I'm trying to make a Freezed class with a generic type that has toJson and fromJson:
import 'package:freezed_annotation/freezed_annotation.dart';
part 'option.freezed.dart';
part 'option.g.dart';
@Freezed(genericArgumentFactories: true)
class Option<TData> with _$Option<TData> {
const factory Option(
{required TData id,
required String name,
String? fontFamily,
required int iconCodePoint}) = _Option;
const factory Option.empty({
@Default(0) int iconCodePoint,
@Default(0 as TData) TData id,
@Default('') String name,
@Default(null) String? fontFamily,
}) = _Empty;
factory Option.fromJson(
Map<String, dynamic> json, TData Function(Object?) fromJsonTData) =>
_$OptionFromJson(json, fromJsonTData);
@override
Map<String, dynamic> toJson(Object? Function(TData) toJsonTData) {
return _$$_OptionToJson<TData>(this as _$_Option<TData>, toJsonTData);
}
Map<String, dynamic> _$$_OptionToJson<TData>(
_$_Option<TData> instance,
Object? Function(TData value) toJsonTData,
) =>
<String, dynamic>{
'id': toJsonTData(instance.id),
'name': instance.name,
'fontFamily': instance.fontFamily,
'iconCodePoint': instance.iconCodePoint,
'runtimeType': instance.$type,
};
}
The build runner executes the code generation without error, but when I try to run the app I get:
Error: The non-abstract class '_$_Option' is missing implementations for these members: lib/…/option/option.freezed.dart:190 - Option._$$_OptionToJson Try to either - provide an implementation, - inherit an implementation from a superclass or mixin, - mark the class as abstract, or - provide a 'noSuchMethod' implementation. class _$_Option<TData> implements _Option<TData> { ^^^^^^^^^ : Context: 'Option._$$_OptionToJson' is defined here. lib/…/option/option.dart:30 Map<String, dynamic> _$$_OptionToJson<TData>( ^^^^^^^^^^^^^^^^ : Error: The non-abstract class '_$_Empty' is missing implementations for these members: lib/…/option/option.freezed.dart:403 - Option._$$_OptionToJson Try to either - provide an implementation, - inherit an implementation from a superclass or mixin, - mark the class as abstract, or - provide a 'noSuchMethod' implementation. class _$_Empty<TData> implements _Empty<TData> { ^^^^^^^^ : Context: 'Option._$$_OptionToJson' is defined here. lib/…/option/option.dart:30 Map<String, dynamic> _$$_OptionToJson<TData>( ^^^^^^^^^^^^^^^^ : Error: Type variables can't be used in static members. lib/…/option/option.freezed.dart:406 this.id = 0 as TData, ^^^^^ : Error: Type variables can't be used as constants. lib/…/option/option.freezed.dart:406 this.id = 0 as TData, ^^^^^ : Error: Type variables can't be used as constants. lib/…/option/option.dart:16 @Default(0 as TData) TData id,
It looks like in the docs we don't need toJson but when I remove it I get this error in all the classes that contain a field of type Option
RangeError (index): Invalid value: Only valid value is 0: -1
when I run the build runner. What am I doing wrong?
