How to use late final keyword in Flutter Dart freezed model?

How to use late final keyword in Flutter Dart freezed model ?

This code generates successfully and has no static analysis error but it does not compile strangely.

import 'dart:convert';

import 'package:freezed_annotation/freezed_annotation.dart';

part 'fb_story.freezed.dart';
part 'fb_story.g.dart';

@freezed
class FbStory with _$FbStory {
  FbStory._();
  const factory FbStory({
    required String id,
    required String data_str,
    @Default(false) bool imageNotAvailable,
    @Default(false) bool videoNotAvailable,
    String? imageUrl,
    String? videoUrl,
  }) = _FbStory;

  late final Map<String, dynamic> data = jsonDecode(data_str);

  factory FbStory.fromJson(Map<String, dynamic> json) =>
      _$FbStoryFromJson(json);
}

Error:

 Error: A constant constructor can't call a non-constant super constructor.

Before, Freezed used to pioneer the late keyword with @late annotation so I guess there should be a way to make this work. class is still freezed, just lazy

Just remove const at factory FbStory

Full code:

import 'dart:convert';

import 'package:freezed_annotation/freezed_annotation.dart';

part 'fb_story.freezed.dart';
part 'fb_story.g.dart';



@freezed
class FbStory with _$FbStory {
  FbStory._();
  factory FbStory({
    required String id,
    required String data_str,
    @Default(false) bool imageNotAvailable,
    @Default(false) bool videoNotAvailable,
    String? imageUrl,
    String? videoUrl,
  }) = _FbStory;

  late final Map<String, dynamic> data = jsonDecode(data_str);

  factory FbStory.fromJson(Map<String, dynamic> json) =>
      _$FbStoryFromJson(json);
}