test: add excluded subpath s3listresult as named parameter

Author: hahnandrew

packages/amplify_core/lib/src/types/storage/list_result.dart

@@ -9,14 +9,14 @@ import 'package:amplify_core/amplify_core.dart';
 class StorageListResult<Item extends StorageItem> {
   /// {@macro amplify_core.storage.list_result}
   const StorageListResult(
-    this.excludedSubpaths,
     this.items, {
+    this.excludedSubpaths,
     required this.hasNextPage,
     this.nextToken,
   });
 
   /// The subpaths that have been excluded
-  final List<String> excludedSubpaths;
+  final List<String>? excludedSubpaths;
 
   /// The objects listed in the current page.
   final List<Item> items;

packages/storage/amplify_storage_s3/example/integration_test/list_test.dart

@@ -84,8 +84,8 @@ void main() {
             expect(listResult.items.length, 3);
             expect(listResult.items.first.path, contains('file1.txt'));
 
-            expect(listResult.excludedSubpaths.length, 1);
-            expect(listResult.excludedSubpaths.first, '$uniquePrefix/subdir/');
+            expect(listResult.excludedSubpaths?.length, 1);
+            expect(listResult.excludedSubpaths?.first, '$uniquePrefix/subdir/');
             expect(listResult.metadata.delimiter, '/');
           });
 
@@ -101,9 +101,9 @@ void main() {
             expect(listResult.items.length, 3);
             expect(listResult.items.first.path, contains('file1.txt'));
 
-            expect(listResult.excludedSubpaths.length, 1);
+            expect(listResult.excludedSubpaths?.length, 1);
             expect(
-              listResult.excludedSubpaths.first,
+              listResult.excludedSubpaths?.first,
               '$uniquePrefix/subdir2#',
             );
             expect(listResult.metadata.delimiter, '#');

packages/storage/amplify_storage_s3_dart/lib/src/model/s3_list_result.dart

@@ -39,8 +39,8 @@ class S3ListResult extends StorageListResult<S3Item> {
     final items = output.contents?.map(S3Item.fromS3Object).toList();
 
     return S3ListResult(
-      subPaths ?? <String>[],
       items ?? const <S3Item>[],
+      excludedSubpaths: subPaths ?? <String>[],
       hasNextPage: paginatedResult.hasNext,
       nextToken: paginatedResult.nextContinuationToken,
       metadata: metadata,
@@ -52,13 +52,13 @@ class S3ListResult extends StorageListResult<S3Item> {
     final items = <S3Item>[...this.items, ...other.items];
 
     final mergedSubPaths = <String>[
-      ...excludedSubpaths,
-      ...other.excludedSubpaths,
+      ...excludedSubpaths ?? <String>[],
+      ...other.excludedSubpaths ?? <String>[],
     ];
 
     return S3ListResult(
-      mergedSubPaths,
       items,
+      excludedSubpaths: mergedSubPaths,
       hasNextPage: other.hasNextPage,
       nextToken: other.nextToken,
       metadata: metadata,

packages/storage/amplify_storage_s3_dart/test/amplify_storage_s3_dart_test.dart

@@ -86,8 +86,8 @@ void main() {
     group('list()', () {
       const testPath = StoragePath.fromString('some/path');
       final testResult = S3ListResult(
-        <String>[],
         <S3Item>[],
+        excludedSubpaths: <String>[],
         hasNextPage: false,
         metadata: S3ListMetadata.fromDelimiter(),
       );