Flutter Code Review

auth_repository.dart

final authRepositoryProvider = StateNotifierProvider<AuthNotifier>(
  (ref) => AuthNotifier(ref.read),
);

class AuthNotifier extends StateNotifier<AuthState> {
  final Reader _read;
  AuthNotifier(this._read) : super(const AuthState()) {
    loadUser();
  }

  Future<bool> signup({
    String firstName,
    String lastName,
    String email,
    String password,
  }) async {
    try {
      state = state.copyWith(isLoading: true);

      final response = await _read(dioProvider).post(
        '/sign_up',
        data: {
          "user": {
            "email": email,
            "password": password,
            "first_name": firstName,
            "last_name": lastName,
          },
        },
      );

      _setAuthValues(response);
      return response.statusCode == 200;
    } on DioError catch (err) {
      final message = err.response?.statusMessage ?? 'Something went wrong!';
      _setErrorMessage(message);
      return false;
    } on SocketException catch (_) {
      const message = 'Please check your connection.';
      _setErrorMessage(message);
      return false;
    }
  }

  void _setErrorMessage(String message) {
    state = state.copyWith(
      isLoading: false,
      errorMessage: message,
    );
  }

  Future<void> _setAuthValues(Response response, [String token]) async {
    final data = Map<String, dynamic>.from(
      response.data,
    );
    final jsonAPI = Japx.decode(data);
    final userFromApi = User.fromMap(jsonAPI['data']);
    final _token = response?.headers?.value('authorization') ?? token;

    final SharedPreferences prefs = await SharedPreferences.getInstance();
    prefs.setString(kTokenKey, _token);
    state = state.copyWith(
      isLoading: false,
      currentUser: userFromApi,
      authToken: _token,
    );
  }
}

auth_state.dart

@freezed
abstract class AuthState with _$AuthState {
  const factory AuthState({
    @Default(false) bool isLoading,
    @Default('') String errorMessage,
    @Default('') String authToken,
    User currentUser,
  }) = _AuthState;

  const AuthState._();
}

signup_form.dart

class SignUpForm extends HookWidget {
  final GlobalKey<FormState> _formKey = GlobalKey<FormState>();

  @override
  Widget build(BuildContext context) {
    final textStyle = Theme.of(context).textTheme.subtitle1;
    final firstNameController = useTextEditingController();
    final lastNameController = useTextEditingController();
    final emailController = useTextEditingController();
    final passwordController = useTextEditingController();
    final signupProvider = useProvider(authRepositoryProvider.state);

    return Form(
      key: _formKey,
      child: Column(
        children: [
          Input(
            label: 'First Name',
            icon: const Icon(Icons.person, size: 25),
            validator: firstNameValidator,
            controller: firstNameController,
          ),
          SizedBox(height: getProportionateScreenHeight(28)),
          Input(
            label: 'Last Name',
            icon: const Icon(Icons.person, size: 25),
            validator: lastNameValidator,
            controller: lastNameController,
          ),
          SizedBox(height: getProportionateScreenHeight(28)),
          Input(
            label: 'Email',
            icon: const Icon(Icons.email, size: 26),
            validator: emailValidator,
            controller: emailController,
          ),
          SizedBox(height: getProportionateScreenHeight(28)),
          Input(
            label: 'Password',
            icon: const Icon(Icons.lock, size: 25),
            isPassword: true,
            validator: passwordValidator,
            controller: passwordController,
          ),
          SizedBox(height: getProportionateScreenHeight(28)),
          SizedBox(
            width: double.infinity,
            child: TextButton(
              onPressed: !signupProvider?.isLoading
                  ? () async {
                      if (_formKey.currentState.validate()) {
                        EasyLoading.show(status: 'Signing Up...');
                        final response =
                            await context.read(authRepositoryProvider).signup(
                                  firstName: firstNameController.text?.trim(),
                                  lastName: lastNameController.text?.trim(),
                                  email: emailController.text?.trim(),
                                  password: passwordController.text?.trim(),
                                );
                        EasyLoading.dismiss();
                        if (response) {
                          _formKey.currentState.reset();
                          HomeRoute(skip: true).show(context);
                        }
                      }
                    }
                  : null,
              child: const Text('SIGN UP'),
            ),
          ),
          SizedBox(
            width: double.infinity,
            child: OutlinedButton(
              onPressed: () {
                HomeRoute(skip: true).show(context);
              },
              child: const Text('CONTINUE AS A GUEST'),
            ),
          ),
          SizedBox(height: getProportionateScreenHeight(32)),
          Row(
            mainAxisAlignment: MainAxisAlignment.center,
            children: [
              Text(
                'Do you have an account?',
                style: textStyle.copyWith(
                  color: kTextColor,
                ),
              ),
              const SizedBox(width: 8),
              GestureDetector(
                onTap: () {
                  LoginRoute().show(context);
                },
                child: Text(
                  'Log In',
                  style: textStyle.copyWith(
                    color: kPrimaryColor,
                  ),
                ),
              ),
            ],
          )
        ],
      ),
    );
  }
}

user.dart

import 'package:json_annotation/json_annotation.dart';

part 'user.g.dart';

@JsonSerializable(nullable: false)
class User {
  final int id;
  final String firstName;
  final String lastName;
  final String email;
  final String password;

  const User({
    this.id,
    this.firstName,
    this.lastName,
    this.password,
    this.email,
  });

  factory User.fromMap(Map<String, dynamic> json) => _$UserFromJson(json);
  Map<String, dynamic> toMap() => _$UserToJson(this);

  @override
  String toString() {
    return "$firstName $lastName";
  }
}