diff --git a/lib/base/base_api.dart b/lib/base/base_api.dart
index 2f1fe00..19ae163 100644
--- a/lib/base/base_api.dart
+++ b/lib/base/base_api.dart
@@ -2,10 +2,9 @@ import 'dart:convert';
 import 'dart:io';
 
 import 'package:http/http.dart' as http;
-import 'package:meta/meta.dart';
 
 class BaseApi {
-  BaseApi({@required this.client});
+  BaseApi({required this.client});
 
   final http.Client client;
 
diff --git a/lib/base/dependencies.dart b/lib/base/dependencies.dart
new file mode 100644
index 0000000..814d58b
--- /dev/null
+++ b/lib/base/dependencies.dart
@@ -0,0 +1,56 @@
+import 'dart:async';
+
+import 'package:flutter/services.dart';
+import 'package:flutter_workshop/feature/home/home_bloc.dart';
+import 'package:flutter_workshop/feature/login/login_bloc.dart';
+import 'package:flutter_workshop/model/donation/donation.dart';
+import 'package:flutter_workshop/model/donation/donation_api.dart';
+import 'package:flutter_workshop/model/login/login_api.dart';
+import 'package:flutter_workshop/model/login/login_response.dart';
+import 'package:flutter_workshop/service/session.dart';
+import 'package:flutter_workshop/service/shared_preferences_storage.dart';
+import 'package:flutter_workshop/util/http_event.dart';
+import 'package:http/http.dart' as http;
+import 'package:provider/provider.dart';
+import 'package:provider/single_child_widget.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+Future<List<SingleChildWidget>> getDependencies() async {
+  final http.Client _httpClient = http.Client();
+
+  final SharedPreferences _sharedPreferences =
+      await SharedPreferences.getInstance();
+
+  final SharedPreferencesStorage _sharedPreferencesStorage =
+      SharedPreferencesStorage(_sharedPreferences);
+
+  final Session _session =
+      Session(diskStorageProvider: _sharedPreferencesStorage);
+
+  await SystemChrome.setPreferredOrientations(
+    [
+      DeviceOrientation.portraitUp,
+      DeviceOrientation.portraitDown,
+      DeviceOrientation.landscapeLeft,
+      DeviceOrientation.landscapeRight,
+    ],
+  );
+
+  return [
+    Provider<LoginBloc>(
+      create: (_) => LoginBloc(
+        controller: StreamController<HttpEvent<LoginResponse>>.broadcast(),
+        loginApi: LoginApi(client: _httpClient),
+        sessionProvider: _session,
+      ),
+    ),
+    Provider<HomeBloc?>(
+      create: (_) => HomeBloc(
+        controller: StreamController<List<Donation>>.broadcast(),
+        donationApi: DonationApi(client: _httpClient),
+        diskStorageProvider: _sharedPreferencesStorage,
+        sessionProvider: _session,
+      ),
+    ),
+  ];
+}
diff --git a/lib/base/my_app.dart b/lib/base/my_app.dart
index e838988..33437eb 100644
--- a/lib/base/my_app.dart
+++ b/lib/base/my_app.dart
@@ -5,18 +5,18 @@ import 'package:provider/single_child_widget.dart';
 
 class MyApp extends StatefulWidget {
   const MyApp({
-    Key key,
+    Key? key,
     this.dependencies,
   }) : super(key: key);
 
-  final List<SingleChildWidget> dependencies;
+  final List<SingleChildWidget>? dependencies;
 
   @override
   _MyAppState createState() => _MyAppState();
 }
 
 class _MyAppState extends State<MyApp> {
-  List<SingleChildWidget> _appDependencies;
+  List<SingleChildWidget>? _appDependencies;
 
   @override
   void initState() {
@@ -27,7 +27,7 @@ class _MyAppState extends State<MyApp> {
   @override
   Widget build(BuildContext context) {
     return MultiProvider(
-      providers: _appDependencies,
+      providers: _appDependencies!,
       child: BaseMaterialApp(),
     );
   }
diff --git a/lib/config/l10n.dart b/lib/config/l10n.dart
index d4fee57..704697c 100644
--- a/lib/config/l10n.dart
+++ b/lib/config/l10n.dart
@@ -15,7 +15,7 @@ class StringLocalizationsDelegate extends LocalizationsDelegate<L10n> {
     this.testingLocale,
   });
 
-  final Locale testingLocale;
+  final Locale? testingLocale;
 
   @override
   bool isSupported(Locale locale) =>
@@ -38,28 +38,29 @@ class L10n {
   });
 
   final Locale _locale;
-  final Locale testingLocale;
+  final Locale? testingLocale;
   final String defaultLanguageCode = supportedLanguageCodes.first;
   final Map<String, Map<String, String>> _localizedValues = Strings().map;
 
   String _get(String key) {
     if (_localizedValues[key] == null) return key;
 
-    final languageCode = testingLocale ?? _locale;
+    final languageCode = testingLocale?.languageCode ?? _locale.languageCode;
 
-    return _localizedValues[key][languageCode] ??
-        _localizedValues[key][defaultLanguageCode] ??
+    return _localizedValues[key]![languageCode] ??
+        _localizedValues[key]![defaultLanguageCode] ??
         key;
   }
 
-  static String getString(
+  static String? getString(
     BuildContext context,
-    String key,
+    String? key,
   ) =>
       key == null
           ? null
           : Localizations.of<L10n>(
               context,
               L10n,
-            )._get(key);
+            )!
+              ._get(key);
 }
diff --git a/lib/config/routes.dart b/lib/config/routes.dart
index 137fe8b..86d16eb 100644
--- a/lib/config/routes.dart
+++ b/lib/config/routes.dart
@@ -7,14 +7,14 @@ import 'package:flutter_workshop/feature/login/login_bloc.dart';
 import 'package:flutter_workshop/util/navigation.dart';
 import 'package:provider/provider.dart';
 
-MaterialPageRoute getRouteFactory(settings) {
-  MaterialPageRoute route;
+MaterialPageRoute? getRouteFactory(settings) {
+  MaterialPageRoute? route;
   switch (settings.name) {
     case Home.routeName:
       {
         route = Navigation.makeRoute(Consumer<HomeBloc>(
           builder: (context, bloc, child) => Home(bloc: bloc),
-        ));
+        )) as MaterialPageRoute<dynamic>?;
       }
       break;
 
@@ -22,7 +22,7 @@ MaterialPageRoute getRouteFactory(settings) {
       {
         route = Navigation.makeRoute(Consumer<LoginBloc>(
           builder: (context, bloc, child) => Login(bloc: bloc),
-        ));
+        )) as MaterialPageRoute<dynamic>?;
       }
       break;
 
@@ -31,7 +31,7 @@ MaterialPageRoute getRouteFactory(settings) {
         final DetailArguments args = settings.arguments;
         route = Navigation.makeRoute(Detail(
           donation: args.donation,
-        ));
+        )) as MaterialPageRoute<dynamic>?;
       }
       break;
   }
diff --git a/lib/custom/adaptive_view.dart b/lib/custom/adaptive_view.dart
index 0beabc9..96c3357 100644
--- a/lib/custom/adaptive_view.dart
+++ b/lib/custom/adaptive_view.dart
@@ -4,13 +4,13 @@ const double MEDUIM_SCREEN_MIN_WIDTH = 720;
 const double LARGE_SCREEN_MIN_WIDTH = 1200;
 
 class AdaptiveView extends StatelessWidget {
-  final Widget smallView;
-  final Widget mediumView;
-  final Widget largeView;
-  final FormFactor forcedFormFactor;
+  final Widget? smallView;
+  final Widget? mediumView;
+  final Widget? largeView;
+  final FormFactor? forcedFormFactor;
 
   const AdaptiveView({
-    Key key,
+    Key? key,
     this.smallView,
     this.mediumView,
     this.largeView,
@@ -23,7 +23,7 @@ class AdaptiveView extends StatelessWidget {
     final formFactor =
         forcedFormFactor ?? _getFormFactor(MediaQuery.of(context).size.width);
 
-    return _getView(formFactor);
+    return _getView(formFactor)!;
   }
 
   FormFactor _getFormFactor(double width) {
@@ -38,14 +38,12 @@ class AdaptiveView extends StatelessWidget {
     return FormFactor.small;
   }
 
-  Widget _getView(FormFactor formFactor) {
+  Widget? _getView(FormFactor formFactor) {
     switch (formFactor) {
       case FormFactor.large:
         return largeView ?? mediumView ?? smallView;
-        break;
       case FormFactor.medium:
         return mediumView ?? largeView ?? smallView;
-        break;
       default:
         return smallView ?? mediumView ?? largeView;
     }
diff --git a/lib/custom/custom_alert_dialog.dart b/lib/custom/custom_alert_dialog.dart
index c7cc482..10367bd 100644
--- a/lib/custom/custom_alert_dialog.dart
+++ b/lib/custom/custom_alert_dialog.dart
@@ -6,7 +6,7 @@ import 'package:flutter_workshop/config/platform_independent_constants.dart';
 
 class CustomAlertDialog extends StatelessWidget {
   const CustomAlertDialog({
-    Key key,
+    Key? key,
     this.onConfirmed,
     this.confirmationText,
     this.cancellationText,
@@ -15,17 +15,17 @@ class CustomAlertDialog extends StatelessWidget {
     this.hasCancelButton = false,
   }) : super(key: key);
 
-  final VoidCallback onConfirmed;
-  final String confirmationText;
-  final String cancellationText;
-  final String titleText;
-  final String contentText;
+  final VoidCallback? onConfirmed;
+  final String? confirmationText;
+  final String? cancellationText;
+  final String? titleText;
+  final String? contentText;
   final bool hasCancelButton;
 
   @override
   Widget build(BuildContext context) {
-    final Text title = titleText == null ? null : Text(titleText);
-    final Text content = contentText == null ? null : Text(contentText);
+    final Text? title = titleText == null ? null : Text(titleText!);
+    final Text? content = contentText == null ? null : Text(contentText!);
 
     return AlertDialog(
       title: title,
diff --git a/lib/custom/custom_app_bar.dart b/lib/custom/custom_app_bar.dart
index e4b86bc..3c560e3 100644
--- a/lib/custom/custom_app_bar.dart
+++ b/lib/custom/custom_app_bar.dart
@@ -1,14 +1,14 @@
 import 'package:flutter/material.dart';
 
 class CustomAppBar extends StatelessWidget implements PreferredSizeWidget {
-  const CustomAppBar({Key key, this.actions, this.title}) : super(key: key);
+  const CustomAppBar({Key? key, this.actions, this.title}) : super(key: key);
 
-  final List<Widget> actions;
-  final String title;
+  final List<Widget>? actions;
+  final String? title;
 
   @override
   Widget build(BuildContext context) {
-    final String computedTitle = title == null ? '' : title;
+    final String computedTitle = title == null ? '' : title!;
 
     return AppBar(
       brightness: Brightness.light,
diff --git a/lib/custom/custom_button.dart b/lib/custom/custom_button.dart
index d23207e..1f574a8 100644
--- a/lib/custom/custom_button.dart
+++ b/lib/custom/custom_button.dart
@@ -5,9 +5,9 @@ class PrimaryContainedButton extends StatelessWidget {
   final VoidCallback onPressed;
 
   const PrimaryContainedButton({
-    Key key,
-    @required this.child,
-    @required this.onPressed,
+    Key? key,
+    required this.child,
+    required this.onPressed,
   }) : super(key: key);
 
   @override
@@ -31,13 +31,13 @@ class PrimaryContainedButton extends StatelessWidget {
 }
 
 class PrimaryTextButton extends StatelessWidget {
-  final String text;
-  final VoidCallback onPressed;
+  final String? text;
+  final VoidCallback? onPressed;
 
   const PrimaryTextButton({
-    Key key,
-    @required this.text,
-    @required this.onPressed,
+    Key? key,
+    required this.text,
+    required this.onPressed,
   }) : super(key: key);
 
   @override
@@ -55,7 +55,7 @@ class PrimaryTextButton extends StatelessWidget {
       style: flatButtonStyle,
       onPressed: onPressed,
       child: Text(
-        text,
+        text!,
         style: const TextStyle(
           fontWeight: FontWeight.bold,
         ),
diff --git a/lib/feature/detail/detail.dart b/lib/feature/detail/detail.dart
index aa9ad23..f468492 100644
--- a/lib/feature/detail/detail.dart
+++ b/lib/feature/detail/detail.dart
@@ -5,12 +5,12 @@ import 'package:flutter_workshop/model/user/user.dart';
 
 class Detail extends StatelessWidget {
   static const routeName = '/detail';
-  final Donation donation;
+  final Donation? donation;
   final bool showAppBar;
 
   const Detail({
-    Key key,
-    @required this.donation,
+    Key? key,
+    required this.donation,
     this.showAppBar = true,
   }) : super(key: key);
 
@@ -24,9 +24,9 @@ class Detail extends StatelessWidget {
 }
 
 class _Body extends StatelessWidget {
-  final Donation donation;
+  final Donation? donation;
 
-  const _Body({Key key, @required this.donation}) : super(key: key);
+  const _Body({Key? key, required this.donation}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -36,11 +36,11 @@ class _Body extends StatelessWidget {
         children: <Widget>[
           _Carousel(donation: donation),
           _VerticalMargin(),
-          _Title(title: donation.title),
+          _Title(title: donation!.title),
           _VerticalMargin(),
-          Text(donation.description),
+          Text(donation!.description!),
           _VerticalMargin(),
-          _Donator(user: donation.user),
+          _Donator(user: donation!.user),
         ],
       ),
     );
@@ -48,11 +48,11 @@ class _Body extends StatelessWidget {
 }
 
 class _Carousel extends StatelessWidget {
-  final Donation donation;
+  final Donation? donation;
 
   const _Carousel({
-    Key key,
-    @required this.donation,
+    Key? key,
+    required this.donation,
   }) : super(key: key);
 
   @override
@@ -62,9 +62,9 @@ class _Carousel extends StatelessWidget {
       height: size,
       child: ListView.builder(
         scrollDirection: Axis.horizontal,
-        itemCount: donation.images.length,
+        itemCount: donation!.images.length,
         itemBuilder: (BuildContext context, int index) {
-          final String url = donation.images[index].url;
+          final String? url = donation!.images[index].url;
           return _Image(
             url: url,
             size: size,
@@ -76,13 +76,13 @@ class _Carousel extends StatelessWidget {
 }
 
 class _Image extends StatelessWidget {
-  final String url;
+  final String? url;
   final double size;
 
   const _Image({
-    Key key,
-    @required this.url,
-    @required this.size,
+    Key? key,
+    required this.url,
+    required this.size,
   }) : super(key: key);
 
   @override
@@ -92,7 +92,7 @@ class _Image extends StatelessWidget {
       child: ClipRRect(
         borderRadius: BorderRadius.circular(10.0),
         child: Image.network(
-          url,
+          url!,
           height: size,
           width: size,
           fit: BoxFit.cover,
@@ -103,14 +103,14 @@ class _Image extends StatelessWidget {
 }
 
 class _Title extends StatelessWidget {
-  final String title;
+  final String? title;
 
-  const _Title({Key key, @required this.title}) : super(key: key);
+  const _Title({Key? key, required this.title}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     return Text(
-      title,
+      title!,
       style: const TextStyle(
         fontSize: 24,
         fontWeight: FontWeight.w600,
@@ -122,19 +122,19 @@ class _Title extends StatelessWidget {
 class _Donator extends StatelessWidget {
   final User user;
 
-  const _Donator({Key key, @required this.user}) : super(key: key);
+  const _Donator({Key? key, required this.user}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
-    final ImageProvider backgroundImage = user.avatarUrl == null
+    final ImageProvider? backgroundImage = user.avatarUrl == null
         ? null
         : NetworkImage(
-            user.avatarUrl,
+            user.avatarUrl!,
           );
 
-    final Widget child = user.avatarUrl == null
+    final Widget? child = user.avatarUrl == null
         ? Text(
-            user.name[0].toUpperCase(),
+            user.name![0].toUpperCase(),
           )
         : null;
 
@@ -147,7 +147,7 @@ class _Donator extends StatelessWidget {
           foregroundColor: Colors.white,
         ),
         const SizedBox(width: 16),
-        Text(user.name)
+        Text(user.name!)
       ],
     );
   }
@@ -161,7 +161,7 @@ class _VerticalMargin extends StatelessWidget {
 }
 
 class DetailArguments {
-  final Donation donation;
+  final Donation? donation;
 
   DetailArguments({this.donation});
 }
diff --git a/lib/feature/home/home.dart b/lib/feature/home/home.dart
index 2afd88c..cbee0b6 100644
--- a/lib/feature/home/home.dart
+++ b/lib/feature/home/home.dart
@@ -18,27 +18,27 @@ class Home extends StatefulWidget {
   static const Key largeScreenCTAKey = Key(homeLargeScreenCTAKey);
   static const routeName = '/home';
 
-  final HomeBloc bloc;
+  final HomeBloc? bloc;
 
-  const Home({Key key, this.bloc}) : super(key: key);
+  const Home({Key? key, this.bloc}) : super(key: key);
 
   @override
   _HomeState createState() => _HomeState();
 }
 
 class _HomeState extends State<Home> {
-  Navigation _navigation;
+  late Navigation _navigation;
 
   @override
   void initState() {
     super.initState();
     _navigation = Navigation(context);
-    widget.bloc.loadDonations();
+    widget.bloc!.loadDonations();
   }
 
   @override
   Widget build(BuildContext context) {
-    final donationListStream = widget.bloc.stream;
+    final donationListStream = widget.bloc!.stream;
 
     return Scaffold(
       appBar: CustomAppBar(
@@ -56,9 +56,9 @@ class _HomeState extends State<Home> {
 
   List<Widget> _buildAppBarActions() {
     return <Widget>[
-      FutureBuilder<User>(
-        future: widget.bloc.loadCurrentUser(),
-        builder: (BuildContext context, AsyncSnapshot<User> snapshot) {
+      FutureBuilder<User?>(
+        future: widget.bloc!.loadCurrentUser(),
+        builder: (BuildContext context, AsyncSnapshot<User?> snapshot) {
           return snapshot.hasData
               ? _UserAvatar(
                   user: snapshot.data,
@@ -73,7 +73,7 @@ class _HomeState extends State<Home> {
   }
 
   Future _logout() async {
-    await widget.bloc.logout();
+    await widget.bloc!.logout();
     setState(() {});
     return Navigator.of(context).pop();
   }
@@ -103,9 +103,9 @@ class _DonationListStreamBuilder extends StatelessWidget {
   final Function(Donation) onTapListItem;
 
   const _DonationListStreamBuilder({
-    Key key,
-    @required this.stream,
-    @required this.onTapListItem,
+    Key? key,
+    required this.stream,
+    required this.onTapListItem,
   }) : super(key: key);
 
   @override
@@ -145,11 +145,11 @@ class _DonationListStreamBuilder extends StatelessWidget {
 }
 
 class _LargeScreenView extends StatefulWidget {
-  final List<Donation> list;
+  final List<Donation>? list;
 
   const _LargeScreenView({
-    Key key,
-    @required this.list,
+    Key? key,
+    required this.list,
   }) : super(key: key);
 
   @override
@@ -157,7 +157,7 @@ class _LargeScreenView extends StatefulWidget {
 }
 
 class __LargeScreenViewState extends State<_LargeScreenView> {
-  Donation _selectedDonation;
+  Donation? _selectedDonation;
 
   @override
   Widget build(BuildContext context) {
@@ -182,7 +182,7 @@ class __LargeScreenViewState extends State<_LargeScreenView> {
             decoration: BoxDecoration(
               border: Border(
                 left: BorderSide(
-                  color: Colors.grey[300],
+                  color: Colors.grey[300]!,
                   width: 1.0,
                 ),
               ),
@@ -202,7 +202,7 @@ class __LargeScreenViewState extends State<_LargeScreenView> {
 }
 
 class _LargeScreenCTA extends StatelessWidget {
-  const _LargeScreenCTA({Key key}) : super(key: key);
+  const _LargeScreenCTA({Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -212,21 +212,21 @@ class _LargeScreenCTA extends StatelessWidget {
         L10n.getString(
           context,
           'home_large_screen_call_to_action',
-        ),
+        )!,
       ),
     );
   }
 }
 
 class _ListView extends StatelessWidget {
-  final List<Donation> list;
+  final List<Donation>? list;
   final Function(Donation) onTapItem;
-  final int selectedDonationId;
+  final int? selectedDonationId;
 
   const _ListView({
-    Key key,
-    @required this.list,
-    @required this.onTapItem,
+    Key? key,
+    required this.list,
+    required this.onTapItem,
     this.selectedDonationId,
   }) : super(key: key);
 
@@ -236,9 +236,9 @@ class _ListView extends StatelessWidget {
       isAlwaysShown: true,
       child: ListView.builder(
         padding: const EdgeInsets.only(top: 8),
-        itemCount: list.length,
+        itemCount: list!.length,
         itemBuilder: (BuildContext context, int index) {
-          final Donation listItem = list[index];
+          final Donation listItem = list![index];
 
           final color = listItem.id == selectedDonationId
               ? Theme.of(context).primaryColor.withOpacity(0.25)
@@ -261,23 +261,23 @@ class _ListView extends StatelessWidget {
 }
 
 class _UserAvatar extends StatelessWidget {
-  final User user;
+  final User? user;
   final GestureTapCallback onTap;
 
   const _UserAvatar({
-    Key key,
-    @required this.user,
-    @required this.onTap,
+    Key? key,
+    required this.user,
+    required this.onTap,
   }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
-    Widget child = Text(user.name.substring(0, 1).toUpperCase());
-    ImageProvider backgroundImage;
+    Widget? child = Text(user!.name!.substring(0, 1).toUpperCase());
+    ImageProvider? backgroundImage;
 
-    if (user.avatarUrl != null && user.name.isNotEmpty) {
+    if (user!.avatarUrl != null && user!.name!.isNotEmpty) {
       child = null;
-      backgroundImage = NetworkImage(user.avatarUrl);
+      backgroundImage = NetworkImage(user!.avatarUrl!);
     }
 
     return GestureDetector(
@@ -294,15 +294,15 @@ class _UserAvatar extends StatelessWidget {
 }
 
 class _ListItemTile extends StatelessWidget {
-  final int index;
+  final int? index;
   final Donation donation;
   final GestureTapCallback onTap;
 
   const _ListItemTile({
-    Key key,
+    Key? key,
     this.index,
-    @required this.donation,
-    @required this.onTap,
+    required this.donation,
+    required this.onTap,
   }) : super(key: key);
 
   @override
@@ -321,14 +321,14 @@ class _ListItemTile extends StatelessWidget {
 class _DonationImage extends StatelessWidget {
   final List<DonationImage> images;
 
-  const _DonationImage({Key key, @required this.images}) : super(key: key);
+  const _DonationImage({Key? key, required this.images}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     return ClipRRect(
       borderRadius: BorderRadius.circular(5.0),
       child: Image.network(
-        images.first.url,
+        images.first.url!,
         height: 75,
         width: 75,
         fit: BoxFit.cover,
@@ -338,14 +338,14 @@ class _DonationImage extends StatelessWidget {
 }
 
 class _DonationTitle extends StatelessWidget {
-  final String text;
+  final String? text;
 
-  const _DonationTitle({Key key, @required this.text}) : super(key: key);
+  const _DonationTitle({Key? key, required this.text}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     return Text(
-      text,
+      text!,
       maxLines: 1,
       overflow: TextOverflow.ellipsis,
     );
@@ -353,16 +353,16 @@ class _DonationTitle extends StatelessWidget {
 }
 
 class _DonationSubtitle extends StatelessWidget {
-  final String text;
+  final String? text;
 
-  const _DonationSubtitle({Key key, @required this.text}) : super(key: key);
+  const _DonationSubtitle({Key? key, required this.text}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     return Padding(
       padding: const EdgeInsets.only(top: 4.0),
       child: Text(
-        text,
+        text!,
         maxLines: 2,
         overflow: TextOverflow.ellipsis,
       ),
@@ -371,9 +371,9 @@ class _DonationSubtitle extends StatelessWidget {
 }
 
 class _LoginButton extends StatelessWidget {
-  final VoidCallback onPressed;
+  final VoidCallback? onPressed;
 
-  const _LoginButton({Key key, this.onPressed}) : super(key: key);
+  const _LoginButton({Key? key, this.onPressed}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
diff --git a/lib/feature/home/home_bloc.dart b/lib/feature/home/home_bloc.dart
index a0e3a8c..6edbab6 100644
--- a/lib/feature/home/home_bloc.dart
+++ b/lib/feature/home/home_bloc.dart
@@ -9,10 +9,10 @@ import 'package:meta/meta.dart';
 
 class HomeBloc {
   HomeBloc({
-    @required this.donationApi,
-    @required this.controller,
-    @required this.diskStorageProvider,
-    @required this.sessionProvider,
+    required this.donationApi,
+    required this.controller,
+    required this.diskStorageProvider,
+    required this.sessionProvider,
   });
 
   final DonationApi donationApi;
@@ -33,7 +33,7 @@ class HomeBloc {
     }
   }
 
-  Future<User> loadCurrentUser() async => diskStorageProvider.getUser();
+  Future<User?> loadCurrentUser() async => diskStorageProvider.getUser();
 
   Future<List<bool>> logout() async => sessionProvider.logUserOut();
 }
diff --git a/lib/feature/login/login.dart b/lib/feature/login/login.dart
index 23090ea..b616353 100644
--- a/lib/feature/login/login.dart
+++ b/lib/feature/login/login.dart
@@ -22,9 +22,9 @@ class Login extends StatefulWidget {
   static const Key passwordVisibilityToggledKey =
       Key(loginPasswordVisibilityToggleValueKey);
 
-  final LoginBloc bloc;
+  final LoginBloc? bloc;
 
-  const Login({Key key, this.bloc}) : super(key: key);
+  const Login({Key? key, this.bloc}) : super(key: key);
 
   @override
   _LoginState createState() => _LoginState();
@@ -57,7 +57,7 @@ class _LoginState extends State<Login> {
   }
 
   void _listenForLoginResponse() {
-    widget.bloc.stream.listen((HttpEvent<LoginResponse> event) {
+    widget.bloc!.stream.listen((HttpEvent<LoginResponse> event) {
       if (event.isLoading) {
         return;
       }
@@ -78,12 +78,12 @@ class _LoginState extends State<Login> {
     );
   }
 
-  Future<void> _onLoginFailure(int statusCode) {
+  Future<void> _onLoginFailure(int? statusCode) {
     final Map<int, String> map = <int, String>{
       HttpStatus.badRequest: 'login_error_bad_credentials'
     };
 
-    final String messageKey = map[statusCode] ?? 'common_error_server_generic';
+    final String messageKey = map[statusCode!] ?? 'common_error_server_generic';
 
     return showDialog(
       context: context,
@@ -96,13 +96,13 @@ class _LoginState extends State<Login> {
 
 class SmallScreenView extends StatelessWidget {
   const SmallScreenView({
-    Key key,
-    @required this.bloc,
+    Key? key,
+    required this.bloc,
     this.horizontalPadding,
   }) : super(key: key);
 
-  final LoginBloc bloc;
-  final double horizontalPadding;
+  final LoginBloc? bloc;
+  final double? horizontalPadding;
 
   @override
   Widget build(BuildContext context) {
@@ -120,22 +120,22 @@ class SmallScreenView extends StatelessWidget {
 
 class LargeScreenView extends StatelessWidget {
   const LargeScreenView({
-    Key key,
-    @required this.bloc,
+    Key? key,
+    required this.bloc,
     this.horizontalPadding,
     this.formFlexFactor,
     this.headlineStyle,
   }) : super(key: key);
 
-  final LoginBloc bloc;
-  final double horizontalPadding;
-  final int formFlexFactor;
-  final TextStyle headlineStyle;
+  final LoginBloc? bloc;
+  final double? horizontalPadding;
+  final int? formFlexFactor;
+  final TextStyle? headlineStyle;
 
   @override
   Widget build(BuildContext context) {
     final theme = Theme.of(context);
-    final texStyle = headlineStyle ?? theme.textTheme.headline4;
+    final texStyle = headlineStyle ?? theme.textTheme.headline4!;
 
     return Row(
       children: [
@@ -163,7 +163,7 @@ class LargeScreenView extends StatelessWidget {
                 mainAxisAlignment: MainAxisAlignment.center,
                 children: <Widget>[
                   Text(
-                    L10n.getString(context, 'login_welcome'),
+                    L10n.getString(context, 'login_welcome')!,
                     style: texStyle.copyWith(
                       color: Colors.white,
                     ),
@@ -179,9 +179,9 @@ class LargeScreenView extends StatelessWidget {
 }
 
 class LoginForm extends StatefulWidget {
-  final LoginBloc bloc;
+  final LoginBloc? bloc;
 
-  const LoginForm({Key key, @required this.bloc}) : super(key: key);
+  const LoginForm({Key? key, required this.bloc}) : super(key: key);
 
   @override
   _LoginFormState createState() => _LoginFormState();
@@ -212,13 +212,13 @@ class _LoginFormState extends State<LoginForm> {
           ),
           const _VerticalSpacer(),
           StreamBuilder<HttpEvent<LoginResponse>>(
-            stream: widget.bloc.stream,
+            stream: widget.bloc!.stream,
             builder: (
               BuildContext context,
               AsyncSnapshot<HttpEvent<LoginResponse>> snapshot,
             ) {
               final bool isLoading =
-                  snapshot.hasData && snapshot.data.isLoading;
+                  snapshot.hasData && snapshot.data!.isLoading;
               return _SubmitButton(
                 formState: _formKey.currentState,
                 isLoading: isLoading,
@@ -233,7 +233,7 @@ class _LoginFormState extends State<LoginForm> {
     );
   }
 
-  Future<void> _sendLoginRequest() => widget.bloc.login(
+  Future<void> _sendLoginRequest() => widget.bloc!.login(
         email: _emailController.text,
         password: _passwordController.text,
       );
@@ -243,8 +243,8 @@ class _EmailField extends StatelessWidget {
   final TextEditingController controller;
 
   const _EmailField({
-    Key key,
-    @required this.controller,
+    Key? key,
+    required this.controller,
   }) : super(key: key);
 
   @override
@@ -258,9 +258,9 @@ class _EmailField extends StatelessWidget {
           'login_email',
         ),
       ),
-      validator: (String input) => L10n.getString(
+      validator: (String? input) => L10n.getString(
         context,
-        validateEmail(input),
+        validateEmail(input!),
       ),
     );
   }
@@ -272,10 +272,10 @@ class _PasswordField extends StatelessWidget {
   final VoidCallback onVisibilityTogglePressed;
 
   const _PasswordField({
-    Key key,
-    @required this.controller,
-    @required this.isPasswordVisible,
-    @required this.onVisibilityTogglePressed,
+    Key? key,
+    required this.controller,
+    required this.isPasswordVisible,
+    required this.onVisibilityTogglePressed,
   }) : super(key: key);
 
   @override
@@ -294,9 +294,9 @@ class _PasswordField extends StatelessWidget {
         ),
       ),
       obscureText: !isPasswordVisible,
-      validator: (String input) => L10n.getString(
+      validator: (String? input) => L10n.getString(
         context,
-        validatePassword(input),
+        validatePassword(input!),
       ),
     );
   }
@@ -307,9 +307,9 @@ class _PasswordVisibilityToggle extends StatelessWidget {
   final VoidCallback onPressed;
 
   const _PasswordVisibilityToggle({
-    Key key,
-    @required this.isPasswordVisible,
-    @required this.onPressed,
+    Key? key,
+    required this.isPasswordVisible,
+    required this.onPressed,
   }) : super(key: key);
 
   @override
@@ -347,27 +347,27 @@ class _PasswordVisibilityToggle extends StatelessWidget {
 
 class _SubmitButton extends StatelessWidget {
   final bool isLoading;
-  final FormState formState;
+  final FormState? formState;
   final VoidCallback onPressed;
 
   const _SubmitButton({
-    Key key,
-    @required this.isLoading,
-    @required this.formState,
-    @required this.onPressed,
+    Key? key,
+    required this.isLoading,
+    required this.formState,
+    required this.onPressed,
   }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
     final Widget child = isLoading
         ? const _ButtonProgressIndicator()
-        : Text(L10n.getString(context, 'login_title'));
+        : Text(L10n.getString(context, 'login_title')!);
 
     return PrimaryContainedButton(
       key: Login.submitButtonKey,
       child: child,
       onPressed: () {
-        if (formState.validate()) {
+        if (formState!.validate()) {
           onPressed.call();
         }
       },
@@ -402,7 +402,7 @@ class _CredentialsHint extends StatelessWidget {
           L10n.getString(
             context,
             'login_try_these_creds',
-          ),
+          )!,
           style: const TextStyle(
             color: Colors.grey,
           ),
diff --git a/lib/feature/login/login_bloc.dart b/lib/feature/login/login_bloc.dart
index 455b909..d0d5cee 100644
--- a/lib/feature/login/login_bloc.dart
+++ b/lib/feature/login/login_bloc.dart
@@ -6,13 +6,12 @@ import 'package:flutter_workshop/model/login/login_response.dart';
 import 'package:flutter_workshop/model/user/user.dart';
 import 'package:flutter_workshop/service/session_provider.dart';
 import 'package:flutter_workshop/util/http_event.dart';
-import 'package:meta/meta.dart';
 
 class LoginBloc {
   LoginBloc({
-    @required this.loginApi,
-    @required this.controller,
-    @required this.sessionProvider,
+    required this.loginApi,
+    required this.controller,
+    required this.sessionProvider,
   });
 
   final LoginApi loginApi;
@@ -23,7 +22,7 @@ class LoginBloc {
 
   Future<void> dispose() => controller.close();
 
-  Future<void> login({String email, String password}) async {
+  Future<void> login({String? email, String? password}) async {
     try {
       final LoginRequest request = LoginRequest(
         email: email,
@@ -34,7 +33,7 @@ class LoginBloc {
 
       final HttpEvent<LoginResponse> event = await loginApi.login(request);
 
-      if (event.data != null) await _saveToPreferences(event.data);
+      if (event.data != null) await _saveToPreferences(event.data!);
 
       controller.sink.add(event);
     } catch (error) {
diff --git a/lib/main.dart b/lib/main.dart
index e87a2be..3bfbe58 100644
--- a/lib/main.dart
+++ b/lib/main.dart
@@ -1,62 +1,14 @@
 import 'dart:async';
 
 import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
+import 'package:flutter_workshop/base/dependencies.dart';
 import 'package:flutter_workshop/base/my_app.dart';
-import 'package:flutter_workshop/feature/home/home_bloc.dart';
-import 'package:flutter_workshop/feature/login/login_bloc.dart';
-import 'package:flutter_workshop/model/donation/donation.dart';
-import 'package:flutter_workshop/model/donation/donation_api.dart';
-import 'package:flutter_workshop/model/login/login_api.dart';
-import 'package:flutter_workshop/model/login/login_response.dart';
-import 'package:flutter_workshop/service/session.dart';
-import 'package:flutter_workshop/service/shared_preferences_storage.dart';
-import 'package:flutter_workshop/util/http_event.dart';
-import 'package:http/http.dart' as http;
-import 'package:provider/provider.dart';
 import 'package:provider/single_child_widget.dart';
-import 'package:shared_preferences/shared_preferences.dart';
 
 Future<void> main() async {
   WidgetsFlutterBinding.ensureInitialized();
 
-  final http.Client _httpClient = http.Client();
-
-  final SharedPreferences _sharedPreferences =
-      await SharedPreferences.getInstance();
-
-  final SharedPreferencesStorage _sharedPreferencesStorage =
-      SharedPreferencesStorage(_sharedPreferences);
-
-  final Session _session =
-      Session(diskStorageProvider: _sharedPreferencesStorage);
-
-  await SystemChrome.setPreferredOrientations(
-    [
-      DeviceOrientation.portraitUp,
-      DeviceOrientation.portraitDown,
-      DeviceOrientation.landscapeLeft,
-      DeviceOrientation.landscapeRight,
-    ],
-  );
-
-  List<SingleChildWidget> providers = [
-    Provider<LoginBloc>(
-      create: (_) => LoginBloc(
-        controller: StreamController<HttpEvent<LoginResponse>>.broadcast(),
-        loginApi: LoginApi(client: _httpClient),
-        sessionProvider: _session,
-      ),
-    ),
-    Provider<HomeBloc>(
-      create: (_) => HomeBloc(
-        controller: StreamController<List<Donation>>.broadcast(),
-        donationApi: DonationApi(client: _httpClient),
-        diskStorageProvider: _sharedPreferencesStorage,
-        sessionProvider: _session,
-      ),
-    ),
-  ];
+  List<SingleChildWidget> providers = await getDependencies();
 
   runApp(MyApp(dependencies: providers));
 }
diff --git a/lib/model/donation/donation.dart b/lib/model/donation/donation.dart
index 071ca1e..ca0ef21 100644
--- a/lib/model/donation/donation.dart
+++ b/lib/model/donation/donation.dart
@@ -6,9 +6,9 @@ part 'donation.g.dart';
 
 @JsonSerializable()
 class Donation {
-  final int id;
-  final String title;
-  final String description;
+  final int? id;
+  final String? title;
+  final String? description;
   final User user;
   @JsonKey(name: 'listing_images')
   final List<DonationImage> images;
@@ -24,7 +24,7 @@ class Donation {
   factory Donation.fromJson(Map<String, dynamic> json) =>
       _$DonationFromJson(json);
 
-  factory Donation.fake({User user}) {
+  factory Donation.fake({User? user}) {
     const id = 1;
     const title = 'Donation';
     const description =
diff --git a/lib/model/donation/donation_api.dart b/lib/model/donation/donation_api.dart
index 0c85098..8a2a581 100644
--- a/lib/model/donation/donation_api.dart
+++ b/lib/model/donation/donation_api.dart
@@ -7,7 +7,7 @@ import 'package:http/http.dart' as http;
 import 'package:meta/meta.dart';
 
 class DonationApi extends BaseApi {
-  DonationApi({@required http.Client client}) : super(client: client);
+  DonationApi({required http.Client client}) : super(client: client);
 
   Future<List<Donation>> getDonations() async {
     final String url = '${baseUrl}users/4/listings';
diff --git a/lib/model/donation/donation_image.dart b/lib/model/donation/donation_image.dart
index 09772fb..abe12e8 100644
--- a/lib/model/donation/donation_image.dart
+++ b/lib/model/donation/donation_image.dart
@@ -4,7 +4,7 @@ part 'donation_image.g.dart';
 
 @JsonSerializable()
 class DonationImage {
-  final String url;
+  final String? url;
 
   DonationImage(this.url);
 
diff --git a/lib/model/login/login_api.dart b/lib/model/login/login_api.dart
index e22259c..61f95e9 100644
--- a/lib/model/login/login_api.dart
+++ b/lib/model/login/login_api.dart
@@ -9,13 +9,13 @@ import 'package:flutter_workshop/model/login/login_response.dart';
 import 'package:meta/meta.dart';
 
 class LoginApi extends BaseApi {
-  LoginApi({@required http.Client client}) : super(client: client);
+  LoginApi({required http.Client client}) : super(client: client);
 
   Future<HttpEvent<LoginResponse>> login(LoginRequest request) async {
     const String url = 'https://reqres.in/api/login';
     final http.Response response = await post(url, request.toJson());
 
-    LoginResponse data;
+    LoginResponse? data;
 
     if (response.statusCode == HttpStatus.ok) {
       data = LoginResponse.fromJson(jsonDecode(response.body));
diff --git a/lib/model/login/login_request.dart b/lib/model/login/login_request.dart
index ab83d54..82fae3a 100644
--- a/lib/model/login/login_request.dart
+++ b/lib/model/login/login_request.dart
@@ -4,8 +4,8 @@ class LoginRequest {
     this.password,
   });
 
-  final String email;
-  final String password;
+  final String? email;
+  final String? password;
 
   Map<String, dynamic> toJson() => <String, dynamic>{
         'email': email,
diff --git a/lib/model/login/login_response.dart b/lib/model/login/login_response.dart
index 13cd1c3..0cdea49 100644
--- a/lib/model/login/login_response.dart
+++ b/lib/model/login/login_response.dart
@@ -4,7 +4,7 @@ part 'login_response.g.dart';
 
 @JsonSerializable()
 class LoginResponse {
-  final String token;
+  final String? token;
 
   LoginResponse(this.token);
 
diff --git a/lib/model/user/user.dart b/lib/model/user/user.dart
index 6342c53..eb2897b 100644
--- a/lib/model/user/user.dart
+++ b/lib/model/user/user.dart
@@ -6,10 +6,10 @@ part 'user.g.dart';
 
 @JsonSerializable()
 class User {
-  int id;
-  String name;
+  int? id;
+  String? name;
   @JsonKey(name: 'image_url')
-  String avatarUrl;
+  String? avatarUrl;
 
   User(
     this.id,
@@ -20,10 +20,10 @@ class User {
   factory User.fromJson(Map<String, dynamic> json) => _$UserFromJson(json);
 
   factory User.fromEncodedJson(String encoded) =>
-      encoded == null ? null : User.fromJson(jsonDecode(encoded));
+      User.fromJson(jsonDecode(encoded));
 
   User.fake({
-    String avatarUrl =
+    String? avatarUrl =
         'https://firebasestorage.googleapis.com/v0/b/givapp-938de.appspot.com/o/randomuser_women_30.jpeg?alt=media&token=823cbd79-f1f1-4c83-8f6d-8f8fea537f2c',
   })  : id = 1,
         name = 'Eve Holt',
diff --git a/lib/service/disk_storage_provider.dart b/lib/service/disk_storage_provider.dart
index b821864..bd6ffbc 100644
--- a/lib/service/disk_storage_provider.dart
+++ b/lib/service/disk_storage_provider.dart
@@ -2,9 +2,9 @@ import 'package:flutter_workshop/model/user/user.dart';
 
 abstract class DiskStorageProvider {
   Future<bool> setUser(User user);
-  User getUser();
+  User? getUser();
   Future<bool> clearUser();
-  Future<bool> setAccessToken(String token);
-  String getAccessToken();
+  Future<bool> setAccessToken(String? token);
+  String? getAccessToken();
   Future<bool> clearToken();
 }
diff --git a/lib/service/session.dart b/lib/service/session.dart
index 12cbe17..6af53d2 100644
--- a/lib/service/session.dart
+++ b/lib/service/session.dart
@@ -1,17 +1,16 @@
 import 'package:flutter_workshop/model/user/user.dart';
 import 'package:flutter_workshop/service/disk_storage_provider.dart';
-import 'package:meta/meta.dart';
 
 import 'session_provider.dart';
 
 class Session implements SessionProvider {
-  Session({@required this.diskStorageProvider});
+  Session({required this.diskStorageProvider});
 
   final DiskStorageProvider diskStorageProvider;
 
   @override
   Future<List<bool>> logUserIn(
-    String token,
+    String? token,
     User user,
   ) =>
       Future.wait(
diff --git a/lib/service/session_provider.dart b/lib/service/session_provider.dart
index 73276e7..496d076 100644
--- a/lib/service/session_provider.dart
+++ b/lib/service/session_provider.dart
@@ -1,6 +1,6 @@
 import 'package:flutter_workshop/model/user/user.dart';
 
 abstract class SessionProvider {
-  Future<List<bool>> logUserIn(String token, User user);
+  Future<List<bool>> logUserIn(String? token, User user);
   Future<List<bool>> logUserOut();
 }
diff --git a/lib/service/shared_preferences_storage.dart b/lib/service/shared_preferences_storage.dart
index 7e2ffc5..982e676 100644
--- a/lib/service/shared_preferences_storage.dart
+++ b/lib/service/shared_preferences_storage.dart
@@ -11,13 +11,13 @@ class SharedPreferencesStorage implements DiskStorageProvider {
   final SharedPreferences sharedPreferences;
 
   @override
-  User getUser() {
+  User? getUser() {
     try {
-      return User.fromEncodedJson(
-        sharedPreferences.getString(
-          _userKey,
-        ),
+      final encodedJson = sharedPreferences.getString(
+        _userKey,
       );
+
+      return encodedJson == null ? null : User.fromEncodedJson(encodedJson);
     } catch (e) {
       return null;
     }
@@ -30,14 +30,14 @@ class SharedPreferencesStorage implements DiskStorageProvider {
       );
 
   @override
-  String getAccessToken() => sharedPreferences.getString(
+  String? getAccessToken() => sharedPreferences.getString(
         _accessTokenKey,
       );
 
   @override
-  Future<bool> setAccessToken(String token) => sharedPreferences.setString(
+  Future<bool> setAccessToken(String? token) => sharedPreferences.setString(
         _accessTokenKey,
-        token,
+        token!,
       );
 
   @override
diff --git a/lib/util/custom_form_field_validator.dart b/lib/util/custom_form_field_validator.dart
index 07e3d74..f9b33ce 100644
--- a/lib/util/custom_form_field_validator.dart
+++ b/lib/util/custom_form_field_validator.dart
@@ -1,7 +1,7 @@
-String validateEmail(String input) {
+String? validateEmail(String input) {
   const Pattern pattern =
       r'^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$';
-  final RegExp regex = RegExp(pattern);
+  final RegExp regex = RegExp(pattern as String);
 
   if (input.trim().isEmpty) {
     return 'validation_message_email_required';
@@ -14,7 +14,7 @@ String validateEmail(String input) {
   return null;
 }
 
-String validatePassword(String input) {
+String? validatePassword(String input) {
   if (input.trim().isEmpty) {
     return 'validation_message_password_required';
   }
diff --git a/lib/util/http_event.dart b/lib/util/http_event.dart
index e3b62ad..739e2d2 100644
--- a/lib/util/http_event.dart
+++ b/lib/util/http_event.dart
@@ -6,8 +6,8 @@ class HttpEvent<T> {
   });
 
   final EventState state;
-  final T data;
-  final int statusCode;
+  final T? data;
+  final int? statusCode;
 
   bool get isLoading => state == EventState.loading;
 }
diff --git a/lib/util/navigation.dart b/lib/util/navigation.dart
index e844e94..12c58a8 100644
--- a/lib/util/navigation.dart
+++ b/lib/util/navigation.dart
@@ -5,9 +5,9 @@ class Navigation {
 
   final BuildContext context;
 
-  Future<T> pushNamed<T extends Object>(
+  Future pushNamed(
     String routeName, {
-    Object arguments,
+    Object? arguments,
     bool clearStack = false,
   }) {
     return clearStack
diff --git a/pubspec.lock b/pubspec.lock
index 2ee5650..91e934d 100644
--- a/pubspec.lock
+++ b/pubspec.lock
@@ -7,35 +7,35 @@ packages:
       name: _fe_analyzer_shared
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "14.0.0"
+    version: "22.0.0"
   analyzer:
     dependency: transitive
     description:
       name: analyzer
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.41.2"
+    version: "1.7.1"
   archive:
     dependency: transitive
     description:
       name: archive
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.13"
+    version: "3.1.2"
   args:
     dependency: transitive
     description:
       name: args
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.0"
+    version: "2.1.1"
   async:
     dependency: transitive
     description:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0"
+    version: "2.6.1"
   boolean_selector:
     dependency: transitive
     description:
@@ -49,56 +49,56 @@ packages:
       name: build
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.6.2"
+    version: "2.0.2"
   build_config:
     dependency: transitive
     description:
       name: build_config
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.4.5"
+    version: "1.0.0"
   build_daemon:
     dependency: transitive
     description:
       name: build_daemon
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.10"
+    version: "3.0.0"
   build_resolvers:
     dependency: transitive
     description:
       name: build_resolvers
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.5.3"
+    version: "2.0.3"
   build_runner:
     dependency: "direct dev"
     description:
       name: build_runner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.11.1"
+    version: "2.0.4"
   build_runner_core:
     dependency: transitive
     description:
       name: build_runner_core
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "6.1.7"
+    version: "7.0.0"
   built_collection:
     dependency: transitive
     description:
       name: built_collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.3.2"
+    version: "5.0.0"
   built_value:
     dependency: transitive
     description:
       name: built_value
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "7.1.0"
+    version: "8.0.6"
   characters:
     dependency: transitive
     description:
@@ -119,7 +119,7 @@ packages:
       name: checked_yaml
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.4"
+    version: "2.0.1"
   cli_util:
     dependency: transitive
     description:
@@ -140,7 +140,7 @@ packages:
       name: code_builder
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.7.0"
+    version: "4.0.0"
   collection:
     dependency: transitive
     description:
@@ -154,35 +154,35 @@ packages:
       name: convert
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.1"
+    version: "3.0.0"
   coverage:
     dependency: transitive
     description:
       name: coverage
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.15.2"
+    version: "1.0.3"
   crypto:
     dependency: transitive
     description:
       name: crypto
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.5"
+    version: "3.0.1"
   cupertino_icons:
     dependency: "direct main"
     description:
       name: cupertino_icons
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.2"
+    version: "1.0.3"
   dart_style:
     dependency: transitive
     description:
       name: dart_style
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.12"
+    version: "2.0.1"
   fake_async:
     dependency: transitive
     description:
@@ -203,14 +203,14 @@ packages:
       name: file
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "6.0.0"
+    version: "6.1.0"
   fixnum:
     dependency: transitive
     description:
       name: fixnum
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.10.11"
+    version: "1.0.0"
   flutter:
     dependency: "direct main"
     description: flutter
@@ -236,6 +236,13 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  frontend_server_client:
+    dependency: transitive
+    description:
+      name: frontend_server_client
+      url: "https://pub.dartlang.org"
+    source: hosted
+    version: "2.1.0"
   fuchsia_remote_debug_protocol:
     dependency: transitive
     description: flutter
@@ -247,28 +254,28 @@ packages:
       name: glob
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "2.0.1"
   graphs:
     dependency: transitive
     description:
       name: graphs
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.0"
+    version: "2.0.0"
   http:
     dependency: "direct main"
     description:
       name: http
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.13.1"
+    version: "0.13.3"
   http_multi_server:
     dependency: transitive
     description:
       name: http_multi_server
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.2.0"
+    version: "3.0.1"
   http_parser:
     dependency: transitive
     description:
@@ -289,7 +296,7 @@ packages:
       name: io
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.4"
+    version: "1.0.0"
   js:
     dependency: transitive
     description:
@@ -303,21 +310,21 @@ packages:
       name: json_annotation
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.1.1"
+    version: "4.0.1"
   json_serializable:
     dependency: "direct dev"
     description:
       name: json_serializable
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.5.1"
+    version: "4.1.3"
   logging:
     dependency: transitive
     description:
       name: logging
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.11.4"
+    version: "1.0.1"
   matcher:
     dependency: transitive
     description:
@@ -338,14 +345,14 @@ packages:
       name: mime
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.9.6+3"
+    version: "1.0.0"
   mockito:
     dependency: "direct dev"
     description:
       name: mockito
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.1.4"
+    version: "5.0.9"
   nested:
     dependency: transitive
     description:
@@ -359,35 +366,21 @@ packages:
       name: network_image_mock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
-  node_interop:
-    dependency: transitive
-    description:
-      name: node_interop
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.0.3"
-  node_io:
-    dependency: transitive
-    description:
-      name: node_io
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.1.0"
+    version: "2.0.1"
   node_preamble:
     dependency: transitive
     description:
       name: node_preamble
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.8"
+    version: "2.0.0"
   package_config:
     dependency: transitive
     description:
       name: package_config
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.9.3"
+    version: "2.0.0"
   path:
     dependency: transitive
     description:
@@ -450,7 +443,7 @@ packages:
       name: process
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.0.0"
+    version: "4.2.1"
   provider:
     dependency: "direct main"
     description:
@@ -464,28 +457,21 @@ packages:
       name: pub_semver
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.4.4"
+    version: "2.0.0"
   pubspec_parse:
     dependency: transitive
     description:
       name: pubspec_parse
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.8"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.1.3"
+    version: "1.0.0"
   shared_preferences:
     dependency: "direct main"
     description:
       name: shared_preferences
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.5"
+    version: "2.0.6"
   shared_preferences_linux:
     dependency: transitive
     description:
@@ -534,21 +520,21 @@ packages:
       name: shelf_packages_handler
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.0.1"
+    version: "3.0.0"
   shelf_static:
     dependency: transitive
     description:
       name: shelf_static
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.9+2"
+    version: "1.0.0"
   shelf_web_socket:
     dependency: transitive
     description:
       name: shelf_web_socket
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.4+1"
+    version: "1.0.1"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -560,7 +546,7 @@ packages:
       name: source_gen
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.9.10+3"
+    version: "1.0.1"
   source_map_stack_trace:
     dependency: transitive
     description:
@@ -581,7 +567,7 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0"
+    version: "1.8.1"
   stack_trace:
     dependency: transitive
     description:
@@ -602,7 +588,7 @@ packages:
       name: stream_transform
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0"
+    version: "2.0.0"
   string_scanner:
     dependency: transitive
     description:
@@ -616,7 +602,7 @@ packages:
       name: sync_http
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.0"
+    version: "0.3.0"
   term_glyph:
     dependency: transitive
     description:
@@ -630,28 +616,28 @@ packages:
       name: test
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.16.5"
+    version: "1.16.8"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19"
+    version: "0.3.0"
   test_core:
     dependency: transitive
     description:
       name: test_core
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.3.15"
+    version: "0.3.19"
   timing:
     dependency: transitive
     description:
       name: timing
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.1+3"
+    version: "1.0.0"
   typed_data:
     dependency: transitive
     description:
@@ -672,35 +658,35 @@ packages:
       name: vm_service
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "5.5.0"
+    version: "6.2.0"
   watcher:
     dependency: transitive
     description:
       name: watcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.9.7+15"
+    version: "1.0.0"
   web_socket_channel:
     dependency: transitive
     description:
       name: web_socket_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0"
+    version: "2.1.0"
   webdriver:
     dependency: transitive
     description:
       name: webdriver
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.2"
+    version: "3.0.0"
   webkit_inspection_protocol:
     dependency: transitive
     description:
       name: webkit_inspection_protocol
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.5.3"
+    version: "1.0.0"
   win32:
     dependency: transitive
     description:
@@ -721,7 +707,7 @@ packages:
       name: yaml
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.2.1"
+    version: "3.1.0"
 sdks:
   dart: ">=2.12.0 <3.0.0"
   flutter: ">=1.20.0"
diff --git a/pubspec.yaml b/pubspec.yaml
index 7f5da7d..63e2068 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -14,7 +14,7 @@ description: A sample Flutter application.
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.2.2 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter:
@@ -22,13 +22,13 @@ dependencies:
   flutter_localizations:
     sdk: flutter
 
-  http: ^0.13.1
+  http: ^0.13.3
   provider: ^5.0.0
-  shared_preferences: ^2.0.5
+  shared_preferences: ^2.0.6
 
   # The following adds the Cupertino Icons font to your application.
   # Use with the CupertinoIcons class for iOS style icons.
-  cupertino_icons: ^1.0.2
+  cupertino_icons: ^1.0.3
 
 dev_dependencies:
   flutter_driver:
@@ -36,12 +36,12 @@ dev_dependencies:
   flutter_test:
     sdk: flutter
 
-  build_runner: ^1.8.1
-  json_annotation: ^3.1.1
-  json_serializable: ^3.5.1
-  mockito: ^4.1.3
-  network_image_mock: 1.1.0
-  test: ^1.14.3
+  build_runner: ^2.0.4
+  json_annotation: ^4.0.1
+  json_serializable: ^4.1.3
+  mockito: ^5.0.9
+  network_image_mock: ^2.0.1
+  test: ^1.16.8
 
 
 # For information on the generic Dart part of this file, see the
diff --git a/test/adaptive_vew_test.dart b/test/adaptive_vew_test.dart
index a8d8cc5..f231d73 100644
--- a/test/adaptive_vew_test.dart
+++ b/test/adaptive_vew_test.dart
@@ -9,10 +9,10 @@ import 'test_util/test_util.dart';
 
 void main() {
   Widget makeTestableWidget({
-    Widget smallView,
-    Widget mediumView,
-    Widget largeView,
-    FormFactor formFactor,
+    Widget? smallView,
+    Widget? mediumView,
+    Widget? largeView,
+    FormFactor? formFactor,
   }) {
     return TestUtil.makeTestableWidget(
       dependencies: [
diff --git a/test/custom_form_field_validator_test.dart b/test/custom_form_field_validator_test.dart
index 4e0930b..b8541ee 100644
--- a/test/custom_form_field_validator_test.dart
+++ b/test/custom_form_field_validator_test.dart
@@ -3,22 +3,22 @@ import 'package:test/test.dart';
 
 void main() {
   test('empty email returns error string', () {
-    final String result = validateEmail('');
+    final String? result = validateEmail('');
     expect(result, 'validation_message_email_required');
   });
 
   test('invalid email returns error string', () {
-    final String result = validateEmail('invalid email');
+    final String? result = validateEmail('invalid email');
     expect(result, 'validation_message_email_invalid');
   });
 
   test('empty password returns error string', () {
-    final String result = validatePassword('');
+    final String? result = validatePassword('');
     expect(result, 'validation_message_password_required');
   });
 
   test('short password returns error string', () {
-    final String result = validatePassword('12345');
+    final String? result = validatePassword('12345');
     expect(result, 'validation_message_password_too_short');
   });
 }
diff --git a/test/detail_test.dart b/test/detail_test.dart
index 3cc76e6..ba7cc00 100644
--- a/test/detail_test.dart
+++ b/test/detail_test.dart
@@ -66,8 +66,8 @@ void main() {
         ),
       );
 
-      expect(find.text(fakeDonation.title), findsOneWidget);
-      expect(find.text(fakeDonation.description), findsOneWidget);
+      expect(find.text(fakeDonation.title!), findsOneWidget);
+      expect(find.text(fakeDonation.description!), findsOneWidget);
     });
   });
 
@@ -82,7 +82,7 @@ void main() {
         ),
       );
 
-      expect(find.text(fakeDonation.user.name), findsOneWidget);
+      expect(find.text(fakeDonation.user.name!), findsOneWidget);
     });
   });
 
@@ -99,7 +99,7 @@ void main() {
       );
 
       expect(
-        find.text(Donation.fake().user.name[0]),
+        find.text(Donation.fake().user.name![0]),
         findsOneWidget,
       );
     });
diff --git a/test/donation_api_test.dart b/test/donation_api_test.dart
index 4b0823e..f3f02bb 100644
--- a/test/donation_api_test.dart
+++ b/test/donation_api_test.dart
@@ -14,7 +14,7 @@ void main() {
     const String _fakeResponseBody =
         '[{"id":127,"title":"Livro A vida do bebê","description":"Livro do pediatra Dr Rinaldo de Lamare","geonames_city_id":"6698115","geonames_state_id":"3463504","geonames_country_id":"3469034","is_active":true,"updated_at":"2019-04-18T01:47:14.841Z","user":{"id":80,"name":"Leila Fernandes","country_calling_code":"55","phone_number":"61992457329","image_url":"https://platform-lookaside.fbsbx.com/platform/profilepic/?asid=2184645801651822\u0026width=640\u0026ext=1558106954\u0026hash=AeSR9xd7OYoqRFTX","bio":null,"created_at":"2019-04-17T15:29:14.211Z"},"categories":[{"id":33,"simple_name":"Livros","canonical_name":"Livros"}],"listing_images":[{"id":444,"url":"https://firebasestorage.googleapis.com/v0/b/givapp-938de.appspot.com/o/listings%2F1555551883274-89d414c0-5970-11e9-f3fe-f96200bfa261.jpg?alt=media\u0026token=e8a51fc1-4388-4348-babe-693b9c1b99ae","position":0}]}]';
 
-    when(_mockClient.get(any, headers: anyNamed('headers')))
+    when(_mockClient.get(any!, headers: anyNamed('headers')))
         .thenAnswer((_) async => http.Response(_fakeResponseBody, 200));
 
     expect(await _donationApi.getDonations(), isA<List<Donation>>());
diff --git a/test/home_bloc_test.dart b/test/home_bloc_test.dart
index db76c0c..ad863c0 100644
--- a/test/home_bloc_test.dart
+++ b/test/home_bloc_test.dart
@@ -18,12 +18,12 @@ class MockHomeResponseStreamSink extends Mock
     implements StreamSink<List<Donation>> {}
 
 void main() {
-  MockHomeResponseStreamController _mockController;
-  MockHomeResponseStreamSink _mockSink;
-  MockDonationApi _mockDonationApi;
-  MockSessionProvider _mockSessionProvider;
-  MockDiskStorageProvider _mockDiskStorageProvider;
-  HomeBloc _bloc;
+  late MockHomeResponseStreamController _mockController;
+  late MockHomeResponseStreamSink _mockSink;
+  late MockDonationApi _mockDonationApi;
+  late MockSessionProvider _mockSessionProvider;
+  late MockDiskStorageProvider _mockDiskStorageProvider;
+  late HomeBloc _bloc;
 
   setUp(() {
     _mockController = MockHomeResponseStreamController();
@@ -52,14 +52,14 @@ void main() {
         .thenAnswer((_) async => Donation.fakeList());
 
     await _bloc.loadDonations();
-    verify(_mockSink.add(any));
+    verify(_mockSink.add(any!));
   });
 
   test('adds error to stream sink if api throws an exception', () async {
     when(_mockDonationApi.getDonations()).thenThrow(Error());
 
     await _bloc.loadDonations();
-    verify(_mockSink.addError(any)).called(1);
+    verify(_mockSink.addError(any!)).called(1);
   });
 
   test('recovers user from disk storage', () async {
diff --git a/test/home_test.dart b/test/home_test.dart
index 3efe9f2..82ebdc1 100644
--- a/test/home_test.dart
+++ b/test/home_test.dart
@@ -22,7 +22,7 @@ import 'test_util/test_util.dart';
 
 void main() {
   final TestWidgetsFlutterBinding binding =
-      TestWidgetsFlutterBinding.ensureInitialized();
+      TestWidgetsFlutterBinding.ensureInitialized() as TestWidgetsFlutterBinding;
 
   final MockHomeBloc _mockHomeBloc = MockHomeBloc();
   final MockLoginBloc _mockLoginBloc = MockLoginBloc();
@@ -95,7 +95,7 @@ void main() {
       await tester.tap(loginButton);
       await tester.pumpAndSettle();
 
-      verify(_mockNavigationObserver.didPush(any, any));
+      verify(_mockNavigationObserver.didPush(any!, any));
       expect(find.byType(Login), findsOneWidget);
     });
 
@@ -121,7 +121,7 @@ void main() {
         await tester.tap(firstItem);
         await tester.pumpAndSettle();
 
-        verify(_mockNavigationObserver.didPush(any, any));
+        verify(_mockNavigationObserver.didPush(any!, any));
         expect(find.byType(Detail), findsOneWidget);
 
         await controller.close();
diff --git a/test/login_api_test.dart b/test/login_api_test.dart
index e4cf800..9c09403 100644
--- a/test/login_api_test.dart
+++ b/test/login_api_test.dart
@@ -10,8 +10,8 @@ import 'test_util/fakes.dart';
 import 'test_util/mocks.dart';
 
 void main() {
-  MockClient _mockClient;
-  LoginApi _loginApi;
+  late MockClient _mockClient;
+  late LoginApi _loginApi;
   final LoginRequest _loginRequest = LoginRequest(
     email: 'ab@cd.com',
     password: '123456',
@@ -25,7 +25,7 @@ void main() {
   test('returns LoginResponse data if the http call succeeds', () async {
     when(
       _mockClient.post(
-        any,
+        any!,
         body: anyNamed('body'),
         headers: anyNamed('headers'),
       ),
@@ -40,7 +40,7 @@ void main() {
   test('returns null data if the http call fails', () async {
     when(
       _mockClient.post(
-        any,
+        any!,
         body: anyNamed('body'),
         headers: anyNamed('headers'),
       ),
diff --git a/test/login_bloc_test.dart b/test/login_bloc_test.dart
index 921e158..ae32840 100644
--- a/test/login_bloc_test.dart
+++ b/test/login_bloc_test.dart
@@ -18,11 +18,11 @@ class MockLoginResponseStreamSink extends Mock
     implements StreamSink<HttpEvent<LoginResponse>> {}
 
 Future<void> main() async {
-  MockLoginResponseStreamController _mockController;
-  MockLoginResponseStreamSink _mockSink;
-  MockLoginApi _mockLoginApi;
-  MockSessionProvider _mockSessionProvider;
-  LoginBloc _bloc;
+  late MockLoginResponseStreamController _mockController;
+  late MockLoginResponseStreamSink _mockSink;
+  late MockLoginApi _mockLoginApi;
+  late MockSessionProvider _mockSessionProvider;
+  late LoginBloc _bloc;
 
   setUp(() async {
     _mockController = MockLoginResponseStreamController();
@@ -42,34 +42,34 @@ Future<void> main() async {
 
   test('calls login api', () async {
     await _bloc.login(email: 'test@test.com', password: '123456');
-    verify(_mockLoginApi.login(any));
+    verify(_mockLoginApi.login(any!));
   });
 
   test(
       'adds loading and success events to stream sink if api returns a LoginReponse',
       () async {
-    when(_mockLoginApi.login(any)).thenAnswer(
+    when(_mockLoginApi.login(any!)).thenAnswer(
         (_) async => HttpEvent<LoginResponse>(data: LoginResponse('token')));
 
     await _bloc.login(email: 'test@test.com', password: '123456');
-    verify(_mockSink.add(any)).called(2);
+    verify(_mockSink.add(any!)).called(2);
   });
 
   test('adds error to stream sink if api throws an exception', () async {
-    when(_mockLoginApi.login(any)).thenThrow(Error());
+    when(_mockLoginApi.login(any!)).thenThrow(Error());
 
     await _bloc.login(email: 'test@test.com', password: '123456');
-    verify(_mockSink.addError(any)).called(1);
+    verify(_mockSink.addError(any!)).called(1);
   });
 
   test('creates session if api returns a LoginReponse', () async {
     const token = 'i am a token';
 
-    when(_mockLoginApi.login(any)).thenAnswer(
+    when(_mockLoginApi.login(any!)).thenAnswer(
         (_) async => HttpEvent<LoginResponse>(data: LoginResponse(token)));
 
     await _bloc.login(email: 'test@test.com', password: '123456');
-    verify(_mockSessionProvider.logUserIn(token, any));
+    verify(_mockSessionProvider.logUserIn(token, any!));
   });
 
   test('gets contoller stream', () async {
diff --git a/test/login_test.dart b/test/login_test.dart
index c4e4e83..77d5034 100644
--- a/test/login_test.dart
+++ b/test/login_test.dart
@@ -18,15 +18,15 @@ import 'test_util/mocks.dart';
 import 'test_util/test_util.dart';
 
 void main() {
-  MockLoginBloc _mockLoginBloc;
+  MockLoginBloc? _mockLoginBloc;
   MockHomeBloc _mockHomeBloc;
-  MockNavigatorObserver _mockNavigationObserver;
-  Widget _testableWidget;
-  Finder _emailField;
-  Finder _passwordField;
-  Finder _submitButton;
-  Finder _passwordVisibilityToggle;
-  StreamController<HttpEvent<LoginResponse>> _streamController;
+  MockNavigatorObserver? _mockNavigationObserver;
+  late Widget _testableWidget;
+  late Finder _emailField;
+  late Finder _passwordField;
+  late Finder _submitButton;
+  late Finder _passwordVisibilityToggle;
+  late StreamController<HttpEvent<LoginResponse>> _streamController;
 
   setUp(() {
     _mockLoginBloc = MockLoginBloc();
@@ -41,7 +41,7 @@ void main() {
       dependencies: [
         Provider<HomeBloc>(create: (_) => _mockHomeBloc),
       ],
-      navigatorObservers: <NavigatorObserver>[_mockNavigationObserver],
+      navigatorObservers: <NavigatorObserver?>[_mockNavigationObserver],
       testingLocale: supportedLocales.first,
     );
 
@@ -50,7 +50,7 @@ void main() {
     _submitButton = find.byKey(Login.submitButtonKey);
     _passwordVisibilityToggle = find.byKey(Login.passwordVisibilityToggledKey);
 
-    when(_mockLoginBloc.stream).thenAnswer((_) => _streamController.stream);
+    when(_mockLoginBloc!.stream).thenAnswer((_) => _streamController.stream);
   });
 
   group('attempts login', () {
@@ -65,7 +65,7 @@ void main() {
       await tester.enterText(_passwordField, password);
       await tester.tap(_submitButton);
 
-      verify(_mockLoginBloc.login(email: email, password: password));
+      verify(_mockLoginBloc!.login(email: email, password: password));
     });
 
     testWidgets('does not attempt login if email and password are empty',
@@ -74,7 +74,7 @@ void main() {
 
       await tester.tap(_submitButton);
 
-      verifyNever(_mockLoginBloc.login(email: '', password: ''));
+      verifyNever(_mockLoginBloc!.login(email: '', password: ''));
     });
 
     testWidgets('does not attempt login if email is not a valid email',
@@ -88,7 +88,7 @@ void main() {
       await tester.enterText(_passwordField, password);
       await tester.tap(_submitButton);
 
-      verifyNever(_mockLoginBloc.login(email: email, password: password));
+      verifyNever(_mockLoginBloc!.login(email: email, password: password));
     });
 
     testWidgets('does not attempt login if password is too short',
@@ -102,7 +102,7 @@ void main() {
       await tester.enterText(_passwordField, password);
       await tester.tap(_submitButton);
 
-      verifyNever(_mockLoginBloc.login(email: email, password: password));
+      verifyNever(_mockLoginBloc!.login(email: email, password: password));
     });
   });
 
@@ -226,7 +226,7 @@ void main() {
 
       await tester.pumpAndSettle();
 
-      verify(_mockNavigationObserver.didPush(any, any));
+      verify(_mockNavigationObserver!.didPush(any!, any));
       expect(find.byType(Home), findsOneWidget);
     });
 
diff --git a/test/session_test.dart b/test/session_test.dart
index fac8e6f..c1cfab6 100644
--- a/test/session_test.dart
+++ b/test/session_test.dart
@@ -6,8 +6,8 @@ import 'package:flutter_workshop/model/user/user.dart';
 import 'test_util/mocks.dart';
 
 void main() {
-  MockDiskStorageProvider _mockStorage;
-  Session _session;
+  late MockDiskStorageProvider _mockStorage;
+  late Session _session;
 
   setUp(() {
     _mockStorage = MockDiskStorageProvider();
@@ -24,7 +24,7 @@ void main() {
         // Given
         const token = 'i am a token';
         when(_mockStorage.setAccessToken(any)).thenAnswer((_) async => true);
-        when(_mockStorage.setUser(any)).thenAnswer((_) async => true);
+        when(_mockStorage.setUser(any!)).thenAnswer((_) async => true);
 
         // When
         await _session.logUserIn(token, User.fake());
@@ -37,7 +37,7 @@ void main() {
         // Given
         final user = User.fake();
         when(_mockStorage.setAccessToken(any)).thenAnswer((_) async => true);
-        when(_mockStorage.setUser(any)).thenAnswer((_) async => true);
+        when(_mockStorage.setUser(any!)).thenAnswer((_) async => true);
 
         // When
         await _session.logUserIn('any token', user);
diff --git a/test/test_util/test_util.dart b/test/test_util/test_util.dart
index 1e56363..a66d4b1 100644
--- a/test/test_util/test_util.dart
+++ b/test/test_util/test_util.dart
@@ -9,10 +9,10 @@ import 'package:provider/single_child_widget.dart';
 
 class TestUtil {
   static Widget makeTestableWidget({
-    Widget subject,
-    List<SingleChildWidget> dependencies,
-    List<NavigatorObserver> navigatorObservers,
-    Locale testingLocale,
+    Widget? subject,
+    required List<SingleChildWidget> dependencies,
+    List<NavigatorObserver?>? navigatorObservers,
+    Locale? testingLocale,
   }) {
     return MultiProvider(
       providers: dependencies,
@@ -25,25 +25,25 @@ class TestUtil {
         supportedLocales: supportedLocales,
         onGenerateRoute: getRouteFactory,
         home: subject,
-        navigatorObservers: navigatorObservers ?? const <NavigatorObserver>[],
+        navigatorObservers: navigatorObservers as List<NavigatorObserver>? ?? const <NavigatorObserver>[],
       ),
     );
   }
 
   static Finder findInternationalizedText(String localizationKey) {
-    final Map<String, String> localizationMap = Strings().map[localizationKey];
+    final Map<String, String>? localizationMap = Strings().map[localizationKey];
 
     return find.byElementPredicate((Element candidate) {
       if (candidate.widget is Text) {
-        final Text textWidget = candidate.widget;
+        final Text textWidget = candidate.widget as Text;
         return (textWidget.data != null)
-            ? localizationMap.containsValue(textWidget.data)
-            : localizationMap.containsValue(textWidget.textSpan.toPlainText());
+            ? localizationMap!.containsValue(textWidget.data)
+            : localizationMap!.containsValue(textWidget.textSpan!.toPlainText());
       }
 
       if (candidate.widget is EditableText) {
-        final EditableText editable = candidate.widget;
-        return localizationMap.containsValue(editable.controller.text);
+        final EditableText editable = candidate.widget as EditableText;
+        return localizationMap!.containsValue(editable.controller.text);
       }
 
       return false;
diff --git a/test_driver/app_test.dart b/test_driver/app_test.dart
index 1c9c66a..7f7eb6b 100644
--- a/test_driver/app_test.dart
+++ b/test_driver/app_test.dart
@@ -13,7 +13,7 @@ void main() {
     final passwordVisibilityToggleVisibleFinder =
         find.byValueKey(loginPasswordVisibilityToggleVisibleValueKey);
 
-    FlutterDriver driver;
+    FlutterDriver? driver;
 
     // Connect to the Flutter driver before running any tests.
     setUpAll(() async {
@@ -23,26 +23,26 @@ void main() {
     // Close the connection to the driver after the tests have completed.
     tearDownAll(() async {
       if (driver != null) {
-        await driver.close();
+        await driver!.close();
       }
     });
 
     test('password visibility toggle shows correct icon', () async {
       final homeLoginButtonFinder = find.byValueKey(homeLoginButtonValueKey);
 
-      await driver.tap(homeLoginButtonFinder);
+      await driver!.tap(homeLoginButtonFinder);
 
-      await driver.waitFor(passwordVisibilityToggleObscureFinder,
+      await driver!.waitFor(passwordVisibilityToggleObscureFinder,
           timeout: defaultWaitForTimeout);
 
-      await driver.tap(passwordVisibilityToggleFinder);
+      await driver!.tap(passwordVisibilityToggleFinder);
 
-      await driver.waitFor(passwordVisibilityToggleVisibleFinder,
+      await driver!.waitFor(passwordVisibilityToggleVisibleFinder,
           timeout: defaultWaitForTimeout);
 
-      await driver.tap(passwordVisibilityToggleFinder);
+      await driver!.tap(passwordVisibilityToggleFinder);
 
-      await driver.waitFor(passwordVisibilityToggleObscureFinder,
+      await driver!.waitFor(passwordVisibilityToggleObscureFinder,
           timeout: defaultWaitForTimeout);
     });
   });