Fix test.

components/grouping.test.ts

@@ -1,7 +1,7 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT License.
 
-import {generateGroups, sortItems, generateItems} from './grouping.ts'
+import {generateGroups, sortItems, generateItems} from './grouping'
 
 test('groups', () => {
 	const results = [