterface {
       }
       else {
         $missing_packages = $stage->getStageComposer()->getPackagesNotIn($active_composer);
+        // Saving only the packages whose name starts with drupal/.
         $missing_packages = array_filter($missing_packages, function (string $key) {
           return strpos($key, 'drupal/') === 0;
         }, ARRAY_FILTER_USE_KEY);