[#8] Show no internet connection error dialog

lib/l10n/app_en.arb

@@ -5,6 +5,8 @@
     "loginButton": "Log in",
     "invalidEmailError": "Please enter the valid email format.",
     "invalidPasswordError": "Password must be at least 8 characters long.",
-    "unauthenticatedError": "Your email or password is incorrect.\nPlease try again.",
+    "unauthorizedError": "Your email or password is incorrect.\nPlease try again.",
+    "noInternetConnectionError": "You seem to be offline.\nPlease try again!",
+    "genericError": "Something went wrong.\nPlease try again!",
     "loginFailAlertTitle": "Unable to log in"
 }

lib/screens/login/login_view_model.dart

@@ -2,11 +2,14 @@ import 'dart:async';
 
 import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:survey_flutter/uimodels/app_error.dart';
+import 'package:survey_flutter/utils/internet_connection_manager.dart';
 
 final loginViewModelProvider =
     AsyncNotifierProvider.autoDispose<LoginViewModel, void>(LoginViewModel.new);
 
 class LoginViewModel extends AutoDisposeAsyncNotifier<void> {
+  late InternetConnectionManager internetConnectionManager;
+
   bool isValidEmail(String? email) {
     // Just use a simple rule, no fancy Regex!
     return !(email == null || !email.contains('@'));
@@ -19,11 +22,30 @@ class LoginViewModel extends AutoDisposeAsyncNotifier<void> {
   login({required String email, required String password}) async {
     state = const AsyncLoading();
     // TODO: Integrate with API
-    // For now, assume its returns error
-    state = const AsyncError(
-      AppError.unauthenticated,
-      StackTrace.empty,
-    );
+
+    // Handling error part:
+
+    // If it returns unauthorized error (401)
+    //state = const AsyncError(
+    //  AppError.unauthorized,
+    //  StackTrace.empty,
+    //);
+
+    // If it returns timeout error, then check Internet connection
+    internetConnectionManager = ref.read(internetConnectionManagerProvider);
+    final isConnected = await internetConnectionManager.hasConnection();
+
+    if (!isConnected) {
+      state = const AsyncError(
+        AppError.noInternetConnection,
+        StackTrace.empty,
+      );
+    } else {
+      state = const AsyncError(
+        AppError.generic,
+        StackTrace.empty,
+      );
+    }
   }
 
   @override

lib/uimodels/app_error.dart

@@ -1,13 +1,21 @@
 import 'package:flutter/material.dart';
 import 'package:survey_flutter/utils/build_context_ext.dart';
 
-enum AppError { unauthenticated }
+enum AppError {
+  unauthorized,
+  noInternetConnection,
+  generic,
+}
 
 extension AppErrorExtension on AppError {
   String description(BuildContext context) {
     switch (this) {
-      case AppError.unauthenticated:
-        return context.localizations.unauthenticatedError;
+      case AppError.unauthorized:
+        return context.localizations.unauthorizedError;
+      case AppError.noInternetConnection:
+        return context.localizations.noInternetConnectionError;
+      case AppError.generic:
+        return context.localizations.genericError;
     }
   }
 }

lib/utils/internet_connection_manager.dart

@@ -0,0 +1,21 @@
+import 'package:internet_connection_checker/internet_connection_checker.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+
+abstract class InternetConnectionManager {
+  Future<bool> hasConnection();
+}
+
+final internetConnectionManagerProvider =
+    Provider<InternetConnectionManager>((_) {
+  return InternetConnectionManagerImpl();
+});
+
+class InternetConnectionManagerImpl extends InternetConnectionManager {
+  final InternetConnectionChecker _internetConnectionChecker =
+      InternetConnectionChecker();
+
+  @override
+  Future<bool> hasConnection() async {
+    return await _internetConnectionChecker.hasConnection;
+  }
+}

pubspec.lock

@@ -404,6 +404,14 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  internet_connection_checker:
+    dependency: "direct main"
+    description:
+      name: internet_connection_checker
+      sha256: "1c683e63e89c9ac66a40748b1b20889fd9804980da732bf2b58d6d5456c8e876"
+      url: "https://pub.dev"
+    source: hosted
+    version: "1.0.0+1"
   intl:
     dependency: "direct main"
     description:

pubspec.yaml

@@ -46,6 +46,7 @@ dependencies:
   japx: ^2.0.5
   equatable: ^2.0.0
   injectable: ^1.5.0
+  internet_connection_checker: ^1.0.0+1
 
 dev_dependencies:
   build_runner: ^2.4.4

test/mocks/generate_mocks.dart

@@ -3,12 +3,14 @@ import 'package:mockito/annotations.dart';
 import 'package:survey_flutter/api/authentication_api_service.dart';
 import 'package:survey_flutter/repositories/authentication_repository.dart';
 import 'package:survey_flutter/utils/async_listener.dart';
+import 'package:survey_flutter/utils/internet_connection_manager.dart';
 
 @GenerateMocks([
   AsyncListener,
   AuthenticationApiService,
   AuthenticationRepository,
   DioError,
+  InternetConnectionManager,
 ])
 main() {
   // empty class to generate mock repository classes

test/screens/login/login_view_model_test.dart

@@ -2,16 +2,23 @@ import 'package:flutter_riverpod/flutter_riverpod.dart';
 import 'package:flutter_test/flutter_test.dart';
 import 'package:mockito/mockito.dart';
 import 'package:survey_flutter/screens/login/login_view_model.dart';
+import 'package:survey_flutter/utils/internet_connection_manager.dart';
 
 import '../../mocks/generate_mocks.mocks.dart';
 
 void main() {
   group('LoginViewModel', () {
     late ProviderContainer container;
+    late MockInternetConnectionManager mockInternetConnectionManager;
     late MockAsyncListener listener;
 
     setUp(() {
-      container = ProviderContainer();
+      mockInternetConnectionManager = MockInternetConnectionManager();
+      container = ProviderContainer(overrides: [
+        internetConnectionManagerProvider
+            .overrideWithValue(mockInternetConnectionManager),
+      ]);
+
       listener = MockAsyncListener();
       container.listen(
         loginViewModelProvider,
@@ -76,9 +83,30 @@ void main() {
       });
     });
 
+    // TODO: Update when integrating with API
     group('login', () {
-      test('When logging in unsuccessfully, it emits error correspondingly',
+      //  test('When logging in unsuccessfully, it emits error correspondingly',
+      //      () async {
+      //    const data = AsyncData<void>(null);
+      //    // verify initial value from build method
+      //    verify(listener(null, data));
+
+      //    final loginViewModel = container.read(loginViewModelProvider.notifier);
+      //    await loginViewModel.login(
+      //        email: '[email protected]', password: '12345678');
+
+      //    verifyInOrder([
+      //      listener(data, isA<AsyncLoading>()),
+      //      listener(isA<AsyncLoading<void>>(), isA<AsyncError<void>>()),
+      //    ]);
+      //    verifyNoMoreInteractions(listener);
+      //  });
+
+      test(
+          'When logging in without Internet connection, it emits error correspondingly',
           () async {
+        when(mockInternetConnectionManager.hasConnection())
+            .thenAnswer((_) async => false);
         const data = AsyncData<void>(null);
         // verify initial value from build method
         verify(listener(null, data));