[Fix] Role Resource

- Added `Role::getObject` that returns an object instance of the model
- Refactored `Role::getModel` to return string similar to `Permission::getModel`

src/AttachToRole.php

@@ -24,7 +24,7 @@ class AttachToRole extends Action
      */
     public function handle(ActionFields $fields, Collection $models)
     {
-        $role = Role::getModel()->find($fields['role']);
+        $role = Role::getObject()->find($fields['role']);
         foreach ($models as $model) {
             $role->givePermissionTo($model);
         }
@@ -39,7 +39,7 @@ public function handle(ActionFields $fields, Collection $models)
     public function fields(NovaRequest $request)
     {
         return [
-            Select::make('Role')->options(Role::getModel()->get()->pluck('name', 'id')->toArray())->displayUsingLabels(),
+            Select::make('Role')->options(Role::getObject()->get()->pluck('name', 'id')->toArray())->displayUsingLabels(),
         ];
     }
 }

src/Permission.php

@@ -63,8 +63,10 @@ public function __construct($resource = null)
 
     /**
      * The model the resource corresponds to.
+     *
+     * @return string
      */
-    public static function getModel()
+    public static function getModel(): string
     {
         return app(PermissionRegistrar::class)->getPermissionClass();
     }

src/Role.php

@@ -63,12 +63,20 @@ public function __construct($resource = null)
 
     /**
      * The model the resource corresponds to.
+     *
+     * @return string
      */
-    public static function getModel()
+    public static function getModel(): string
     {
-        $object = app(PermissionRegistrar::class)->getRoleClass();
+        return app(PermissionRegistrar::class)->getRoleClass();
+    }
 
-        return \is_string($object) ? app($object) : $object;
+    /**
+     * An object instance of the model the resource corresponds to.
+     */
+    public static function getObject()
+    {
+        return app(static::getModel());
     }
 
     /**