Fix generic argument factories support (#643)

* Don't shorten "annotation"

* Support generic argument factories irrespective of `@JsonSerializable` annotations

generator/CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## 8.0.3
+
+- fix [#627](https://github.com/trevorwang/retrofit.dart/issues/627) where generic argument constructors on any class not directly marked with `@JsonSerializable(genericArgumentFactories: true)`
+
+- fix some typos in this changelog.
+
 ## 8.0.2
 
 - fix #630 Null check operator used on a null value
@@ -123,7 +129,7 @@
 
 ## 2.0.0-beta1
 
-- Nullsafety support
+- Null safety support
 
 ## 1.4.1
 
@@ -135,7 +141,7 @@
 
 ## 1.3.8
 
-- Send list params duplicative in multipart
+- Send list params duplication in multipart
 
 ## 1.3.7
 
@@ -190,7 +196,7 @@
 
 ## 1.2.0
 
-- Add `HttpReposne` to handle the original response
+- Add `HttpResponse` to handle the original response
 
 ## 1.1.0
 
@@ -253,11 +259,11 @@ Added bean class support for `@Body()` annotation.
 
 Here's the example.
 
-```
+```dart
     Future<String> createUser(@Body() User user);
 ```
 
-```
+```dart
     class User {
         Map<String, dynamic> toJson() => {};
     }

generator/lib/src/generator.dart

@@ -10,10 +10,10 @@ import 'package:built_collection/built_collection.dart';
 import 'package:code_builder/code_builder.dart';
 import 'package:dart_style/dart_style.dart';
 import 'package:dio/dio.dart';
+import 'package:protobuf/protobuf.dart';
 import 'package:retrofit/retrofit.dart' as retrofit;
 import 'package:source_gen/source_gen.dart';
 import 'package:tuple/tuple.dart';
-import 'package:protobuf/protobuf.dart';
 
 const _analyzerIgnores =
     '// ignore_for_file: unnecessary_brace_in_string_interps,no_leading_underscores_for_local_identifiers';
@@ -93,20 +93,20 @@ class RetrofitGenerator extends GeneratorForAnnotation<retrofit.RestApi> {
       parser: parser ?? retrofit.Parser.JsonSerializable,
     );
     final baseUrl = clientAnnotation.baseUrl;
-    final annotClassConsts = element.constructors
+    final annotateClassConsts = element.constructors
         .where((c) => !c.isFactory && !c.isDefaultConstructor);
     final classBuilder = Class((c) {
       c
         ..name = className
         ..types.addAll(element.typeParameters.map((e) => refer(e.name)))
         ..fields.addAll([_buildDioFiled(), _buildBaseUrlFiled(baseUrl)])
         ..constructors.addAll(
-          annotClassConsts.map(
+          annotateClassConsts.map(
             (e) => _generateConstructor(baseUrl, superClassConst: e),
           ),
         )
         ..methods.addAll(_parseMethods(element));
-      if (annotClassConsts.isEmpty) {
+      if (annotateClassConsts.isEmpty) {
         c.constructors.add(_generateConstructor(baseUrl));
         c.implements.add(refer(_generateTypeParameterizedName(element)));
       } else {
@@ -205,8 +205,8 @@ class RetrofitGenerator extends GeneratorForAnnotation<retrofit.RestApi> {
         ...element.methods,
         ...element.mixins.expand((i) => i.methods)
       ].where((m) {
-        final methodAnnot = _getMethodAnnotation(m);
-        return methodAnnot != null &&
+        final methodAnnotation = _getMethodAnnotation(m);
+        return methodAnnotation != null &&
             m.isAbstract &&
             (m.returnType.isDartAsyncFuture || m.returnType.isDartAsyncStream);
       }).map((m) => _generateMethod(m)!);
@@ -232,19 +232,19 @@ class RetrofitGenerator extends GeneratorForAnnotation<retrofit.RestApi> {
 
   ConstantReader? _getMethodAnnotation(MethodElement method) {
     for (final type in _methodsAnnotations) {
-      final annot = _getMethodAnnotationByType(method, type);
-      if (annot != null) {
-        return annot;
+      final annotation = _getMethodAnnotationByType(method, type);
+      if (annotation != null) {
+        return annotation;
       }
     }
     return null;
   }
 
   ConstantReader? _getMethodAnnotationByType(MethodElement method, Type type) {
-    final annot =
+    final annotation =
         _typeChecker(type).firstAnnotationOf(method, throwOnUnresolved: false);
-    if (annot != null) {
-      return ConstantReader(annot);
+    if (annotation != null) {
+      return ConstantReader(annotation);
     }
     return null;
   }
@@ -286,14 +286,14 @@ class RetrofitGenerator extends GeneratorForAnnotation<retrofit.RestApi> {
     MethodElement m,
     Type type,
   ) {
-    final annot = <ParameterElement, ConstantReader>{};
+    final annotation = <ParameterElement, ConstantReader>{};
     for (final p in m.parameters) {
       final a = _typeChecker(type).firstAnnotationOf(p);
       if (a != null) {
-        annot[p] = ConstantReader(a);
+        annotation[p] = ConstantReader(a);
       }
     }
-    return annot;
+    return annotation;
   }
 
   Tuple2<ParameterElement, ConstantReader>? _getAnnotation(
@@ -980,7 +980,38 @@ You should create a new class to encapsulate the response.
       } catch (_) {}
     }
 
-    return genericArgumentFactories;
+    return genericArgumentFactories ||
+        hasGenericArgumentFactoriesCompatibleSignature(dartType);
+  }
+
+  /// Checks for a compatible fromJson signature for generic argument factories
+  // TODO: But does the code work with multiple generic types?
+  bool hasGenericArgumentFactoriesCompatibleSignature(DartType? dartType) {
+    if (dartType == null) return false;
+    final element = dartType.element;
+    if (element is! InterfaceElement) return false;
+
+    final typeParameters = element.typeParameters;
+    if (typeParameters.isEmpty) return false;
+
+    final constructors = element.constructors;
+    if (constructors.isEmpty) return false;
+    final fromJson = constructors
+        .firstWhereOrNull((constructor) => constructor.name == 'fromJson');
+
+    if (fromJson == null || fromJson.parameters.length == 1) return false;
+
+    final fromJsonArguments = fromJson.parameters;
+
+    if (typeParameters.length != (fromJsonArguments.length - 1)) {
+      // TODO: better error. theoretically this should never be hit
+      // "invalid fromJson"?
+      // throw Exception(
+      //     'Not the right amount of arguments: \n$typeParameters\n$fromJsonArguments');
+      // throw Exception('Invalid fromJson found');
+      return false; // or error? we shouldn't get here at all, theoretically
+    }
+    return true;
   }
 
   String _getInnerJsonSerializableMapperFn(DartType dartType) {

generator/pubspec.yaml

@@ -6,7 +6,7 @@ topics:
   - build-runner
   - codegen
   - api
-version: 8.0.1
+version: 8.0.3
 environment:
   sdk: '>=2.19.0 <4.0.0'