Strict done!!

overlord/src/app/role/role-list/role-list.component.ts

@@ -15,8 +15,8 @@ import { RoleListDatasource } from './role-list-datasource';
 export class RoleListComponent implements OnInit {
   @ViewChild(MatPaginator, { static: true }) paginator?: MatPaginator;
   @ViewChild(MatSort, { static: true }) sort?: MatSort;
-  dataSource: RoleListDatasource;
-  list: Role[];
+  list: Role[] = [];
+  dataSource: RoleListDatasource = new RoleListDatasource(this.list);
   /** Columns displayed in the table. Columns IDs can be added, removed, or reordered. */
   displayedColumns = ['name', 'permissions'];
 
@@ -28,6 +28,6 @@ export class RoleListComponent implements OnInit {
 
       this.list = data.list;
     });
-    this.dataSource = new RoleListDatasource(this.paginator, this.sort, this.list);
+    this.dataSource = new RoleListDatasource(this.list, this.paginator, this.sort);
   }
 }