Freezed vs Plain Class

class.dart

@freezed
class UserCardsState with _$UserCardsState {
  const UserCardsState._();

  bool get inProgress => maybeMap(
        fetching: (_) => true,
        orElse: () => false,
      );
  bool get isFetched => maybeMap(
        fetched: (_) => true,
        orElse: () => false,
      );

  factory UserCardsState.initial({
    @Default(<UserCard>[]) final List<UserCard> cards,
  }) = _InitialUserCardsState;

  factory UserCardsState.fetching({
    @Default(<UserCard>[]) final List<UserCard> cards,
  }) = _FetchingUserCardsState;

  factory UserCardsState.fetched({
    required final List<UserCard> cards,
  }) = _FetchedUserCardsState;

  factory UserCardsState.error({
    @Default(<UserCard>[]) final List<UserCard> cards,
    @Default('No Message') final String message,
  }) = _ErrorUserCardsState;
}

freezedclass.dart

import 'package:collection/collection.dart';
import 'package:flutter/material.dart';
import 'package:m10/features/transfer_linked_card/model/transfer_linked_card_model.dart';

/// interface
@immutable
abstract class UserCardsState {
  const UserCardsState({
    required this.userCards,
  });

  final List<UserCard> userCards;

  @override
  int get hashCode;

  @override
  bool operator ==(Object other);
}

class InitialUserCardsState extends UserCardsState {
  const InitialUserCardsState([
    final List<UserCard>? cards,
  ]) : super(
          userCards: cards ?? const <UserCard>[],
        );

  @override
  bool operator ==(Object other) {
    return identical(this, other) ||
        (other.runtimeType == runtimeType &&
            other is InitialUserCardsState &&
            const DeepCollectionEquality().equals(other.userCards, userCards));
  }

  @override
  int get hashCode =>
      Object.hash(runtimeType, const DeepCollectionEquality().hash(userCards));
}

class FetchingUserCardsState extends UserCardsState {
  const FetchingUserCardsState([
    final List<UserCard>? cards,
  ]) : super(
          userCards: cards ?? const <UserCard>[],
        );

  @override
  bool operator ==(Object other) {
    return identical(this, other) ||
        (other.runtimeType == runtimeType &&
            other is FetchingUserCardsState &&
            const DeepCollectionEquality().equals(other.userCards, userCards));
  }

  @override
  int get hashCode =>
      Object.hash(runtimeType, const DeepCollectionEquality().hash(userCards));
}

class FetchedUserCardsState extends UserCardsState {
  const FetchedUserCardsState({
    required final List<UserCard> cards,
  }) : super(userCards: cards);

  @override
  bool operator ==(Object other) {
    return identical(this, other) ||
        (other.runtimeType == runtimeType &&
            other is FetchedUserCardsState &&
            const DeepCollectionEquality().equals(other.userCards, userCards));
  }

  @override
  int get hashCode =>
      Object.hash(runtimeType, const DeepCollectionEquality().hash(userCards));
}

class ErrorUserCardsState extends UserCardsState {
  const ErrorUserCardsState({
    final List<UserCard>? cards,
    this.message = 'Empty Message',
  }) : super(userCards: cards ?? const <UserCard>[]);

  final String message;

  @override
  bool operator ==(Object other) {
    return identical(this, other) ||
        (other.runtimeType == runtimeType &&
            other is ErrorUserCardsState &&
            const DeepCollectionEquality().equals(other.userCards, userCards) &&
            const DeepCollectionEquality().equals(other.message, message));
  }

  @override
  int get hashCode => Object.hash(
        runtimeType,
        const DeepCollectionEquality().hash(userCards),
        const DeepCollectionEquality().hash(message),
      );
}