Issue #3271144: Ensure new, changed or deleted service definitions are in the correct state after an update

package_manager/tests/modules/package_manager_test_api/src/SystemChangeRecorder.php

@@ -97,36 +97,35 @@ class SystemChangeRecorder implements EventSubscriberInterface {
     // Check if a permission added in the updated module is available.
     $results['new permission exists'] = array_key_exists('added permission', $permissions) ? 'exists' : 'not exists';
 
-    // Check if changes to an existing service are picked up. The service itself
-    // is defined in updated_module, which is not, and should not be, a hard
-    // dependency of package_manager_test_api. So, we use ::hasService() to
-    // prevent an exception if updated_module is not installed.
-    if (\Drupal::hasService('updated_module.existing_service')) {
-      $results['value of existing service'] = \Drupal::service('updated_module.existing_service')->value;
-    }
-
+    // Check if changes to an existing service are picked up.
+    $this->recordServiceValue('updated_module.existing_service', $results);
     // Check if a service removed from the updated module is available.
-    if (\Drupal::service('updated_module.deleted_service')) {
-      $results['deleted service exists'] = 'exists';
-      $results['value of deleted service'] = \Drupal::service('updated_module.deleted_service')->value;
-    }
-    else {
-      $results['deleted service exists'] = 'not exists';
-    }
-
+    $this->recordServiceValue('updated_module.deleted_service', $results);
     // Check if a service added in the updated module is available.
-    if (\Drupal::hasService('updated_module.added_service')) {
-      $results['new service exists'] = 'exists';
-      $results['value of added service'] = \Drupal::service('updated_module.added_service')->value;
-    }
-    else {
-      $results['new service exists'] = 'not exists';
-    }
+    $this->recordServiceValue('updated_module.added_service', $results);
 
     $phase = $event instanceof PreApplyEvent ? 'pre' : 'post';
     $this->state->set("system_changes:$phase", $results);
   }
 
+  /**
+   * Checks if a given service exists, and records its ->value property.
+   *
+   * @param string $service_id
+   *   The ID of the service to check.
+   * @param array $results
+   *   The current set of results, passed by reference.
+   */
+  private function recordServiceValue(string $service_id, array &$results): void {
+    if (\Drupal::hasService($service_id)) {
+      $results["$service_id exists"] = 'exists';
+      $results["value of $service_id"] = \Drupal::service($service_id)->value;
+    }
+    else {
+      $results["$service_id exists"] = 'not exists';
+    }
+  }
+
   /**
    * Writes the results of ::recordSystemState() to file.
    *