Custom types and custom encoding example not working

[apomalyn]

Hello there! 👋

First, thank you for this amazing package!

I wanted to point out that the following example isn't working as expected.

@JsonSerializable()
class Sample1 {
  Sample1(this.value);

  factory Sample1.fromJson(Map<String, dynamic> json) =>
      _$Sample1FromJson(json);

  // Sample2 is NOT annotated with @JsonSerializable(), but that's okay
  // The class has a `fromJson` constructor and a `toJson` method, which is
  // all that is required.
  final Sample2 value;

  Map<String, dynamic> toJson() => _$Sample1ToJson(this);
}

class Sample2 {
  Sample2(this.value);

  // The convention is for `fromJson` to take a single parameter of type
  // `Map<String, dynamic>` but any JSON-compatible type is allowed.
  factory Sample2.fromJson(int value) => Sample2(value);
  final int value;

  // The convention is for `toJson` to take return a type of
  // `Map<String, dynamic>` but any JSON-compatible type is allowed.
  int toJson() => value;
}

toJson should return:

{ "value": 5 }

but instead returns:

 {'value': Instance of 'Sample2'}

Tests used

void main() {
  group("Sample", () {
    final sample = Sample1(Sample2(5));

    test("toJson", () { // Failing
      expect(sample.toJson(), { 
        "value": 5,
      });
    });

    test("fromJson", () { // Working as expected
      final decoded = Sample1.fromJson({
        "value": 5,
      });

      expect(decoded.value, isA<Sample2>());
      expect(decoded.value.value, 5);
    });
  });
}

I'm probably missing something silly, so sorry if this is the case.

Also, using a converter is possible to fix it but annoying when Sample2 is used in a lot of class.

[apomalyn]

Well, misunderstanding on my side. It works as expected if I use jsonEncode...