[Bug] Can't use private constructors

[Jei-sKappa]

This is my class:

import 'package:dart_mappable/dart_mappable.dart';

part 'my_class.mapper.dart';

@MappableClass()
class MyClass with MyClassMappable {
  const MyClass({
    required this.myString,
  }) : myNumber = null;

  @MappableConstructor()
  const MyClass._({
    required this.myString,
    required this.myNumber,
  });

  final String myString;
  final int? myNumber;
}

As you can see I want to use MyClass._ as constructor for dart mappable because I don't want to expose myNumber int the constructor.

The problem is that is the generated code:

// coverage:ignore-file
// GENERATED CODE - DO NOT MODIFY BY HAND
// ignore_for_file: type=lint
// ignore_for_file: unused_element, unnecessary_cast, override_on_non_overriding_member
// ignore_for_file: strict_raw_type, inference_failure_on_untyped_parameter

part of 'my_class.dart';

class MyClassMapper extends ClassMapperBase<MyClass> {
  MyClassMapper._();

  static MyClassMapper? _instance;
  static MyClassMapper ensureInitialized() {
    if (_instance == null) {
      MapperContainer.globals.use(_instance = MyClassMapper._());
    }
    return _instance!;
  }

  @override
  final String id = 'MyClass';

  static String _$myString(MyClass v) => v.myString;
  static const Field<MyClass, String> _f$myString =
      Field('myString', _$myString, key: 'my_string');
  static int? _$myNumber(MyClass v) => v.myNumber;
  static const Field<MyClass, int> _f$myNumber =
      Field('myNumber', _$myNumber, key: 'my_number', mode: FieldMode.member);

  @override
  final MappableFields<MyClass> fields = const {
    #myString: _f$myString,
    #myNumber: _f$myNumber,
  };

  static MyClass _instantiate(DecodingData data) {
    return MyClass(myString: data.dec(_f$myString)); // This should use MyClass._
  }

  @override
  final Function instantiate = _instantiate;

  static MyClass fromMap(Map<String, dynamic> map) {
    return ensureInitialized().decodeMap<MyClass>(map);
  }

  static MyClass fromJson(String json) {
    return ensureInitialized().decodeJson<MyClass>(json);
  }
}

mixin MyClassMappable {
  String toJson() {
    return MyClassMapper.ensureInitialized()
        .encodeJson<MyClass>(this as MyClass);
  }

  Map<String, dynamic> toMap() {
    return MyClassMapper.ensureInitialized()
        .encodeMap<MyClass>(this as MyClass);
  }

  MyClassCopyWith<MyClass, MyClass, MyClass> get copyWith =>
      _MyClassCopyWithImpl(this as MyClass, $identity, $identity);
  @override
  String toString() {
    return MyClassMapper.ensureInitialized().stringifyValue(this as MyClass);
  }

  @override
  bool operator ==(Object other) {
    return MyClassMapper.ensureInitialized()
        .equalsValue(this as MyClass, other);
  }

  @override
  int get hashCode {
    return MyClassMapper.ensureInitialized().hashValue(this as MyClass);
  }
}

extension MyClassValueCopy<$R, $Out> on ObjectCopyWith<$R, MyClass, $Out> {
  MyClassCopyWith<$R, MyClass, $Out> get $asMyClass =>
      $base.as((v, t, t2) => _MyClassCopyWithImpl(v, t, t2));
}

abstract class MyClassCopyWith<$R, $In extends MyClass, $Out>
    implements ClassCopyWith<$R, $In, $Out> {
  $R call({String? myString});
  MyClassCopyWith<$R2, $In, $Out2> $chain<$R2, $Out2>(Then<$Out2, $R2> t);
}

class _MyClassCopyWithImpl<$R, $Out>
    extends ClassCopyWithBase<$R, MyClass, $Out>
    implements MyClassCopyWith<$R, MyClass, $Out> {
  _MyClassCopyWithImpl(super.value, super.then, super.then2);

  @override
  late final ClassMapperBase<MyClass> $mapper =
      MyClassMapper.ensureInitialized();
  @override
  $R call({String? myString}) =>
      $apply(FieldCopyWithData({if (myString != null) #myString: myString}));
  @override
  MyClass $make(CopyWithData data) =>
      MyClass(myString: data.get(#myString, or: $value.myString)); // This should use MyClass._

  @override
  MyClassCopyWith<$R2, MyClass, $Out2> $chain<$R2, $Out2>(Then<$Out2, $R2> t) =>
      _MyClassCopyWithImpl($value, $cast, t);
}

As you can see generated code is using MyClass constructor instead of MyClass._