🐛 Applies strict type conversion for finalizing the multipart file

dio/CHANGELOG.md

@@ -8,6 +8,7 @@ See the [Migration Guide][] for the complete breaking changes list.**
 - Raise the min Dart SDK version to 2.18.0.
 - Add constructor for `DioExceptionType.badCertificate`.
 - Create type alias `DioMediaType` for `http_parser`'s `MediaType`.
+- Fix the type conversion regression when using `MultipartFile.fromBytes`.
 
 ## 5.4.3+1
 

dio/lib/src/form_data.dart

@@ -1,7 +1,7 @@
 import 'dart:async';
 import 'dart:convert';
 import 'dart:math' as math;
-import 'dart:typed_data';
+import 'dart:typed_data' show Uint8List;
 
 import 'multipart_file.dart';
 import 'options.dart';
@@ -188,7 +188,7 @@ class FormData {
       for (final file in files) {
         writeUtf8('--$boundary$_rn');
         writeUtf8(_headerForFile(file));
-        await writeStreamToSink(file.value.finalize(), controller);
+        await writeStreamToSink<Uint8List>(file.value.finalize(), controller);
         writeLine();
       }
     }).then((_) {

dio/lib/src/multipart_file.dart

@@ -1,7 +1,7 @@
-import 'dart:async';
-import 'dart:convert';
+import 'dart:convert' show utf8;
+import 'dart:typed_data' show Uint8List;
 
-import 'package:http_parser/http_parser.dart';
+import 'package:http_parser/http_parser.dart' show MediaType;
 
 import 'multipart_file/io_multipart_file.dart'
     if (dart.library.html) 'multipart_file/browser_multipart_file.dart';
@@ -32,7 +32,7 @@ class MultipartFile {
     this.filename,
     DioMediaType? contentType,
     Map<String, List<String>>? headers,
-  })  : _data = (() => stream),
+  })  : _dataBuilder = (() => stream),
         headers = caseInsensitiveKeyMap(headers),
         contentType = contentType ?? MediaType('application', 'octet-stream');
 
@@ -48,7 +48,7 @@ class MultipartFile {
     this.filename,
     DioMediaType? contentType,
     Map<String, List<String>>? headers,
-  })  : _data = data,
+  })  : _dataBuilder = data,
         headers = caseInsensitiveKeyMap(headers),
         contentType = contentType ?? MediaType('application', 'octet-stream');
 
@@ -112,7 +112,7 @@ class MultipartFile {
   final DioMediaType? contentType;
 
   /// The stream builder that will emit the file's contents for every call.
-  final Stream<List<int>> Function() _data;
+  final Stream<List<int>> Function() _dataBuilder;
 
   /// Whether [finalize] has been called.
   bool get isFinalized => _isFinalized;
@@ -153,7 +153,7 @@ class MultipartFile {
 
   bool _isFinalized = false;
 
-  Stream<List<int>> finalize() {
+  Stream<Uint8List> finalize() {
     if (isFinalized) {
       throw StateError(
         'The MultipartFile has already been finalized. '
@@ -162,15 +162,16 @@ class MultipartFile {
       );
     }
     _isFinalized = true;
-    return _data.call();
+    return _dataBuilder()
+        .map((e) => e is Uint8List ? e : Uint8List.fromList(e));
   }
 
   /// Clone MultipartFile, returning a new instance of the same object.
   /// This is useful if your request failed and you wish to retry it,
   /// such as an unauthorized exception can be solved by refreshing the token.
   MultipartFile clone() {
     return MultipartFile.fromStream(
-      _data,
+      _dataBuilder,
       length,
       filename: filename,
       contentType: contentType,

dio/lib/src/utils.dart

@@ -21,8 +21,8 @@ const kReleaseMode = bool.fromEnvironment('dart.vm.product');
 /// Pipes all data and errors from [stream] into [sink]. Completes [Future] once
 /// [stream] is done. Unlike [store], [sink] remains open after [stream] is
 /// done.
-Future writeStreamToSink(Stream stream, EventSink sink) {
-  final completer = Completer();
+Future<void> writeStreamToSink<T>(Stream<T> stream, EventSink<T> sink) {
+  final completer = Completer<void>();
   stream.listen(
     sink.add,
     onError: sink.addError,

dio/test/formdata_test.dart

@@ -37,6 +37,14 @@ void main() async {
               },
               contentType: DioMediaType.parse('text/plain'),
             ),
+            MultipartFile.fromBytes(
+              utf8.encode('hello world again.').toList(),
+              filename: '3.txt',
+              headers: {
+                'test': <String>['d'],
+              },
+              contentType: DioMediaType.parse('text/plain'),
+            ),
           ],
         });
         final fmStr = await fm.readAsBytes();
@@ -91,6 +99,19 @@ void main() async {
             ),
           ),
         );
+        fm1.files.add(
+          MapEntry(
+            'files',
+            MultipartFile.fromBytes(
+              utf8.encode('hello world again.'),
+              filename: '3.txt',
+              headers: {
+                'test': <String>['d'],
+              },
+              contentType: DioMediaType.parse('text/plain'),
+            ),
+          ),
+        );
         expect(fmStr.length, fm1.length);
       },
       testOn: 'vm',
@@ -125,6 +146,14 @@ void main() async {
               },
               contentType: DioMediaType.parse('text/plain'),
             ),
+            MultipartFile.fromBytes(
+              utf8.encode('hello world again.'),
+              filename: '3.txt',
+              headers: {
+                'test': <String>['d'],
+              },
+              contentType: DioMediaType.parse('text/plain'),
+            ),
           ],
         });
         final fmStr = await fm.readAsBytes();

dio/test/mock/_formdata

@@ -34,4 +34,10 @@ test: c
 我很好人类
 哈哈哈哈哈😆
 
+----dio-boundary-3788753558
+content-disposition: form-data; name="files"; filename="3.txt"
+content-type: text/plain
+test: d
+
+hello world again.
 ----dio-boundary-3788753558--

dio_test/lib/src/test/download_tests.dart

@@ -64,7 +64,7 @@ void downloadTests(
           cancelToken.cancel();
         });
 
-        final completer = Completer();
+        final completer = Completer<Never>();
         res.data!.stream.listen(
           (event) {},
           onError: (e, s) {