How to implement BlocTest function? - flutter

Question

I'm trying to implement blocTesting for my flutter app starting with authentication feature. Below are the Authentication and login related files required for this. I'd really appreciate if someone could show me on how I can implement blocTesting based on my code because I've been facing problems in doing so. Below are the bloc, state and event files for the auth bloc.
Authbloc.dart
import 'dart:async';
import 'package:bloc/bloc.dart';
import 'package:equatable/equatable.dart';
part 'authentication_event.dart';
part 'authentication_state.dart';
class AuthenticationBloc extends Bloc<AuthenticationEvent, AuthenticationState> {
final AuthenticationRepository authenticationRepository = AuthenticationRepository();
final SettingsRepository _settingsRepository = SettingsRepository();
AuthenticationBloc() : super(AuthenticationInitial()) {
// Register events here
on<AuthenticationStarted>(_onAuthenticationStarted);
on<AuthenticationLoggedIn>(_onAuthenticationLoggedIn);
on<AuthenticationLoggedOut>(_onAuthenticationLoggedOut);
}
Future<void> _onAuthenticationStarted(AuthenticationStarted event, Emitter<AuthenticationState> emit) async {
try {
final bool hasToken = await authenticationRepository.hasToken();
if (hasToken) {
final Settings _settings = await _settingsRepository.getSettings();
final SysConfig _sysConfig = await _settingsRepository.getSysconfig();
final CountriesModelList _countries = await _settingsRepository.getCountries();
final ReasonsModelList _reasons = await _settingsRepository.getReasons();
final NotificationOptionsList _notificationOptions = await _settingsRepository.getNotificationOptions();
emit(
AuthenticationLoadSuccess(
settings: _settings,
sysConfig: _sysConfig,
countries: _countries,
reasons: _reasons,
notificationOptions: _notificationOptions,
),
);
} else {
emit(AuthenticationUnauthenticated());
}
} catch (e) {
final MYException _exception = e as MYException;
emit(AuthenticationLoadFailure(exception: _exception));
}
}
Future<void> _onAuthenticationLoggedIn(AuthenticationLoggedIn event, Emitter<AuthenticationState> emit) async {
emit(AuthenticationLoadInProgress());
await authenticationRepository.persistToken(event.token);
final Settings _settings = await _settingsRepository.getSettings();
final SysConfig _sysConfig = await _settingsRepository.getSysconfig();
final CountriesModelList _countries = await _settingsRepository.getCountries();
final ReasonsModelList _reasons = await _settingsRepository.getReasons();
final NotificationOptionsList _notificationOptions = await _settingsRepository.getNotificationOptions();
emit(
AuthenticationLoadSuccess(
settings: _settings,
sysConfig: _sysConfig,
countries: _countries,
reasons: _reasons,
notificationOptions: _notificationOptions,
),
);
}
Future<void> _onAuthenticationLoggedOut(AuthenticationLoggedOut event, Emitter<AuthenticationState> emit) async {
await authenticationRepository.deleteToken();
await Future<dynamic>.delayed(const Duration(seconds: 2));
emit(AuthenticationUnauthenticated());
add(AuthenticationStarted());
}
}
Authstate.dart
part of 'authentication_bloc.dart';
abstract class AuthenticationEvent extends Equatable {
const AuthenticationEvent();
#override
List<Object> get props => <Object>[];
}
class AuthenticationStarted extends AuthenticationEvent {}
class AuthenticationLoggedIn extends AuthenticationEvent {
final String token;
const AuthenticationLoggedIn({required this.token});
#override
List<Object> get props => <Object>[token];
}
class AuthenticationLoggedOut extends AuthenticationEvent {}
AuthEvent.dart
part of 'authentication_bloc.dart';
abstract class AuthenticationState extends Equatable {
const AuthenticationState();
#override
List<Object> get props => <Object>[];
}
class AuthenticationInitial extends AuthenticationState {}
class AuthenticationUnauthenticated extends AuthenticationState {}
class AuthenticationLoadSuccess extends AuthenticationState {
final SysConfig sysConfig;
final Settings settings;
final CountriesModelList countries;
final ReasonsModelList reasons;
final NotificationOptionsList notificationOptions;
const AuthenticationLoadSuccess({required this.sysConfig, required this.settings, required this.countries, required this.reasons, required this.notificationOptions});
#override
List<Object> get props => <Object>[sysConfig, settings, countries, reasons, notificationOptions];
}
class AuthenticationLoadInProgress extends AuthenticationState {}
class AuthenticationLoadFailure extends AuthenticationState {
final MYException exception;
const AuthenticationLoadFailure({required this.exception});
#override
List<Object> get props => <Object>[exception];
}

Answer 1

you have to change a lot of thinks.
First of all you need to add the repository/ies to your bloc constructor to inject the mocks.
class AuthenticationBloc extends Bloc<AuthenticationEvent, AuthenticationState> {
late final AuthenticationRepository authenticationRepository;
final SettingsRepository _settingsRepository = SettingsRepository();
AuthenticationBloc({required this.authenticationRepository}) : super(AuthenticationInitial()) {
// Register events here
on<AuthenticationStarted>(_onAuthenticationStarted);
on<AuthenticationLoggedIn>(_onAuthenticationLoggedIn);
on<AuthenticationLoggedOut>(_onAuthenticationLoggedOut);
}
Then you can use the mock when creating the bloc in the setup method
setUp(() {
authenticationRepositoryMock = MockWeatherRepository();
authenticationBloc = AuthenticationBloc(authenticationRepository: authenticationRepositoryMock );
});
Then you have to return that bloc in the build function of your blocTest and also you have to setup the mock behavior there
build: () {
when(() => authenticationRepositoryMock .hasToken()).thenAnswer((_) async => true);
return bloc;
},
Then add an event to your bloc in the act function
act: (dynamic b) => b.add(AuthenticationStarted()),
And then you can check the result in the expect function. (i think the initial state will not be emitted here)
expect: () => [
AuthenticationLoadSuccess(...),
It also a good idea to mock the SettingsRepository.