chore: move delimiter to S3ListPluginOptions

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

@@ -19,6 +19,7 @@ void main() {
       '$uniquePrefix/file1.txt',
       '$uniquePrefix/file2.txt',
       '$uniquePrefix/subdir/file3.txt',
+      '$uniquePrefix/subdir2#file4.txt',
     ];
     group('standard config', () {
       setUpAll(() async {
@@ -70,20 +71,46 @@ void main() {
       });
 
       group('list() with options', () {
-        testWidgets(
-            'should list all files with unique prefix excluding subPaths',
-            (_) async {
-          final listResult = await Amplify.Storage.list(
-            path: StoragePath.fromString('$uniquePrefix/'),
-            options: const StorageListOptions(
-              pluginOptions: S3ListPluginOptions(
-                excludeSubPaths: true,
+        group('excluding sub paths', () {
+          testWidgets('default delimiter', (_) async {
+            final listResult = await Amplify.Storage.list(
+              path: StoragePath.fromString('$uniquePrefix/'),
+              options: const StorageListOptions(
+                pluginOptions: S3ListPluginOptions(
+                  excludeSubPaths: true,
+                ),
               ),
-            ),
-          ).result;
+            ).result as S3ListResult;
+
+            expect(listResult.items.length, 3);
+            expect(listResult.items.first.path, contains('file1.txt'));
+
+            expect(listResult.metadata.subPaths.length, 1);
+            expect(listResult.metadata.subPaths.first, '$uniquePrefix/subdir/');
+            expect(listResult.metadata.delimiter, '/');
+          });
+
+          testWidgets('custom delimiter', (_) async {
+            final listResult = await Amplify.Storage.list(
+              path: StoragePath.fromString('$uniquePrefix/'),
+              options: const StorageListOptions(
+                pluginOptions: S3ListPluginOptions(
+                  excludeSubPaths: true,
+                  delimiter: '#',
+                ),
+              ),
+            ).result as S3ListResult;
 
-          expect(listResult.items.length, 2);
-          expect(listResult.items.first.path, contains('file1.txt'));
+            expect(listResult.items.length, 3);
+            expect(listResult.items.first.path, contains('file1.txt'));
+
+            expect(listResult.metadata.subPaths.length, 1);
+            expect(
+              listResult.metadata.subPaths.first,
+              '$uniquePrefix/subdir2#',
+            );
+            expect(listResult.metadata.delimiter, '#');
+          });
         });
 
         testWidgets('should respect pageSize limitation', (_) async {
@@ -130,7 +157,7 @@ void main() {
             ),
           ).result;
 
-          expect(listResult.items.length, 3);
+          expect(listResult.items.length, uploadedPaths.length);
           expect(listResult.nextToken, isNull);
         });
       });

packages/storage/amplify_storage_s3/lib/src/amplify_storage_s3_impl.dart

@@ -12,9 +12,7 @@ import 'package:amplify_storage_s3_dart/amplify_storage_s3_dart.dart';
 /// {@endtemplate}
 class AmplifyStorageS3 extends AmplifyStorageS3Dart {
   /// {@macro amplify_storage_s3_.amplify_storage_s3_plugin}
-  AmplifyStorageS3({
-    super.delimiter,
-  });
+  AmplifyStorageS3();
 
   /// A plugin key which can be used with `Amplify.Storage.getPlugin` to retrieve
   /// a S3-specific Storage category interface.

packages/storage/amplify_storage_s3_dart/lib/src/amplify_storage_s3_dart_impl.dart

@@ -30,10 +30,8 @@ class AmplifyStorageS3Dart extends StoragePluginInterface
     with AWSDebuggable, AWSLoggerMixin {
   /// {@macro amplify_storage_s3_dart.amplify_storage_s3_plugin_dart}
   AmplifyStorageS3Dart({
-    String? delimiter,
     @visibleForTesting DependencyManager? dependencyManagerOverride,
-  })  : _delimiter = delimiter,
-        _dependencyManagerOverride = dependencyManagerOverride;
+  }) : _dependencyManagerOverride = dependencyManagerOverride;
 
   /// {@template amplify_storage_s3_dart.plugin_key}
   /// A plugin key which can be used with `Amplify.Storage.getPlugin` to retrieve
@@ -42,8 +40,6 @@ class AmplifyStorageS3Dart extends StoragePluginInterface
   static const StoragePluginKey<AmplifyStorageS3Dart> pluginKey =
       _AmplifyStorageS3DartPluginKey();
 
-  final String? _delimiter;
-
   final DependencyManager? _dependencyManagerOverride;
 
   @override
@@ -112,7 +108,6 @@ class AmplifyStorageS3Dart extends StoragePluginInterface
         StorageS3Service(
           credentialsProvider: credentialsProvider,
           s3PluginConfig: s3PluginConfig,
-          delimiter: _delimiter,
           pathResolver: _pathResolver,
           logger: logger,
           dependencyManager: dependencies,

packages/storage/amplify_storage_s3_dart/lib/src/model/s3_list_plugin_options.dart

@@ -13,12 +13,15 @@ class S3ListPluginOptions extends StorageListPluginOptions {
   /// {@macro storage.amplify_storage_s3.list_plugin_options}
   const S3ListPluginOptions({
     bool excludeSubPaths = false,
+    String delimiter = '/',
   }) : this._(
           excludeSubPaths: excludeSubPaths,
+          delimiter: delimiter,
         );
 
   const S3ListPluginOptions._({
     this.excludeSubPaths = false,
+    this.delimiter = '/',
     this.listAll = false,
   });
 
@@ -40,6 +43,10 @@ class S3ListPluginOptions extends StorageListPluginOptions {
   /// default value is `false`.
   final bool excludeSubPaths;
 
+  /// The delimiter to use when evaluating sub paths. If [excludeSubPaths] is
+  /// false, this value has no impact on behavior.
+  final String delimiter;
+
   /// Whether to list all objects under a given path without pagination. The
   /// default value is `false`.
   ///

packages/storage/amplify_storage_s3_dart/lib/src/storage_s3_service/service/storage_s3_service_impl.dart

@@ -36,7 +36,6 @@ class StorageS3Service {
     required AWSIamAmplifyAuthProvider credentialsProvider,
     required AWSLogger logger,
     required DependencyManager dependencyManager,
-    String? delimiter,
   }) {
     final usePathStyle = s3PluginConfig.bucket.contains('.');
 
@@ -61,7 +60,6 @@ class StorageS3Service {
       credentialsProvider: credentialsProvider,
       logger: logger,
       dependencyManager: dependencyManager,
-      delimiter: delimiter,
     );
   }
 
@@ -72,9 +70,7 @@ class StorageS3Service {
     required AWSIamAmplifyAuthProvider credentialsProvider,
     required AWSLogger logger,
     required DependencyManager dependencyManager,
-    String? delimiter,
   })  : _s3PluginConfig = s3PluginConfig,
-        _delimiter = delimiter ?? '/',
         _defaultS3ClientConfig = s3ClientConfig,
         // dependencyManager.get() => S3Client is used for unit tests
         _defaultS3Client = dependencyManager.get() ??
@@ -99,7 +95,6 @@ class StorageS3Service {
       sigv4.S3ServiceConfiguration(signPayload: false);
 
   final S3PluginConfig _s3PluginConfig;
-  final String _delimiter;
   final smithy_aws.S3ClientConfig _defaultS3ClientConfig;
   final s3.S3Client _defaultS3Client;
   final S3PathResolver _pathResolver;
@@ -141,7 +136,9 @@ class StorageS3Service {
           ..prefix = resolvedPath
           ..maxKeys = options.pageSize
           ..continuationToken = options.nextToken
-          ..delimiter = s3PluginOptions.excludeSubPaths ? _delimiter : null;
+          ..delimiter = s3PluginOptions.excludeSubPaths
+              ? s3PluginOptions.delimiter
+              : null;
       });
 
       try {
@@ -164,7 +161,9 @@ class StorageS3Service {
         builder
           ..bucket = _s3PluginConfig.bucket
           ..prefix = resolvedPath
-          ..delimiter = s3PluginOptions.excludeSubPaths ? _delimiter : null;
+          ..delimiter = s3PluginOptions.excludeSubPaths
+              ? s3PluginOptions.delimiter
+              : null;
       });
 
       listResult = await _defaultS3Client.listObjectsV2(request).result;