Change variable names and add tests.

src/GroupServiceProvider.php

@@ -31,7 +31,7 @@ class GroupServiceProvider extends ServiceProviderBase {
       []
     );
 
-    $handlers = [
+    $handler_info = [
       'access_control' => 'Drupal\group\Plugin\Group\RelationHandler\EmptyAccessControl',
       'entity_reference' => 'Drupal\group\Plugin\Group\RelationHandler\EmptyEntityReference',
       'operation_provider' => 'Drupal\group\Plugin\Group\RelationHandler\EmptyOperationProvider',
@@ -41,10 +41,10 @@ class GroupServiceProvider extends ServiceProviderBase {
     ];
 
     // Keep track of which services are expected to be decorated.
-    $decoratable_service_ids = array_map(fn($handler) => "group.relation_handler.$handler", array_keys($handlers));
+    $decoratable_service_ids = array_map(fn($handler_id) => "group.relation_handler.$handler_id", array_keys($handler_info));
 
     // Keep track of the services that represent each relation type's handlers.
-    $services = [];
+    $handlers = [];
     foreach ($discovery->getDefinitions() as $group_relation_type_id => $group_relation_type) {
       assert($group_relation_type instanceof GroupRelationTypeInterface);
       // Skip plugins that whose provider is not installed.
@@ -52,28 +52,28 @@ class GroupServiceProvider extends ServiceProviderBase {
         continue;
       }
 
-      foreach ($handlers as $handler => $handler_class) {
-        $service_name = "group.relation_handler.$handler.$group_relation_type_id";
+      foreach ($handler_info as $handler_id => $handler_class) {
+        $service_name = "group.relation_handler.$handler_id.$group_relation_type_id";
         $decoratable_service_ids[] = $service_name;
 
         // Either get the existing service or define it and pass it the default
         // one to decorate.
         $definition = $container->has($service_name)
           ? $container->getDefinition($service_name)
-          : new Definition($handler_class, [new Reference("group.relation_handler.$handler")]);
+          : new Definition($handler_class, [new Reference("group.relation_handler.$handler_id")]);
 
         // All handlers must be public and cannot be shared.
         $definition->setPublic(TRUE);
         $definition->setShared(FALSE);
         $container->setDefinition($service_name, $definition);
 
-        $services[$service_name] = new Reference($service_name);
+        $handlers[$service_name] = new Reference($service_name);
       }
     }
 
-    // Add the services to the relation type manager using a service locator.
+    // Add the handlers to the relation type manager using a service locator.
     $manager = $container->getDefinition('group_relation_type.manager');
-    $manager->addArgument(ServiceLocatorTagPass::register($container, $services));
+    $manager->addArgument(ServiceLocatorTagPass::register($container, $handlers));
 
     // Set the shared flag to FALSE for any service that decorates a base
     // handler or a relation type specific handler. This is a quality-of-life

tests/src/Kernel/RelationHandlerTest.php

@@ -55,4 +55,12 @@ class RelationHandlerTest extends GroupKernelTestBase {
     $this->assertSame($expected, $relation_manager->getPermissionProvider('entity_test_relation')->getAdminPermission(), $message);
   }
 
+  /**
+   * Tests that decorators are automatically set as non-shared services.
+   */
+  public function testDecoratorNotShared() {
+    $this->assertFalse($this->container->getDefinition('group.relation_handler_decorator.permission_provider.bar')->isShared());
+    $this->assertFalse($this->container->getDefinition('group.relation_handler_decorator.permission_provider.baz.node_relation')->isShared());
+  }
+
 }