Question: How to inherit fields from a base class without repeating them in the subclass?

[shijianoo]

Hi, thank you for the great work on Freezed!

I'm trying to model a subclass that extends a base class, and I want to avoid repeating all the fields from the base class in the subclass constructor. Here's what I have:

@freezed
abstract class BaseDeviceInfo {
  const factory BaseDeviceInfo({
    @Default('') String name,
    @Default(0) int pid,
    @Default(0) int psn,
    @Default('') String model,
    @Default('') String fvn,
    @Default('') String hvn,
    @Default(0) int maxDepth,
  }) = _BaseDeviceInfo;
}

@unfreezed
abstract class SHC27TDeviceInfo extends BaseDeviceInfo with _$SHC27TDeviceInfo {
  SHC27TDeviceInfo._() : super();

  const factory SHC27TDeviceInfo({
    @Default('') String uls,
    @Default('') String ull,
    @Default(0) int mainBoardNo,
    @Default(false) bool isconnected,
  }) = _SHC27TDeviceInfo;
}

I know this does not compile, but my goal is to:

Inherit all the fields and default values from BaseDeviceInfo

Add a few new fields in the subclass (uls, ull, etc.)

Avoid repeating all the parameters from the base class again

Be able to instantiate SHC27TDeviceInfo() with no arguments (using default values), or with some optional named parameters

examples:

// 1. Use all default values from both base and subclass
final device1 = SHC27TDeviceInfo();

// 2. Only override a few fields from subclass or base class
final device2 = SHC27TDeviceInfo(uls: 'COM1', isconnected: true);

// 3. Provide a few fields from the base class only
final device3 = SHC27TDeviceInfo(name: 'SensorX', pid: 123);

// 4. Provide mixed base + subclass fields
final device4 = SHC27TDeviceInfo(
  name: 'SensorY',
  model: 'SHC27T',
  uls: '/dev/ttyUSB0',
  isconnected: true,
);

In many Freezed examples, the subclass constructor repeats all base class fields again, which becomes verbose and error-prone.

Is there a recommended way to do this kind of model composition/inheritance with Freezed?

Thanks a lot in advance!

[shijianoo]

Is anyone there?