diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
new file mode 100644
index 0000000..90c7212
--- /dev/null
+++ b/.github/workflows/publish.yml
@@ -0,0 +1,47 @@
+name: Release
+
+on:
+  workflow_dispatch:
+  release:
+    types: [published]
+
+jobs:
+  test:
+    name: Test and Analyze
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Setup Flutter
+        uses: subosito/flutter-action@v1
+        with:
+          channel: 'stable'
+
+      - name: Download pub dependencies
+        run: flutter pub get
+
+      - name: Check formatting
+        run: flutter format --set-exit-if-changed --dry-run .
+
+      - name: Run analyzer
+        run: flutter analyze
+
+      - name: Run tests
+        run: flutter test
+  publish:
+    name: Publish to pub.dev
+    if: success()
+    needs: test
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: flutter_bloc_patterns
+        uses: k-paxian/dart-package-publisher@master
+        with:
+          accessToken: ${{ secrets.OAUTH_ACCESS_TOKEN }}
+          refreshToken: ${{ secrets.OAUTH_REFRESH_TOKEN }}
+          format: true
+          skipTests: true
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
new file mode 100644
index 0000000..b3e6c9d
--- /dev/null
+++ b/.github/workflows/test.yml
@@ -0,0 +1,29 @@
+name: Flutter analyze and tests
+
+on:
+  pull_request:
+    branches:
+      - 'master'
+    tags-ignore:
+      - 'v*'
+
+jobs:
+  on-pull-request:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: subosito/flutter-action@v1
+        with:
+          channel: 'stable'
+
+      - name: Download pub dependencies
+        run: flutter pub get
+
+      - name: Check formatting
+        run: flutter format --set-exit-if-changed --dry-run .
+
+      - name: Run analyzer
+        run: flutter analyze
+
+      - name: Run tests
+        run: flutter test
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2ce2aea..e38ae4c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,10 @@
+# Changelog
+
+## [0.9.0] * Breaking Changes *
+
+* Migrating to `bloc` 7.0.0 and `flutter_bloc` 7.0.1,
+* Migrating to `null-safety`.
+
 ## [0.8.0] * Breaking Changes *
 
 * Migrating to `bloc` 6.1.1 and `flutter_bloc` 6.1.1.
diff --git a/README.md b/README.md
index 9a5f6d7..c647aa5 100644
--- a/README.md
+++ b/README.md
@@ -134,7 +134,7 @@ Where:
 
 ## Dart version
 
-- Dart 2: >= 2.6.0
+- Dart 2: >= 2.12.0
 
 ## Author
 - [Karol Lisiewicz](https://github.com/klisiewicz)
diff --git a/example/android/app/build.gradle b/example/android/app/build.gradle
index 9a7b2ed..4fda472 100644
--- a/example/android/app/build.gradle
+++ b/example/android/app/build.gradle
@@ -32,9 +32,6 @@ android {
         main.java.srcDirs += 'src/main/kotlin'
     }
 
-    lintOptions {
-        disable 'InvalidPackage'
-    }
 
     defaultConfig {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
@@ -43,7 +40,7 @@ android {
         targetSdkVersion 28
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        testInstrumentationRunner 'androidx.test.runner.AndroidJUnitRunner'
     }
 
     buildTypes {
@@ -53,6 +50,9 @@ android {
             signingConfig signingConfigs.debug
         }
     }
+    lint {
+        disable 'InvalidPackage'
+    }
 }
 
 flutter {
@@ -62,6 +62,6 @@ flutter {
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
     testImplementation 'junit:junit:4.12'
-    androidTestImplementation 'com.android.support.test:runner:1.0.2'
-    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
+    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.0'
 }
diff --git a/example/android/build.gradle b/example/android/build.gradle
index b7faad8..d7006c2 100644
--- a/example/android/build.gradle
+++ b/example/android/build.gradle
@@ -1,12 +1,12 @@
 buildscript {
-    ext.kotlin_version = '1.2.71'
+    ext.kotlin_version = '1.3.40'
     repositories {
         google()
         jcenter()
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.2.1'
+        classpath 'com.android.tools.build:gradle:7.1.1'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 }
diff --git a/example/android/gradle.properties b/example/android/gradle.properties
index 1441b1d..2324ab5 100644
--- a/example/android/gradle.properties
+++ b/example/android/gradle.properties
@@ -1,3 +1,5 @@
 org.gradle.jvmargs=-Xmx1536M
 
 android.enableR8=true
+android.useAndroidX=true
+android.enableJetifier=true
diff --git a/example/android/gradle/wrapper/gradle-wrapper.properties b/example/android/gradle/wrapper/gradle-wrapper.properties
index 2819f02..595fb86 100644
--- a/example/android/gradle/wrapper/gradle-wrapper.properties
+++ b/example/android/gradle/wrapper/gradle-wrapper.properties
@@ -3,4 +3,4 @@ distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.2-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.2-all.zip
diff --git a/example/lib/src/album/model/album.dart b/example/lib/src/album/model/album.dart
index 5e9d9db..f836f95 100644
--- a/example/lib/src/album/model/album.dart
+++ b/example/lib/src/album/model/album.dart
@@ -3,17 +3,17 @@ import 'package:flutter/foundation.dart';
 @immutable
 class Album {
   final int id;
-  final String title;
+  final String? title;
 
   const Album({
-    @required this.id,
+    required this.id,
     this.title,
-  }) : assert(id != null);
+  });
 
   factory Album.fromJson(Map<String, dynamic> json) {
     return Album(
       id: json['id'] as int,
-      title: json['title'] as String,
+      title: json['title'] as String?,
     );
   }
 }
diff --git a/example/lib/src/album/model/photo.dart b/example/lib/src/album/model/photo.dart
index 4e359e6..0c8a7f5 100644
--- a/example/lib/src/album/model/photo.dart
+++ b/example/lib/src/album/model/photo.dart
@@ -5,13 +5,13 @@ class Photo {
   final String thumbnailUrl;
 
   Photo({
-    this.id,
-    this.title,
-    this.url,
-    this.thumbnailUrl,
+    required this.id,
+    required this.title,
+    required this.url,
+    required this.thumbnailUrl,
   });
 
-  factory Photo.fromJson(dynamic json) {
+  factory Photo.fromJson(Map json) {
     return Photo(
       id: json['id'] as int,
       title: json['title'] as String,
diff --git a/example/lib/src/album/model/photo_repository.dart b/example/lib/src/album/model/photo_repository.dart
index 6199bc5..e1cac66 100644
--- a/example/lib/src/album/model/photo_repository.dart
+++ b/example/lib/src/album/model/photo_repository.dart
@@ -3,36 +3,45 @@ import 'dart:io';
 
 import 'package:example/src/album/model/album.dart';
 import 'package:example/src/album/model/photo.dart';
-import 'package:example/src/common/url.dart';
 import 'package:flutter_bloc_patterns/page.dart';
 import 'package:flutter_bloc_patterns/paged_filter_list.dart';
 import 'package:http/http.dart' as http;
 
 class PagedFilterPhotoRepository
     implements PagedListFilterRepository<Photo, Album> {
-  static const _photosUrl = '$baseUrl/photos';
-
   @override
-  Future<List<Photo>> getAll(Page page) => getBy(page, null);
+  Future<List<Photo>> getAll(Page page) async {
+    final uri = _buildUri(page, null);
+    return _getPhotosFrom(uri);
+  }
 
   @override
   Future<List<Photo>> getBy(Page page, Album album) async {
-    final response = await http.get(_buildUrl(page, album));
+    final uri = _buildUri(page, album);
+    return _getPhotosFrom(uri);
+  }
 
+  Future<List<Photo>> _getPhotosFrom(Uri uri) async {
+    final response = await http.get(uri);
     if (response.statusCode != HttpStatus.ok) {
       throw Exception('Failed to load photos');
     }
-
     final dynamic postsJson = json.decode(response.body);
     return (postsJson is List)
-        ? postsJson.map((photo) => Photo.fromJson(photo)).toList()
+        ? postsJson.map((photo) => Photo.fromJson(photo as Map)).toList()
         : [];
   }
 
-  String _buildUrl(Page page, Album album) {
-    final pageQuery = '_start=${page.offset}&_limit=${page.size}';
-    final userQuery = (album != null) ? 'albumId=${album.id}' : null;
-    final query = pageQuery + (userQuery != null ? '&$userQuery' : '');
-    return '$_photosUrl/?$query';
+  static Uri _buildUri(Page page, Album? album) {
+    return Uri(
+      scheme: 'http',
+      host: 'jsonplaceholder.typicode.com',
+      path: 'photos',
+      queryParameters: {
+        '_start': '${page.offset}',
+        '_limit': '${page.size}',
+        if (album != null) 'albumId': '${album.id}'
+      },
+    );
   }
 }
diff --git a/example/lib/src/album/ui/photos_list_empty.dart b/example/lib/src/album/ui/photos_list_empty.dart
index b4a6d07..3293361 100644
--- a/example/lib/src/album/ui/photos_list_empty.dart
+++ b/example/lib/src/album/ui/photos_list_empty.dart
@@ -1,10 +1,12 @@
 import 'package:flutter/material.dart';
 
 class PhotosListEmpty extends StatelessWidget {
-  const PhotosListEmpty({Key key}) : super(key: key);
+  const PhotosListEmpty({Key? key}) : super(key: key);
 
   @override
-  Widget build(BuildContext context) => const Center(
-        child: Text('No photos found'),
-      );
+  Widget build(BuildContext context) {
+    return const Center(
+      child: Text('No photos found'),
+    );
+  }
 }
diff --git a/example/lib/src/album/ui/photos_list_paged.dart b/example/lib/src/album/ui/photos_list_paged.dart
index f4c8102..156e405 100644
--- a/example/lib/src/album/ui/photos_list_paged.dart
+++ b/example/lib/src/album/ui/photos_list_paged.dart
@@ -10,8 +10,8 @@ class PhotosListPaged extends StatelessWidget {
 
   const PhotosListPaged(
     this.page, {
-    Key key,
-    @required this.onLoadNextPage,
+    Key? key,
+    required this.onLoadNextPage,
   }) : super(key: key);
 
   @override
@@ -30,7 +30,10 @@ class PhotosListPaged extends StatelessWidget {
 class _PhotoGridItem extends StatelessWidget {
   final Photo photo;
 
-  const _PhotoGridItem(this.photo, {Key key}) : super(key: key);
+  const _PhotoGridItem(
+    this.photo, {
+    Key? key,
+  }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
diff --git a/example/lib/src/common/error_message.dart b/example/lib/src/common/error_message.dart
index 6d27a5a..3e8a0c3 100644
--- a/example/lib/src/common/error_message.dart
+++ b/example/lib/src/common/error_message.dart
@@ -1,13 +1,17 @@
 import 'package:flutter/widgets.dart';
 
 class ErrorMessage extends StatelessWidget {
-  final dynamic error;
+  final Object error;
 
   const ErrorMessage({
-    Key key,
-    this.error,
+    required this.error,
+    Key? key,
   }) : super(key: key);
 
   @override
-  Widget build(BuildContext context) => Center(child: Text(error.toString()));
+  Widget build(BuildContext context) {
+    return Center(
+      child: Text(error.toString()),
+    );
+  }
 }
diff --git a/example/lib/src/common/loading_indicator.dart b/example/lib/src/common/loading_indicator.dart
index c4b6f94..6368882 100644
--- a/example/lib/src/common/loading_indicator.dart
+++ b/example/lib/src/common/loading_indicator.dart
@@ -1,10 +1,12 @@
 import 'package:flutter/material.dart';
 
 class LoadingIndicator extends StatelessWidget {
-  const LoadingIndicator({Key key}) : super(key: key);
+  const LoadingIndicator({Key? key}) : super(key: key);
 
   @override
-  Widget build(BuildContext context) => const Center(
-        child: CircularProgressIndicator(),
-      );
+  Widget build(BuildContext context) {
+    return const Center(
+      child: CircularProgressIndicator(),
+    );
+  }
 }
diff --git a/example/lib/src/common/loading_page_indicator.dart b/example/lib/src/common/loading_page_indicator.dart
index 0f8c996..40655d0 100644
--- a/example/lib/src/common/loading_page_indicator.dart
+++ b/example/lib/src/common/loading_page_indicator.dart
@@ -1,17 +1,19 @@
 import 'package:flutter/material.dart';
 
 class LoadingPageIndicator extends StatelessWidget {
-  const LoadingPageIndicator({Key key}) : super(key: key);
+  const LoadingPageIndicator({Key? key}) : super(key: key);
 
   @override
-  Widget build(BuildContext context) => Container(
-        padding: const EdgeInsets.symmetric(vertical: 8),
-        child: const Center(
-          child: SizedBox(
-            width: 24,
-            height: 24,
-            child: CircularProgressIndicator(strokeWidth: 1.5),
-          ),
+  Widget build(BuildContext context) {
+    return const Padding(
+      padding: EdgeInsets.symmetric(vertical: 8),
+      child: Center(
+        child: SizedBox(
+          width: 24,
+          height: 24,
+          child: CircularProgressIndicator(strokeWidth: 1.5),
         ),
-      );
+      ),
+    );
+  }
 }
diff --git a/example/lib/src/common/url.dart b/example/lib/src/common/url.dart
deleted file mode 100644
index 2f26906..0000000
--- a/example/lib/src/common/url.dart
+++ /dev/null
@@ -1 +0,0 @@
-const baseUrl = 'https://jsonplaceholder.typicode.com';
\ No newline at end of file
diff --git a/example/lib/src/list_app.dart b/example/lib/src/list_app.dart
index 34222ad..9ecd4da 100644
--- a/example/lib/src/list_app.dart
+++ b/example/lib/src/list_app.dart
@@ -5,7 +5,6 @@ import 'package:example/src/post/model/post_repository.dart';
 import 'package:example/src/post/ui/posts_list.dart';
 import 'package:example/src/post/ui/posts_list_empty.dart';
 import 'package:flutter/material.dart';
-import 'package:flutter/widgets.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:flutter_bloc_patterns/base_list.dart';
 import 'package:flutter_bloc_patterns/view.dart';
@@ -32,7 +31,7 @@ class PostsPage extends StatefulWidget {
 }
 
 class _PostsPageState extends State<PostsPage> {
-  ListBloc<Post> listBloc;
+  late ListBloc<Post> listBloc;
 
   @override
   void initState() {
@@ -45,11 +44,11 @@ class _PostsPageState extends State<PostsPage> {
     return Scaffold(
       appBar: AppBar(title: const Text('Posts')),
       body: ViewStateBuilder<List<Post>, ListBloc<Post>>(
-        cubit: listBloc,
+        bloc: listBloc,
         onLoading: (context) => const LoadingIndicator(),
-        onSuccess: (context, List<Post> posts) =>
+        onSuccess: (context, posts) =>
             PostsList(posts, onRefresh: _refreshPosts),
-        onRefreshing: (context, List<Post> posts) =>
+        onRefreshing: (context, posts) =>
             PostsList(posts, onRefresh: _refreshPosts),
         onEmpty: (context) => const PostsListEmpty(),
         onError: (context, error) => ErrorMessage(error: error),
diff --git a/example/lib/src/list_details_app.dart b/example/lib/src/list_details_app.dart
index 65e46dd..a5032e7 100644
--- a/example/lib/src/list_details_app.dart
+++ b/example/lib/src/list_details_app.dart
@@ -31,7 +31,7 @@ class _PostsPage extends StatefulWidget {
 }
 
 class _PostsPageState extends State<_PostsPage> {
-  ListBloc<Post> listBloc;
+  late ListBloc<Post> listBloc;
 
   @override
   void initState() {
@@ -44,7 +44,7 @@ class _PostsPageState extends State<_PostsPage> {
     return Scaffold(
       appBar: AppBar(title: const Text('Posts')),
       body: ViewStateBuilder<List<Post>, ListBloc<Post>>(
-        cubit: listBloc,
+        bloc: listBloc,
         onLoading: (context) => const LoadingIndicator(),
         onSuccess: (context, posts) => PostsList(
           posts,
@@ -70,14 +70,17 @@ class _PostsPageState extends State<_PostsPage> {
 class _PostDetailPage extends StatefulWidget {
   final int postId;
 
-  const _PostDetailPage(this.postId, {Key key}) : super(key: key);
+  const _PostDetailPage(
+    this.postId, {
+    Key? key,
+  }) : super(key: key);
 
   @override
   _PostDetailPageState createState() => _PostDetailPageState();
 }
 
 class _PostDetailPageState extends State<_PostDetailPage> {
-  DetailsBloc<PostDetails, int> detailsBloc;
+  late DetailsBloc<PostDetails, int> detailsBloc;
 
   @override
   void initState() {
@@ -90,19 +93,22 @@ class _PostDetailPageState extends State<_PostDetailPage> {
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(title: const Text('Post')),
-      body: ViewStateBuilder<PostDetails, DetailsBloc<PostDetails, int>>(
-        cubit: detailsBloc,
-        onLoading: (context) => const LoadingIndicator(),
-        onSuccess: (context, post) => _PostDetailsContent(post),
+      body: ViewStateListener(
+        bloc: detailsBloc,
         onEmpty: _showSnackbarAndPopPage,
-        onError: (context, error) => ErrorMessage(error: error),
+        child: ViewStateBuilder<PostDetails, DetailsBloc<PostDetails, int>>(
+          bloc: detailsBloc,
+          onLoading: (context) => const LoadingIndicator(),
+          onSuccess: (context, post) => _PostDetailsContent(post),
+          onError: (context, error) => ErrorMessage(error: error),
+        ),
       ),
     );
   }
 
-  Widget _showSnackbarAndPopPage(BuildContext context) {
-    WidgetsBinding.instance.addPostFrameCallback((_) {
-      Scaffold.of(context)
+  void _showSnackbarAndPopPage(BuildContext context) {
+    WidgetsBinding.instance?.addPostFrameCallback((_) {
+      ScaffoldMessenger.of(context)
           .showSnackBar(
             const SnackBar(
               content: Text('Post not found!'),
@@ -110,11 +116,8 @@ class _PostDetailPageState extends State<_PostDetailPage> {
             ),
           )
           .closed
-          .then((reason) {
-        Navigator.pop(context);
-      });
+          .then((reason) => Navigator.pop(context));
     });
-    return Container();
   }
 
   @override
@@ -127,7 +130,10 @@ class _PostDetailPageState extends State<_PostDetailPage> {
 class _PostDetailsContent extends StatelessWidget {
   final PostDetails post;
 
-  const _PostDetailsContent(this.post, {Key key}) : super(key: key);
+  const _PostDetailsContent(
+    this.post, {
+    Key? key,
+  }) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -156,6 +162,7 @@ class _Route {
   static const String post = '/post';
 }
 
+// ignore: avoid_classes_with_only_static_members
 class _Router {
   static Route<dynamic> generateRoute(RouteSettings settings) {
     switch (settings.name) {
@@ -172,7 +179,7 @@ class _Router {
             create: (_) => DetailsBloc<PostDetails, int>(
               PostDetailsRepository(),
             ),
-            child: _PostDetailPage(settings.arguments as int),
+            child: _PostDetailPage(settings.arguments! as int),
           ),
         );
       default:
diff --git a/example/lib/src/list_filter_app.dart b/example/lib/src/list_filter_app.dart
index d0fe4db..b3dd6ea 100644
--- a/example/lib/src/list_filter_app.dart
+++ b/example/lib/src/list_filter_app.dart
@@ -36,7 +36,7 @@ class _PostsPage extends StatefulWidget {
 }
 
 class _PostsPageState extends State<_PostsPage> {
-  FilterListBloc<Post, User> listBloc;
+  late FilterListBloc<Post, User> listBloc;
   _Posts selectedPosts = _Posts.all;
 
   @override
@@ -59,7 +59,7 @@ class _PostsPageState extends State<_PostsPage> {
 
   Widget _buildBody() {
     return ViewStateBuilder<List<Post>, FilterListBloc<Post, User>>(
-      cubit: listBloc,
+      bloc: listBloc,
       onLoading: (context) => const LoadingIndicator(),
       onSuccess: (context, posts) => PostsList(posts, onRefresh: _refreshPosts),
       onRefreshing: (context, posts) =>
diff --git a/example/lib/src/list_paged_app.dart b/example/lib/src/list_paged_app.dart
index 4e5c0fb..7008a47 100644
--- a/example/lib/src/list_paged_app.dart
+++ b/example/lib/src/list_paged_app.dart
@@ -31,7 +31,7 @@ class _PostsPage extends StatefulWidget {
 }
 
 class _PostsPageState extends State<_PostsPage> {
-  PagedListBloc<Post> _listBloc;
+  late PagedListBloc<Post> _listBloc;
 
   @override
   void initState() {
@@ -45,7 +45,7 @@ class _PostsPageState extends State<_PostsPage> {
     return Scaffold(
       appBar: AppBar(title: const Text('Posts')),
       body: ViewStateBuilder<PagedList<Post>, PagedListBloc>(
-        cubit: _listBloc,
+        bloc: _listBloc,
         onLoading: (context) => const LoadingIndicator(),
         onSuccess: (context, page) => PostsListPaged(
           page,
diff --git a/example/lib/src/list_paged_filter_app.dart b/example/lib/src/list_paged_filter_app.dart
index ef7ee72..4b3e186 100644
--- a/example/lib/src/list_paged_filter_app.dart
+++ b/example/lib/src/list_paged_filter_app.dart
@@ -35,16 +35,13 @@ class _PhotosPage extends StatefulWidget {
 
 class _PhotosPageState extends State<_PhotosPage> {
   final _myAlbum = const Album(id: 1);
-  PagedListFilterBloc<Photo, Album> _photosBloc;
+  late PagedListFilterBloc<Photo, Album> _photosBloc;
 
   @override
   void initState() {
     super.initState();
     _photosBloc = BlocProvider.of<PagedListFilterBloc<Photo, Album>>(context)
-      ..loadFirstPage(
-        pageSize: 12,
-        filter: _myAlbum,
-      );
+      ..loadFirstPage(pageSize: 12, filter: _myAlbum);
   }
 
   @override
@@ -52,7 +49,7 @@ class _PhotosPageState extends State<_PhotosPage> {
     return Scaffold(
       appBar: AppBar(title: const Text('Photos')),
       body: ViewStateBuilder<PagedList<Photo>, PagedListFilterBloc>(
-        cubit: _photosBloc,
+        bloc: _photosBloc,
         onLoading: (context) => const LoadingIndicator(),
         onSuccess: (context, page) => PhotosListPaged(
           page,
diff --git a/example/lib/src/post/model/post.dart b/example/lib/src/post/model/post.dart
index a5e1465..c281aa9 100644
--- a/example/lib/src/post/model/post.dart
+++ b/example/lib/src/post/model/post.dart
@@ -3,11 +3,11 @@ class Post {
   final String title;
 
   Post({
-    this.id,
-    this.title,
+    required this.id,
+    required this.title,
   });
 
-  factory Post.fromJson(dynamic json) {
+  factory Post.fromJson(Map json) {
     return Post(
       id: json['id'] as int,
       title: json['title'] as String,
diff --git a/example/lib/src/post/model/post_details.dart b/example/lib/src/post/model/post_details.dart
index 62d368e..7df4421 100644
--- a/example/lib/src/post/model/post_details.dart
+++ b/example/lib/src/post/model/post_details.dart
@@ -4,15 +4,12 @@ class PostDetails extends Post {
   final String body;
 
   PostDetails({
-    int id,
-    String title,
-    this.body,
-  }) : super(
-          id: id,
-          title: title,
-        );
+    required int id,
+    required String title,
+    required this.body,
+  }) : super(id: id, title: title);
 
-  factory PostDetails.fromJson(dynamic json) {
+  factory PostDetails.fromJson(Map json) {
     return PostDetails(
       id: json['id'] as int,
       title: json['title'] as String,
diff --git a/example/lib/src/post/model/post_repository.dart b/example/lib/src/post/model/post_repository.dart
index 639f74c..b623666 100644
--- a/example/lib/src/post/model/post_repository.dart
+++ b/example/lib/src/post/model/post_repository.dart
@@ -1,7 +1,6 @@
 import 'dart:convert';
 import 'dart:io';
 
-import 'package:example/src/common/url.dart';
 import 'package:example/src/post/model/post.dart';
 import 'package:example/src/post/model/post_details.dart';
 import 'package:example/src/user/model/user.dart';
@@ -12,59 +11,68 @@ import 'package:flutter_bloc_patterns/page.dart';
 import 'package:flutter_bloc_patterns/paged_list.dart';
 import 'package:http/http.dart' as http;
 
-const _postsUrl = '$baseUrl/posts';
-
 class PostListRepository implements ListRepository<Post> {
   @override
-  Future<List<Post>> getAll() => _getPostsFromUrl(_postsUrl);
+  Future<List<Post>> getAll() => _getPostsFromUrl();
 }
 
 class FilterPostRepository implements FilterListRepository<Post, User> {
   @override
-  Future<List<Post>> getAll() => _getPostsFromUrl(_postsUrl);
+  Future<List<Post>> getAll() => _getPostsFromUrl();
 
   @override
   Future<List<Post>> getBy(User user) {
-    if (user == null || user.id == null) {
-      return _getPostsFromUrl(_postsUrl);
-    } else {
-      return _getPostsFromUrl('$_postsUrl?userId=${user.id}');
-    }
+    return _getPostsFromUrl(query: {'userId': user.id});
   }
 }
 
 class PagedPostRepository implements PagedListRepository<Post> {
   @override
-  Future<List<Post>> getAll(Page page) =>
-      _getPostsFromUrl('$_postsUrl?_start=${page.offset}&_limit=${page.size}');
+  Future<List<Post>> getAll(Page page) {
+    return _getPostsFromUrl(
+      query: {
+        '_start': '${page.offset}',
+        '_limit': '${page.size}',
+      },
+    );
+  }
 }
 
 class PostDetailsRepository implements DetailsRepository<PostDetails, int> {
   @override
-  Future<PostDetails> getById(int id) async {
-    final response = await http.get('$_postsUrl/$id');
-
+  Future<PostDetails?> getById(int id) async {
+    final uri = Uri(
+      scheme: 'http',
+      host: 'jsonplaceholder.typicode.com',
+      path: 'posts/$id',
+    );
+    final response = await http.get(uri);
     if (response.statusCode == HttpStatus.notFound) {
       return null;
     } else if (response.statusCode != HttpStatus.ok) {
       throw Exception('Failed to load post with id $id');
     }
-    final dynamic postJson = json.decode(response.body);
+    final Map postJson = json.decode(response.body) as Map;
     return PostDetails.fromJson(postJson);
   }
 }
 
-Future<List<Post>> _getPostsFromUrl(String url) async {
-  final response = await http.get(url);
-
+Future<List<Post>> _getPostsFromUrl({
+  Map<String, dynamic>? query,
+}) async {
+  final uri = Uri(
+    scheme: 'http',
+    host: 'jsonplaceholder.typicode.com',
+    path: 'posts',
+    queryParameters: query,
+  );
+  final response = await http.get(uri);
   if (response.statusCode != HttpStatus.ok) {
     throw Exception('Failed to load post');
   }
-
   final dynamic postsJson = json.decode(response.body);
   if (postsJson is List) {
-    final List<Post> posts =
-        postsJson.map((post) => Post.fromJson(post)).toList();
+    final posts = postsJson.map((post) => Post.fromJson(post as Map)).toList();
     // Shuffle the list to achieve refresh impression
     return posts..shuffle();
   } else {
diff --git a/example/lib/src/post/ui/posts_list.dart b/example/lib/src/post/ui/posts_list.dart
index 4f1d61d..afd2b34 100644
--- a/example/lib/src/post/ui/posts_list.dart
+++ b/example/lib/src/post/ui/posts_list.dart
@@ -4,12 +4,12 @@ import 'package:flutter_bloc_patterns/view.dart';
 
 class PostsList extends StatelessWidget {
   final List<Post> posts;
-  final VoidCallback onRefresh;
-  final ValueSetter<Post> onPostSelected;
+  final VoidCallback? onRefresh;
+  final ValueSetter<Post>? onPostSelected;
 
   const PostsList(
     this.posts, {
-    Key key,
+    Key? key,
     this.onRefresh,
     this.onPostSelected,
   }) : super(key: key);
@@ -32,12 +32,12 @@ class PostsList extends StatelessWidget {
 
 class PostListItem extends StatelessWidget {
   final Post post;
-  final ValueSetter<Post> onPostSelected;
+  final ValueSetter<Post>? onPostSelected;
 
   const PostListItem(
     this.post, {
     this.onPostSelected,
-    Key key,
+    Key? key,
   }) : super(key: key);
 
   @override
diff --git a/example/lib/src/post/ui/posts_list_empty.dart b/example/lib/src/post/ui/posts_list_empty.dart
index 7a1f282..50dc1cf 100644
--- a/example/lib/src/post/ui/posts_list_empty.dart
+++ b/example/lib/src/post/ui/posts_list_empty.dart
@@ -1,9 +1,12 @@
 import 'package:flutter/material.dart';
 
 class PostsListEmpty extends StatelessWidget {
-  const PostsListEmpty({Key key}) : super(key: key);
+  const PostsListEmpty({Key? key}) : super(key: key);
 
   @override
-  Widget build(BuildContext context) =>
-      const Center(child: Text('No posts found'));
+  Widget build(BuildContext context) {
+    return const Center(
+      child: Text('No posts found'),
+    );
+  }
 }
diff --git a/example/lib/src/post/ui/posts_list_paged.dart b/example/lib/src/post/ui/posts_list_paged.dart
index 1934d0f..5c47d2e 100644
--- a/example/lib/src/post/ui/posts_list_paged.dart
+++ b/example/lib/src/post/ui/posts_list_paged.dart
@@ -11,8 +11,8 @@ class PostsListPaged extends StatelessWidget {
 
   const PostsListPaged(
     this.page, {
-    Key key,
-    @required this.onLoadNextPage,
+    Key? key,
+    required this.onLoadNextPage,
   }) : super(key: key);
 
   @override
diff --git a/example/lib/src/user/model/user.dart b/example/lib/src/user/model/user.dart
index 3c079b5..b40905d 100644
--- a/example/lib/src/user/model/user.dart
+++ b/example/lib/src/user/model/user.dart
@@ -1,9 +1,9 @@
 import 'package:equatable/equatable.dart';
 
-class User extends Equatable {
+class User with EquatableMixin {
   final String id;
 
-  const User(this.id) : assert(id != null);
+  const User(this.id);
 
   @override
   List<Object> get props => [id];
diff --git a/example/pubspec.lock b/example/pubspec.lock
index b270197..b9db62c 100644
--- a/example/pubspec.lock
+++ b/example/pubspec.lock
@@ -7,89 +7,89 @@ packages:
       name: async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.5.0-nullsafety.1"
+    version: "2.8.2"
   bloc:
     dependency: transitive
     description:
       name: bloc
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "6.1.1"
+    version: "7.0.0"
   boolean_selector:
     dependency: transitive
     description:
       name: boolean_selector
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0"
   characters:
     dependency: transitive
     description:
       name: characters
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.3"
+    version: "1.2.0"
   charcode:
     dependency: transitive
     description:
       name: charcode
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.3.1"
   clock:
     dependency: transitive
     description:
       name: clock
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0"
   collection:
     dependency: transitive
     description:
       name: collection
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.15.0-nullsafety.3"
+    version: "1.15.0"
   cupertino_icons:
     dependency: "direct main"
     description:
       name: cupertino_icons
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.1.3"
+    version: "1.0.4"
   equatable:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: equatable
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.5"
+    version: "2.0.3"
   fake_async:
     dependency: transitive
     description:
       name: fake_async
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0"
   flutter:
     dependency: "direct main"
     description: flutter
     source: sdk
     version: "0.0.0"
   flutter_bloc:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: flutter_bloc
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "6.1.1"
+    version: "7.2.0"
   flutter_bloc_patterns:
     dependency: "direct main"
     description:
       path: ".."
       relative: true
     source: path
-    version: "0.8.0"
+    version: "0.9.0"
   flutter_test:
     dependency: "direct dev"
     description: flutter
@@ -101,70 +101,63 @@ packages:
       name: http
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.0+4"
+    version: "0.13.4"
   http_parser:
     dependency: transitive
     description:
       name: http_parser
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.1.3"
+    version: "4.0.0"
   infinite_widgets:
     dependency: "direct main"
     description:
       name: infinite_widgets
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.1"
+    version: "2.0.0"
   lint:
     dependency: "direct main"
     description:
       name: lint
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.1"
+    version: "1.8.2"
   matcher:
     dependency: transitive
     description:
       name: matcher
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.12.10-nullsafety.1"
+    version: "0.12.11"
   meta:
     dependency: transitive
     description:
       name: meta
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.7.0"
   nested:
     dependency: transitive
     description:
       name: nested
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.4"
+    version: "1.0.0"
   path:
     dependency: transitive
     description:
       name: path
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.1"
-  pedantic:
-    dependency: transitive
-    description:
-      name: pedantic
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "1.8.0+1"
+    version: "1.8.0"
   provider:
     dependency: transitive
     description:
       name: provider
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.3.2+2"
+    version: "6.0.2"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -176,56 +169,56 @@ packages:
       name: source_span
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.8.0-nullsafety.2"
+    version: "1.8.1"
   stack_trace:
     dependency: transitive
     description:
       name: stack_trace
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.10.0-nullsafety.1"
+    version: "1.10.0"
   stream_channel:
     dependency: transitive
     description:
       name: stream_channel
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.1"
+    version: "2.1.0"
   string_scanner:
     dependency: transitive
     description:
       name: string_scanner
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.1.0-nullsafety.1"
+    version: "1.1.0"
   term_glyph:
     dependency: transitive
     description:
       name: term_glyph
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.2.0-nullsafety.1"
+    version: "1.2.0"
   test_api:
     dependency: transitive
     description:
       name: test_api
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.2.19-nullsafety.2"
+    version: "0.4.3"
   typed_data:
     dependency: transitive
     description:
       name: typed_data
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.3.0-nullsafety.3"
+    version: "1.3.0"
   vector_math:
     dependency: transitive
     description:
       name: vector_math
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "2.1.0-nullsafety.3"
+    version: "2.1.1"
 sdks:
-  dart: ">=2.10.0-110 <2.11.0"
+  dart: ">=2.15.0-7.0.dev <3.0.0"
   flutter: ">=1.16.0"
diff --git a/example/pubspec.yaml b/example/pubspec.yaml
index 4b4d8a4..9003a8d 100644
--- a/example/pubspec.yaml
+++ b/example/pubspec.yaml
@@ -1,19 +1,22 @@
 name: example
 description: BLoC pattern samples.
+publish_to: 'none'
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.6.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
 
 dependencies:
+  cupertino_icons: ^1.0.4
+  equatable: ^2.0.3
   flutter:
     sdk: flutter
-  http: ^0.12.0+4
+  flutter_bloc: ^7.0.1
   flutter_bloc_patterns:
     path: ../
-  cupertino_icons: ^0.1.3
-  infinite_widgets: ^1.0.1
-  lint: ^1.1.1
+  http: ^0.13.4
+  infinite_widgets: ^2.0.0
+  lint: ^1.8.2
 
 dev_dependencies:
   flutter_test:
diff --git a/lib/src/details/details_bloc.dart b/lib/src/details/details_bloc.dart
index f7e9432..a4044ea 100644
--- a/lib/src/details/details_bloc.dart
+++ b/lib/src/details/details_bloc.dart
@@ -1,7 +1,5 @@
 import 'package:bloc/bloc.dart';
 import 'package:flutter_bloc_patterns/details.dart';
-import 'package:flutter_bloc_patterns/src/details/details_events.dart';
-import 'package:flutter_bloc_patterns/src/details/details_repository.dart';
 import 'package:flutter_bloc_patterns/src/view/view_state.dart';
 import 'package:flutter_bloc_patterns/src/view/view_state_builder.dart';
 
@@ -16,12 +14,10 @@ import 'package:flutter_bloc_patterns/src/view/view_state_builder.dart';
 class DetailsBloc<T, I> extends Bloc<DetailsEvent, ViewState> {
   final DetailsRepository<T, I> _repository;
 
-  DetailsBloc(this._repository)
-      : assert(_repository != null),
-        super(const Initial());
+  DetailsBloc(this._repository) : super(const Initial());
 
   /// Loads an element with given [id].
-  void loadElement([I id]) => add(LoadDetails(id));
+  void loadElement(I id) => add(LoadDetails(id));
 
   @override
   Stream<ViewState> mapEventToState(DetailsEvent event) async* {
@@ -35,8 +31,6 @@ class DetailsBloc<T, I> extends Bloc<DetailsEvent, ViewState> {
       yield const Loading();
       final element = await _repository.getById(id);
       yield element != null ? Success<T>(element) : const Empty();
-    } on ElementNotFoundException {
-      yield const Empty();
     } catch (e) {
       yield Failure(e);
     }
diff --git a/lib/src/details/details_events.dart b/lib/src/details/details_events.dart
index 85e45fc..5b371ca 100644
--- a/lib/src/details/details_events.dart
+++ b/lib/src/details/details_events.dart
@@ -13,10 +13,10 @@ abstract class DetailsEvent extends Equatable {
 class LoadDetails<I> extends DetailsEvent {
   final I id;
 
-  const LoadDetails([this.id]);
+  const LoadDetails(this.id);
 
   @override
-  List<Object> get props => [id];
+  List<Object?> get props => [id];
 
   @override
   String toString() => 'LoadDetails: $id';
diff --git a/lib/src/details/details_repository.dart b/lib/src/details/details_repository.dart
index 2865914..977fc09 100644
--- a/lib/src/details/details_repository.dart
+++ b/lib/src/details/details_repository.dart
@@ -4,19 +4,6 @@
 /// [I] - the element's id type.
 abstract class DetailsRepository<T, I> {
   /// Retrieves an element with given id. When there's no element matching the
-  /// given [id] null should be returned or [ElementNotFoundException] should
-  /// be thrown.
-  Future<T> getById(I id);
-}
-
-/// Exception indicating that element with [id] was not found in the
-/// repository.
-class ElementNotFoundException<I> implements Exception {
-  final I id;
-
-  ElementNotFoundException(this.id);
-
-  @override
-  String toString() =>
-      'ElementNotFoundException: Unable to find element with id $id.';
+  /// given [id] `null` should be returned.
+  Future<T?> getById(I id);
 }
diff --git a/lib/src/list/base/list_bloc.dart b/lib/src/list/base/list_bloc.dart
index 0ed643f..06e91c3 100644
--- a/lib/src/list/base/list_bloc.dart
+++ b/lib/src/list/base/list_bloc.dart
@@ -15,8 +15,7 @@ import 'package:flutter_bloc_patterns/src/view/view_state_builder.dart';
 /// [T] - type of list items.
 class ListBloc<T> extends FilterListBloc<T, void> {
   ListBloc(ListRepository<T> repository)
-      : assert(repository != null),
-        super(_FilterRepositoryAdapter(repository));
+      : super(_FilterRepositoryAdapter(repository));
 }
 
 class _FilterRepositoryAdapter<T> extends FilterListRepository<T, void> {
diff --git a/lib/src/list/base/list_events.dart b/lib/src/list/base/list_events.dart
index 4469c8f..c1d830d 100644
--- a/lib/src/list/base/list_events.dart
+++ b/lib/src/list/base/list_events.dart
@@ -11,12 +11,12 @@ abstract class ListEvent extends Equatable {
 ///
 /// [F] - the filter type.
 class LoadList<F> extends ListEvent {
-  final F filter;
+  final F? filter;
 
   const LoadList([this.filter]);
 
   @override
-  List<Object> get props => [filter];
+  List<Object?> get props => [filter];
 
   @override
   String toString() => 'LoadList: $filter';
@@ -26,12 +26,12 @@ class LoadList<F> extends ListEvent {
 ///
 /// [F] - the filter type.
 class RefreshList<F> extends ListEvent {
-  final F filter;
+  final F? filter;
 
   const RefreshList([this.filter]);
 
   @override
-  List<Object> get props => [filter];
+  List<Object?> get props => [filter];
 
   @override
   String toString() => 'RefreshList: $filter';
diff --git a/lib/src/list/filter/filter_list_bloc.dart b/lib/src/list/filter/filter_list_bloc.dart
index 63e9121..2ee60e0 100644
--- a/lib/src/list/filter/filter_list_bloc.dart
+++ b/lib/src/list/filter/filter_list_bloc.dart
@@ -18,21 +18,20 @@ import 'package:flutter_bloc_patterns/src/view/view_state_builder.dart';
 /// [F] - the type of filter.
 class FilterListBloc<T, F> extends Bloc<ListEvent, ViewState> {
   final FilterListRepository<T, F> _repository;
-  F _filter;
+  F? _filter;
 
   FilterListBloc(FilterListRepository<T, F> repository)
-      : assert(repository != null),
-        _repository = repository,
+      : _repository = repository,
         super(const Initial());
 
-  F get filter => _filter;
+  F? get filter => _filter;
 
   /// Loads elements using the given [filter].
   ///
   /// It's most suitable for initial data fetch or for retry action when
   /// the first fetch fails. It can also be used when [filter] changes when a
   /// full reload is required.
-  void loadElements({F filter}) => add(LoadList(filter));
+  void loadElements({F? filter}) => add(LoadList(filter));
 
   /// Refreshes elements using the given [filter].
   ///
@@ -41,7 +40,7 @@ class FilterListBloc<T, F> extends Bloc<ListEvent, ViewState> {
   ///
   /// It can be used when [filter] changes and there's no need for displaying a
   /// loading indicator.
-  void refreshElements({F filter}) => add(RefreshList(filter));
+  void refreshElements({F? filter}) => add(RefreshList(filter));
 
   @override
   Stream<ViewState> mapEventToState(ListEvent event) async* {
@@ -55,12 +54,12 @@ class FilterListBloc<T, F> extends Bloc<ListEvent, ViewState> {
   bool _isRefreshPossible(ListEvent event) =>
       state is Success || state is Empty;
 
-  Stream<ViewState> _mapLoadList(F filter) async* {
+  Stream<ViewState> _mapLoadList(F? filter) async* {
     yield const Loading();
     yield* _getListState(filter);
   }
 
-  Stream<ViewState> _mapRefreshList(F filter) async* {
+  Stream<ViewState> _mapRefreshList(F? filter) async* {
     final elements = _getCurrentStateElements();
     yield Refreshing(elements);
     yield* _getListState(filter);
@@ -69,7 +68,7 @@ class FilterListBloc<T, F> extends Bloc<ListEvent, ViewState> {
   List<T> _getCurrentStateElements() =>
       (state is Success<List<T>>) ? (state as Success<List<T>>).data : [];
 
-  Stream<ViewState> _getListState(F filter) async* {
+  Stream<ViewState> _getListState(F? filter) async* {
     try {
       final List<T> elements = await _getElementsFromRepository(filter);
       yield elements.isNotEmpty
@@ -82,7 +81,7 @@ class FilterListBloc<T, F> extends Bloc<ListEvent, ViewState> {
     }
   }
 
-  Future<List<T>> _getElementsFromRepository(F filter) {
+  Future<List<T>> _getElementsFromRepository(F? filter) {
     if (filter != null) {
       return _repository.getBy(filter);
     } else {
diff --git a/lib/src/list/paged/page.dart b/lib/src/list/paged/page.dart
index 7b9fb1b..ecc11d9 100644
--- a/lib/src/list/paged/page.dart
+++ b/lib/src/list/paged/page.dart
@@ -12,13 +12,13 @@ class Page extends Equatable {
   /// [size] - the size of the page to be returned.
   const Page({
     this.number = 0,
-    this.size,
+    required this.size,
   })  : assert(number >= 0, 'Page index must not be less than zero'),
         assert(size >= 1, 'Page size must not be less than one');
 
   /// Creates first page.
   /// [size] - the size of the page to be returned.
-  const Page.first({int size}) : this(number: 0, size: size);
+  const Page.first({required int size}) : this(number: 0, size: size);
 
   /// Returns the offset to be taken according to page and page size.
   int get offset => size * number;
diff --git a/lib/src/list/paged/paged_list.dart b/lib/src/list/paged/paged_list.dart
index d5b2b40..0daa9ec 100644
--- a/lib/src/list/paged/paged_list.dart
+++ b/lib/src/list/paged/paged_list.dart
@@ -16,11 +16,10 @@ class PagedList<T> extends Equatable {
   /// [elements] - list of elements, cannot be null or empty,
   /// [hasReachedMax] - flag informing if all elements has already been fetched.
   /// True if there are more pages, false otherwise.
-  PagedList(List<T> elements, {this.hasReachedMax = false})
-      : assert(
-          elements != null && elements.isNotEmpty,
-          'Elements cannot be empty',
-        ),
+  PagedList(
+    List<T> elements, {
+    this.hasReachedMax = false,
+  })  : assert(elements.isNotEmpty, 'Elements cannot be empty'),
         elements = UnmodifiableListView(elements);
 
   bool get hasMoreElements => !hasReachedMax;
diff --git a/lib/src/list/paged/paged_list_bloc.dart b/lib/src/list/paged/paged_list_bloc.dart
index d7b1776..9e99e23 100644
--- a/lib/src/list/paged/paged_list_bloc.dart
+++ b/lib/src/list/paged/paged_list_bloc.dart
@@ -1,6 +1,5 @@
 import 'package:flutter_bloc_patterns/paged_filter_list.dart';
 import 'package:flutter_bloc_patterns/src/list/paged/page.dart';
-import 'package:flutter_bloc_patterns/src/list/paged/paged_list_filter_bloc.dart';
 import 'package:flutter_bloc_patterns/src/list/paged/paged_list_repository.dart';
 import 'package:flutter_bloc_patterns/src/view/view_state_builder.dart';
 
@@ -14,8 +13,7 @@ import 'package:flutter_bloc_patterns/src/view/view_state_builder.dart';
 /// [T] - the type of list elements.
 class PagedListBloc<T> extends PagedListFilterBloc<T, void> {
   PagedListBloc(PagedListRepository<T> repository)
-      : assert(repository != null),
-        super(_PagedListRepositoryAdapter<T>(repository));
+      : super(_PagedListRepositoryAdapter<T>(repository));
 }
 
 class _PagedListRepositoryAdapter<T>
diff --git a/lib/src/list/paged/paged_list_events.dart b/lib/src/list/paged/paged_list_events.dart
index fc6e6e7..9110a76 100644
--- a/lib/src/list/paged/paged_list_events.dart
+++ b/lib/src/list/paged/paged_list_events.dart
@@ -13,12 +13,15 @@ abstract class PagedListEvent extends Equatable {
 /// [F] - the filter type.
 class LoadPage<F> extends PagedListEvent {
   final Page page;
-  final F filter;
+  final F? filter;
 
-  const LoadPage(this.page, {this.filter}) : assert(page != null);
+  const LoadPage(
+    this.page, {
+    this.filter,
+  });
 
   @override
-  List<Object> get props => [page, filter];
+  List<Object?> get props => [page, filter];
 
   @override
   String toString() => 'LoadPage: $page ${filter ?? ''}';
diff --git a/lib/src/list/paged/paged_list_filter_bloc.dart b/lib/src/list/paged/paged_list_filter_bloc.dart
index 90a14e9..161a171 100644
--- a/lib/src/list/paged/paged_list_filter_bloc.dart
+++ b/lib/src/list/paged/paged_list_filter_bloc.dart
@@ -1,7 +1,6 @@
 import 'package:bloc/bloc.dart';
 import 'package:flutter_bloc_patterns/paged_filter_list.dart';
 import 'package:flutter_bloc_patterns/src/list/paged/page.dart';
-import 'package:flutter_bloc_patterns/src/list/paged/paged_list.dart';
 import 'package:flutter_bloc_patterns/src/list/paged/paged_list_events.dart';
 import 'package:flutter_bloc_patterns/src/list/paged/paged_list_repository.dart';
 import 'package:flutter_bloc_patterns/src/view/view_state.dart';
@@ -22,37 +21,39 @@ class PagedListFilterBloc<T, F> extends Bloc<PagedListEvent, ViewState> {
   static const defaultPageSize = 10;
 
   final PagedListFilterRepository<T, F> _repository;
-  F _filter;
+  F? _filter;
 
   PagedListFilterBloc(PagedListFilterRepository<T, F> repository)
-      : assert(repository != null),
-        _repository = repository,
+      : _repository = repository,
         super(const Initial());
 
   List<T> get _currentElements => (state is Success<PagedList<T>>)
       ? (state as Success<PagedList<T>>).data.elements
       : [];
 
-  Page _page;
+  Page? _page;
 
-  F get filter => _filter;
+  F? get filter => _filter;
 
   /// Loads elements using the given [filter] and [pageSize]. When no size
   /// is given [_defaultPageSize] is used.
   ///
   /// It's most suitable for initial data fetch or for retry action when
   /// the first fetch fails.
-  void loadFirstPage({int pageSize = defaultPageSize, F filter}) {
+  void loadFirstPage({
+    int pageSize = defaultPageSize,
+    F? filter,
+  }) {
     _page = Page.first(size: pageSize);
     _filter = filter;
-    add(LoadPage(_page, filter: _filter));
+    add(LoadPage(_page!, filter: _filter));
   }
 
   /// Loads next page. When no page has been loaded before the first one is
   /// loaded with the default page size [_defaultPageSize].
   void loadNextPage() {
     _page = _page?.next() ?? const Page.first(size: defaultPageSize);
-    add(LoadPage(_page, filter: _filter));
+    add(LoadPage(_page!, filter: _filter));
   }
 
   @override
@@ -62,10 +63,10 @@ class PagedListFilterBloc<T, F> extends Bloc<PagedListEvent, ViewState> {
     }
   }
 
-  Stream<ViewState> _mapLoadPage(Page page, F filter) async* {
+  Stream<ViewState> _mapLoadPage(Page page, F? filter) async* {
     try {
       yield* _emitLoadingWhenFirstPage(page);
-      final List<T> pageElements = await _repository.getBy(page, filter);
+      final pageElements = await _getElements(page, filter);
       yield* (pageElements.isEmpty)
           ? _emitEmptyPageLoaded(page)
           : _emitNextPageLoaded(page, pageElements);
@@ -76,6 +77,12 @@ class PagedListFilterBloc<T, F> extends Bloc<PagedListEvent, ViewState> {
     }
   }
 
+  Future<List<T>> _getElements(Page page, F? filter) async {
+    return filter != null
+        ? _repository.getBy(page, filter)
+        : _repository.getAll(page);
+  }
+
   Stream<ViewState> _emitLoadingWhenFirstPage(Page page) async* {
     if (page.isFirst) {
       yield const Loading();
diff --git a/lib/src/view/refresh_view.dart b/lib/src/view/refresh_view.dart
index 12733f8..03351bf 100644
--- a/lib/src/view/refresh_view.dart
+++ b/lib/src/view/refresh_view.dart
@@ -1,7 +1,6 @@
 import 'dart:async';
 
 import 'package:flutter/material.dart';
-import 'package:flutter/widgets.dart';
 
 /// A widget that wraps a [widget] with a [RefreshIndicator] designed to
 /// be used with BLoC pattern.
@@ -10,17 +9,17 @@ import 'package:flutter/widgets.dart';
 /// executed. The indicator remains visible until the widget is rebuilt.
 class RefreshView extends StatefulWidget {
   final Widget child;
-  final VoidCallback onRefresh;
+  final VoidCallback? onRefresh;
   final double displacement;
-  final Color color;
-  final Color backgroundColor;
+  final Color? color;
+  final Color? backgroundColor;
   final ScrollNotificationPredicate notificationPredicate;
-  final String semanticsLabel;
-  final String semanticsValue;
+  final String? semanticsLabel;
+  final String? semanticsValue;
 
   const RefreshView({
-    Key key,
-    @required this.child,
+    Key? key,
+    required this.child,
     this.onRefresh,
     this.backgroundColor,
     this.color,
@@ -28,17 +27,14 @@ class RefreshView extends StatefulWidget {
     this.notificationPredicate = defaultScrollNotificationPredicate,
     this.semanticsLabel,
     this.semanticsValue,
-  })  : assert(child != null),
-        assert(displacement != null),
-        assert(notificationPredicate != null),
-        super(key: key);
+  }) : super(key: key);
 
   @override
   _RefreshViewState createState() => _RefreshViewState();
 }
 
 class _RefreshViewState extends State<RefreshView> {
-  Completer<void> _refreshCompleter = Completer();
+  Completer<void>? _refreshCompleter;
 
   @override
   Widget build(BuildContext context) {
@@ -57,8 +53,8 @@ class _RefreshViewState extends State<RefreshView> {
     );
   }
 
-  Future<void> _refresh() {
+  Future<void> _refresh() async {
     widget.onRefresh?.call();
-    return _refreshCompleter.future;
+    return _refreshCompleter?.future;
   }
 }
diff --git a/lib/src/view/view_state.dart b/lib/src/view/view_state.dart
index 984e674..023cd99 100644
--- a/lib/src/view/view_state.dart
+++ b/lib/src/view/view_state.dart
@@ -7,7 +7,7 @@ abstract class ViewState extends Equatable {
   const ViewState();
 
   @override
-  List<Object> get props => [];
+  List<Object?> get props => [];
 }
 
 /// The initial view state.
@@ -35,7 +35,7 @@ class Refreshing<T> extends ViewState {
   const Refreshing(this.data);
 
   @override
-  List<Object> get props => [data];
+  List<Object?> get props => [data];
 
   @override
   String toString() => 'Refreshing: $data';
@@ -57,7 +57,7 @@ class Success<T> extends ViewState {
   const Success(this.data) : assert(data != null);
 
   @override
-  List<Object> get props => [data];
+  List<Object?> get props => [data];
 
   @override
   String toString() => 'Success: $data';
@@ -66,12 +66,12 @@ class Success<T> extends ViewState {
 /// State indicating that loading or refreshing has failed. It contains an
 /// exact [error] that has occurred.
 class Failure extends ViewState {
-  final dynamic error;
+  final Object error;
 
-  const Failure(this.error) : assert(error != null);
+  const Failure(this.error);
 
   @override
-  List<Object> get props => [error];
+  List<Object?> get props => [error];
 
   @override
   String toString() => 'Failure: $error';
diff --git a/lib/src/view/view_state_builder.dart b/lib/src/view/view_state_builder.dart
index ee3a495..c8515c4 100644
--- a/lib/src/view/view_state_builder.dart
+++ b/lib/src/view/view_state_builder.dart
@@ -1,4 +1,3 @@
-import 'package:bloc/bloc.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:flutter_bloc_patterns/src/view/view_state.dart';
@@ -25,7 +24,7 @@ typedef EmptyBuilder = Widget Function(BuildContext context);
 /// which may allow a view to react differently on different errors.
 typedef ErrorBuilder = Widget Function(
   BuildContext context,
-  dynamic error,
+  Object error,
 );
 
 /// Signature for the [buildWhen] function which takes the previous [ViewState]
@@ -47,22 +46,22 @@ typedef ViewStateBuilderCondition = bool Function(
 /// [onError] builder function for an error state.
 ///
 /// [T] - the type of elements,
-/// [C] - the type of cubit.
-class ViewStateBuilder<T, C extends Cubit<ViewState>>
-    extends BlocBuilder<C, ViewState> {
+/// [B] - the type of bloc.
+class ViewStateBuilder<T, B extends BlocBase<ViewState>>
+    extends BlocBuilder<B, ViewState> {
   ViewStateBuilder({
-    Key key,
-    C cubit,
-    InitialBuilder onReady,
-    LoadingBuilder onLoading,
-    RefreshingBuilder<T> onRefreshing,
-    SuccessBuilder<T> onSuccess,
-    EmptyBuilder onEmpty,
-    ErrorBuilder onError,
-    ViewStateBuilderCondition buildWhen,
+    Key? key,
+    B? bloc,
+    InitialBuilder? onReady,
+    LoadingBuilder? onLoading,
+    RefreshingBuilder<T>? onRefreshing,
+    SuccessBuilder<T>? onSuccess,
+    EmptyBuilder? onEmpty,
+    ErrorBuilder? onError,
+    ViewStateBuilderCondition? buildWhen,
   }) : super(
           key: key,
-          cubit: cubit,
+          bloc: bloc,
           buildWhen: buildWhen,
           builder: (BuildContext context, ViewState state) {
             if (state is Initial) {
diff --git a/lib/src/view/view_state_listener.dart b/lib/src/view/view_state_listener.dart
index 8229879..4b1d79a 100644
--- a/lib/src/view/view_state_listener.dart
+++ b/lib/src/view/view_state_listener.dart
@@ -18,10 +18,7 @@ typedef EmptyCallback = void Function(BuildContext context);
 
 /// Callback function for an error. It contains an [error] that has caused
 /// which may allow a view to react differently on different errors.
-typedef ErrorCallback = void Function(
-  BuildContext context,
-  dynamic error,
-);
+typedef ErrorCallback = void Function(BuildContext context, Object error);
 
 /// Signature for the [listenWhen] function which takes the previous [ViewState]
 /// and the current [ViewState] and is responsible for returning a [bool] which
@@ -46,22 +43,22 @@ typedef ViewStateListenerCondition = bool Function(
 /// [onError] callback function for an error state.
 ///
 /// [T] - the type of elements,
-/// [C] - the type of cubit.
-class ViewStateListener<T, C extends Cubit<ViewState>>
-    extends BlocListener<C, ViewState> {
+/// [B] - the type of bloc.
+class ViewStateListener<T, B extends BlocBase<ViewState>>
+    extends BlocListener<B, ViewState> {
   ViewStateListener({
-    Key key,
-    C cubit,
-    ViewStateListenerCondition listenWhen,
-    LoadingCallback onLoading,
-    RefreshingCallback<T> onRefreshing,
-    SuccessCallback<T> onSuccess,
-    EmptyCallback onEmpty,
-    ErrorCallback onError,
-    Widget child,
+    Key? key,
+    B? bloc,
+    ViewStateListenerCondition? listenWhen,
+    LoadingCallback? onLoading,
+    RefreshingCallback<T>? onRefreshing,
+    SuccessCallback<T>? onSuccess,
+    EmptyCallback? onEmpty,
+    ErrorCallback? onError,
+    Widget? child,
   }) : super(
           key: key,
-          cubit: cubit,
+          bloc: bloc,
           listenWhen: listenWhen,
           child: child,
           listener: (BuildContext context, ViewState state) {
diff --git a/pubspec.yaml b/pubspec.yaml
index 2066192..d1b9a6e 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,21 +1,22 @@
 name: flutter_bloc_patterns
 description: A set of most common BLoC use cases build on top of flutter_bloc library.
-version: 0.8.0
+version: 0.9.0
 homepage: https://github.com/klisiewicz/flutter-bloc-patterns
 
 environment:
-  sdk: ">=2.6.0 <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
+  bloc: ^7.0.0
+  collection: ^1.15.0
+  equatable: ^2.0.3
   flutter:
     sdk: flutter
-  equatable: ^1.2.5
-  bloc: ^6.1.1
-  flutter_bloc: ^6.1.1
+  flutter_bloc: ^7.0.1
 
 dev_dependencies:
+  bloc_test: ^8.0.0
   flutter_test:
     sdk: flutter
-  bloc_test: ^7.1.0
-  lint: ^1.3.0
-  mockito: ^4.1.4
+  lint: ^1.8.2
+  mocktail: ^0.2.0
diff --git a/test/src/details/details_bloc_test.dart b/test/src/details/details_bloc_test.dart
index 032c157..e2ccd70 100644
--- a/test/src/details/details_bloc_test.dart
+++ b/test/src/details/details_bloc_test.dart
@@ -6,12 +6,14 @@ import 'package:flutter_test/flutter_test.dart';
 import 'details_repository_mock.dart';
 
 void main() {
-  DetailsBloc<String, int> detailsBloc;
+  late DetailsBloc<String, int> detailsBloc;
 
-  Future<void> thenExpectStates(Iterable<ViewState> states) async => expect(
-        detailsBloc,
-        emitsInOrder(states),
-      );
+  Future<void> thenExpectStates(Iterable<ViewState> states) async {
+    expect(
+      detailsBloc.stream,
+      emitsInOrder(states),
+    );
+  }
 
   group('repository with elements', () {
     const _existingId = 1;
@@ -64,7 +66,7 @@ void main() {
     final _exception = Exception('Oh no!');
     final _error = Error();
 
-    void givenFailingRepository(error) =>
+    void givenFailingRepository(Object error) =>
         detailsBloc = DetailsBloc(FailingDetailsRepository(error));
 
     void whenLoadingElement() => detailsBloc.loadElement(0);
@@ -78,17 +80,6 @@ void main() {
       ]);
     });
 
-    test(
-        'should emit [$Loading, $Empty] when $ElementNotFoundException is thrown',
-        () {
-      givenFailingRepository(ElementNotFoundException(0));
-      whenLoadingElement();
-      thenExpectStates(const [
-        Loading(),
-        Empty(),
-      ]);
-    });
-
     test('should emit [$Loading, $Failure] when an error is thrown', () {
       givenFailingRepository(_error);
       whenLoadingElement();
diff --git a/test/src/details/details_bloc_view_state_test.dart b/test/src/details/details_bloc_view_state_test.dart
index 413934e..05f57c7 100644
--- a/test/src/details/details_bloc_view_state_test.dart
+++ b/test/src/details/details_bloc_view_state_test.dart
@@ -8,7 +8,7 @@ import 'details_repository_mock.dart';
 
 void main() {
   const someData = 0;
-  DetailsBloc<int, int> bloc;
+  late DetailsBloc<int, int> bloc;
 
   setUp(() {
     bloc = DetailsBloc(InMemoryDetailsRepository());
diff --git a/test/src/details/details_repository_mock.dart b/test/src/details/details_repository_mock.dart
index 4ddcd29..a386402 100644
--- a/test/src/details/details_repository_mock.dart
+++ b/test/src/details/details_repository_mock.dart
@@ -8,14 +8,14 @@ class InMemoryDetailsRepository<T, I> extends DetailsRepository<T, I> {
   InMemoryDetailsRepository([this.elements = const {}]);
 
   @override
-  Future<T> getById(I id) => Future.delayed(_delay, () => elements[id]);
+  Future<T?> getById(I id) => Future.delayed(_delay, () => elements[id]);
 }
 
 class FailingDetailsRepository<T, I> extends DetailsRepository<T, I> {
-  final dynamic error;
+  final Object error;
 
   FailingDetailsRepository(this.error);
 
   @override
-  Future<T> getById(I id) async => Future.delayed(_delay, () => throw error);
+  Future<T?> getById(I id) async => Future.delayed(_delay, () => throw error);
 }
diff --git a/test/src/list/base/list_bloc_test.dart b/test/src/list/base/list_bloc_test.dart
index dc5eda8..1dcca0e 100644
--- a/test/src/list/base/list_bloc_test.dart
+++ b/test/src/list/base/list_bloc_test.dart
@@ -2,15 +2,15 @@ import 'package:flutter_bloc_patterns/src/list/base/list_bloc.dart';
 import 'package:flutter_bloc_patterns/src/list/base/list_repository.dart';
 import 'package:flutter_bloc_patterns/src/view/view_state.dart';
 import 'package:flutter_test/flutter_test.dart';
-import 'package:mockito/mockito.dart' as mock;
+import 'package:mocktail/mocktail.dart' as m;
 
 import '../../util/bdd.dart';
 import '../../util/bloc_state_assertion.dart';
 import 'list_repository_mock.dart';
 
 void main() {
-  ListBloc<int> bloc;
-  ListRepository<int> repository;
+  late ListBloc<int> bloc;
+  late ListRepository<int> repository;
 
   setUp(() {
     repository = ListRepositoryMock<int>();
@@ -18,13 +18,12 @@ void main() {
   });
 
   void emptyRepository() =>
-      mock.when(repository.getAll()).thenAnswer((_) async => []);
+      m.when(repository.getAll).thenAnswer((_) async => []);
 
   void repositoryWithElements() =>
-      mock.when(repository.getAll()).thenAnswer((_) async => _someData);
+      m.when(repository.getAll).thenAnswer((_) async => _someData);
 
-  void failingRepository() =>
-      mock.when(repository.getAll()).thenThrow(_exception);
+  void failingRepository() => m.when(repository.getAll).thenThrow(_exception);
 
   void loadingElements() => bloc.loadElements();
 
@@ -45,15 +44,19 @@ void main() {
         () {
       given(repositoryWithElements);
       when(loadingElements);
-      then(() =>
-          withBloc(bloc).expectStates(const [Loading(), Success(_someData)]));
+      then(
+        () =>
+            withBloc(bloc).expectStates(const [Loading(), Success(_someData)]),
+      );
     });
 
     test('should emit [$Loading, $Failure(error)] when loading data fails', () {
       given(failingRepository);
       when(loadingElements);
-      then(() =>
-          withBloc(bloc).expectStates([const Loading(), Failure(_exception)]));
+      then(
+        () =>
+            withBloc(bloc).expectStates([const Loading(), Failure(_exception)]),
+      );
     });
   });
 
diff --git a/test/src/list/base/list_bloc_view_state_test.dart b/test/src/list/base/list_bloc_view_state_test.dart
index 3eedb33..8830153 100644
--- a/test/src/list/base/list_bloc_view_state_test.dart
+++ b/test/src/list/base/list_bloc_view_state_test.dart
@@ -7,7 +7,7 @@ import '../../view/view_state_matchers.dart';
 import '../filter/filter_list_repository_mock.dart';
 
 void main() {
-  ListBloc<int> bloc;
+  late ListBloc<int> bloc;
 
   setUp(() {
     bloc = ListBloc(InMemoryFilterRepository());
diff --git a/test/src/list/base/list_repository_mock.dart b/test/src/list/base/list_repository_mock.dart
index 2a7e885..bf3ba1c 100644
--- a/test/src/list/base/list_repository_mock.dart
+++ b/test/src/list/base/list_repository_mock.dart
@@ -1,4 +1,4 @@
 import 'package:flutter_bloc_patterns/src/list/base/list_repository.dart';
-import 'package:mockito/mockito.dart';
+import 'package:mocktail/mocktail.dart';
 
 class ListRepositoryMock<T> extends Mock implements ListRepository<T> {}
diff --git a/test/src/list/filter/filter_list_bloc_test.dart b/test/src/list/filter/filter_list_bloc_test.dart
index 47ee048..02e9d70 100644
--- a/test/src/list/filter/filter_list_bloc_test.dart
+++ b/test/src/list/filter/filter_list_bloc_test.dart
@@ -12,11 +12,12 @@ void main() {
   const _matchingFilter = 1;
   const _matchingElements = [1];
 
-  FilterListBloc<int, int> bloc;
+  late FilterListBloc<int, int> bloc;
 
-  void loadingElements({int filter}) => bloc.loadElements(filter: filter);
+  void loadingElements({int? filter}) => bloc.loadElements(filter: filter);
 
-  void refreshingElements({int filter}) => bloc.refreshElements(filter: filter);
+  void refreshingElements({int? filter}) =>
+      bloc.refreshElements(filter: filter);
 
   group('empty repository', () {
     setUp(() {
@@ -24,7 +25,7 @@ void main() {
     });
 
     test('should emit [$Loading, $Empty] state when no filter is set', () {
-      when(() => loadingElements());
+      when(loadingElements);
       then(() => withBloc(bloc).expectStates(const [Loading(), Empty()]));
     });
 
@@ -50,7 +51,7 @@ void main() {
     test(
         'should emit [$Loading, $Success] with all elements when no filter is set',
         () {
-      when(() => loadingElements());
+      when(loadingElements);
       then(
         () =>
             withBloc(bloc).expectStates(const [Loading(), Success(_someData)]),
diff --git a/test/src/list/filter/filter_list_repository_mock.dart b/test/src/list/filter/filter_list_repository_mock.dart
index 27ec029..9765e45 100644
--- a/test/src/list/filter/filter_list_repository_mock.dart
+++ b/test/src/list/filter/filter_list_repository_mock.dart
@@ -11,7 +11,7 @@ class InMemoryFilterRepository<T, F> extends FilterListRepository<T, F> {
   Future<List<T>> getAll() async => Future.delayed(_delay, () => elements);
 
   @override
-  Future<List<T>> getBy(F filter) {
+  Future<List<T>> getBy(F? filter) {
     return Future.delayed(
       _delay,
       () => elements.where((item) => item == filter).toList(),
@@ -20,7 +20,7 @@ class InMemoryFilterRepository<T, F> extends FilterListRepository<T, F> {
 }
 
 class FailingFilterRepository<T, F> extends FilterListRepository<T, F> {
-  final dynamic error;
+  final Object error;
 
   FailingFilterRepository(this.error);
 
@@ -28,5 +28,5 @@ class FailingFilterRepository<T, F> extends FilterListRepository<T, F> {
   Future<List<T>> getAll() => Future.delayed(_delay, () => throw error);
 
   @override
-  Future<List<T>> getBy(F filter) => Future.delayed(_delay, () => throw error);
+  Future<List<T>> getBy(F? filter) => Future.delayed(_delay, () => throw error);
 }
diff --git a/test/src/list/paged/paged_list_bloc_test.dart b/test/src/list/paged/paged_list_bloc_test.dart
index 4a1b18b..37cd4ea 100644
--- a/test/src/list/paged/paged_list_bloc_test.dart
+++ b/test/src/list/paged/paged_list_bloc_test.dart
@@ -1,5 +1,4 @@
 import 'package:flutter_bloc_patterns/paged_list.dart';
-import 'package:flutter_bloc_patterns/src/list/paged/paged_list.dart';
 import 'package:flutter_bloc_patterns/src/view/view_state.dart';
 import 'package:flutter_test/flutter_test.dart';
 
@@ -8,8 +7,8 @@ import '../../util/bloc_state_assertion.dart';
 import 'paged_list_repository_mock.dart';
 
 void main() {
-  PagedListBloc<int> bloc;
-  PagedListRepository<int> repository;
+  late PagedListBloc<int> bloc;
+  late PagedListRepository<int> repository;
 
   void loadingFirstPage() => bloc.loadFirstPage(pageSize: 3);
 
@@ -92,10 +91,12 @@ void main() {
           const Loading(),
           Success(PagedList(firstPage, hasReachedMax: false)),
           Success(PagedList(firstPage + secondPage, hasReachedMax: false)),
-          Success(PagedList(
-            firstPage + secondPage + thirdPage,
-            hasReachedMax: true,
-          )),
+          Success(
+            PagedList(
+              firstPage + secondPage + thirdPage,
+              hasReachedMax: true,
+            ),
+          ),
         ]);
       });
     });
diff --git a/test/src/list/paged/paged_list_filter_bloc_test.dart b/test/src/list/paged/paged_list_filter_bloc_test.dart
index 9dab759..74e569e 100644
--- a/test/src/list/paged/paged_list_filter_bloc_test.dart
+++ b/test/src/list/paged/paged_list_filter_bloc_test.dart
@@ -9,13 +9,17 @@ import '../../util/bloc_state_assertion.dart';
 import 'paged_list_filter_repository_mock.dart';
 
 void main() {
+  const filter = 1;
   const pageSize = 3;
 
-  PagedListFilterBloc<int, int> bloc;
-  PagedListFilterRepository<int, int> repository;
+  late PagedListFilterBloc<int, int> bloc;
+  late PagedListFilterRepository<int, int> repository;
 
-  void loadingFirstPage({int filter}) =>
-      bloc.loadFirstPage(pageSize: pageSize, filter: filter);
+  void loadingFirstPage({
+    required int filter,
+  }) {
+    bloc.loadFirstPage(pageSize: pageSize, filter: filter);
+  }
 
   void loadingNextPage() => bloc.loadNextPage();
 
@@ -27,7 +31,7 @@ void main() {
 
     test('should emit [$Loading, $Empty] when first page contains no elements',
         () {
-      when(loadingFirstPage);
+      when(() => loadingFirstPage(filter: filter));
       then(
         () => withBloc(bloc).expectStates(const [
           Loading(),
@@ -42,7 +46,6 @@ void main() {
   });
 
   group('repository with elements', () {
-    const filter = 1;
     const elements = [1, 1, 0, 1, 2, 3, 1, 1, 0];
     final firstPage = List<int>.generate(3, (i) => filter);
     final secondPage = List<int>.generate(2, (i) => filter);
@@ -55,9 +58,7 @@ void main() {
     test(
         'should emit [$Loading, $Success] with elements matching the filter when loading first page',
         () {
-      when(() {
-        loadingFirstPage(filter: filter);
-      });
+      when(() => loadingFirstPage(filter: filter));
 
       then(() {
         withBloc(bloc).expectStates([
@@ -99,7 +100,7 @@ void main() {
       });
 
       test('should emit [$Loading, $Failure] when error occurs', () {
-        when(loadingFirstPage);
+        when(() => loadingFirstPage(filter: 1));
 
         then(
           () => withBloc(bloc).expectStates([
@@ -123,7 +124,7 @@ void main() {
       });
 
       test('should emit [$Loading, $Empty] when first page was not found', () {
-        when(loadingFirstPage);
+        when(() => loadingFirstPage(filter: filter));
         then(
           () => withBloc(bloc).expectStates(const [
             Loading(),
diff --git a/test/src/list/paged/paged_list_filter_repository_mock.dart b/test/src/list/paged/paged_list_filter_repository_mock.dart
index 481b4bb..03a0014 100644
--- a/test/src/list/paged/paged_list_filter_repository_mock.dart
+++ b/test/src/list/paged/paged_list_filter_repository_mock.dart
@@ -11,7 +11,9 @@ class InMemoryPagedListFilterRepository<T, F>
   InMemoryPagedListFilterRepository(this.elements);
 
   @override
-  Future<List<T>> getAll(Page page) => getBy(page, null);
+  Future<List<T>> getAll(Page page) async {
+    return InMemoryPagedListRepository(elements).getAll(page);
+  }
 
   @override
   Future<List<T>> getBy(Page page, F filter) {
@@ -23,13 +25,13 @@ class InMemoryPagedListFilterRepository<T, F>
 
 class FailingPagedListFilterRepository<T, F>
     implements PagedListFilterRepository<T, F> {
-  final dynamic error;
+  final Object error;
 
   FailingPagedListFilterRepository(this.error);
 
   @override
-  Future<List<T>> getAll(Page page) => throw error;
+  Future<List<T>> getAll(Page page) => Future.error(error);
 
   @override
-  Future<List<T>> getBy(Page page, F filter) => throw error;
+  Future<List<T>> getBy(Page page, F filter) => Future.error(error);
 }
diff --git a/test/src/list/paged/paged_list_repository_mock.dart b/test/src/list/paged/paged_list_repository_mock.dart
index 528d077..087de73 100644
--- a/test/src/list/paged/paged_list_repository_mock.dart
+++ b/test/src/list/paged/paged_list_repository_mock.dart
@@ -22,7 +22,7 @@ class InMemoryPagedListRepository<T> implements PagedListRepository<T> {
 }
 
 class FailingPagedRepository<T> implements PagedListRepository<T> {
-  final dynamic error;
+  final Object error;
 
   FailingPagedRepository(this.error);
 
diff --git a/test/src/util/bloc_state_assertion.dart b/test/src/util/bloc_state_assertion.dart
index b793733..060ff11 100644
--- a/test/src/util/bloc_state_assertion.dart
+++ b/test/src/util/bloc_state_assertion.dart
@@ -12,7 +12,7 @@ class BlocStateAssertion {
 
   Future<void> expectStates(Iterable<ViewState> states) {
     return expectLater(
-      _bloc,
+      _bloc.stream,
       emitsInOrder(states),
     );
   }
diff --git a/test/src/util/view_test_util.dart b/test/src/util/view_test_util.dart
index 807ccdc..ec2d77b 100644
--- a/test/src/util/view_test_util.dart
+++ b/test/src/util/view_test_util.dart
@@ -1,5 +1,5 @@
 import 'package:flutter/material.dart';
 
-Widget makeTestableWidget({Widget child}) => MaterialApp(
-  home: Material(child: child),
-);
\ No newline at end of file
+Widget makeTestableWidget({Widget? child}) => MaterialApp(
+      home: Material(child: child),
+    );
diff --git a/test/src/view/view_state_builder_test.dart b/test/src/view/view_state_builder_test.dart
index 85d16bf..013a373 100644
--- a/test/src/view/view_state_builder_test.dart
+++ b/test/src/view/view_state_builder_test.dart
@@ -2,26 +2,31 @@ import 'package:bloc/bloc.dart';
 import 'package:bloc_test/bloc_test.dart';
 import 'package:flutter_bloc_patterns/src/view/view_state.dart';
 import 'package:flutter_test/flutter_test.dart';
-import 'package:mockito/mockito.dart';
+import 'package:mocktail/mocktail.dart';
 
 import 'view_state_builder_util.dart';
+import 'view_state_fakes.dart';
 import 'view_state_keys.dart';
 
-class MockTestBloc extends MockBloc<ViewState> implements Bloc<int, ViewState> {
-}
+class MockTestBloc extends MockBloc<int, ViewState> {}
 
 void main() {
-  Bloc<int, ViewState> bloc;
+  late Bloc<int, ViewState> bloc;
   const someData = 0;
   final someError = Exception();
 
+  setUpAll(() {
+    registerVieStateFallbackValue();
+    registerBuildContextFallbackValue();
+  });
+
   setUp(() {
     bloc = MockTestBloc();
   });
 
   testWidgets('should display onReady widget when bloc is in initial state',
       (WidgetTester tester) async {
-    when(bloc.state).thenReturn(const Initial());
+    when(() => bloc.state).thenReturn(const Initial());
 
     await tester.pumpWidget(makeTestableViewStateBuilder(bloc));
 
@@ -30,7 +35,7 @@ void main() {
 
   testWidgets('should display onLoading widget when bloc is in loading state',
       (WidgetTester tester) async {
-    when(bloc.state).thenReturn(const Loading());
+    when(() => bloc.state).thenReturn(const Loading());
 
     await tester.pumpWidget(makeTestableViewStateBuilder(bloc));
 
@@ -40,7 +45,7 @@ void main() {
   testWidgets(
       'should display onRefreshing widget when bloc is in refreshing state',
       (WidgetTester tester) async {
-    when(bloc.state).thenReturn(const Refreshing(someData));
+    when(() => bloc.state).thenReturn(const Refreshing(someData));
 
     await tester.pumpWidget(makeTestableViewStateBuilder(bloc));
 
@@ -49,7 +54,7 @@ void main() {
 
   testWidgets('should display onEmpty widget when bloc is in empty state',
       (WidgetTester tester) async {
-    when(bloc.state).thenReturn(const Empty());
+    when(() => bloc.state).thenReturn(const Empty());
 
     await tester.pumpWidget(makeTestableViewStateBuilder(bloc));
 
@@ -58,7 +63,7 @@ void main() {
 
   testWidgets('should display onSuccess widget when bloc is in success state',
       (WidgetTester tester) async {
-    when(bloc.state).thenReturn(const Success(someData));
+    when(() => bloc.state).thenReturn(const Success(someData));
 
     await tester.pumpWidget(makeTestableViewStateBuilder(bloc));
 
@@ -67,7 +72,7 @@ void main() {
 
   testWidgets('should display onError widget when bloc is in failure state',
       (WidgetTester tester) async {
-    when(bloc.state).thenReturn(Failure(someError));
+    when(() => bloc.state).thenReturn(Failure(someError));
 
     await tester.pumpWidget(makeTestableViewStateBuilder(bloc));
 
diff --git a/test/src/view/view_state_builder_util.dart b/test/src/view/view_state_builder_util.dart
index 4b8edeb..f26e59a 100644
--- a/test/src/view/view_state_builder_util.dart
+++ b/test/src/view/view_state_builder_util.dart
@@ -6,10 +6,10 @@ import 'package:flutter_bloc_patterns/src/view/view_state_builder.dart';
 import '../util/view_test_util.dart';
 import 'view_state_keys.dart';
 
-Widget makeTestableViewStateBuilder<T, C extends Cubit<ViewState>>(C cubit) {
+Widget makeTestableViewStateBuilder<T, B extends BlocBase<ViewState>>(B bloc) {
   return makeTestableWidget(
-    child: ViewStateBuilder<T, C>(
-      cubit: cubit,
+    child: ViewStateBuilder<T, B>(
+      bloc: bloc,
       onReady: (context) => const SizedBox.shrink(key: readyKey),
       onLoading: (context) => const SizedBox.shrink(key: loadKey),
       onRefreshing: (context, data) => const SizedBox.shrink(key: refreshKey),
diff --git a/test/src/view/view_state_fakes.dart b/test/src/view/view_state_fakes.dart
new file mode 100644
index 0000000..04e6fd4
--- /dev/null
+++ b/test/src/view/view_state_fakes.dart
@@ -0,0 +1,16 @@
+import 'package:flutter/widgets.dart';
+import 'package:flutter_bloc_patterns/src/view/view_state.dart';
+import 'package:mocktail/mocktail.dart';
+
+// ignore: avoid_implementing_value_types
+class ViewStateFake extends Fake implements ViewState {}
+
+class BuildContextFake extends Fake implements BuildContext {}
+
+void registerVieStateFallbackValue() {
+  registerFallbackValue(ViewStateFake());
+}
+
+void registerBuildContextFallbackValue() {
+  registerFallbackValue(BuildContextFake());
+}
diff --git a/test/src/view/view_state_listener_test.dart b/test/src/view/view_state_listener_test.dart
index fb631de..e8b7f26 100644
--- a/test/src/view/view_state_listener_test.dart
+++ b/test/src/view/view_state_listener_test.dart
@@ -1,15 +1,14 @@
 import 'package:bloc_test/bloc_test.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
-import 'package:flutter_bloc_patterns/src/view/view_state.dart';
 import 'package:flutter_bloc_patterns/view.dart';
 import 'package:flutter_test/flutter_test.dart';
-import 'package:mockito/mockito.dart';
+import 'package:mocktail/mocktail.dart';
 
 import '../util/view_test_util.dart';
+import 'view_state_fakes.dart';
 
-class MockTestBloc extends MockBloc<ViewState> implements Bloc<int, ViewState> {
-}
+class MockTestBloc extends MockBloc<int, ViewState> {}
 
 class LoadingMock extends Mock {
   void call(BuildContext context);
@@ -35,12 +34,17 @@ const _someData = 1;
 final _someException = Exception('Damn, I have failed...');
 
 void main() {
-  Bloc<int, ViewState> bloc;
-  LoadingCallback loadingCallback;
-  SuccessCallback<int> successCallback;
-  RefreshingCallback<int> refreshCallback;
-  EmptyCallback emptyCallback;
-  ErrorCallback errorCallback;
+  late Bloc<int, ViewState> bloc;
+  late LoadingCallback loadingCallback;
+  late SuccessCallback<int> successCallback;
+  late RefreshingCallback<int> refreshCallback;
+  late EmptyCallback emptyCallback;
+  late ErrorCallback errorCallback;
+
+  setUpAll(() {
+    registerVieStateFallbackValue();
+    registerBuildContextFallbackValue();
+  });
 
   setUp(() {
     bloc = MockTestBloc();
@@ -54,7 +58,7 @@ void main() {
   Widget makeTestableViewStateListener() {
     return makeTestableWidget(
       child: ViewStateListener<int, Bloc<int, ViewState>>(
-        cubit: bloc,
+        bloc: bloc,
         onLoading: loadingCallback,
         onRefreshing: refreshCallback,
         onSuccess: successCallback,
@@ -69,79 +73,84 @@ void main() {
       (WidgetTester tester) async {
     whenListen(
       bloc,
-      Stream.fromIterable(const [Initial(), Loading()]),
+      Stream.value(const Loading()),
+      initialState: const Initial(),
     );
 
     await tester.pumpWidget(makeTestableViewStateListener());
 
-    verify(loadingCallback.call(any));
-    verifyNever(successCallback.call(any, any));
-    verifyNever(refreshCallback.call(any, any));
-    verifyNever(emptyCallback.call(any));
-    verifyNever(errorCallback.call(any, any));
+    verify(() => loadingCallback.call(any<BuildContext>()));
+    verifyNever(() => successCallback.call(any<BuildContext>(), any<int>()));
+    verifyNever(() => refreshCallback.call(any<BuildContext>(), any<int>()));
+    verifyNever(() => emptyCallback.call(any<BuildContext>()));
+    verifyNever(() => errorCallback.call(any<BuildContext>(), any<Object>()));
   });
 
   testWidgets('should invoke success callback when loaded',
       (WidgetTester tester) async {
     whenListen(
       bloc,
-      Stream.fromIterable(const [Initial(), Success(_someData)]),
+      Stream.value(const Success(_someData)),
+      initialState: const Initial(),
     );
 
     await tester.pumpWidget(makeTestableViewStateListener());
 
-    verifyNever(loadingCallback.call(any));
-    verify(successCallback.call(any, _someData));
-    verifyNever(refreshCallback.call(any, any));
-    verifyNever(emptyCallback.call(any));
-    verifyNever(errorCallback.call(any, any));
+    verifyNever(() => loadingCallback.call(any()));
+    verify(() => successCallback.call(any(), _someData));
+    verifyNever(() => refreshCallback.call(any(), any()));
+    verifyNever(() => emptyCallback.call(any()));
+    verifyNever(() => errorCallback.call(any(), any()));
   });
 
   testWidgets('should invoke refresh callback when refreshing',
       (WidgetTester tester) async {
     whenListen(
       bloc,
-      Stream.fromIterable(const [Initial(), Refreshing(_someData)]),
+      Stream.value(const Refreshing(_someData)),
+      initialState: const Initial(),
     );
 
     await tester.pumpWidget(makeTestableViewStateListener());
 
-    verifyNever(loadingCallback.call(any));
-    verifyNever(successCallback.call(any, any));
-    verify(refreshCallback.call(any, _someData));
-    verifyNever(emptyCallback.call(any));
-    verifyNever(errorCallback.call(any, any));
+    verifyNever(() => loadingCallback.call(any()));
+    verifyNever(() => successCallback.call(any(), any()));
+    verify(() => refreshCallback.call(any(), _someData));
+    verifyNever(() => emptyCallback.call(any()));
+    verifyNever(() => errorCallback.call(any(), any()));
   });
 
   testWidgets('should invoke empty callback when empty',
       (WidgetTester tester) async {
     whenListen(
       bloc,
-      Stream.fromIterable(const [Initial(), Empty()]),
+      Stream.value(const Empty()),
+      initialState: const Initial(),
     );
 
     await tester.pumpWidget(makeTestableViewStateListener());
 
-    verifyNever(loadingCallback.call(any));
-    verifyNever(successCallback.call(any, any));
-    verifyNever(refreshCallback.call(any, any));
-    verify(emptyCallback.call(any));
-    verifyNever(errorCallback.call(any, any));
+    verifyNever(() => loadingCallback.call(any()));
+    verifyNever(() => successCallback.call(any(), any()));
+    verifyNever(() => refreshCallback.call(any(), any()));
+    verify(() => emptyCallback.call(any()));
+    verifyNever(() => errorCallback.call(any(), any()));
   });
 
   testWidgets('should invoke error callback when error',
       (WidgetTester tester) async {
     whenListen(
       bloc,
-      Stream.fromIterable([const Initial(), Failure(_someException)]),
+      Stream.value(Failure(_someException)),
+      initialState: const Initial(),
     );
 
     await tester.pumpWidget(makeTestableViewStateListener());
 
-    verifyNever(loadingCallback.call(any));
-    verifyNever(successCallback.call(any, any));
-    verifyNever(refreshCallback.call(any, any));
-    verifyNever(emptyCallback.call(any));
-    verify(errorCallback.call(any, _someException));
+    verifyNever(() => loadingCallback.call(any()));
+    verifyNever(() => successCallback.call(any(), any()));
+    verifyNever(() => refreshCallback.call(any(), any()));
+    verifyNever(() => emptyCallback.call(any()));
+    verify(() => errorCallback.call(any(), _someException));
   });
 }