Issue #3275317 by phenaproxima: If you change the path to the Composer...

Issue #3275317 by phenaproxima: If you change the path to the Composer executable, you may still see out-of-date validation errors

automatic_updates.services.yml

@@ -137,3 +137,7 @@ services:
     class: Drupal\automatic_updates\Validator\UpdateReleaseValidator
     tags:
       - { name: event_subscriber }
+  automatic_updates.config_subscriber:
+    class: Drupal\automatic_updates\EventSubscriber\ConfigSubscriber
+    tags:
+      - { name: event_subscriber }

src/EventSubscriber/ConfigSubscriber.php

+<?php
+
+namespace Drupal\automatic_updates\EventSubscriber;
+
+use Drupal\Core\Config\ConfigCrudEvent;
+use Drupal\Core\Config\ConfigEvents;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Clears stored validation results after certain config changes.
+ *
+ * @todo Move this functionality into ReadinessValidationManager when
+ *   https://www.drupal.org/i/3275317#comment-14482995 is resolved.
+ */
+class ConfigSubscriber implements EventSubscriberInterface {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents() {
+    return [
+      ConfigEvents::SAVE => 'onConfigSave',
+    ];
+  }
+
+  /**
+   * Reacts when config is saved.
+   *
+   * @param \Drupal\Core\Config\ConfigCrudEvent $event
+   *   The event object.
+   */
+  public function onConfigSave(ConfigCrudEvent $event): void {
+    if ($event->getConfig()->getName() === 'package_manager.settings' && $event->isChanged('executables.composer')) {
+      \Drupal::service('automatic_updates.readiness_validation_manager')
+        ->clearStoredResults();
+    }
+  }
+
+}

tests/src/Kernel/ReadinessValidation/ReadinessValidationManagerTest.php

@@ -253,4 +253,27 @@ class ReadinessValidationManagerTest extends AutomaticUpdatesKernelTestBase {
     $this->assertEmpty($manager->getResults());
   }
 
+  /**
+   * Tests that certain config changes clear stored results.
+   */
+  public function testStoredResultsClearedOnConfigChanges(): void {
+    $this->enableModules(['automatic_updates']);
+
+    $results = $this->testResults['checker_1']['1 error'];
+    TestSubscriber1::setTestResult($results, ReadinessCheckEvent::class);
+    $this->assertCheckerResultsFromManager($results, TRUE);
+    // The results should be stored.
+    $this->assertCheckerResultsFromManager($results, FALSE);
+    // Changing the configured path to rsync should not clear the results.
+    $this->config('package_manager.settings')
+      ->set('executables.rsync', '/path/to/rsync')
+      ->save();
+    $this->assertCheckerResultsFromManager($results, FALSE);
+    // Changing the configured path to Composer should clear the results.
+    $this->config('package_manager.settings')
+      ->set('executables.composer', '/path/to/composer')
+      ->save();
+    $this->assertNull($this->getResultsFromManager(FALSE));
+  }
+
 }