Fix issue of callAdapter using yield/return incorrectly (#739)

* fix bug of using yield in place of return in certain cases

* fix test

---------

Co-authored-by: Trevor Wang <trevor.wang@qq.com>

generator/CHANGELOG.md

@@ -1,6 +1,7 @@
 
 ## 9.1.8
 
+- Fixed bug of callAdapter using yield/return incorrectly
 - Fixed issue which generated invalid code for the same path parameter appears multiple times.
 
   Example:
@@ -40,7 +41,7 @@
 
     @UseCallAdapter(MyCallAdapter)
     @GET('/')
-    Future<User> getTasks();
+    Future<Either<ApiError, User>> getTasks();
   }
 ```
 

generator/lib/src/generator.dart

@@ -626,8 +626,16 @@ class RetrofitGenerator extends GeneratorForAnnotation<retrofit.RestApi> {
     ConstantReader httpMethod,
     InterfaceType? callAdapter,
   ) {
-    final returnAsyncWrapper =
+    String returnAsyncWrapper =
         m.returnType.isDartAsyncFuture ? 'return' : 'yield';
+    if (callAdapter != null) {
+      final callAdapterOriginalReturnType = callAdapter.superclass
+        ?.typeArguments.firstOrNull as InterfaceType?;
+      returnAsyncWrapper = _isReturnTypeFuture(
+              callAdapterOriginalReturnType?.getDisplayString() ?? '')
+          ? 'return'
+          : 'yield';
+    }
     final path = _generatePath(m, httpMethod);
     final blocks = <Code>[];
 

generator/pubspec.yaml

@@ -8,7 +8,7 @@ topics:
   - rest
   - retrofit
   - codegen
-version: 9.1.6
+version: 9.1.8
 environment:
   sdk: '>=3.3.0 <4.0.0'
 

generator/test/src/generator_test_src.dart

@@ -65,10 +65,31 @@ class MockCallAdapter3<T> extends CallAdapter<Future<T>, Flow<T>> {
 }
 
 @ShouldGenerate(
-  '''
-  @override
-  Flow<User> getUser() {
-    return MockCallAdapter3<User>().adapt(() => _getUser());
+'''
+  Future<User> _getUser() async {
+    final _extra = <String, dynamic>{};
+    final queryParameters = <String, dynamic>{};
+    final _headers = <String, dynamic>{};
+    const Map<String, dynamic>? _data = null;
+    final _options = _setStreamType<User>(
+      Options(method: 'GET', headers: _headers, extra: _extra)
+          .compose(
+            _dio.options,
+            'path',
+            queryParameters: queryParameters,
+            data: _data,
+          )
+          .copyWith(baseUrl: _combineBaseUrls(_dio.options.baseUrl, baseUrl)),
+    );
+    final _result = await _dio.fetch<Map<String, dynamic>>(_options);
+    late User _value;
+    try {
+      _value = User.fromJson(_result.data!);
+    } on Object catch (e, s) {
+      errorLogger?.logError(e, s, _options);
+      rethrow;
+    }
+    return _value;
   }
 ''',
   contains: true,