Map<String, [...]> is incorrectly typed as <String?, [...]> #1188
Description
flutter --version
is:
Flutter 3.0.1 • channel stable • https://github.com/flutter/flutter.git
Framework • revision fb57da5f94 (3 months ago) • 2022-05-19 15:50:29 -0700
Engine • revision caaafc5604
Tools • Dart 2.17.1 • DevTools 2.12.2
Having such code:
import 'package:json_annotation/json_annotation.dart';
part 'json_serialize_bug.g.dart';
void main() {
var testSerialize = TestSerialize(myEnum: MyEnum.one, myMap: {MyEnum.two: 2});
TestSerialize.fromJson(testSerialize.toJson());
}
@JsonSerializable()
class TestSerialize {
final MyEnum myEnum;
final Map<MyEnum, int> myMap;
TestSerialize({
required this.myEnum,
required this.myMap,
});
factory TestSerialize.fromJson(Map<String, dynamic> json) => _$TestSerializeFromJson(json);
Map<String, dynamic> toJson() => _$TestSerializeToJson(this);
}
enum MyEnum {
one, two
}
fails with:
Unhandled exception:
type '_InternalLinkedHashMap<String?, int>' is not a subtype of type 'Map<String, dynamic>' in type cast
#0 _$TestSerializeFromJson (package:test/json_serialize_bug.g.dart:12:29)
#1 new TestSerialize.fromJson (package:test/json_serialize_bug.dart:19:64)
#2 main (package:test/json_serialize_bug.dart:7:17)
#3 _delayEntrypointInvocation.<anonymous closure> (dart:isolate-patch/isolate_patch.dart:297:19)
#4 _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:192:12)
Because _$TestSerializeToJson:
Map<String, dynamic> _$TestSerializeToJson(TestSerialize instance) =>
<String, dynamic>{
'myEnum': _$MyEnumEnumMap[instance.myEnum],
'myMap': instance.myMap.map((k, e) => MapEntry(_$MyEnumEnumMap[k], e)),
};
uses MapEntry which is being resolved to _InternalLinkedHashMap<String?, int> instead of _InternalLinkedHashMap<String, int> and I think, that adding type:
'myMap': instance.myMap.map((k, e) => MapEntry<String, dynamic>(_$MyEnumEnumMap[k]!, e)),
would work, because we can never have null here.