Merge pull request #1217 from jonataslaw/null-safety

Null safety

+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: 60bd88df915880d23877bfc1602e8ddcf4c4dd2a
+  channel: stable
+
+project_type: app

+## [4.0.0-nullsafety.2] 
+- Added append function to StateMixin. Now is possible track loading, success and error handle of your application with ONE LINE OF CODE. Ex: append(()=> api.getUser);
+
+## [4.0.0-nullsafety.0] 
+- Migrate to null-safety 
+- Added ScrollMixin to controllers
+- Added loadingMore status to RxStatus
+- Breaking: It is not possible to initialize Rx with null values.
+
 ## [3.25.6] 
 - Added documentation in French (@kamazoun)
 - Fix logs messages (@damphat)

 import 'package:flutter/material.dart';
 import 'package:get/get.dart';
 
-import 'en_US.dart';
-import 'pt_BR.dart';
+import 'en_us.dart';
+import 'pt_br.dart';
 
 class TranslationService extends Translations {
-  static final locale = Get.deviceLocale;
+  static Locale get locale => Get.deviceLocale!;
   static final fallbackLocale = Locale('en', 'US');
   @override
   Map<String, Map<String, String>> get keys => {

@@ -9,7 +9,7 @@ void main() {
 }
 
 class MyApp extends StatelessWidget {
-  const MyApp({Key key}) : super(key: key);
+  const MyApp({Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

@@ -9,7 +9,8 @@ abstract class IHomeProvider {
 class HomeProvider extends GetConnect implements IHomeProvider {
   @override
   void onInit() {
-    httpClient.defaultDecoder = CasesModel.fromJson;
+    httpClient.defaultDecoder =
+        (val) => CasesModel.fromJson(val as Map<String, dynamic>);
     httpClient.baseUrl = 'https://api.covid19api.com';
   }
 

@@ -3,16 +3,16 @@ import '../domain/entity/cases_model.dart';
 import 'home_api_provider.dart';
 
 class HomeRepository implements IHomeRepository {
-  HomeRepository({this.provider});
+  HomeRepository({required this.provider});
   final IHomeProvider provider;
 
   @override
   Future<CasesModel> getCases() async {
     final cases = await provider.getCases("/summary");
     if (cases.status.hasError) {
-      return Future.error(cases.statusText);
+      return Future.error(cases.statusText!);
     } else {
-      return cases.body;
+      return cases.body!;
     }
   }
 }

 // To parse this JSON data, do
 //
-//     final CasesModel = CasesModelFromJson(jsonString);
+//     final welcome = welcomeFromJson(jsonString);
 
 import 'dart:convert';
 
 class CasesModel {
-  final Global global;
-  final List<Country> countries;
-  final String date;
-
   CasesModel({
-    this.global,
-    this.countries,
-    this.date,
+    required this.id,
+    required this.message,
+    required this.global,
+    required this.countries,
+    required this.date,
   });
 
-  static CasesModel fromRawJson(String str) =>
+  final String id;
+  final String message;
+  final Global global;
+  final List<Country> countries;
+  final DateTime date;
+
+  factory CasesModel.fromRawJson(String str) =>
       CasesModel.fromJson(json.decode(str) as Map<String, dynamic>);
 
   String toRawJson() => json.encode(toJson());
 
-  static CasesModel fromJson(dynamic json) => CasesModel(
-        global: json["Global"] == null
-            ? null
-            : Global.fromJson(json["Global"] as Map<String, dynamic>),
-        countries: json["Countries"] == null
-            ? null
-            : List<Country>.from(
-                (json["Countries"] as List<dynamic>)
-                    .map((x) => Country.fromJson(x as Map<String, dynamic>)),
-              ),
-        date: json["Date"] == null ? null : json["Date"] as String,
+  factory CasesModel.fromJson(Map<String, dynamic> json) => CasesModel(
+        id: json["ID"] as String,
+        message: json["Message"] as String,
+        global: Global.fromJson(json["Global"] as Map<String, dynamic>),
+        countries: List<Country>.from((json["Countries"] as Iterable).map(
+          (x) => Country.fromJson(x as Map<String, dynamic>),
+        )),
+        date: DateTime.parse(json["Date"] as String),
       );
 
   Map<String, dynamic> toJson() => {
-        "Global": global == null ? null : global.toJson(),
-        "Countries": countries == null
-            ? null
-            : List<dynamic>.from(countries.map((x) => x.toJson())),
-        "Date": date == null ? null : date,
+        "ID": id,
+        "Message": message,
+        "Global": global.toJson(),
+        "Countries": List<dynamic>.from(countries.map((x) => x.toJson())),
+        "Date": date.toIso8601String(),
       };
 }
 
 class Country {
+  Country({
+    required this.id,
+    required this.country,
+    required this.countryCode,
+    required this.slug,
+    required this.newConfirmed,
+    required this.totalConfirmed,
+    required this.newDeaths,
+    required this.totalDeaths,
+    required this.newRecovered,
+    required this.totalRecovered,
+    required this.date,
+    required this.premium,
+  });
+
+  final String id;
   final String country;
   final String countryCode;
   final String slug;
@@ -52,20 +69,8 @@ class Country {
   final int totalDeaths;
   final int newRecovered;
   final int totalRecovered;
-  final String date;
-
-  Country({
-    this.country,
-    this.countryCode,
-    this.slug,
-    this.newConfirmed,
-    this.totalConfirmed,
-    this.newDeaths,
-    this.totalDeaths,
-    this.newRecovered,
-    this.totalRecovered,
-    this.date,
-  });
+  final DateTime date;
+  final Premium premium;
 
   factory Country.fromRawJson(String str) =>
       Country.fromJson(json.decode(str) as Map<String, dynamic>);
@@ -73,56 +78,67 @@ class Country {
   String toRawJson() => json.encode(toJson());
 
   factory Country.fromJson(Map<String, dynamic> json) => Country(
-        country: json["Country"] == null ? null : json["Country"] as String,
-        countryCode:
-            json["CountryCode"] == null ? null : json["CountryCode"] as String,
-        slug: json["Slug"] == null ? null : json["Slug"] as String,
-        newConfirmed:
-            json["NewConfirmed"] == null ? null : json["NewConfirmed"] as int,
-        totalConfirmed: json["TotalConfirmed"] == null
-            ? null
-            : json["TotalConfirmed"] as int,
-        newDeaths: json["NewDeaths"] == null ? null : json["NewDeaths"] as int,
-        totalDeaths:
-            json["TotalDeaths"] == null ? null : json["TotalDeaths"] as int,
-        newRecovered:
-            json["NewRecovered"] == null ? null : json["NewRecovered"] as int,
-        totalRecovered: json["TotalRecovered"] == null
-            ? null
-            : json["TotalRecovered"] as int,
-        date: json["Date"] == null ? null : json["Date"] as String,
+        id: json["ID"] as String,
+        country: json["Country"] as String,
+        countryCode: json["CountryCode"] as String,
+        slug: json["Slug"] as String,
+        newConfirmed: json["NewConfirmed"] as int,
+        totalConfirmed: json["TotalConfirmed"] as int,
+        newDeaths: json["NewDeaths"] as int,
+        totalDeaths: json["TotalDeaths"] as int,
+        newRecovered: json["NewRecovered"] as int,
+        totalRecovered: json["TotalRecovered"] as int,
+        date: DateTime.parse(json["Date"] as String),
+        premium: Premium.fromJson(json["Premium"] as Map<String, dynamic>),
       );
 
   Map<String, dynamic> toJson() => {
-        "Country": country == null ? null : country,
-        "CountryCode": countryCode == null ? null : countryCode,
-        "Slug": slug == null ? null : slug,
-        "NewConfirmed": newConfirmed == null ? null : newConfirmed,
-        "TotalConfirmed": totalConfirmed == null ? null : totalConfirmed,
-        "NewDeaths": newDeaths == null ? null : newDeaths,
-        "TotalDeaths": totalDeaths == null ? null : totalDeaths,
-        "NewRecovered": newRecovered == null ? null : newRecovered,
-        "TotalRecovered": totalRecovered == null ? null : totalRecovered,
-        "Date": date == null ? null : date,
+        "ID": id,
+        "Country": country,
+        "CountryCode": countryCode,
+        "Slug": slug,
+        "NewConfirmed": newConfirmed,
+        "TotalConfirmed": totalConfirmed,
+        "NewDeaths": newDeaths,
+        "TotalDeaths": totalDeaths,
+        "NewRecovered": newRecovered,
+        "TotalRecovered": totalRecovered,
+        "Date": date.toIso8601String(),
+        "Premium": premium.toJson(),
       };
 }
 
+class Premium {
+  Premium();
+
+  factory Premium.fromRawJson(String str) =>
+      Premium.fromJson(json.decode(str) as Map<String, dynamic>);
+
+  String toRawJson() => json.encode(toJson());
+
+  factory Premium.fromJson(Map<String, dynamic> json) => Premium();
+
+  Map<String, dynamic> toJson() => {};
+}
+
 class Global {
+  Global({
+    required this.newConfirmed,
+    required this.totalConfirmed,
+    required this.newDeaths,
+    required this.totalDeaths,
+    required this.newRecovered,
+    required this.totalRecovered,
+    required this.date,
+  });
+
   final int newConfirmed;
   final int totalConfirmed;
   final int newDeaths;
   final int totalDeaths;
   final int newRecovered;
   final int totalRecovered;
-
-  Global({
-    this.newConfirmed,
-    this.totalConfirmed,
-    this.newDeaths,
-    this.totalDeaths,
-    this.newRecovered,
-    this.totalRecovered,
-  });
+  final DateTime date;
 
   factory Global.fromRawJson(String str) =>
       Global.fromJson(json.decode(str) as Map<String, dynamic>);
@@ -130,27 +146,22 @@ class Global {
   String toRawJson() => json.encode(toJson());
 
   factory Global.fromJson(Map<String, dynamic> json) => Global(
-        newConfirmed:
-            json["NewConfirmed"] == null ? null : json["NewConfirmed"] as int,
-        totalConfirmed: json["TotalConfirmed"] == null
-            ? null
-            : json["TotalConfirmed"] as int,
-        newDeaths: json["NewDeaths"] == null ? null : json["NewDeaths"] as int,
-        totalDeaths:
-            json["TotalDeaths"] == null ? null : json["TotalDeaths"] as int,
-        newRecovered:
-            json["NewRecovered"] == null ? null : json["NewRecovered"] as int,
-        totalRecovered: json["TotalRecovered"] == null
-            ? null
-            : json["TotalRecovered"] as int,
+        newConfirmed: json["NewConfirmed"] as int,
+        totalConfirmed: json["TotalConfirmed"] as int,
+        newDeaths: json["NewDeaths"] as int,
+        totalDeaths: json["TotalDeaths"] as int,
+        newRecovered: json["NewRecovered"] as int,
+        totalRecovered: json["TotalRecovered"] as int,
+        date: DateTime.parse(json["Date"] as String),
       );
 
   Map<String, dynamic> toJson() => {
-        "NewConfirmed": newConfirmed == null ? null : newConfirmed,
-        "TotalConfirmed": totalConfirmed == null ? null : totalConfirmed,
-        "NewDeaths": newDeaths == null ? null : newDeaths,
-        "TotalDeaths": totalDeaths == null ? null : totalDeaths,
-        "NewRecovered": newRecovered == null ? null : newRecovered,
-        "TotalRecovered": totalRecovered == null ? null : totalRecovered,
+        "NewConfirmed": newConfirmed,
+        "TotalConfirmed": totalConfirmed,
+        "NewDeaths": newDeaths,
+        "TotalDeaths": totalDeaths,
+        "NewRecovered": newRecovered,
+        "TotalRecovered": totalRecovered,
+        "Date": date.toIso8601String(),
       };
 }

@@ -4,22 +4,16 @@ import '../../domain/adapters/repository_adapter.dart';
 import '../../domain/entity/cases_model.dart';
 
 class HomeController extends SuperController<CasesModel> {
-  HomeController({this.homeRepository});
+  HomeController({required this.homeRepository});
 
-  /// inject repo abstraction dependency
   final IHomeRepository homeRepository;
 
-  /// When the controller is initialized, make the http request
   @override
   void onInit() {
     super.onInit();
-    // show loading on start, data on success
-    // and error message on error with 0 boilerplate
-    homeRepository.getCases().then((data) {
-      change(data, status: RxStatus.success());
-    }, onError: (err) {
-      change(null, status: RxStatus.error(err.toString()));
-    });
+
+    //Loading, Success, Error handle with 1 line of code
+    append(() => homeRepository.getCases);
   }
 
   @override

@@ -29,9 +29,9 @@ class CountryView extends GetView<HomeController> {
             ),
             body: Center(
               child: ListView.builder(
-                  itemCount: controller.state.countries.length,
+                  itemCount: controller.state!.countries.length,
                   itemBuilder: (context, index) {
-                    final country = controller.state.countries[index];
+                    final country = controller.state!.countries[index];
                     return ListTile(
                       onTap: () {
                         Get.toNamed('/home/country/details',

@@ -42,7 +42,7 @@ class HomeView extends GetView<HomeController> {
                     ),
                   ),
                   Text(
-                    '${state.global.totalConfirmed}',
+                    '${state!.global.totalConfirmed}',
                     style: TextStyle(fontSize: 45, fontWeight: FontWeight.bold),
                   ),
                   SizedBox(

@@ -18,7 +18,7 @@ publish_to: "none" # Remove this line if you wish to publish to pub.dev
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
 
 dependencies:
   flutter:

@@ -6,8 +6,8 @@ import 'package:get/get.dart';
 import 'package:get_demo/pages/home/domain/adapters/repository_adapter.dart';
 import 'package:get_demo/pages/home/domain/entity/cases_model.dart';
 import 'package:get_demo/pages/home/presentation/controllers/home_controller.dart';
-import 'package:get_demo/routes/app_pages.dart';
-import 'package:get_test/get_test.dart';
+// import 'package:get_demo/routes/app_pages.dart';
+// import 'package:get_test/get_test.dart';
 import 'package:matcher/matcher.dart' as m;
 
 class MockRepository implements IHomeRepository {
@@ -17,7 +17,18 @@ class MockRepository implements IHomeRepository {
 
     if (Random().nextBool()) {
       return CasesModel(
-        global: Global(totalDeaths: 100, totalConfirmed: 200),
+        global: Global(
+            totalDeaths: 100,
+            totalConfirmed: 200,
+            date: DateTime.now(),
+            newConfirmed: 0,
+            newDeaths: 0,
+            newRecovered: 0,
+            totalRecovered: 0),
+        countries: [],
+        date: DateTime.now(),
+        id: '',
+        message: '',
       );
     }
 
@@ -26,6 +37,7 @@ class MockRepository implements IHomeRepository {
 }
 
 void main() {
+  WidgetsFlutterBinding.ensureInitialized();
   setUpAll(() => HttpOverrides.global = null);
   final binding = BindingsBuilder(() {
     Get.lazyPut<IHomeRepository>(() => MockRepository());
@@ -69,13 +81,15 @@ void main() {
     }
 
     if (controller.status.isSuccess) {
-      expect(controller.state.global.totalDeaths, 100);
-      expect(controller.state.global.totalConfirmed, 200);
+      expect(controller.state!.global.totalDeaths, 100);
+      expect(controller.state!.global.totalConfirmed, 200);
     }
   });
 
   /// Tests with GetTests
-  getTest(
+  /// TEMPORARILY REMOVED from the null-safetym branch as
+  /// get_test is not yet null safety.
+  /* getTest(
     "test description",
     getPages: AppPages.routes,
     initialRoute: AppPages.INITIAL,
@@ -104,33 +118,6 @@ void main() {
     ),
     test: (e) {
       expect(find.text("ban:0"), findsOneWidget);
-      expect(e.count.value, 0);
-    },
-  );
-
-  testGetBuilder(
-    'GetBuilder test',
-    widget: GetBuilder<Controller>(
-      init: Controller(),
-      builder: (controller) {
-        return Text("ban:${controller.count}");
-      },
-    ),
-    test: (e) {
-      expect(find.text("ban:0"), findsOneWidget);
-      expect(e.count.value, 0);
-    },
-  );
-
-  testObx(
-    'Obx test',
-    widget: (controller) => Obx(
-      () => Text("ban:${controller.count}"),
-    ),
-    controller: Controller(),
-    test: (e) {
-      expect(find.text("ban:0"), findsOneWidget);
-      expect(e.count.value, 0);
     },
   );
 
@@ -151,7 +138,7 @@ void main() {
     onClose: (c) {
       print('onClose');
     },
-  );
+  );*/
 }
 
 class Controller extends GetxController {

@@ -13,74 +13,74 @@ export 'http/src/response/response.dart';
 export 'sockets/sockets.dart';
 
 abstract class GetConnectInterface with GetLifeCycleBase {
-  List<GetSocket> sockets;
+  List<GetSocket>? sockets;
   GetHttpClient get httpClient;
 
   Future<Response<T>> get<T>(
     String url, {
-    Map<String, String> headers,
-    String contentType,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
+    Map<String, String>? headers,
+    String? contentType,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
   });
 
   Future<Response<T>> request<T>(
     String url,
     String method, {
     dynamic body,
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
   });
   Future<Response<T>> post<T>(
     String url,
     dynamic body, {
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
   });
 
   Future<Response<T>> put<T>(
     String url,
     dynamic body, {
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
   });
 
   Future<Response<T>> delete<T>(
     String url, {
-    Map<String, String> headers,
-    String contentType,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
+    Map<String, String>? headers,
+    String? contentType,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
   });
 
   Future<Response<T>> patch<T>(
     String url,
     dynamic body, {
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
-    Progress uploadProgress,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
+    Progress? uploadProgress,
   });
 
   Future<GraphQLResponse<T>> query<T>(
     String query, {
-    String url,
-    Map<String, dynamic> variables,
-    Map<String, String> headers,
+    String? url,
+    Map<String, dynamic>? variables,
+    Map<String, String>? headers,
   });
 
   Future<GraphQLResponse<T>> mutation<T>(
     String mutation, {
-    String url,
-    Map<String, dynamic> variables,
-    Map<String, String> headers,
+    String? url,
+    Map<String, dynamic>? variables,
+    Map<String, String>? headers,
   });
 
   GetSocket socket(
@@ -103,16 +103,16 @@ class GetConnect extends GetConnectInterface {
 
   bool allowAutoSignedCert;
   String userAgent;
-  String baseUrl;
+  String? baseUrl;
   String defaultContentType = 'application/json; charset=utf-8';
   bool followRedirects;
   int maxRedirects;
   int maxAuthRetries;
-  Decoder defaultDecoder;
+  Decoder? defaultDecoder;
   Duration timeout;
-  List<TrustedCertificate> trustedCertificates;
-  GetHttpClient _httpClient;
-  List<GetSocket> _sockets;
+  List<TrustedCertificate>? trustedCertificates;
+  GetHttpClient? _httpClient;
+  List<GetSocket>? _sockets;
 
   @override
   List<GetSocket> get sockets => _sockets ??= <GetSocket>[];
@@ -132,10 +132,10 @@ class GetConnect extends GetConnectInterface {
   @override
   Future<Response<T>> get<T>(
     String url, {
-    Map<String, String> headers,
-    String contentType,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
+    Map<String, String>? headers,
+    String? contentType,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
   }) {
     _checkIfDisposed();
     return httpClient.get<T>(
@@ -149,13 +149,13 @@ class GetConnect extends GetConnectInterface {
 
   @override
   Future<Response<T>> post<T>(
-    String url,
+    String? url,
     dynamic body, {
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
-    Progress uploadProgress,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
+    Progress? uploadProgress,
   }) {
     _checkIfDisposed();
     return httpClient.post<T>(
@@ -173,11 +173,11 @@ class GetConnect extends GetConnectInterface {
   Future<Response<T>> put<T>(
     String url,
     dynamic body, {
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
-    Progress uploadProgress,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
+    Progress? uploadProgress,
   }) {
     _checkIfDisposed();
     return httpClient.put<T>(
@@ -195,11 +195,11 @@ class GetConnect extends GetConnectInterface {
   Future<Response<T>> patch<T>(
     String url,
     dynamic body, {
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
-    Progress uploadProgress,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
+    Progress? uploadProgress,
   }) {
     _checkIfDisposed();
     return httpClient.patch<T>(
@@ -218,11 +218,11 @@ class GetConnect extends GetConnectInterface {
     String url,
     String method, {
     dynamic body,
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
-    Progress uploadProgress,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
+    Progress? uploadProgress,
   }) {
     _checkIfDisposed();
     return httpClient.request<T>(
@@ -240,10 +240,10 @@ class GetConnect extends GetConnectInterface {
   @override
   Future<Response<T>> delete<T>(
     String url, {
-    Map<String, String> headers,
-    String contentType,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
+    Map<String, String>? headers,
+    String? contentType,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
   }) {
     _checkIfDisposed();
     return httpClient.delete(
@@ -262,14 +262,14 @@ class GetConnect extends GetConnectInterface {
   }) {
     _checkIfDisposed(isHttp: false);
 
-    final _socket = GetSocket(_concatUrl(url), ping: ping);
+    final _socket = GetSocket(_concatUrl(url)!, ping: ping);
     sockets.add(_socket);
     return _socket;
   }
 
-  String _concatUrl(String url) {
+  String? _concatUrl(String? url) {
     if (url == null) return baseUrl;
-    return baseUrl == null ? url : baseUrl + url;
+    return baseUrl == null ? url : baseUrl! + url;
   }
 
   /// query allow made GraphQL raw querys
@@ -294,9 +294,9 @@ class GetConnect extends GetConnectInterface {
   @override
   Future<GraphQLResponse<T>> query<T>(
     String query, {
-    String url,
-    Map<String, dynamic> variables,
-    Map<String, String> headers,
+    String? url,
+    Map<String, dynamic>? variables,
+    Map<String, String>? headers,
   }) async {
     try {
       final res = await post(
@@ -316,7 +316,7 @@ class GetConnect extends GetConnectInterface {
                     ))
                 .toList());
       }
-      return GraphQLResponse<T>(body: res.body['data'] as T);
+      return GraphQLResponse<T>(body: res.body['data'] as T?);
     } on Exception catch (_) {
       return GraphQLResponse<T>(graphQLErrors: [
         GraphQLError(
@@ -330,9 +330,9 @@ class GetConnect extends GetConnectInterface {
   @override
   Future<GraphQLResponse<T>> mutation<T>(
     String mutation, {
-    String url,
-    Map<String, dynamic> variables,
-    Map<String, String> headers,
+    String? url,
+    Map<String, dynamic>? variables,
+    Map<String, String>? headers,
   }) async {
     try {
       final res = await post(
@@ -352,7 +352,7 @@ class GetConnect extends GetConnectInterface {
                     ))
                 .toList());
       }
-      return GraphQLResponse<T>(body: res.body['data'] as T);
+      return GraphQLResponse<T>(body: res.body['data'] as T?);
     } on Exception catch (_) {
       return GraphQLResponse<T>(graphQLErrors: [
         GraphQLError(

 class GetHttpException implements Exception {
   final String message;
 
-  final Uri uri;
+  final Uri? uri;
 
   GetHttpException(this.message, [this.uri]);
 
@@ -11,8 +11,8 @@ class GetHttpException implements Exception {
 
 class GraphQLError {
   GraphQLError({this.code, this.message});
-  final String message;
-  final String code;
+  final String? message;
+  final String? code;
 
   @override
   String toString() => 'GETCONNECT ERROR:\n\tcode:$code\n\tmessage:$message';

 import 'dart:async';
 import 'dart:convert';
-import 'package:flutter/foundation.dart';
 
 import '../src/certificates/certificates.dart';
 import '../src/exceptions/exceptions.dart';
@@ -20,7 +19,7 @@ typedef Progress = Function(double percent);
 
 class GetHttpClient {
   String userAgent;
-  String baseUrl;
+  String? baseUrl;
 
   String defaultContentType = 'application/json; charset=utf-8';
 
@@ -28,7 +27,7 @@ class GetHttpClient {
   int maxRedirects;
   int maxAuthRetries;
 
-  Decoder defaultDecoder;
+  Decoder? defaultDecoder;
 
   Duration timeout;
 
@@ -46,7 +45,7 @@ class GetHttpClient {
     this.maxAuthRetries = 1,
     bool allowAutoSignedCert = false,
     this.baseUrl,
-    List<TrustedCertificate> trustedCertificates,
+    List<TrustedCertificate>? trustedCertificates,
   })  : _httpClient = HttpRequestImpl(
           allowAutoSignedCert: allowAutoSignedCert,
           trustedCertificates: trustedCertificates,
@@ -73,11 +72,11 @@ class GetHttpClient {
     _modifier.removeResponseModifier<T>(interceptor);
   }
 
-  Uri _createUri(String url, Map<String, dynamic> query) {
+  Uri _createUri(String? url, Map<String, dynamic>? query) {
     if (baseUrl != null) {
-      url = baseUrl + url;
+      url = baseUrl! + url!;
     }
-    final uri = Uri.parse(url);
+    final uri = Uri.parse(url!);
     if (query != null) {
       return uri.replace(queryParameters: query);
     }
@@ -85,16 +84,16 @@ class GetHttpClient {
   }
 
   Future<Request<T>> _requestWithBody<T>(
-    String url,
-    String contentType,
+    String? url,
+    String? contentType,
     dynamic body,
     String method,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
-    Progress uploadProgress,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
+    Progress? uploadProgress,
   ) async {
-    List<int> bodyBytes;
-    BodyBytesStream bodyStream;
+    List<int>? bodyBytes;
+    Stream<List<int>>? bodyStream;
     final headers = <String, String>{};
 
     headers['user-agent'] = userAgent;
@@ -146,9 +145,9 @@ class GetHttpClient {
     );
   }
 
-  BodyBytesStream _trackProgress(
+  Stream<List<int>> _trackProgress(
     List<int> bodyBytes,
-    Progress uploadProgress,
+    Progress? uploadProgress,
   ) {
     var total = 0;
     var length = bodyBytes.length;
@@ -164,12 +163,12 @@ class GetHttpClient {
         sink.add(data);
       }),
     );
-    return BodyBytesStream(byteStream);
+    return byteStream;
   }
 
   void _setSimpleHeaders(
     Map<String, String> headers,
-    String contentType,
+    String? contentType,
   ) {
     headers['content-type'] = contentType ?? defaultContentType;
     headers['user-agent'] = userAgent;
@@ -179,7 +178,7 @@ class GetHttpClient {
     HandlerExecute<T> handler, {
     bool authenticate = false,
     int requestNumber = 1,
-    Map<String, String> headers,
+    Map<String, String>? headers,
   }) async {
     try {
       var request = await handler();
@@ -188,7 +187,7 @@ class GetHttpClient {
         request.headers[key] = value;
       });
 
-      if (authenticate) await _modifier.authenticator(request);
+      if (authenticate) await _modifier.authenticator!(request);
       await _modifier.modifyRequest(request);
 
       var response = await _httpClient.send<T>(request);
@@ -238,9 +237,9 @@ class GetHttpClient {
 
   Future<Request<T>> _get<T>(
     String url,
-    String contentType,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
+    String? contentType,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
   ) {
     final headers = <String, String>{};
     _setSimpleHeaders(headers, contentType);
@@ -256,13 +255,13 @@ class GetHttpClient {
   }
 
   Future<Request<T>> _request<T>(
-    String url,
+    String? url,
     String method, {
-    String contentType,
-    @required dynamic body,
-    @required Map<String, dynamic> query,
-    Decoder<T> decoder,
-    @required Progress uploadProgress,
+    String? contentType,
+    required dynamic body,
+    required Map<String, dynamic>? query,
+    Decoder<T>? decoder,
+    required Progress? uploadProgress,
   }) {
     return _requestWithBody<T>(
       url,
@@ -270,16 +269,16 @@ class GetHttpClient {
       body,
       method,
       query,
-      decoder ?? (defaultDecoder as Decoder<T>),
+      decoder ?? (defaultDecoder as Decoder<T>?),
       uploadProgress,
     );
   }
 
   Request<T> _delete<T>(
     String url,
-    String contentType,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
+    String? contentType,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
   ) {
     final headers = <String, String>{};
     _setSimpleHeaders(headers, contentType);
@@ -289,18 +288,18 @@ class GetHttpClient {
       method: 'delete',
       url: uri,
       headers: headers,
-      decoder: decoder ?? (defaultDecoder as Decoder<T>),
+      decoder: decoder ?? (defaultDecoder as Decoder<T>?),
     );
   }
 
   Future<Response<T>> patch<T>(
     String url, {
     dynamic body,
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
-    Progress uploadProgress,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
+    Progress? uploadProgress,
     // List<MultipartFile> files,
   }) async {
     try {
@@ -328,13 +327,13 @@ class GetHttpClient {
   }
 
   Future<Response<T>> post<T>(
-    String url, {
+    String? url, {
     dynamic body,
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
-    Progress uploadProgress,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
+    Progress? uploadProgress,
     // List<MultipartFile> files,
   }) async {
     try {
@@ -365,11 +364,11 @@ class GetHttpClient {
     String url,
     String method, {
     dynamic body,
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
-    Progress uploadProgress,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
+    Progress? uploadProgress,
   }) async {
     try {
       var response = await _performRequest<T>(
@@ -398,11 +397,11 @@ class GetHttpClient {
   Future<Response<T>> put<T>(
     String url, {
     dynamic body,
-    String contentType,
-    Map<String, String> headers,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
-    Progress uploadProgress,
+    String? contentType,
+    Map<String, String>? headers,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
+    Progress? uploadProgress,
   }) async {
     try {
       var response = await _performRequest<T>(
@@ -430,10 +429,10 @@ class GetHttpClient {
 
   Future<Response<T>> get<T>(
     String url, {
-    Map<String, String> headers,
-    String contentType,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
+    Map<String, String>? headers,
+    String? contentType,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
   }) async {
     try {
       var response = await _performRequest<T>(
@@ -514,10 +513,10 @@ class GetHttpClient {
 
   Future<Response<T>> delete<T>(
     String url, {
-    Map<String, String> headers,
-    String contentType,
-    Map<String, dynamic> query,
-    Decoder<T> decoder,
+    Map<String, String>? headers,
+    String? contentType,
+    Map<String, dynamic>? query,
+    Decoder<T>? decoder,
   }) async {
     try {
       var response = await _performRequest<T>(

 import 'dart:async';
 import 'dart:html' as html;
-import 'dart:typed_data';
 
 import '../../certificates/certificates.dart';
 import '../../exceptions/exceptions.dart';
@@ -13,7 +12,7 @@ import '../utils/body_decoder.dart';
 class HttpRequestImpl implements HttpRequestBase {
   HttpRequestImpl({
     bool allowAutoSignedCert = true,
-    List<TrustedCertificate> trustedCertificates,
+    List<TrustedCertificate>? trustedCertificates,
   });
 
   /// The currently active XHRs.
@@ -38,19 +37,20 @@ class HttpRequestImpl implements HttpRequestBase {
       ..responseType = 'blob'
       ..withCredentials = withCredentials;
     request.headers.forEach(xhr.setRequestHeader);
+    request.contentLength ?? -1;
 
     var completer = Completer<Response<T>>();
     xhr.onLoad.first.then((_) {
-      var blob = xhr.response as html.Blob ?? html.Blob([]);
+      var blob = xhr.response as html.Blob? ?? html.Blob([]);
       var reader = html.FileReader();
 
       reader.onLoad.first.then((_) async {
-        var bodyBytes = BodyBytesStream.fromBytes(reader.result as Uint8List);
+        var bodyBytes = BodyBytesStream.fromBytes(reader.result as List<int>);
 
         final stringBody =
             await bodyBytesToString(bodyBytes, xhr.responseHeaders);
 
-        String contentType;
+        String? contentType;
 
         if (xhr.responseHeaders.containsKey('content-type')) {
           contentType = xhr.responseHeaders['content-type'];

@@ -10,24 +10,24 @@ import '../utils/body_decoder.dart';
 
 /// A `dart:io` implementation of `HttpRequestBase`.
 class HttpRequestImpl extends HttpRequestBase {
-  io.HttpClient _httpClient;
-  io.SecurityContext _securityContext;
+  io.HttpClient? _httpClient;
+  io.SecurityContext? _securityContext;
 
   HttpRequestImpl({
     bool allowAutoSignedCert = true,
-    List<TrustedCertificate> trustedCertificates,
+    List<TrustedCertificate>? trustedCertificates,
   }) {
     _httpClient = io.HttpClient();
     if (trustedCertificates != null) {
       _securityContext = io.SecurityContext();
       for (final trustedCertificate in trustedCertificates) {
-        _securityContext
+        _securityContext!
             .setTrustedCertificatesBytes(List.from(trustedCertificate.bytes));
       }
     }
 
     _httpClient = io.HttpClient(context: _securityContext);
-    _httpClient.badCertificateCallback = (_, __, ___) => allowAutoSignedCert;
+    _httpClient!.badCertificateCallback = (_, __, ___) => allowAutoSignedCert;
   }
 
   @override
@@ -36,7 +36,7 @@ class HttpRequestImpl extends HttpRequestBase {
     //var stream = BodyBytesStream.fromBytes(requestBody ?? const []);
 
     try {
-      var ioRequest = (await _httpClient.openUrl(request.method, request.url))
+      var ioRequest = (await _httpClient!.openUrl(request.method, request.url))
         ..followRedirects = request.followRedirects
         ..persistentConnection = request.persistentConnection
         ..maxRedirects = request.maxRedirects
@@ -50,7 +50,7 @@ class HttpRequestImpl extends HttpRequestBase {
         headers[key] = values.join(',');
       });
 
-      final bodyBytes = BodyBytesStream(response);
+      final bodyBytes = (response);
       final stringBody = await bodyBytesToString(bodyBytes, headers);
 
       final body = bodyDecoded<T>(
@@ -77,7 +77,7 @@ class HttpRequestImpl extends HttpRequestBase {
   @override
   void close() {
     if (_httpClient != null) {
-      _httpClient.close(force: true);
+      _httpClient!.close(force: true);
       _httpClient = null;
     }
   }

@@ -16,14 +16,14 @@ class MockClient extends HttpRequestBase {
   @override
   Future<Response<T>> send<T>(Request<T> request) async {
     var requestBody = await request.bodyBytes.toBytes();
-    var bodyBytes = BodyBytesStream.fromBytes(requestBody ?? const []);
+    var bodyBytes = BodyBytesStream.fromBytes(requestBody);
 
     var response = await _handler(request);
 
-    final stringBody = await bodyBytesToString(bodyBytes, response.headers);
+    final stringBody = await bodyBytesToString(bodyBytes, response.headers!);
 
-    var mimeType = response.headers.containsKey('content-type')
-        ? response.headers['content-type']
+    var mimeType = response.headers!.containsKey('content-type')
+        ? response.headers!['content-type']
         : '';
 
     final body = bodyDecoded<T>(

@@ -6,7 +6,7 @@ import '../interface/request_base.dart';
 class HttpRequestImpl extends HttpRequestBase {
   HttpRequestImpl({
     bool allowAutoSignedCert = true,
-    List<TrustedCertificate> trustedCertificates,
+    List<TrustedCertificate>? trustedCertificates,
   });
   @override
   void close() {}

@@ -4,8 +4,8 @@ import '../../../../../get_core/get_core.dart';
 
 import '../../request/request.dart';
 
-T bodyDecoded<T>(Request<T> request, String stringBody, String mimeType) {
-  T body;
+T? bodyDecoded<T>(Request<T> request, String stringBody, String? mimeType) {
+  T? body;
   var bodyToDecode;
 
   if (mimeType != null && mimeType.contains('application/json')) {
@@ -23,9 +23,9 @@ T bodyDecoded<T>(Request<T> request, String stringBody, String mimeType) {
     if (stringBody == '') {
       body = null;
     } else if (request.decoder == null) {
-      body = bodyToDecode as T;
+      body = bodyToDecode as T?;
     } else {
-      body = request.decoder(bodyToDecode);
+      body = request.decoder!(bodyToDecode);
     }
   } on Exception catch (_) {
     body = stringBody as T;

@@ -3,17 +3,17 @@ import 'dart:async';
 import '../request/request.dart';
 import '../response/response.dart';
 
-typedef RequestModifier<T> = FutureOr<Request<T>> Function(Request<T> request);
+typedef RequestModifier<T> = FutureOr<Request<T>> Function(Request<T?> request);
 
 typedef ResponseModifier<T> = FutureOr Function(
-    Request<T> request, Response<T> response);
+    Request<T?> request, Response<T?> response);
 
 typedef HandlerExecute<T> = Future<Request<T>> Function();
 
 class GetModifier<T> {
   final _requestModifiers = <RequestModifier>[];
   final _responseModifiers = <ResponseModifier>[];
-  RequestModifier authenticator;
+  RequestModifier? authenticator;
 
   void addRequestModifier<T>(RequestModifier<T> interceptor) {
     _requestModifiers.add(interceptor as RequestModifier);

@@ -57,9 +57,7 @@ class FormData {
   String _fileHeader(MapEntry<String, MultipartFile> file) {
     var header =
         'content-disposition: form-data; name="${browserEncode(file.key)}"';
-    if (file.value.filename != null) {
     header = '$header; filename="${browserEncode(file.value.filename)}"';
-    }
     header = '$header\r\n'
         'content-type: ${file.value.contentType}';
     return '$header\r\n\r\n';
@@ -83,7 +81,7 @@ class FormData {
           _maxBoundaryLength +
           '\r\n'.length +
           utf8.encode(_fileHeader(file)).length +
-          file.value.length +
+          file.value.length! +
           '\r\n'.length;
     }
 
@@ -109,7 +107,7 @@ class FormData {
     for (final file in files) {
       yield separator;
       yield utf8.encode(_fileHeader(file));
-      yield* file.value.stream;
+      yield* file.value.stream!;
       yield line;
     }
     yield close;

-import 'package:flutter/foundation.dart';
-
 import '../http/stub/file_decoder_stub.dart'
     if (dart.library.html) '../http/html/file_decoder_html.dart'
     if (dart.library.io) '../http/io/file_decoder_io.dart';
@@ -9,7 +7,7 @@ import '../request/request.dart';
 class MultipartFile {
   MultipartFile(
     dynamic data, {
-    @required this.filename,
+    required this.filename,
     this.contentType = 'application/octet-stream',
   }) : _bytes = fileToBytes(data) {
     _length = _bytes.length;
@@ -21,13 +19,13 @@ class MultipartFile {
   final String contentType;
 
   /// This stream will emit the file content of File.
-  BodyBytesStream _stream;
+  Stream<List<int>>? _stream;
 
-  int _length;
+  int? _length;
 
-  BodyBytesStream get stream => _stream;
+  Stream<List<int>>? get stream => _stream;
 
-  int get length => _length;
+  int? get length => _length;
 
   final String filename;
 }

@@ -2,8 +2,6 @@ import 'dart:async';
 import 'dart:convert';
 import 'dart:typed_data';
 
-import 'package:flutter/foundation.dart';
-
 import '../http.dart';
 import '../multipart/form_data.dart';
 
@@ -14,16 +12,16 @@ class Request<T> {
   /// The [Uri] from request
   final Uri url;
 
-  final Decoder<T> decoder;
+  final Decoder<T>? decoder;
 
   /// The Http Method from this [Request]
   /// ex: `GET`,`POST`,`PUT`,`DELETE`
   final String method;
 
-  final int contentLength;
+  final int? contentLength;
 
   /// The BodyBytesStream of body from this [Request]
-  final BodyBytesStream bodyBytes;
+  final Stream<List<int>> bodyBytes;
 
   /// When true, the client will follow redirects to resolves this [Request]
   final bool followRedirects;
@@ -33,45 +31,41 @@ class Request<T> {
 
   final bool persistentConnection;
 
-  final FormData files;
+  final FormData? files;
 
   const Request._({
-    @required this.method,
-    @required this.bodyBytes,
-    @required this.url,
-    @required this.headers,
-    @required this.contentLength,
-    @required this.followRedirects,
-    @required this.maxRedirects,
-    @required this.files,
-    @required this.persistentConnection,
-    @required this.decoder,
+    required this.method,
+    required this.bodyBytes,
+    required this.url,
+    required this.headers,
+    required this.contentLength,
+    required this.followRedirects,
+    required this.maxRedirects,
+    required this.files,
+    required this.persistentConnection,
+    required this.decoder,
   });
 
   factory Request({
-    @required Uri url,
-    @required String method,
-    @required Map<String, String> headers,
-    BodyBytesStream bodyBytes,
+    required Uri url,
+    required String method,
+    required Map<String, String> headers,
+    Stream<List<int>>? bodyBytes,
     bool followRedirects = true,
     int maxRedirects = 4,
-    int contentLength,
-    FormData files,
+    int? contentLength,
+    FormData? files,
     bool persistentConnection = true,
-    Decoder<T> decoder,
+    Decoder<T>? decoder,
   }) {
-    assert(url != null);
-    assert(method != null);
-    assert(followRedirects != null);
     if (followRedirects) {
-      assert(maxRedirects != null);
       assert(maxRedirects > 0);
     }
     return Request._(
       url: url,
       method: method,
       bodyBytes: bodyBytes ??= BodyBytesStream.fromBytes(const []),
-      headers: Map.from(headers ??= <String, String>{}),
+      headers: Map.from(headers),
       followRedirects: followRedirects,
       maxRedirects: maxRedirects,
       contentLength: contentLength,
@@ -82,11 +76,9 @@ class Request<T> {
   }
 }
 
-class BodyBytesStream extends StreamView<List<int>> {
-  BodyBytesStream(Stream<List<int>> stream) : super(stream);
-
-  factory BodyBytesStream.fromBytes(List<int> bytes) =>
-      BodyBytesStream(Stream.fromIterable([bytes]));
+extension BodyBytesStream on Stream<List<int>> {
+  static Stream<List<int>> fromBytes(List<int> bytes) =>
+      Stream.fromIterable([bytes]);
 
   Future<Uint8List> toBytes() {
     var completer = Completer<Uint8List>();
@@ -95,7 +87,7 @@ class BodyBytesStream extends StreamView<List<int>> {
         Uint8List.fromList(bytes),
       ),
     );
-    listen(sink.add,
+    listen((val) => sink.add(val),
         onError: completer.completeError,
         onDone: sink.close,
         cancelOnError: true);

@@ -5,8 +5,8 @@ import '../request/request.dart';
 import '../status/http_status.dart';
 
 class GraphQLResponse<T> extends Response<T> {
-  final List<GraphQLError> graphQLErrors;
-  GraphQLResponse({T body, this.graphQLErrors}) : super(body: body);
+  final List<GraphQLError>? graphQLErrors;
+  GraphQLResponse({T? body, this.graphQLErrors}) : super(body: body);
 }
 
 class Response<T> {
@@ -21,16 +21,16 @@ class Response<T> {
   });
 
   /// The Http [Request] linked with this [Response].
-  final Request request;
+  final Request? request;
 
   /// The response headers.
-  final Map<String, String> headers;
+  final Map<String, String>? headers;
 
   /// The status code returned by the server.
-  final int statusCode;
+  final int? statusCode;
 
   /// Human-readable context for [statusCode].
-  final String statusText;
+  final String? statusText;
 
   /// [HttpStatus] from [Response]. `status.connectionError` is true
   /// when statusCode is null. `status.isUnauthorized` is true when
@@ -49,19 +49,19 @@ class Response<T> {
   bool get unauthorized => status.isUnauthorized;
 
   /// The response body as a Stream of Bytes.
-  final BodyBytesStream bodyBytes;
+  final Stream<List<int>>? bodyBytes;
 
   /// The response body as a Stream of Bytes.
-  final String bodyString;
+  final String? bodyString;
 
   /// The decoded body of this [Response]. You can access the
   /// body parameters as Map
   /// Ex: body['title'];
-  final T body;
+  final T? body;
 }
 
 Future<String> bodyBytesToString(
-    BodyBytesStream bodyBytes, Map<String, String> headers) {
+    Stream<List<int>> bodyBytes, Map<String, String> headers) {
   return bodyBytes.bytesToString(_encodingForHeaders(headers));
 }
 
@@ -70,13 +70,13 @@ Future<String> bodyBytesToString(
 /// Defaults to [latin1] if the headers don't specify a charset or if that
 /// charset is unknown.
 Encoding _encodingForHeaders(Map<String, String> headers) =>
-    _encodingForCharset(_contentTypeForHeaders(headers).parameters['charset']);
+    _encodingForCharset(_contentTypeForHeaders(headers).parameters!['charset']);
 
 /// Returns the [Encoding] that corresponds to [charset].
 ///
 /// Returns [fallback] if [charset] is null or if no [Encoding] was found that
 /// corresponds to [charset].
-Encoding _encodingForCharset(String charset, [Encoding fallback = latin1]) {
+Encoding _encodingForCharset(String? charset, [Encoding fallback = latin1]) {
   if (charset == null) return fallback;
   return Encoding.getByName(charset) ?? fallback;
 }
@@ -92,10 +92,10 @@ HeaderValue _contentTypeForHeaders(Map<String, String> headers) {
 
 class HeaderValue {
   String _value;
-  Map<String, String> _parameters;
-  Map<String, String> _unmodifiableParameters;
+  Map<String, String?>? _parameters;
+  Map<String, String?>? _unmodifiableParameters;
 
-  HeaderValue([this._value = '', Map<String, String> parameters]) {
+  HeaderValue([this._value = '', Map<String, String>? parameters]) {
     if (parameters != null) {
       _parameters = HashMap<String, String>.from(parameters);
     }
@@ -103,7 +103,7 @@ class HeaderValue {
 
   static HeaderValue parse(String value,
       {String parameterSeparator = ';',
-      String valueSeparator,
+      String? valueSeparator,
       bool preserveBackslash = false}) {
     var result = HeaderValue();
     result._parse(value, parameterSeparator, valueSeparator, preserveBackslash);
@@ -116,9 +116,9 @@ class HeaderValue {
     _parameters ??= HashMap<String, String>();
   }
 
-  Map<String, String> get parameters {
+  Map<String, String?>? get parameters {
     _ensureParameters();
-    _unmodifiableParameters ??= UnmodifiableMapView(_parameters);
+    _unmodifiableParameters ??= UnmodifiableMapView(_parameters!);
     return _unmodifiableParameters;
   }
 
@@ -126,15 +126,15 @@ class HeaderValue {
   String toString() {
     var stringBuffer = StringBuffer();
     stringBuffer.write(_value);
-    if (parameters != null && parameters.isNotEmpty) {
-      _parameters.forEach((name, value) {
+    if (parameters != null && parameters!.isNotEmpty) {
+      _parameters!.forEach((name, value) {
         stringBuffer..write('; ')..write(name)..write('=')..write(value);
       });
     }
     return stringBuffer.toString();
   }
 
-  void _parse(String value, String parameterSeparator, String valueSeparator,
+  void _parse(String value, String parameterSeparator, String? valueSeparator,
       bool preserveBackslash) {
     var index = 0;
 
@@ -173,7 +173,7 @@ class HeaderValue {
     }
 
     void parseParameters() {
-      var parameters = HashMap<String, String>();
+      var parameters = HashMap<String, String?>();
       _parameters = UnmodifiableMapView(parameters);
 
       String parseParameterName() {
@@ -191,7 +191,7 @@ class HeaderValue {
         return value.substring(start, index).toLowerCase();
       }
 
-      String parseParameterValue() {
+      String? parseParameterValue() {
         if (!done() && value[index] == '\"') {
           var stringBuffer = StringBuffer();
           index++;

 class HttpStatus {
   HttpStatus(this.code);
 
-  final int code;
+  final int? code;
 
   static const int continue_ = 100;
   static const int switchingProtocols = 101;
@@ -83,7 +83,7 @@ class HttpStatus {
       between(internalServerError, networkConnectTimeoutError);
 
   bool between(int begin, int end) {
-    return !connectionError && code >= begin && code <= end;
+    return !connectionError && code! >= begin && code! <= end;
   }
 
   bool get isOk => between(200, 299);

-import 'dart:async';
 import 'dart:convert';
-import '../request/request.dart';
 
 bool isTokenChar(int byte) {
   return byte > 31 && byte < 128 && !SEPARATOR_MAP[byte];
@@ -52,10 +50,9 @@ String validateField(String field) {
   return field.toLowerCase();
 }
 
-BodyBytesStream toBodyBytesStream(Stream<List<int>> stream) {
-  if (stream is BodyBytesStream) return stream;
-  return BodyBytesStream(stream);
-}
+// Stream<List<int>> toBodyBytesStream(Stream<List<int>> stream) {
+//   return (stream);
+// }
 
 final _asciiOnly = RegExp(r'^[\x00-\x7F]+$');
 

 import 'dart:convert';
 
 class Close {
-  final String message;
-  final int reason;
+  final String? message;
+  final int? reason;
 
   Close(this.message, this.reason);
 
@@ -19,31 +19,31 @@ typedef CloseSocket = void Function(Close);
 typedef MessageSocket = void Function(dynamic val);
 
 class SocketNotifier {
-  var _onMessages = <MessageSocket>[];
-  var _onEvents = <String, MessageSocket>{};
-  var _onCloses = <CloseSocket>[];
-  var _onErrors = <CloseSocket>[];
+  List<void Function(dynamic)>? _onMessages = <MessageSocket>[];
+  Map<String, void Function(dynamic)>? _onEvents = <String, MessageSocket>{};
+  List<void Function(Close)>? _onCloses = <CloseSocket>[];
+  List<void Function(Close)>? _onErrors = <CloseSocket>[];
 
-  OpenSocket open;
+  late OpenSocket open;
 
   void addMessages(MessageSocket socket) {
-    _onMessages.add((socket));
+    _onMessages!.add((socket));
   }
 
   void addEvents(String event, MessageSocket socket) {
-    _onEvents[event] = socket;
+    _onEvents![event] = socket;
   }
 
   void addCloses(CloseSocket socket) {
-    _onCloses.add(socket);
+    _onCloses!.add(socket);
   }
 
   void addErrors(CloseSocket socket) {
-    _onErrors.add((socket));
+    _onErrors!.add((socket));
   }
 
   void notifyData(dynamic data) {
-    for (var item in _onMessages) {
+    for (var item in _onMessages!) {
       item(data);
     }
     if (data is String) {
@@ -52,14 +52,14 @@ class SocketNotifier {
   }
 
   void notifyClose(Close err) {
-    for (var item in _onCloses) {
+    for (var item in _onCloses!) {
       item(err);
     }
   }
 
   void notifyError(Close err) {
     // rooms.removeWhere((key, value) => value.contains(_ws));
-    for (var item in _onErrors) {
+    for (var item in _onErrors!) {
       item(err);
     }
   }
@@ -69,8 +69,8 @@ class SocketNotifier {
       var msg = jsonDecode(message);
       final event = msg['type'];
       final data = msg['data'];
-      if (_onEvents.containsKey(event)) {
-        _onEvents[event](data);
+      if (_onEvents!.containsKey(event)) {
+        _onEvents![event]!(data);
       }
     } on Exception catch (_) {
       return;

@@ -15,8 +15,8 @@ enum ConnectionStatus {
 
 class BaseWebSocket {
   String url;
-  WebSocket socket;
-  SocketNotifier socketNotifier = SocketNotifier();
+  WebSocket? socket;
+  SocketNotifier? socketNotifier = SocketNotifier();
   Duration ping;
   bool isDisposed = false;
   bool allowSelfSigned;
@@ -30,39 +30,39 @@ class BaseWebSocket {
         ? url.replaceAll('https:', 'wss:')
         : url.replaceAll('http:', 'ws:');
   }
-  ConnectionStatus connectionStatus;
-  Timer _t;
+  ConnectionStatus? connectionStatus;
+  Timer? _t;
 
   void connect() {
     try {
       connectionStatus = ConnectionStatus.connecting;
       socket = WebSocket(url);
-      socket.onOpen.listen((e) {
+      socket!.onOpen.listen((e) {
         socketNotifier?.open();
         _t = Timer?.periodic(ping, (t) {
-          socket.send('');
+          socket!.send('');
         });
         connectionStatus = ConnectionStatus.connected;
       });
 
-      socket.onMessage.listen((event) {
-        socketNotifier.notifyData(event.data);
+      socket!.onMessage.listen((event) {
+        socketNotifier!.notifyData(event.data);
       });
 
-      socket.onClose.listen((e) {
+      socket!.onClose.listen((e) {
         _t?.cancel();
 
         connectionStatus = ConnectionStatus.closed;
-        socketNotifier.notifyClose(Close(e.reason, e.code));
+        socketNotifier!.notifyClose(Close(e.reason, e.code));
       });
-      socket.onError.listen((event) {
+      socket!.onError.listen((event) {
         _t?.cancel();
-        socketNotifier.notifyError(Close(event.toString(), 0));
+        socketNotifier!.notifyError(Close(event.toString(), 0));
         connectionStatus = ConnectionStatus.closed;
       });
     } on Exception catch (e) {
       _t?.cancel();
-      socketNotifier.notifyError(Close(e.toString(), 500));
+      socketNotifier!.notifyError(Close(e.toString(), 500));
       connectionStatus = ConnectionStatus.closed;
       //  close(500, e.toString());
     }
@@ -70,35 +70,35 @@ class BaseWebSocket {
 
   // ignore: use_setters_to_change_properties
   void onOpen(OpenSocket fn) {
-    socketNotifier.open = fn;
+    socketNotifier!.open = fn;
   }
 
   void onClose(CloseSocket fn) {
-    socketNotifier.addCloses(fn);
+    socketNotifier!.addCloses(fn);
   }
 
   void onError(CloseSocket fn) {
-    socketNotifier.addErrors(fn);
+    socketNotifier!.addErrors(fn);
   }
 
   void onMessage(MessageSocket fn) {
-    socketNotifier.addMessages(fn);
+    socketNotifier!.addMessages(fn);
   }
 
   void on(String event, MessageSocket message) {
-    socketNotifier.addEvents(event, message);
+    socketNotifier!.addEvents(event, message);
   }
 
-  void close([int status, String reason]) {
-    if (socket != null) socket.close(status, reason);
+  void close([int? status, String? reason]) {
+    if (socket != null) socket!.close(status, reason);
   }
 
   void send(dynamic data) {
     if (connectionStatus == ConnectionStatus.closed) {
       connect();
     }
-    if (socket != null && socket.readyState == WebSocket.OPEN) {
-      socket.send(data);
+    if (socket != null && socket!.readyState == WebSocket.OPEN) {
+      socket!.send(data);
     } else {
       Get.log('WebSocket not connected, message $data not sent');
     }
@@ -109,7 +109,7 @@ class BaseWebSocket {
   }
 
   void dispose() {
-    socketNotifier.dispose();
+    socketNotifier!.dispose();
     socketNotifier = null;
     isDisposed = true;
   }

@@ -15,8 +15,8 @@ enum ConnectionStatus {
 
 class BaseWebSocket {
   String url;
-  WebSocket socket;
-  SocketNotifier socketNotifier = SocketNotifier();
+  WebSocket? socket;
+  SocketNotifier? socketNotifier = SocketNotifier();
   bool isDisposed = false;
   BaseWebSocket(
     this.url, {
@@ -26,7 +26,7 @@ class BaseWebSocket {
   Duration ping;
   bool allowSelfSigned;
 
-  ConnectionStatus connectionStatus;
+  ConnectionStatus? connectionStatus;
 
   Future connect() async {
     if (isDisposed) {
@@ -38,51 +38,52 @@ class BaseWebSocket {
           ? await _connectForSelfSignedCert(url)
           : await WebSocket.connect(url);
 
-      socket.pingInterval = ping;
+      socket!.pingInterval = ping;
       socketNotifier?.open();
       connectionStatus = ConnectionStatus.connected;
 
-      socket.listen((data) {
-        socketNotifier.notifyData(data);
+      socket!.listen((data) {
+        socketNotifier!.notifyData(data);
       }, onError: (err) {
-        socketNotifier.notifyError(Close(err.toString(), 1005));
+        socketNotifier!.notifyError(Close(err.toString(), 1005));
       }, onDone: () {
         connectionStatus = ConnectionStatus.closed;
-        socketNotifier
-            .notifyClose(Close('Connection Closed', socket.closeCode));
+        socketNotifier!
+            .notifyClose(Close('Connection Closed', socket!.closeCode));
       }, cancelOnError: true);
       return;
     } on SocketException catch (e) {
       connectionStatus = ConnectionStatus.closed;
-      socketNotifier.notifyError(Close(e.osError.message, e.osError.errorCode));
+      socketNotifier!
+          .notifyError(Close(e.osError!.message, e.osError!.errorCode));
       return;
     }
   }
 
   // ignore: use_setters_to_change_properties
   void onOpen(OpenSocket fn) {
-    socketNotifier.open = fn;
+    socketNotifier!.open = fn;
   }
 
   void onClose(CloseSocket fn) {
-    socketNotifier.addCloses(fn);
+    socketNotifier!.addCloses(fn);
   }
 
   void onError(CloseSocket fn) {
-    socketNotifier.addErrors(fn);
+    socketNotifier!.addErrors(fn);
   }
 
   void onMessage(MessageSocket fn) {
-    socketNotifier.addMessages(fn);
+    socketNotifier!.addMessages(fn);
   }
 
   void on(String event, MessageSocket message) {
-    socketNotifier.addEvents(event, message);
+    socketNotifier!.addEvents(event, message);
   }
 
-  void close([int status, String reason]) {
+  void close([int? status, String? reason]) {
     if (socket != null) {
-      socket.close(status, reason);
+      socket!.close(status, reason);
     }
   }
 
@@ -92,12 +93,12 @@ class BaseWebSocket {
     }
 
     if (socket != null) {
-      socket.add(data);
+      socket!.add(data);
     }
   }
 
   void dispose() {
-    socketNotifier.dispose();
+    socketNotifier!.dispose();
     socketNotifier = null;
     isDisposed = true;
   }

@@ -36,7 +36,7 @@ class BaseWebSocket {
     throw 'To use sockets you need dart:io or dart:html';
   }
 
-  void close([int status, String reason]) {
+  void close([int? status, String? reason]) {
     throw 'To use sockets you need dart:io or dart:html';
   }
 

@@ -5,7 +5,7 @@ import 'smart_management.dart';
 /// class through extensions
 abstract class GetInterface {
   SmartManagement smartManagement = SmartManagement.full;
-  String reference;
+  String? reference;
   bool isLogEnable = true;
   LogWriterCallback log = defaultLogWriterCallback;
 }

@@ -42,7 +42,7 @@ class BindingsBuilder<T> extends Bindings {
   /// ),
   /// ```
   factory BindingsBuilder.put(InstanceBuilderCallback<T> builder,
-      {String tag, bool permanent = false}) {
+      {String? tag, bool permanent = false}) {
     return BindingsBuilder(
         () => GetInstance().put<T>(builder(), tag: tag, permanent: permanent));
   }

@@ -28,7 +28,7 @@ extension Inst on GetInterface {
   /// Subsequent calls to [Get.lazyPut()] with the same parameters
   /// (<[S]> and optionally [tag] will **not** override the original).
   void lazyPut<S>(InstanceBuilderCallback<S> builder,
-      {String tag, bool fenix = false}) {
+      {String? tag, bool fenix = false}) {
     GetInstance().lazyPut<S>(builder, tag: tag, fenix: fenix);
   }
 
@@ -40,7 +40,7 @@ extension Inst on GetInterface {
   /// Awaits for the resolution of the Future from [builder()] parameter and
   /// stores the Instance returned.
   Future<S> putAsync<S>(AsyncInstanceBuilderCallback<S> builder,
-          {String tag, bool permanent = false}) async =>
+          {String? tag, bool permanent = false}) async =>
       GetInstance().putAsync<S>(builder, tag: tag, permanent: permanent);
 
   /// Creates a new Class Instance [S] from the builder callback[S].
@@ -61,13 +61,13 @@ extension Inst on GetInterface {
   /// Repl b = find();
   /// print(a==b); (false)```
   void create<S>(InstanceBuilderCallback<S> builder,
-          {String tag, bool permanent = true}) =>
+          {String? tag, bool permanent = true}) =>
       GetInstance().create<S>(builder, tag: tag, permanent: permanent);
 
   /// Finds a Instance of the required Class <[S]>(or [tag])
   /// In the case of using [Get.create()], it will generate an Instance
   /// each time you call [Get.find()].
-  S find<S>({String tag}) => GetInstance().find<S>(tag: tag);
+  S find<S>({String? tag}) => GetInstance().find<S>(tag: tag);
 
   /// Injects an [Instance<S>] in memory.
   ///
@@ -84,9 +84,9 @@ extension Inst on GetInterface {
   /// and [Get.delete()]
   /// - [builder] If defined, the [dependency] must be returned from here
   S put<S>(S dependency,
-          {String tag,
+          {String? tag,
           bool permanent = false,
-          InstanceBuilderCallback<S> builder}) =>
+          InstanceBuilderCallback<S>? builder}) =>
       GetInstance().put<S>(dependency, tag: tag, permanent: permanent);
 
   /// Clears all registered instances (and/or tags).
@@ -104,15 +104,16 @@ extension Inst on GetInterface {
   ///
   /// - [tag] Optional "tag" used to register the Instance
   /// - [force] Will delete an Instance even if marked as [permanent].
-  Future<bool> delete<S>({String tag, bool force = false}) async =>
+  Future<bool> delete<S>({String? tag, bool force = false}) async =>
       GetInstance().delete<S>(tag: tag, force: force);
 
   /// Checks if a Class Instance<[S]> (or [tag]) is registered in memory.
   /// - [tag] optional, if you use a [tag] to register the Instance.
-  bool isRegistered<S>({String tag}) => GetInstance().isRegistered<S>(tag: tag);
+  bool isRegistered<S>({String? tag}) =>
+      GetInstance().isRegistered<S>(tag: tag);
 
   /// Checks if an Instance<[S]> (or [tag]) returned from a factory builder
   /// [Get.lazyPut()], is registered in memory.
   /// - [tag] optional, if you use a [tag] to register the Instance.
-  bool isPrepared<S>({String tag}) => GetInstance().isPrepared<S>(tag: tag);
+  bool isPrepared<S>({String? tag}) => GetInstance().isPrepared<S>(tag: tag);
 }

 import 'dart:async';
 import 'dart:collection';
 
-import 'package:flutter/foundation.dart';
-
 import '../../get_core/get_core.dart';
 
 import 'lifecycle.dart';
 
 class InstanceInfo {
-  final bool isPermanent;
-  final bool isSingleton;
-  bool get isCreate => !isSingleton;
+  final bool? isPermanent;
+  final bool? isSingleton;
+  bool get isCreate => !isSingleton!;
   final bool isRegistered;
   final bool isPrepared;
-  final bool isInit;
+  final bool? isInit;
   const InstanceInfo({
-    @required this.isPermanent,
-    @required this.isSingleton,
-    @required this.isRegistered,
-    @required this.isPrepared,
-    @required this.isInit,
+    required this.isPermanent,
+    required this.isSingleton,
+    required this.isRegistered,
+    required this.isPrepared,
+    required this.isInit,
   });
 }
 
@@ -28,7 +26,7 @@ class GetInstance {
 
   const GetInstance._();
 
-  static GetInstance _getInstance;
+  static GetInstance? _getInstance;
 
   T call<T>() => find<T>();
 
@@ -42,13 +40,13 @@ class GetInstance {
 
   /// Holds a reference to [Get.reference] when the Instance was
   /// created to manage the memory.
-  static final Map<String, String> _routesKey = {};
+  static final Map<String, String?> _routesKey = {};
 
   /// Stores the onClose() references of instances created with [Get.create()]
   /// using the [Get.reference].
   /// Experimental feature to keep the lifecycle and memory management with
   /// non-singleton instances.
-  static final Map<String, HashSet<Function>> _routesByCreate = {};
+  static final Map<String?, HashSet<Function>> _routesByCreate = {};
 
   void printInstanceStack() {
     Get.log(_routesKey.toString());
@@ -56,7 +54,7 @@ class GetInstance {
 
   void injector<S>(
     InjectorBuilderCallback<S> fn, {
-    String tag,
+    String? tag,
     bool fenix = false,
     //  bool permanent = false,
   }) {
@@ -73,7 +71,7 @@ class GetInstance {
   /// stores the Instance returned.
   Future<S> putAsync<S>(
     AsyncInstanceBuilderCallback<S> builder, {
-    String tag,
+    String? tag,
     bool permanent = false,
   }) async {
     return put<S>(await builder(), tag: tag, permanent: permanent);
@@ -91,9 +89,9 @@ class GetInstance {
   /// [Get.smartManagement] rules.
   S put<S>(
     S dependency, {
-    String tag,
+    String? tag,
     bool permanent = false,
-    @deprecated InstanceBuilderCallback<S> builder,
+    @deprecated InstanceBuilderCallback<S>? builder,
   }) {
     _insert(
         isSingleton: true,
@@ -127,8 +125,8 @@ class GetInstance {
   /// (<[S]> and optionally [tag] will **not** override the original).
   void lazyPut<S>(
     InstanceBuilderCallback<S> builder, {
-    String tag,
-    bool fenix,
+    String? tag,
+    bool? fenix,
     bool permanent = false,
   }) {
     _insert(
@@ -158,7 +156,7 @@ class GetInstance {
   /// print(a==b); (false)```
   void create<S>(
     InstanceBuilderCallback<S> builder, {
-    String tag,
+    String? tag,
     bool permanent = true,
   }) {
     _insert(
@@ -171,13 +169,12 @@ class GetInstance {
 
   /// Injects the Instance [S] builder into the [_singleton] HashMap.
   void _insert<S>({
-    bool isSingleton,
-    String name,
+    bool? isSingleton,
+    String? name,
     bool permanent = false,
-    InstanceBuilderCallback<S> builder,
+    required InstanceBuilderCallback<S> builder,
     bool fenix = false,
   }) {
-    assert(builder != null);
     final key = _getKey(S, name);
     _singl.putIfAbsent(
       key,
@@ -206,14 +203,12 @@ class GetInstance {
 
     /// Removes [Get.create()] instances registered in [routeName].
     if (_routesByCreate.containsKey(routeName)) {
-      for (final onClose in _routesByCreate[routeName]) {
+      for (final onClose in _routesByCreate[routeName]!) {
         // assure the [DisposableInterface] instance holding a reference
         // to [onClose()] wasn't disposed.
-        if (onClose != null) {
         onClose();
       }
-      }
-      _routesByCreate[routeName].clear();
+      _routesByCreate[routeName]!.clear();
       _routesByCreate.remove(routeName);
     }
 
@@ -222,7 +217,7 @@ class GetInstance {
     }
 
     for (final element in keysToRemove) {
-      _routesKey?.remove(element);
+      _routesKey.remove(element);
     }
     keysToRemove.clear();
   }
@@ -236,14 +231,14 @@ class GetInstance {
   /// (not for Singletons access).
   /// Returns the instance if not initialized, required for Get.create() to
   /// work properly.
-  S _initDependencies<S>({String name}) {
+  S? _initDependencies<S>({String? name}) {
     final key = _getKey(S, name);
-    final isInit = _singl[key].isInit;
-    S i;
+    final isInit = _singl[key]!.isInit;
+    S? i;
     if (!isInit) {
       i = _startController<S>(tag: name);
-      if (_singl[key].isSingleton) {
-        _singl[key].isInit = true;
+      if (_singl[key]!.isSingleton!) {
+        _singl[key]!.isInit = true;
         if (Get.smartManagement != SmartManagement.onlyBuilder) {
           _registerRouteInstance<S>(tag: name);
         }
@@ -254,11 +249,11 @@ class GetInstance {
 
   /// Links a Class instance [S] (or [tag]) to the current route.
   /// Requires usage of [GetMaterialApp].
-  void _registerRouteInstance<S>({String tag}) {
+  void _registerRouteInstance<S>({String? tag}) {
     _routesKey.putIfAbsent(_getKey(S, tag), () => Get.reference);
   }
 
-  InstanceInfo getInstanceInfo<S>({String tag}) {
+  InstanceInfo getInstanceInfo<S>({String? tag}) {
     final build = _getDependency<S>(tag: tag);
 
     return InstanceInfo(
@@ -270,7 +265,7 @@ class GetInstance {
     );
   }
 
-  _InstanceBuilderFactory _getDependency<S>({String tag, String key}) {
+  _InstanceBuilderFactory? _getDependency<S>({String? tag, String? key}) {
     final newKey = key ?? _getKey(S, tag);
 
     if (!_singl.containsKey(newKey)) {
@@ -282,31 +277,30 @@ class GetInstance {
   }
 
   /// Initializes the controller
-  S _startController<S>({String tag}) {
+  S _startController<S>({String? tag}) {
     final key = _getKey(S, tag);
-    final i = _singl[key].getDependency() as S;
+    final i = _singl[key]!.getDependency() as S;
     if (i is GetLifeCycleBase) {
-      if (i.onStart != null) {
       i.onStart();
       if (tag == null) {
         Get.log('Instance "$S" has been initialized');
       } else {
         Get.log('Instance "$S" with tag "$tag" has been initialized');
       }
-      }
-      if (!_singl[key].isSingleton && i.onDelete != null) {
+      if (!_singl[key]!.isSingleton!) {
         _routesByCreate[Get.reference] ??= HashSet<Function>();
-        _routesByCreate[Get.reference].add(i.onDelete);
+        // _routesByCreate[Get.reference]!.add(i.onDelete as Function);
+        _routesByCreate[Get.reference]!.add(i.onDelete);
       }
     }
     return i;
   }
 
-  S putOrFind<S>(InstanceBuilderCallback<S> dep, {String tag}) {
+  S putOrFind<S>(InstanceBuilderCallback<S> dep, {String? tag}) {
     final key = _getKey(S, tag);
 
     if (_singl.containsKey(key)) {
-      return _singl[key].getDependency() as S;
+      return _singl[key]!.getDependency() as S;
     } else {
       return GetInstance().put(dep(), tag: tag);
     }
@@ -317,7 +311,7 @@ class GetInstance {
   /// it will create an instance each time you call [find].
   /// If the registered type <[S]> (or [tag]) is a Controller,
   /// it will initialize it's lifecycle.
-  S find<S>({String tag}) {
+  S find<S>({String? tag}) {
     final key = _getKey(S, tag);
     if (isRegistered<S>(tag: tag)) {
       if (_singl[key] == null) {
@@ -332,7 +326,7 @@ class GetInstance {
       /// `initDependencies`, so we have to return the instance from there
       /// to make it compatible with `Get.create()`.
       final i = _initDependencies<S>(name: tag);
-      return i ?? _singl[key].getDependency() as S;
+      return i ?? _singl[key]!.getDependency() as S;
     } else {
       // ignore: lines_longer_than_80_chars
       throw '"$S" not found. You need to call "Get.put($S())" or "Get.lazyPut(()=>$S())"';
@@ -341,7 +335,7 @@ class GetInstance {
 
   /// Generates the key based on [type] (and optionally a [name])
   /// to register an Instance Builder in the hashmap.
-  String _getKey(Type type, String name) {
+  String _getKey(Type type, String? name) {
     return name == null ? type.toString() : type.toString() + name;
   }
 
@@ -374,7 +368,7 @@ class GetInstance {
   /// - [key] For internal usage, is the processed key used to register
   ///   the Instance. **don't use** it unless you know what you are doing.
   /// - [force] Will delete an Instance even if marked as [permanent].
-  bool delete<S>({String tag, String key, bool force = false}) {
+  bool delete<S>({String? tag, String? key, bool force = false}) {
     final newKey = key ?? _getKey(S, tag);
 
     if (!_singl.containsKey(newKey)) {
@@ -382,7 +376,7 @@ class GetInstance {
       return false;
     }
 
-    final builder = _singl[newKey];
+    final builder = _singl[newKey]!;
 
     if (builder.permanent && !force) {
       Get.log(
@@ -398,7 +392,7 @@ class GetInstance {
       return false;
     }
 
-    if (i is GetLifeCycleBase && i.onDelete != null) {
+    if (i is GetLifeCycleBase) {
       i.onDelete();
       Get.log('"$newKey" onDelete() called');
     }
@@ -430,7 +424,7 @@ class GetInstance {
     });
   }
 
-  void reload<S>({String tag, String key, bool force = false}) {
+  void reload<S>({String? tag, String? key, bool force = false}) {
     final newKey = key ?? _getKey(S, tag);
 
     final builder = _getDependency<S>(tag: tag, key: newKey);
@@ -451,12 +445,12 @@ class GetInstance {
 
   /// Check if a Class Instance<[S]> (or [tag]) is registered in memory.
   /// - [tag] is optional, if you used a [tag] to register the Instance.
-  bool isRegistered<S>({String tag}) => _singl.containsKey(_getKey(S, tag));
+  bool isRegistered<S>({String? tag}) => _singl.containsKey(_getKey(S, tag));
 
   /// Checks if a lazy factory callback ([Get.lazyPut()] that returns an
   /// Instance<[S]> is registered in memory.
   /// - [tag] is optional, if you used a [tag] to register the lazy Instance.
-  bool isPrepared<S>({String tag}) {
+  bool isPrepared<S>({String? tag}) {
     final newKey = _getKey(S, tag);
 
     final builder = _getDependency<S>(tag: tag, key: newKey);
@@ -481,14 +475,14 @@ typedef AsyncInstanceBuilderCallback<S> = Future<S> Function();
 class _InstanceBuilderFactory<S> {
   /// Marks the Builder as a single instance.
   /// For reusing [dependency] instead of [builderFunc]
-  bool isSingleton;
+  bool? isSingleton;
 
   /// When fenix mode is avaliable, when a new instance is need
   /// Instance manager will recreate a new instance of S
   bool fenix;
 
   /// Stores the actual object instance when [isSingleton]=true.
-  S dependency;
+  S? dependency;
 
   /// Generates (and regenerates) the instance when [isSingleton]=false.
   /// Usually used by factory methods
@@ -500,7 +494,7 @@ class _InstanceBuilderFactory<S> {
 
   bool isInit = false;
 
-  String tag;
+  String? tag;
 
   _InstanceBuilderFactory(
     this.isSingleton,
@@ -521,12 +515,12 @@ class _InstanceBuilderFactory<S> {
 
   /// Gets the actual instance by it's [builderFunc] or the persisted instance.
   S getDependency() {
-    if (isSingleton) {
+    if (isSingleton!) {
       if (dependency == null) {
         _showInitLog();
         dependency = builderFunc();
       }
-      return dependency;
+      return dependency!;
     } else {
       return builderFunc();
     }

@@ -5,11 +5,11 @@ import '../../get_core/get_core.dart';
 /// methods.
 /// Used in [DisposableInterface] to avoid the danger of overriding onStart.
 class _InternalFinalCallback<T> {
-  ValueUpdater<T> _callback;
+  ValueUpdater<T>? _callback;
 
-  _InternalFinalCallback({ValueUpdater<T> callback}) : _callback = callback;
+  _InternalFinalCallback({ValueUpdater<T>? callback}) : _callback = callback;
 
-  T call() => _callback.call();
+  T call() => _callback!.call();
 }
 
 /// The [GetLifeCycle]

@@ -14,24 +14,21 @@ class GetModalBottomSheetRoute<T> extends PopupRoute<T> {
     this.modalBarrierColor,
     this.isDismissible = true,
     this.enableDrag = true,
-    @required this.isScrollControlled,
-    RouteSettings settings,
+    required this.isScrollControlled,
+    RouteSettings? settings,
     this.enterBottomSheetDuration = const Duration(milliseconds: 250),
     this.exitBottomSheetDuration = const Duration(milliseconds: 200),
-  })  : assert(isScrollControlled != null),
-        name = "BOTTOMSHEET: ${builder.hashCode}",
-        assert(isDismissible != null),
-        assert(enableDrag != null),
+  })  : name = "BOTTOMSHEET: ${builder.hashCode}",
         super(settings: settings);
-  final bool isPersistent;
-  final WidgetBuilder builder;
-  final ThemeData theme;
+  final bool? isPersistent;
+  final WidgetBuilder? builder;
+  final ThemeData? theme;
   final bool isScrollControlled;
-  final Color backgroundColor;
-  final double elevation;
-  final ShapeBorder shape;
-  final Clip clipBehavior;
-  final Color modalBarrierColor;
+  final Color? backgroundColor;
+  final double? elevation;
+  final ShapeBorder? shape;
+  final Clip? clipBehavior;
+  final Color? modalBarrierColor;
   final bool isDismissible;
   final bool enableDrag;
   final String name;
@@ -47,21 +44,21 @@ class GetModalBottomSheetRoute<T> extends PopupRoute<T> {
   bool get barrierDismissible => isDismissible;
 
   @override
-  final String barrierLabel;
+  final String? barrierLabel;
 
   @override
   Color get barrierColor => modalBarrierColor ?? Colors.black54;
 
-  AnimationController _animationController;
+  AnimationController? _animationController;
 
   @override
   AnimationController createAnimationController() {
     assert(_animationController == null);
     _animationController =
-        BottomSheet.createAnimationController(navigator.overlay);
-    _animationController.duration = enterBottomSheetDuration;
-    _animationController.reverseDuration = exitBottomSheetDuration;
-    return _animationController;
+        BottomSheet.createAnimationController(navigator!.overlay!);
+    _animationController!.duration = enterBottomSheetDuration;
+    _animationController!.reverseDuration = exitBottomSheetDuration;
+    return _animationController!;
   }
 
   @override
@@ -80,10 +77,10 @@ class GetModalBottomSheetRoute<T> extends PopupRoute<T> {
         child: _GetModalBottomSheet<T>(
           route: this,
           backgroundColor: backgroundColor ??
-              sheetTheme?.modalBackgroundColor ??
-              sheetTheme?.backgroundColor,
+              sheetTheme.modalBackgroundColor ??
+              sheetTheme.backgroundColor,
           elevation:
-              elevation ?? sheetTheme?.modalElevation ?? sheetTheme?.elevation,
+              elevation ?? sheetTheme.modalElevation ?? sheetTheme.elevation,
           shape: shape,
           clipBehavior: clipBehavior,
           isScrollControlled: isScrollControlled,
@@ -91,14 +88,14 @@ class GetModalBottomSheetRoute<T> extends PopupRoute<T> {
         ),
       ),
     );
-    if (theme != null) bottomSheet = Theme(data: theme, child: bottomSheet);
+    if (theme != null) bottomSheet = Theme(data: theme!, child: bottomSheet);
     return bottomSheet;
   }
 }
 
 class _GetModalBottomSheet<T> extends StatefulWidget {
   const _GetModalBottomSheet({
-    Key key,
+    Key? key,
     this.route,
     this.backgroundColor,
     this.elevation,
@@ -107,16 +104,14 @@ class _GetModalBottomSheet<T> extends StatefulWidget {
     this.isScrollControlled = false,
     this.enableDrag = true,
     this.isPersistent = false,
-  })  : assert(isScrollControlled != null),
-        assert(enableDrag != null),
-        super(key: key);
+  }) : super(key: key);
   final bool isPersistent;
-  final GetModalBottomSheetRoute<T> route;
+  final GetModalBottomSheetRoute<T>? route;
   final bool isScrollControlled;
-  final Color backgroundColor;
-  final double elevation;
-  final ShapeBorder shape;
-  final Clip clipBehavior;
+  final Color? backgroundColor;
+  final double? elevation;
+  final ShapeBorder? shape;
+  final Clip? clipBehavior;
   final bool enableDrag;
 
   @override
@@ -142,13 +137,13 @@ class _GetModalBottomSheetState<T> extends State<_GetModalBottomSheet<T>> {
     final routeLabel = _getRouteLabel(localizations);
 
     return AnimatedBuilder(
-      animation: widget.route.animation,
+      animation: widget.route!.animation!,
       builder: (context, child) {
         // Disable the initial animation when accessible navigation is on so
         // that the semantics are added to the tree at the correct time.
         final animationValue = mediaQuery.accessibleNavigation
             ? 1.0
-            : widget.route.animation.value;
+            : widget.route!.animation!.value;
         return Semantics(
           scopesRoute: true,
           namesRoute: true,
@@ -160,13 +155,13 @@ class _GetModalBottomSheetState<T> extends State<_GetModalBottomSheet<T>> {
                     animationValue, widget.isScrollControlled),
                 child: widget.isPersistent == false
                     ? BottomSheet(
-                        animationController: widget.route._animationController,
+                        animationController: widget.route!._animationController,
                         onClosing: () {
-                          if (widget.route.isCurrent) {
+                          if (widget.route!.isCurrent) {
                             Navigator.pop(context);
                           }
                         },
-                        builder: widget.route.builder,
+                        builder: widget.route!.builder!,
                         backgroundColor: widget.backgroundColor,
                         elevation: widget.elevation,
                         shape: widget.shape,
@@ -176,13 +171,13 @@ class _GetModalBottomSheetState<T> extends State<_GetModalBottomSheet<T>> {
                     : Scaffold(
                         bottomSheet: BottomSheet(
                           animationController:
-                              widget.route._animationController,
+                              widget.route!._animationController,
                           onClosing: () {
                             // if (widget.route.isCurrent) {
                             //   Navigator.pop(context);
                             // }
                           },
-                          builder: widget.route.builder,
+                          builder: widget.route!.builder!,
                           backgroundColor: widget.backgroundColor,
                           elevation: widget.elevation,
                           shape: widget.shape,
@@ -199,7 +194,7 @@ class _GetModalBottomSheetState<T> extends State<_GetModalBottomSheet<T>> {
 
 class _GetPerModalBottomSheet<T> extends StatefulWidget {
   const _GetPerModalBottomSheet({
-    Key key,
+    Key? key,
     this.route,
     this.isPersistent,
     this.backgroundColor,
@@ -208,16 +203,14 @@ class _GetPerModalBottomSheet<T> extends StatefulWidget {
     this.clipBehavior,
     this.isScrollControlled = false,
     this.enableDrag = true,
-  })  : assert(isScrollControlled != null),
-        assert(enableDrag != null),
-        super(key: key);
-  final bool isPersistent;
-  final GetModalBottomSheetRoute<T> route;
+  }) : super(key: key);
+  final bool? isPersistent;
+  final GetModalBottomSheetRoute<T>? route;
   final bool isScrollControlled;
-  final Color backgroundColor;
-  final double elevation;
-  final ShapeBorder shape;
-  final Clip clipBehavior;
+  final Color? backgroundColor;
+  final double? elevation;
+  final ShapeBorder? shape;
+  final Clip? clipBehavior;
   final bool enableDrag;
 
   @override
@@ -247,13 +240,13 @@ class _GetPerModalBottomSheetState<T>
     final routeLabel = _getRouteLabel(localizations);
 
     return AnimatedBuilder(
-      animation: widget.route.animation,
+      animation: widget.route!.animation!,
       builder: (context, child) {
         // Disable the initial animation when accessible navigation is on so
         // that the semantics are added to the tree at the correct time.
         final animationValue = mediaQuery.accessibleNavigation
             ? 1.0
-            : widget.route.animation.value;
+            : widget.route!.animation!.value;
         return Semantics(
           scopesRoute: true,
           namesRoute: true,
@@ -265,13 +258,13 @@ class _GetPerModalBottomSheetState<T>
                     animationValue, widget.isScrollControlled),
                 child: widget.isPersistent == false
                     ? BottomSheet(
-                        animationController: widget.route._animationController,
+                        animationController: widget.route!._animationController,
                         onClosing: () {
-                          if (widget.route.isCurrent) {
+                          if (widget.route!.isCurrent) {
                             Navigator.pop(context);
                           }
                         },
-                        builder: widget.route.builder,
+                        builder: widget.route!.builder!,
                         backgroundColor: widget.backgroundColor,
                         elevation: widget.elevation,
                         shape: widget.shape,
@@ -281,13 +274,13 @@ class _GetPerModalBottomSheetState<T>
                     : Scaffold(
                         bottomSheet: BottomSheet(
                           animationController:
-                              widget.route._animationController,
+                              widget.route!._animationController,
                           onClosing: () {
                             // if (widget.route.isCurrent) {
                             //   Navigator.pop(context);
                             // }
                           },
-                          builder: widget.route.builder,
+                          builder: widget.route!.builder!,
                           backgroundColor: widget.backgroundColor,
                           elevation: widget.elevation,
                           shape: widget.shape,

@@ -4,15 +4,14 @@ import '../../../get_instance/src/get_instance.dart';
 
 class GetDialogRoute<T> extends PopupRoute<T> {
   GetDialogRoute({
-    @required RoutePageBuilder pageBuilder,
+    required RoutePageBuilder pageBuilder,
     bool barrierDismissible = true,
-    String barrierLabel,
+    String? barrierLabel,
     Color barrierColor = const Color(0x80000000),
     Duration transitionDuration = const Duration(milliseconds: 200),
-    RouteTransitionsBuilder transitionBuilder,
-    RouteSettings settings,
-  })  : assert(barrierDismissible != null),
-        widget = pageBuilder,
+    RouteTransitionsBuilder? transitionBuilder,
+    RouteSettings? settings,
+  })  : widget = pageBuilder,
         name = "DIALOG: ${pageBuilder.hashCode}",
         _barrierDismissible = barrierDismissible,
         _barrierLabel = barrierLabel,
@@ -32,15 +31,15 @@ class GetDialogRoute<T> extends PopupRoute<T> {
   @override
   void dispose() {
     if (Get.smartManagement != SmartManagement.onlyBuilder) {
-      WidgetsBinding.instance.addPostFrameCallback(
+      WidgetsBinding.instance!.addPostFrameCallback(
           (_) => GetInstance().removeDependencyByRoute(name));
     }
     super.dispose();
   }
 
   @override
-  String get barrierLabel => _barrierLabel;
-  final String _barrierLabel;
+  String? get barrierLabel => _barrierLabel;
+  final String? _barrierLabel;
 
   @override
   Color get barrierColor => _barrierColor;
@@ -50,7 +49,7 @@ class GetDialogRoute<T> extends PopupRoute<T> {
   Duration get transitionDuration => _transitionDuration;
   final Duration _transitionDuration;
 
-  final RouteTransitionsBuilder _transitionBuilder;
+  final RouteTransitionsBuilder? _transitionBuilder;
 
   @override
   Widget buildPage(BuildContext context, Animation<double> animation,
@@ -73,6 +72,6 @@ class GetDialogRoute<T> extends PopupRoute<T> {
           ),
           child: child);
     } // Some default transition
-    return _transitionBuilder(context, animation, secondaryAnimation, child);
+    return _transitionBuilder!(context, animation, secondaryAnimation, child);
   }
 }

@@ -14,42 +14,42 @@ import 'routes/transitions_type.dart';
 
 extension ExtensionSnackbar on GetInterface {
   void rawSnackbar({
-    String title,
-    String message,
-    Widget titleText,
-    Widget messageText,
-    Widget icon,
+    String? title,
+    String? message,
+    Widget? titleText,
+    Widget? messageText,
+    Widget? icon,
     bool instantInit = true,
     bool shouldIconPulse = true,
-    double maxWidth,
+    double? maxWidth,
     EdgeInsets margin = const EdgeInsets.all(0.0),
     EdgeInsets padding = const EdgeInsets.all(16),
     double borderRadius = 0.0,
-    Color borderColor,
+    Color? borderColor,
     double borderWidth = 1.0,
     Color backgroundColor = const Color(0xFF303030),
-    Color leftBarIndicatorColor,
-    List<BoxShadow> boxShadows,
-    Gradient backgroundGradient,
-    Widget mainButton,
-    OnTap onTap,
+    Color? leftBarIndicatorColor,
+    List<BoxShadow>? boxShadows,
+    Gradient? backgroundGradient,
+    Widget? mainButton,
+    OnTap? onTap,
     Duration duration = const Duration(seconds: 3),
     bool isDismissible = true,
     SnackDismissDirection dismissDirection = SnackDismissDirection.VERTICAL,
     bool showProgressIndicator = false,
-    AnimationController progressIndicatorController,
-    Color progressIndicatorBackgroundColor,
-    Animation<Color> progressIndicatorValueColor,
+    AnimationController? progressIndicatorController,
+    Color? progressIndicatorBackgroundColor,
+    Animation<Color>? progressIndicatorValueColor,
     SnackPosition snackPosition = SnackPosition.BOTTOM,
     SnackStyle snackStyle = SnackStyle.FLOATING,
     Curve forwardAnimationCurve = Curves.easeOutCirc,
     Curve reverseAnimationCurve = Curves.easeOutCirc,
     Duration animationDuration = const Duration(seconds: 1),
-    SnackbarStatusCallback snackbarStatus,
-    double barBlur = 0.0,
+    SnackbarStatusCallback? snackbarStatus,
+    double? barBlur = 0.0,
     double overlayBlur = 0.0,
-    Color overlayColor,
-    Form userInputForm,
+    Color? overlayColor,
+    Form? userInputForm,
   }) async {
     final getBar = GetBar(
       snackbarStatus: snackbarStatus,
@@ -76,7 +76,7 @@ extension ExtensionSnackbar on GetInterface {
       onTap: onTap,
       isDismissible: isDismissible,
       dismissDirection: dismissDirection,
-      showProgressIndicator: showProgressIndicator ?? false,
+      showProgressIndicator: showProgressIndicator,
       progressIndicatorController: progressIndicatorController,
       progressIndicatorBackgroundColor: progressIndicatorBackgroundColor,
       progressIndicatorValueColor: progressIndicatorValueColor,
@@ -92,62 +92,60 @@ extension ExtensionSnackbar on GetInterface {
     if (instantInit) {
       getBar.show();
     } else {
-      SchedulerBinding.instance.addPostFrameCallback((_) {
+      SchedulerBinding.instance!.addPostFrameCallback((_) {
         getBar.show();
       });
     }
   }
 
-  Future<T> showSnackbar<T>(GetBar snackbar) {
+  Future<T?>? showSnackbar<T>(GetBar snackbar) {
     return key?.currentState?.push(SnackRoute<T>(snack: snackbar));
   }
 
   void snackbar<T>(
     String title,
     String message, {
-    Color colorText,
-    Duration duration,
+    Color? colorText,
+    Duration? duration,
 
     /// with instantInit = false you can put snackbar on initState
     bool instantInit = true,
-    SnackPosition snackPosition,
-    Widget titleText,
-    Widget messageText,
-    Widget icon,
-    bool shouldIconPulse,
-    double maxWidth,
-    EdgeInsets margin,
-    EdgeInsets padding,
-    double borderRadius,
-    Color borderColor,
-    double borderWidth,
-    Color backgroundColor,
-    Color leftBarIndicatorColor,
-    List<BoxShadow> boxShadows,
-    Gradient backgroundGradient,
-    TextButton mainButton,
-    OnTap onTap,
-    bool isDismissible,
-    bool showProgressIndicator,
-    SnackDismissDirection dismissDirection,
-    AnimationController progressIndicatorController,
-    Color progressIndicatorBackgroundColor,
-    Animation<Color> progressIndicatorValueColor,
-    SnackStyle snackStyle,
-    Curve forwardAnimationCurve,
-    Curve reverseAnimationCurve,
-    Duration animationDuration,
-    double barBlur,
-    double overlayBlur,
-    SnackbarStatusCallback snackbarStatus,
-    Color overlayColor,
-    Form userInputForm,
+    SnackPosition? snackPosition,
+    Widget? titleText,
+    Widget? messageText,
+    Widget? icon,
+    bool? shouldIconPulse,
+    double? maxWidth,
+    EdgeInsets? margin,
+    EdgeInsets? padding,
+    double? borderRadius,
+    Color? borderColor,
+    double? borderWidth,
+    Color? backgroundColor,
+    Color? leftBarIndicatorColor,
+    List<BoxShadow>? boxShadows,
+    Gradient? backgroundGradient,
+    TextButton? mainButton,
+    OnTap? onTap,
+    bool? isDismissible,
+    bool? showProgressIndicator,
+    SnackDismissDirection? dismissDirection,
+    AnimationController? progressIndicatorController,
+    Color? progressIndicatorBackgroundColor,
+    Animation<Color>? progressIndicatorValueColor,
+    SnackStyle? snackStyle,
+    Curve? forwardAnimationCurve,
+    Curve? reverseAnimationCurve,
+    Duration? animationDuration,
+    double? barBlur,
+    double? overlayBlur,
+    SnackbarStatusCallback? snackbarStatus,
+    Color? overlayColor,
+    Form? userInputForm,
   }) async {
     final getBar = GetBar(
         snackbarStatus: snackbarStatus,
-        titleText: (title == null)
-            ? null
-            : titleText ??
+        titleText: titleText ??
             Text(
               title,
               style: TextStyle(
@@ -200,7 +198,7 @@ extension ExtensionSnackbar on GetInterface {
       showSnackbar<T>(getBar);
     } else {
       routing.isSnackbar = true;
-      SchedulerBinding.instance.addPostFrameCallback((_) {
+      SchedulerBinding.instance!.addPostFrameCallback((_) {
         showSnackbar<T>(getBar);
       });
     }
@@ -212,33 +210,27 @@ extension ExtensionDialog on GetInterface {
   /// You can pass a [transitionDuration] and/or [transitionCurve],
   /// overriding the defaults when the dialog shows up and closes.
   /// When the dialog closes, uses those animations in reverse.
-  Future<T> dialog<T>(
+  Future<T?> dialog<T>(
     Widget widget, {
     bool barrierDismissible = true,
-    Color barrierColor,
+    Color? barrierColor,
     bool useSafeArea = true,
     bool useRootNavigator = true,
-    Object arguments,
-    Duration transitionDuration,
-    Curve transitionCurve,
-    String name,
-    RouteSettings routeSettings,
+    Object? arguments,
+    Duration? transitionDuration,
+    Curve? transitionCurve,
+    String? name,
+    RouteSettings? routeSettings,
   }) {
-    assert(widget != null);
-    assert(barrierDismissible != null);
-    assert(useSafeArea != null);
-    assert(useRootNavigator != null);
-    assert(debugCheckHasMaterialLocalizations(context));
+    assert(debugCheckHasMaterialLocalizations(context!));
 
     //  final theme = Theme.of(context, shadowThemeOnly: true);
-    final theme = Theme.of(context);
+    final theme = Theme.of(context!);
     return generalDialog<T>(
       pageBuilder: (buildContext, animation, secondaryAnimation) {
         final pageChild = widget;
         Widget dialog = Builder(builder: (context) {
-          return theme != null
-              ? Theme(data: theme, child: pageChild)
-              : pageChild;
+          return Theme(data: theme, child: pageChild);
         });
         if (useSafeArea) {
           dialog = SafeArea(child: dialog);
@@ -246,7 +238,7 @@ extension ExtensionDialog on GetInterface {
         return dialog;
       },
       barrierDismissible: barrierDismissible,
-      barrierLabel: MaterialLocalizations.of(context).modalBarrierDismissLabel,
+      barrierLabel: MaterialLocalizations.of(context!).modalBarrierDismissLabel,
       barrierColor: barrierColor ?? Colors.black54,
       transitionDuration: transitionDuration ?? defaultDialogTransitionDuration,
       transitionBuilder: (context, animation, secondaryAnimation, child) {
@@ -265,20 +257,18 @@ extension ExtensionDialog on GetInterface {
   }
 
   /// Api from showGeneralDialog with no context
-  Future<T> generalDialog<T>({
-    @required RoutePageBuilder pageBuilder,
+  Future<T?> generalDialog<T>({
+    required RoutePageBuilder pageBuilder,
     bool barrierDismissible = false,
-    String barrierLabel,
+    String? barrierLabel,
     Color barrierColor = const Color(0x80000000),
     Duration transitionDuration = const Duration(milliseconds: 200),
-    RouteTransitionsBuilder transitionBuilder,
+    RouteTransitionsBuilder? transitionBuilder,
     bool useRootNavigator = true,
-    RouteSettings routeSettings,
+    RouteSettings? routeSettings,
   }) {
-    assert(pageBuilder != null);
-    assert(useRootNavigator != null);
     assert(!barrierDismissible || barrierLabel != null);
-    return Navigator.of(overlayContext, rootNavigator: useRootNavigator)
+    return Navigator.of(overlayContext!, rootNavigator: useRootNavigator)
         .push<T>(GetDialogRoute<T>(
       pageBuilder: pageBuilder,
       barrierDismissible: barrierDismissible,
@@ -291,32 +281,32 @@ extension ExtensionDialog on GetInterface {
   }
 
   /// Custom UI Dialog.
-  Future<T> defaultDialog<T>({
+  Future<T?> defaultDialog<T>({
     String title = "Alert",
-    TextStyle titleStyle,
-    Widget content,
-    VoidCallback onConfirm,
-    VoidCallback onCancel,
-    VoidCallback onCustom,
-    Color cancelTextColor,
-    Color confirmTextColor,
-    String textConfirm,
-    String textCancel,
-    String textCustom,
-    Widget confirm,
-    Widget cancel,
-    Widget custom,
-    Color backgroundColor,
+    TextStyle? titleStyle,
+    Widget? content,
+    VoidCallback? onConfirm,
+    VoidCallback? onCancel,
+    VoidCallback? onCustom,
+    Color? cancelTextColor,
+    Color? confirmTextColor,
+    String? textConfirm,
+    String? textCancel,
+    String? textCustom,
+    Widget? confirm,
+    Widget? cancel,
+    Widget? custom,
+    Color? backgroundColor,
     bool barrierDismissible = true,
-    Color buttonColor,
+    Color? buttonColor,
     String middleText = "Dialog made in 3 lines of code",
-    TextStyle middleTextStyle,
+    TextStyle? middleTextStyle,
     double radius = 20.0,
     //   ThemeData themeData,
-    List<Widget> actions,
+    List<Widget>? actions,
 
     // onWillPop Scope
-    WillPopCallback onWillPop,
+    WillPopCallback? onWillPop,
   }) {
     var leanCancel = onCancel != null || textCancel != null;
     var leanConfirm = onConfirm != null || textConfirm != null;
@@ -332,7 +322,7 @@ extension ExtensionDialog on GetInterface {
             padding: EdgeInsets.symmetric(horizontal: 10, vertical: 8),
             shape: RoundedRectangleBorder(
                 side: BorderSide(
-                    color: buttonColor ?? theme.accentColor,
+                    color: buttonColor ?? theme!.accentColor,
                     width: 2,
                     style: BorderStyle.solid),
                 borderRadius: BorderRadius.circular(100)),
@@ -343,7 +333,7 @@ extension ExtensionDialog on GetInterface {
           },
           child: Text(
             textCancel ?? "Cancel",
-            style: TextStyle(color: cancelTextColor ?? theme.accentColor),
+            style: TextStyle(color: cancelTextColor ?? theme!.accentColor),
           ),
         ));
       }
@@ -356,14 +346,14 @@ extension ExtensionDialog on GetInterface {
             style: TextButton.styleFrom(
               tapTargetSize: MaterialTapTargetSize.shrinkWrap,
               //color: buttonColor ?? theme.accentColor,
-              backgroundColor: buttonColor ?? theme.accentColor,
+              backgroundColor: buttonColor ?? theme!.accentColor,
               shape: RoundedRectangleBorder(
                   borderRadius: BorderRadius.circular(100)),
             ),
             child: Text(
               textConfirm ?? "Ok",
               style:
-                  TextStyle(color: confirmTextColor ?? theme.backgroundColor),
+                  TextStyle(color: confirmTextColor ?? theme!.backgroundColor),
             ),
             onPressed: () {
               onConfirm?.call();
@@ -374,7 +364,7 @@ extension ExtensionDialog on GetInterface {
     Widget baseAlertDialog = AlertDialog(
       titlePadding: EdgeInsets.all(8),
       contentPadding: EdgeInsets.all(8),
-      backgroundColor: backgroundColor ?? theme.dialogBackgroundColor,
+      backgroundColor: backgroundColor ?? theme!.dialogBackgroundColor,
       shape: RoundedRectangleBorder(
           borderRadius: BorderRadius.all(Radius.circular(radius))),
       title: Text(title, textAlign: TextAlign.center, style: titleStyle),
@@ -383,7 +373,7 @@ extension ExtensionDialog on GetInterface {
         mainAxisSize: MainAxisSize.min,
         children: [
           content ??
-              Text(middleText ?? "",
+              Text(middleText,
                   textAlign: TextAlign.center, style: middleTextStyle),
           SizedBox(height: 16),
           ButtonTheme(
@@ -420,39 +410,32 @@ extension ExtensionDialog on GetInterface {
 }
 
 extension ExtensionBottomSheet on GetInterface {
-  Future<T> bottomSheet<T>(
+  Future<T?> bottomSheet<T>(
     Widget bottomsheet, {
-    Color backgroundColor,
-    double elevation,
+    Color? backgroundColor,
+    double? elevation,
     bool persistent = true,
-    ShapeBorder shape,
-    Clip clipBehavior,
-    Color barrierColor,
-    bool ignoreSafeArea,
+    ShapeBorder? shape,
+    Clip? clipBehavior,
+    Color? barrierColor,
+    bool? ignoreSafeArea,
     bool isScrollControlled = false,
     bool useRootNavigator = false,
     bool isDismissible = true,
     bool enableDrag = true,
-    RouteSettings settings,
-    Duration enterBottomSheetDuration,
-    Duration exitBottomSheetDuration,
+    RouteSettings? settings,
+    Duration? enterBottomSheetDuration,
+    Duration? exitBottomSheetDuration,
   }) {
-    assert(bottomsheet != null);
-    assert(persistent != null);
-    assert(isScrollControlled != null);
-    assert(useRootNavigator != null);
-    assert(isDismissible != null);
-    assert(enableDrag != null);
-
-    return Navigator.of(overlayContext, rootNavigator: useRootNavigator)
+    return Navigator.of(overlayContext!, rootNavigator: useRootNavigator)
         .push(GetModalBottomSheetRoute<T>(
       builder: (_) => bottomsheet,
       isPersistent: persistent,
       // theme: Theme.of(key.currentContext, shadowThemeOnly: true),
-      theme: Theme.of(key.currentContext),
+      theme: Theme.of(key!.currentContext!),
       isScrollControlled: isScrollControlled,
-      barrierLabel:
-          MaterialLocalizations.of(key.currentContext).modalBarrierDismissLabel,
+      barrierLabel: MaterialLocalizations.of(key!.currentContext!)
+          .modalBarrierDismissLabel,
       backgroundColor: backgroundColor ?? Colors.transparent,
       elevation: elevation,
       shape: shape,
@@ -491,18 +474,18 @@ extension GetNavigation on GetInterface {
   ///
   /// By default, GetX will prevent you from push a route that you already in,
   /// if you want to push anyway, set [preventDuplicates] to false
-  Future<T> to<T>(
+  Future<T?>? to<T>(
     dynamic page, {
-    bool opaque,
-    Transition transition,
-    Curve curve,
-    Duration duration,
-    int id,
+    bool? opaque,
+    Transition? transition,
+    Curve? curve,
+    Duration? duration,
+    int? id,
     bool fullscreenDialog = false,
     dynamic arguments,
-    Bindings binding,
+    Bindings? binding,
     bool preventDuplicates = true,
-    bool popGesture,
+    bool? popGesture,
   }) {
     var routeName = "/${page.runtimeType.toString()}";
     if (preventDuplicates && routeName == currentRoute) {
@@ -558,12 +541,12 @@ you can only use widgets and widget functions here''';
   /// if you want to push anyway, set [preventDuplicates] to false
   ///
   /// Note: Always put a slash on the route ('/page1'), to avoid unnexpected errors
-  Future<T> toNamed<T>(
+  Future<T?>? toNamed<T>(
     String page, {
     dynamic arguments,
-    int id,
+    int? id,
     bool preventDuplicates = true,
-    Map<String, String> parameters,
+    Map<String, String>? parameters,
   }) {
     if (preventDuplicates && page == currentRoute) {
       return null;
@@ -596,12 +579,12 @@ you can only use widgets and widget functions here''';
   /// if you want to push anyway, set [preventDuplicates] to false
   ///
   /// Note: Always put a slash on the route ('/page1'), to avoid unnexpected errors
-  Future<T> offNamed<T>(
+  Future<T?>? offNamed<T>(
     String page, {
     dynamic arguments,
-    int id,
+    int? id,
     bool preventDuplicates = true,
-    Map<String, String> parameters,
+    Map<String, String>? parameters,
   }) {
     if (preventDuplicates && page == currentRoute) {
       return null;
@@ -630,7 +613,7 @@ you can only use widgets and widget functions here''';
   /// or also like this:
   /// `Get.until((route) => !Get.isDialogOpen())`, to make sure the
   /// dialog is closed
-  void until(RoutePredicate predicate, {int id}) {
+  void until(RoutePredicate predicate, {int? id}) {
     // if (key.currentState.mounted) // add this if appear problems on future with route navigate
     // when widget don't mounted
     return global(id)?.currentState?.popUntil(predicate);
@@ -654,7 +637,7 @@ you can only use widgets and widget functions here''';
   /// or also like this:
   /// `Get.until((route) => !Get.isDialogOpen())`, to make sure the dialog
   /// is closed
-  Future<T> offUntil<T>(Route<T> page, RoutePredicate predicate, {int id}) {
+  Future<T?>? offUntil<T>(Route<T> page, RoutePredicate predicate, {int? id}) {
     // if (key.currentState.mounted) // add this if appear problems on future with route navigate
     // when widget don't mounted
     return global(id)?.currentState?.pushAndRemoveUntil<T>(page, predicate);
@@ -678,12 +661,12 @@ you can only use widgets and widget functions here''';
   /// to make sure the dialog is closed
   ///
   /// Note: Always put a slash on the route name ('/page1'), to avoid unexpected errors
-  Future<T> offNamedUntil<T>(
+  Future<T?>? offNamedUntil<T>(
     String page,
     RoutePredicate predicate, {
-    int id,
+    int? id,
     dynamic arguments,
-    Map<String, String> parameters,
+    Map<String, String>? parameters,
   }) {
     if (parameters != null) {
       final uri = Uri(path: page, queryParameters: parameters);
@@ -708,12 +691,12 @@ you can only use widgets and widget functions here''';
   /// The `offNamed()` pop a page, and goes to the next. The
   /// `offAndToNamed()` goes to the next page, and removes the previous one.
   /// The route transition animation is different.
-  Future<T> offAndToNamed<T>(
+  Future<T?>? offAndToNamed<T>(
     String page, {
     dynamic arguments,
-    int id,
+    int? id,
     dynamic result,
-    Map<String, String> parameters,
+    Map<String, String>? parameters,
   }) {
     if (parameters != null) {
       final uri = Uri(path: page, queryParameters: parameters);
@@ -732,7 +715,7 @@ you can only use widgets and widget functions here''';
   ///
   /// [id] is for when you are using nested navigation,
   /// as explained in documentation
-  void removeRoute(Route<dynamic> route, {int id}) {
+  void removeRoute(Route<dynamic> route, {int? id}) {
     return global(id)?.currentState?.removeRoute(route);
   }
 
@@ -756,12 +739,12 @@ you can only use widgets and widget functions here''';
   /// as explained in documentation
   ///
   /// Note: Always put a slash on the route ('/page1'), to avoid unexpected errors
-  Future<T> offAllNamed<T>(
+  Future<T?>? offAllNamed<T>(
     String newRouteName, {
-    RoutePredicate predicate,
+    RoutePredicate? predicate,
     dynamic arguments,
-    int id,
-    Map<String, String> parameters,
+    int? id,
+    Map<String, String>? parameters,
   }) {
     if (parameters != null) {
       final uri = Uri(path: newRouteName, queryParameters: parameters);
@@ -777,11 +760,11 @@ you can only use widgets and widget functions here''';
 
   /// Returns true if a Snackbar, Dialog or BottomSheet is currently OPEN
   bool get isOverlaysOpen =>
-      (isSnackbarOpen || isDialogOpen || isBottomSheetOpen);
+      (isSnackbarOpen! || isDialogOpen! || isBottomSheetOpen!);
 
   /// Returns true if there is no Snackbar, Dialog or BottomSheet open
   bool get isOverlaysClosed =>
-      (!isSnackbarOpen && !isDialogOpen && !isBottomSheetOpen);
+      (!isSnackbarOpen! && !isDialogOpen! && !isBottomSheetOpen!);
 
   /// **Navigation.popUntil()** shortcut.<br><br>
   ///
@@ -796,10 +779,10 @@ you can only use widgets and widget functions here''';
   /// It has the advantage of not needing context, so you can call
   /// from your business logic.
   void back<T>({
-    T result,
+    T? result,
     bool closeOverlays = false,
     bool canPop = true,
-    int id,
+    int? id,
   }) {
     if (closeOverlays && isOverlaysOpen) {
       navigator?.popUntil((route) {
@@ -821,8 +804,8 @@ you can only use widgets and widget functions here''';
   ///
   /// [id] is for when you are using nested navigation,
   /// as explained in documentation
-  void close(int times, [int id]) {
-    if ((times == null) || (times < 1)) {
+  void close(int times, [int? id]) {
+    if (times < 1) {
       times = 1;
     }
     var count = 0;
@@ -856,25 +839,25 @@ you can only use widgets and widget functions here''';
   ///
   /// By default, GetX will prevent you from push a route that you already in,
   /// if you want to push anyway, set [preventDuplicates] to false
-  Future<T> off<T>(
+  Future<T?>? off<T>(
     dynamic page, {
     bool opaque = false,
-    Transition transition,
-    Curve curve,
-    bool popGesture,
-    int id,
+    Transition? transition,
+    Curve? curve,
+    bool? popGesture,
+    int? id,
     dynamic arguments,
-    Bindings binding,
+    Bindings? binding,
     bool fullscreenDialog = false,
     bool preventDuplicates = true,
-    Duration duration,
+    Duration? duration,
   }) {
     var routeName = "/${page.runtimeType.toString()}";
     if (preventDuplicates && routeName == currentRoute) {
       return null;
     }
     return global(id)?.currentState?.pushReplacement(GetPageRoute(
-        opaque: opaque ?? true,
+        opaque: opaque,
         page: _resolve(page, 'off'),
         binding: binding,
         settings: RouteSettings(arguments: arguments),
@@ -917,24 +900,24 @@ you can only use widgets and widget functions here''';
   ///
   /// By default, GetX will prevent you from push a route that you already in,
   /// if you want to push anyway, set [preventDuplicates] to false
-  Future<T> offAll<T>(
+  Future<T?>? offAll<T>(
     dynamic page, {
-    RoutePredicate predicate,
+    RoutePredicate? predicate,
     bool opaque = false,
-    bool popGesture,
-    int id,
+    bool? popGesture,
+    int? id,
     dynamic arguments,
-    Bindings binding,
+    Bindings? binding,
     bool fullscreenDialog = false,
-    Transition transition,
-    Curve curve,
-    Duration duration,
+    Transition? transition,
+    Curve? curve,
+    Duration? duration,
   }) {
     var routeName = "/${page.runtimeType.toString()}";
 
     return global(id)?.currentState?.pushAndRemoveUntil<T>(
         GetPageRoute<T>(
-          opaque: opaque ?? true,
+          opaque: opaque,
           popGesture: popGesture ?? defaultPopGesture,
           page: _resolve(page, 'offAll'),
           binding: binding,
@@ -948,32 +931,28 @@ you can only use widgets and widget functions here''';
         predicate ?? (route) => false);
   }
 
-  void addPages(List<GetPage> getPages) {
+  void addPages(List<GetPage>? getPages) {
     if (getPages != null) {
-      if (routeTree == null) {
       routeTree = ParseRouteTree();
-      }
 
       routeTree.addRoutes(getPages);
     }
   }
 
   void addPage(GetPage getPage) {
-    if (getPage != null) {
-      if (routeTree == null) routeTree = ParseRouteTree();
+    routeTree = ParseRouteTree();
     routeTree.addRoute(getPage);
   }
-  }
 
   /// change default config of Get
   void config(
-      {bool enableLog,
-      LogWriterCallback logWriterCallback,
-      bool defaultPopGesture,
-      bool defaultOpaqueRoute,
-      Duration defaultDurationTransition,
-      bool defaultGlobalState,
-      Transition defaultTransition}) {
+      {bool? enableLog,
+      LogWriterCallback? logWriterCallback,
+      bool? defaultPopGesture,
+      bool? defaultOpaqueRoute,
+      Duration? defaultDurationTransition,
+      bool? defaultGlobalState,
+      Transition? defaultTransition}) {
     if (enableLog != null) {
       Get.isLogEnable = enableLog;
     }
@@ -1014,7 +993,7 @@ you can only use widgets and widget functions here''';
   /// Your entire application will be rebuilt, and touch events will not
   /// work until the end of rendering.
   void forceAppUpdate() {
-    engine.performReassemble();
+    engine!.performReassemble();
   }
 
   void appUpdate() => getxController.update();
@@ -1027,18 +1006,18 @@ you can only use widgets and widget functions here''';
     getxController.setThemeMode(themeMode);
   }
 
-  GlobalKey<NavigatorState> addKey(GlobalKey<NavigatorState> newKey) {
+  GlobalKey<NavigatorState>? addKey(GlobalKey<NavigatorState>? newKey) {
     getxController.key = newKey;
     return key;
   }
 
-  GlobalKey<NavigatorState> nestedKey(int key) {
+  GlobalKey<NavigatorState>? nestedKey(int key) {
     keys.putIfAbsent(key, () => GlobalKey<NavigatorState>());
     return keys[key];
   }
 
-  GlobalKey<NavigatorState> global(int k) {
-    GlobalKey<NavigatorState> _key;
+  GlobalKey<NavigatorState>? global(int? k) {
+    GlobalKey<NavigatorState>? _key;
     if (k == null) {
       _key = key;
     } else {
@@ -1048,7 +1027,7 @@ you can only use widgets and widget functions here''';
       _key = keys[k];
     }
 
-    if (_key.currentContext == null && !testMode) {
+    if (_key!.currentContext == null && !testMode) {
       throw """You are trying to use contextless navigation without
       a GetMaterialApp or Get.key.
       If you are testing your app, you can use:
@@ -1065,7 +1044,7 @@ you can only use widgets and widget functions here''';
 Since version 2.8 it is possible to access the properties 
 [Get.arguments] and [Get.currentRoute] directly. 
 [routeSettings] is useless and should not be used.''')
-  RouteSettings get routeSettings => null;
+  RouteSettings? get routeSettings => null;
 
   /// give current arguments
   dynamic get arguments => routing.args;
@@ -1077,16 +1056,16 @@ Since version 2.8 it is possible to access the properties
   String get previousRoute => routing.previous;
 
   /// check if snackbar is open
-  bool get isSnackbarOpen => routing.isSnackbar;
+  bool? get isSnackbarOpen => routing.isSnackbar;
 
   /// check if dialog is open
-  bool get isDialogOpen => routing.isDialog;
+  bool? get isDialogOpen => routing.isDialog;
 
   /// check if bottomsheet is open
-  bool get isBottomSheetOpen => routing.isBottomSheet;
+  bool? get isBottomSheetOpen => routing.isBottomSheet;
 
   /// check a raw current route
-  Route<dynamic> get rawRoute => routing.route;
+  Route<dynamic>? get rawRoute => routing.route;
 
   /// check if popGesture is enable
   bool get isPopGestureEnable => defaultPopGesture;
@@ -1095,28 +1074,28 @@ Since version 2.8 it is possible to access the properties
   bool get isOpaqueRouteDefault => defaultOpaqueRoute;
 
   /// give access to currentContext
-  BuildContext get context => key?.currentContext;
+  BuildContext? get context => key?.currentContext;
 
   /// give access to current Overlay Context
-  BuildContext get overlayContext {
-    BuildContext overlay;
-    key?.currentState?.overlay?.context?.visitChildElements((element) {
+  BuildContext? get overlayContext {
+    BuildContext? overlay;
+    key?.currentState?.overlay?.context.visitChildElements((element) {
       overlay = element;
     });
     return overlay;
   }
 
   /// give access to Theme.of(context)
-  ThemeData get theme {
-    ThemeData _theme;
+  ThemeData? get theme {
+    ThemeData? _theme;
     if (context != null) {
-      _theme = Theme.of(context);
+      _theme = Theme.of(context!);
     }
     return _theme;
   }
 
   ///The current [WidgetsBinding]
-  WidgetsBinding get engine {
+  WidgetsBinding? get engine {
     if (WidgetsBinding.instance == null) {
       WidgetsFlutterBinding();
     }
@@ -1126,9 +1105,9 @@ Since version 2.8 it is possible to access the properties
   //TODO: Change to ui.SingletonFlutterWindow rather dynamic
   //when Flutter update stable. dynamic is used to avoid Breaking Changes
   /// The window to which this binding is bound.
-  dynamic get window => ui.window;
+  ui.SingletonFlutterWindow get window => ui.window;
 
-  Locale get deviceLocale => ui.window.locale;
+  Locale? get deviceLocale => ui.window.locale;
 
   ///The number of device pixels for each logical pixel.
   double get pixelRatio => ui.window.devicePixelRatio;
@@ -1153,23 +1132,23 @@ Since version 2.8 it is possible to access the properties
   double get textScaleFactor => ui.window.textScaleFactor;
 
   /// give access to TextTheme.of(context)
-  TextTheme get textTheme => theme?.textTheme;
+  TextTheme? get textTheme => theme?.textTheme;
 
   /// give access to Mediaquery.of(context)
-  MediaQueryData get mediaQuery => MediaQuery.of(context);
+  MediaQueryData get mediaQuery => MediaQuery.of(context!);
 
   /// Check if dark mode theme is enable
-  bool get isDarkMode => (theme.brightness == Brightness.dark);
+  bool get isDarkMode => (theme!.brightness == Brightness.dark);
 
   /// Check if dark mode theme is enable on platform on android Q+
   bool get isPlatformDarkMode =>
       (ui.window.platformBrightness == Brightness.dark);
 
   /// give access to Theme.of(context).iconTheme.color
-  Color get iconColor => theme?.iconTheme?.color;
+  Color? get iconColor => theme?.iconTheme.color;
 
   /// give access to FocusScope.of(context)
-  FocusNode get focusScope => FocusManager.instance.primaryFocus;
+  FocusNode? get focusScope => FocusManager.instance.primaryFocus;
 
   // /// give access to Immutable MediaQuery.of(context).size.height
   // double get height => MediaQuery.of(context).size.height;
@@ -1177,16 +1156,16 @@ Since version 2.8 it is possible to access the properties
   // /// give access to Immutable MediaQuery.of(context).size.width
   // double get width => MediaQuery.of(context).size.width;
 
-  GlobalKey<NavigatorState> get key => getxController?.key;
+  GlobalKey<NavigatorState>? get key => getxController.key;
 
-  Map<int, GlobalKey<NavigatorState>> get keys => getxController?.keys;
+  Map<int, GlobalKey<NavigatorState>> get keys => getxController.keys;
 
   GetMaterialController get rootController => getxController;
 
   bool get defaultPopGesture => getxController.defaultPopGesture;
   bool get defaultOpaqueRoute => getxController.defaultOpaqueRoute;
 
-  Transition get defaultTransition => getxController.defaultTransition;
+  Transition? get defaultTransition => getxController.defaultTransition;
 
   Duration get defaultTransitionDuration {
     return getxController.defaultTransitionDuration;
@@ -1204,15 +1183,15 @@ Since version 2.8 it is possible to access the properties
 
   Routing get routing => getxController.routing;
 
-  Map<String, String> get parameters => getxController.parameters;
-  set parameters(Map<String, String> newParameters) =>
+  Map<String, String?> get parameters => getxController.parameters;
+  set parameters(Map<String, String?> newParameters) =>
       getxController.parameters = newParameters;
 
   ParseRouteTree get routeTree => getxController.routeTree;
   set routeTree(ParseRouteTree tree) => getxController.routeTree = tree;
 
-  CustomTransition get customTransition => getxController.customTransition;
-  set customTransition(CustomTransition newTransition) =>
+  CustomTransition? get customTransition => getxController.customTransition;
+  set customTransition(CustomTransition? newTransition) =>
       getxController.customTransition = newTransition;
 
   bool get testMode => getxController.testMode;
@@ -1224,4 +1203,4 @@ Since version 2.8 it is possible to access the properties
 /// It replaces the Flutter Navigator, but needs no context.
 /// You can to use navigator.push(YourRoute()) rather
 /// Navigator.push(context, YourRoute());
-NavigatorState get navigator => GetNavigation(Get).key.currentState;
+NavigatorState? get navigator => GetNavigation(Get).key!.currentState;

@@ -10,16 +10,18 @@ import 'root_controller.dart';
 
 class GetCupertinoApp extends StatelessWidget {
   const GetCupertinoApp({
-    Key key,
+    Key? key,
     this.theme,
     this.navigatorKey,
     this.home,
-    this.routes = const <String, WidgetBuilder>{},
+    Map<String, Widget Function(BuildContext)> this.routes =
+        const <String, WidgetBuilder>{},
     this.initialRoute,
     this.onGenerateRoute,
     this.onGenerateInitialRoutes,
     this.onUnknownRoute,
-    this.navigatorObservers = const <NavigatorObserver>[],
+    List<NavigatorObserver> this.navigatorObservers =
+        const <NavigatorObserver>[],
     this.builder,
     this.translationsKeys,
     this.translations,
@@ -58,78 +60,70 @@ class GetCupertinoApp extends StatelessWidget {
     this.highContrastTheme,
     this.highContrastDarkTheme,
     this.actions,
-  })  : assert(routes != null),
-        assert(navigatorObservers != null),
-        assert(title != null),
-        assert(showPerformanceOverlay != null),
-        assert(checkerboardRasterCacheImages != null),
-        assert(checkerboardOffscreenLayers != null),
-        assert(showSemanticsDebugger != null),
-        assert(debugShowCheckedModeBanner != null),
-        routeInformationProvider = null,
+  })  : routeInformationProvider = null,
         routeInformationParser = null,
         routerDelegate = null,
         backButtonDispatcher = null,
         super(key: key);
 
-  final GlobalKey<NavigatorState> navigatorKey;
-  final Widget home;
-  final Map<String, WidgetBuilder> routes;
-  final String initialRoute;
-  final RouteFactory onGenerateRoute;
-  final InitialRouteListFactory onGenerateInitialRoutes;
-  final RouteFactory onUnknownRoute;
-  final List<NavigatorObserver> navigatorObservers;
-  final TransitionBuilder builder;
+  final GlobalKey<NavigatorState>? navigatorKey;
+  final Widget? home;
+  final Map<String, WidgetBuilder>? routes;
+  final String? initialRoute;
+  final RouteFactory? onGenerateRoute;
+  final InitialRouteListFactory? onGenerateInitialRoutes;
+  final RouteFactory? onUnknownRoute;
+  final List<NavigatorObserver>? navigatorObservers;
+  final TransitionBuilder? builder;
   final String title;
-  final GenerateAppTitle onGenerateTitle;
-  final CustomTransition customTransition;
-  final Color color;
-  final Map<String, Map<String, String>> translationsKeys;
-  final Translations translations;
-  final TextDirection textDirection;
-  final Locale locale;
-  final Locale fallbackLocale;
-  final Iterable<LocalizationsDelegate<dynamic>> localizationsDelegates;
-  final LocaleListResolutionCallback localeListResolutionCallback;
-  final LocaleResolutionCallback localeResolutionCallback;
+  final GenerateAppTitle? onGenerateTitle;
+  final CustomTransition? customTransition;
+  final Color? color;
+  final Map<String, Map<String, String>>? translationsKeys;
+  final Translations? translations;
+  final TextDirection? textDirection;
+  final Locale? locale;
+  final Locale? fallbackLocale;
+  final Iterable<LocalizationsDelegate<dynamic>>? localizationsDelegates;
+  final LocaleListResolutionCallback? localeListResolutionCallback;
+  final LocaleResolutionCallback? localeResolutionCallback;
   final Iterable<Locale> supportedLocales;
   final bool showPerformanceOverlay;
   final bool checkerboardRasterCacheImages;
   final bool checkerboardOffscreenLayers;
   final bool showSemanticsDebugger;
   final bool debugShowCheckedModeBanner;
-  final Map<LogicalKeySet, Intent> shortcuts;
-  final ThemeData highContrastTheme;
-  final ThemeData highContrastDarkTheme;
-  final Map<Type, Action<Intent>> actions;
-  final Function(Routing) routingCallback;
-  final Transition defaultTransition;
-  final bool opaqueRoute;
-  final VoidCallback onInit;
-  final VoidCallback onReady;
-  final VoidCallback onDispose;
-  final bool enableLog;
-  final LogWriterCallback logWriterCallback;
-  final bool popGesture;
+  final Map<LogicalKeySet, Intent>? shortcuts;
+  final ThemeData? highContrastTheme;
+  final ThemeData? highContrastDarkTheme;
+  final Map<Type, Action<Intent>>? actions;
+  final Function(Routing?)? routingCallback;
+  final Transition? defaultTransition;
+  final bool? opaqueRoute;
+  final VoidCallback? onInit;
+  final VoidCallback? onReady;
+  final VoidCallback? onDispose;
+  final bool? enableLog;
+  final LogWriterCallback? logWriterCallback;
+  final bool? popGesture;
   final SmartManagement smartManagement;
-  final Bindings initialBinding;
-  final Duration transitionDuration;
-  final bool defaultGlobalState;
-  final List<GetPage> getPages;
-  final GetPage unknownRoute;
-  final RouteInformationProvider routeInformationProvider;
-  final RouteInformationParser<Object> routeInformationParser;
-  final RouterDelegate<Object> routerDelegate;
-  final BackButtonDispatcher backButtonDispatcher;
-  final CupertinoThemeData theme;
+  final Bindings? initialBinding;
+  final Duration? transitionDuration;
+  final bool? defaultGlobalState;
+  final List<GetPage>? getPages;
+  final GetPage? unknownRoute;
+  final RouteInformationProvider? routeInformationProvider;
+  final RouteInformationParser<Object>? routeInformationParser;
+  final RouterDelegate<Object>? routerDelegate;
+  final BackButtonDispatcher? backButtonDispatcher;
+  final CupertinoThemeData? theme;
 
   const GetCupertinoApp.router({
-    Key key,
+    Key? key,
     this.theme,
     this.routeInformationProvider,
-    @required this.routeInformationParser,
-    @required this.routerDelegate,
+    required RouteInformationParser<Object> this.routeInformationParser,
+    required RouterDelegate<Object> this.routerDelegate,
     this.backButtonDispatcher,
     this.builder,
     this.title = '',
@@ -169,15 +163,7 @@ class GetCupertinoApp extends StatelessWidget {
     this.defaultGlobalState,
     this.getPages,
     this.unknownRoute,
-  })  : assert(routeInformationParser != null),
-        assert(routerDelegate != null),
-        assert(title != null),
-        assert(showPerformanceOverlay != null),
-        assert(checkerboardRasterCacheImages != null),
-        assert(checkerboardOffscreenLayers != null),
-        assert(showSemanticsDebugger != null),
-        assert(debugShowCheckedModeBanner != null),
-        navigatorObservers = null,
+  })  : navigatorObservers = null,
         navigatorKey = null,
         onGenerateRoute = null,
         home = null,
@@ -201,7 +187,7 @@ class GetCupertinoApp extends StatelessWidget {
         onDispose?.call();
       },
       initState: (i) {
-        Get.engine.addPostFrameCallback((timeStamp) {
+        Get.engine!.addPostFrameCallback((timeStamp) {
           onReady?.call();
         });
         if (locale != null) Get.locale = locale;
@@ -209,9 +195,9 @@ class GetCupertinoApp extends StatelessWidget {
         if (fallbackLocale != null) Get.fallbackLocale = fallbackLocale;
 
         if (translations != null) {
-          Get.addTranslations(translations.keys);
+          Get.addTranslations(translations!.keys);
         } else if (translationsKeys != null) {
-          Get.addTranslations(translationsKeys);
+          Get.addTranslations(translationsKeys!);
         }
 
         Get.customTransition = customTransition;
@@ -233,8 +219,8 @@ class GetCupertinoApp extends StatelessWidget {
       },
       builder: (_) => routerDelegate != null
           ? CupertinoApp.router(
-              routerDelegate: routerDelegate,
-              routeInformationParser: routeInformationParser,
+              routerDelegate: routerDelegate!,
+              routeInformationParser: routeInformationParser!,
               backButtonDispatcher: backButtonDispatcher,
               routeInformationProvider: routeInformationProvider,
               key: _.unikey,
@@ -245,24 +231,22 @@ class GetCupertinoApp extends StatelessWidget {
                       (rtlLanguages.contains(Get.locale?.languageCode)
                           ? TextDirection.rtl
                           : TextDirection.ltr),
-                  child: builder == null ? child : builder(context, child),
+                  child: builder == null ? child! : builder!(context, child),
                 );
               },
-              title: title ?? '',
+              title: title,
               onGenerateTitle: onGenerateTitle,
               color: color,
               locale: Get.locale ?? locale,
               localizationsDelegates: localizationsDelegates,
               localeListResolutionCallback: localeListResolutionCallback,
               localeResolutionCallback: localeResolutionCallback,
-              supportedLocales:
-                  supportedLocales ?? const <Locale>[Locale('en', 'US')],
-              showPerformanceOverlay: showPerformanceOverlay ?? false,
-              checkerboardRasterCacheImages:
-                  checkerboardRasterCacheImages ?? false,
-              checkerboardOffscreenLayers: checkerboardOffscreenLayers ?? false,
-              showSemanticsDebugger: showSemanticsDebugger ?? false,
-              debugShowCheckedModeBanner: debugShowCheckedModeBanner ?? true,
+              supportedLocales: supportedLocales,
+              showPerformanceOverlay: showPerformanceOverlay,
+              checkerboardRasterCacheImages: checkerboardRasterCacheImages,
+              checkerboardOffscreenLayers: checkerboardOffscreenLayers,
+              showSemanticsDebugger: showSemanticsDebugger,
+              debugShowCheckedModeBanner: debugShowCheckedModeBanner,
               shortcuts: shortcuts,
             )
           : CupertinoApp(
@@ -285,31 +269,29 @@ class GetCupertinoApp extends StatelessWidget {
                   : <NavigatorObserver>[
                       GetObserver(routingCallback, Get.routing)
                     ]
-                ..addAll(navigatorObservers)),
+                ..addAll(navigatorObservers!)),
               builder: (context, child) {
                 return Directionality(
                   textDirection: textDirection ??
                       (rtlLanguages.contains(Get.locale?.languageCode)
                           ? TextDirection.rtl
                           : TextDirection.ltr),
-                  child: builder == null ? child : builder(context, child),
+                  child: builder == null ? child! : builder!(context, child),
                 );
               },
-              title: title ?? '',
+              title: title,
               onGenerateTitle: onGenerateTitle,
               color: color,
               locale: Get.locale ?? locale,
               localizationsDelegates: localizationsDelegates,
               localeListResolutionCallback: localeListResolutionCallback,
               localeResolutionCallback: localeResolutionCallback,
-              supportedLocales:
-                  supportedLocales ?? const <Locale>[Locale('en', 'US')],
-              showPerformanceOverlay: showPerformanceOverlay ?? false,
-              checkerboardRasterCacheImages:
-                  checkerboardRasterCacheImages ?? false,
-              checkerboardOffscreenLayers: checkerboardOffscreenLayers ?? false,
-              showSemanticsDebugger: showSemanticsDebugger ?? false,
-              debugShowCheckedModeBanner: debugShowCheckedModeBanner ?? true,
+              supportedLocales: supportedLocales,
+              showPerformanceOverlay: showPerformanceOverlay,
+              checkerboardRasterCacheImages: checkerboardRasterCacheImages,
+              checkerboardOffscreenLayers: checkerboardOffscreenLayers,
+              showSemanticsDebugger: showSemanticsDebugger,
+              debugShowCheckedModeBanner: debugShowCheckedModeBanner,
               shortcuts: shortcuts,
               //   actions: actions,
             ));

@@ -10,15 +10,17 @@ import 'root_controller.dart';
 
 class GetMaterialApp extends StatelessWidget {
   const GetMaterialApp({
-    Key key,
+    Key? key,
     this.navigatorKey,
     this.home,
-    this.routes = const <String, WidgetBuilder>{},
+    Map<String, Widget Function(BuildContext)> this.routes =
+        const <String, WidgetBuilder>{},
     this.initialRoute,
     this.onGenerateRoute,
     this.onGenerateInitialRoutes,
     this.onUnknownRoute,
-    this.navigatorObservers = const <NavigatorObserver>[],
+    List<NavigatorObserver> this.navigatorObservers =
+        const <NavigatorObserver>[],
     this.builder,
     this.textDirection,
     this.title = '',
@@ -61,81 +63,72 @@ class GetMaterialApp extends StatelessWidget {
     this.highContrastTheme,
     this.highContrastDarkTheme,
     this.actions,
-  })  : assert(routes != null),
-        assert(navigatorObservers != null),
-        assert(title != null),
-        assert(debugShowMaterialGrid != null),
-        assert(showPerformanceOverlay != null),
-        assert(checkerboardRasterCacheImages != null),
-        assert(checkerboardOffscreenLayers != null),
-        assert(showSemanticsDebugger != null),
-        assert(debugShowCheckedModeBanner != null),
-        routeInformationProvider = null,
+  })  : routeInformationProvider = null,
         routeInformationParser = null,
         routerDelegate = null,
         backButtonDispatcher = null,
         super(key: key);
 
-  final GlobalKey<NavigatorState> navigatorKey;
-  final Widget home;
-  final Map<String, WidgetBuilder> routes;
-  final String initialRoute;
-  final RouteFactory onGenerateRoute;
-  final InitialRouteListFactory onGenerateInitialRoutes;
-  final RouteFactory onUnknownRoute;
-  final List<NavigatorObserver> navigatorObservers;
-  final TransitionBuilder builder;
+  final GlobalKey<NavigatorState>? navigatorKey;
+  final Widget? home;
+  final Map<String, WidgetBuilder>? routes;
+  final String? initialRoute;
+  final RouteFactory? onGenerateRoute;
+  final InitialRouteListFactory? onGenerateInitialRoutes;
+  final RouteFactory? onUnknownRoute;
+  final List<NavigatorObserver>? navigatorObservers;
+  final TransitionBuilder? builder;
   final String title;
-  final GenerateAppTitle onGenerateTitle;
-  final ThemeData theme;
-  final ThemeData darkTheme;
+  final GenerateAppTitle? onGenerateTitle;
+  final ThemeData? theme;
+  final ThemeData? darkTheme;
   final ThemeMode themeMode;
-  final CustomTransition customTransition;
-  final Color color;
-  final Map<String, Map<String, String>> translationsKeys;
-  final Translations translations;
-  final TextDirection textDirection;
-  final Locale locale;
-  final Locale fallbackLocale;
-  final Iterable<LocalizationsDelegate<dynamic>> localizationsDelegates;
-  final LocaleListResolutionCallback localeListResolutionCallback;
-  final LocaleResolutionCallback localeResolutionCallback;
+  final CustomTransition? customTransition;
+  final Color? color;
+  final Map<String, Map<String, String>>? translationsKeys;
+  final Translations? translations;
+  final TextDirection? textDirection;
+  final Locale? locale;
+  final Locale? fallbackLocale;
+  final Iterable<LocalizationsDelegate<dynamic>>? localizationsDelegates;
+  final LocaleListResolutionCallback? localeListResolutionCallback;
+  final LocaleResolutionCallback? localeResolutionCallback;
   final Iterable<Locale> supportedLocales;
   final bool showPerformanceOverlay;
   final bool checkerboardRasterCacheImages;
   final bool checkerboardOffscreenLayers;
   final bool showSemanticsDebugger;
   final bool debugShowCheckedModeBanner;
-  final Map<LogicalKeySet, Intent> shortcuts;
-  final ThemeData highContrastTheme;
-  final ThemeData highContrastDarkTheme;
-  final Map<Type, Action<Intent>> actions;
+  final Map<LogicalKeySet, Intent>? shortcuts;
+  final ThemeData? highContrastTheme;
+  final ThemeData? highContrastDarkTheme;
+  final Map<Type, Action<Intent>>? actions;
   final bool debugShowMaterialGrid;
-  final ValueChanged<Routing> routingCallback;
-  final Transition defaultTransition;
-  final bool opaqueRoute;
-  final VoidCallback onInit;
-  final VoidCallback onReady;
-  final VoidCallback onDispose;
-  final bool enableLog;
-  final LogWriterCallback logWriterCallback;
-  final bool popGesture;
+  final ValueChanged<Routing?>? routingCallback;
+  final Transition? defaultTransition;
+  final bool? opaqueRoute;
+  final VoidCallback? onInit;
+  final VoidCallback? onReady;
+  final VoidCallback? onDispose;
+  final bool? enableLog;
+  final LogWriterCallback? logWriterCallback;
+  final bool? popGesture;
   final SmartManagement smartManagement;
-  final Bindings initialBinding;
-  final Duration transitionDuration;
-  final bool defaultGlobalState;
-  final List<GetPage> getPages;
-  final GetPage unknownRoute;
-  final RouteInformationProvider routeInformationProvider;
-  final RouteInformationParser<Object> routeInformationParser;
-  final RouterDelegate<Object> routerDelegate;
-  final BackButtonDispatcher backButtonDispatcher;
+  final Bindings? initialBinding;
+  final Duration? transitionDuration;
+  final bool? defaultGlobalState;
+  final List<GetPage>? getPages;
+  final GetPage? unknownRoute;
+  final RouteInformationProvider? routeInformationProvider;
+  final RouteInformationParser<Object>? routeInformationParser;
+  final RouterDelegate<Object>? routerDelegate;
+  final BackButtonDispatcher? backButtonDispatcher;
 
   const GetMaterialApp.router({
-    Key key,
+    Key? key,
     this.routeInformationProvider,
-    @required this.routeInformationParser,
-    @required this.routerDelegate,
+    required RouteInformationParser<Object> this.routeInformationParser,
+    required RouterDelegate<Object> this.routerDelegate,
     this.backButtonDispatcher,
     this.builder,
     this.title = '',
@@ -179,16 +172,7 @@ class GetMaterialApp extends StatelessWidget {
     this.defaultGlobalState,
     this.getPages,
     this.unknownRoute,
-  })  : assert(routeInformationParser != null),
-        assert(routerDelegate != null),
-        assert(title != null),
-        assert(debugShowMaterialGrid != null),
-        assert(showPerformanceOverlay != null),
-        assert(checkerboardRasterCacheImages != null),
-        assert(checkerboardOffscreenLayers != null),
-        assert(showSemanticsDebugger != null),
-        assert(debugShowCheckedModeBanner != null),
-        navigatorObservers = null,
+  })  : navigatorObservers = null,
         navigatorKey = null,
         onGenerateRoute = null,
         home = null,
@@ -211,7 +195,7 @@ class GetMaterialApp extends StatelessWidget {
         onDispose?.call();
       },
       initState: (i) {
-        Get.engine.addPostFrameCallback((timeStamp) {
+        Get.engine!.addPostFrameCallback((timeStamp) {
           onReady?.call();
         });
         if (locale != null) Get.locale = locale;
@@ -219,9 +203,9 @@ class GetMaterialApp extends StatelessWidget {
         if (fallbackLocale != null) Get.fallbackLocale = fallbackLocale;
 
         if (translations != null) {
-          Get.addTranslations(translations.keys);
+          Get.addTranslations(translations!.keys);
         } else if (translationsKeys != null) {
-          Get.addTranslations(translationsKeys);
+          Get.addTranslations(translationsKeys!);
         }
 
         Get.customTransition = customTransition;
@@ -243,8 +227,8 @@ class GetMaterialApp extends StatelessWidget {
       },
       builder: (_) => routerDelegate != null
           ? MaterialApp.router(
-              routerDelegate: routerDelegate,
-              routeInformationParser: routeInformationParser,
+              routerDelegate: routerDelegate!,
+              routeInformationParser: routeInformationParser!,
               backButtonDispatcher: backButtonDispatcher,
               routeInformationProvider: routeInformationProvider,
               key: _.unikey,
@@ -254,28 +238,26 @@ class GetMaterialApp extends StatelessWidget {
                       (rtlLanguages.contains(Get.locale?.languageCode)
                           ? TextDirection.rtl
                           : TextDirection.ltr),
-                  child: builder == null ? child : builder(context, child),
+                  child: builder == null ? child! : builder!(context, child),
                 );
               },
-              title: title ?? '',
+              title: title,
               onGenerateTitle: onGenerateTitle,
               color: color,
               theme: _.theme ?? theme ?? ThemeData.fallback(),
               darkTheme: darkTheme,
-              themeMode: _.themeMode ?? themeMode ?? ThemeMode.system,
+              themeMode: _.themeMode ?? themeMode,
               locale: Get.locale ?? locale,
               localizationsDelegates: localizationsDelegates,
               localeListResolutionCallback: localeListResolutionCallback,
               localeResolutionCallback: localeResolutionCallback,
-              supportedLocales:
-                  supportedLocales ?? const <Locale>[Locale('en', 'US')],
-              debugShowMaterialGrid: debugShowMaterialGrid ?? false,
-              showPerformanceOverlay: showPerformanceOverlay ?? false,
-              checkerboardRasterCacheImages:
-                  checkerboardRasterCacheImages ?? false,
-              checkerboardOffscreenLayers: checkerboardOffscreenLayers ?? false,
-              showSemanticsDebugger: showSemanticsDebugger ?? false,
-              debugShowCheckedModeBanner: debugShowCheckedModeBanner ?? true,
+              supportedLocales: supportedLocales,
+              debugShowMaterialGrid: debugShowMaterialGrid,
+              showPerformanceOverlay: showPerformanceOverlay,
+              checkerboardRasterCacheImages: checkerboardRasterCacheImages,
+              checkerboardOffscreenLayers: checkerboardOffscreenLayers,
+              showSemanticsDebugger: showSemanticsDebugger,
+              debugShowCheckedModeBanner: debugShowCheckedModeBanner,
               shortcuts: shortcuts,
             )
           : MaterialApp(
@@ -297,35 +279,33 @@ class GetMaterialApp extends StatelessWidget {
                   : <NavigatorObserver>[
                       GetObserver(routingCallback, Get.routing)
                     ]
-                ..addAll(navigatorObservers)),
+                ..addAll(navigatorObservers!)),
               builder: (context, child) {
                 return Directionality(
                   textDirection: textDirection ??
                       (rtlLanguages.contains(Get.locale?.languageCode)
                           ? TextDirection.rtl
                           : TextDirection.ltr),
-                  child: builder == null ? child : builder(context, child),
+                  child: builder == null ? child! : builder!(context, child),
                 );
               },
-              title: title ?? '',
+              title: title,
               onGenerateTitle: onGenerateTitle,
               color: color,
               theme: _.theme ?? theme ?? ThemeData.fallback(),
               darkTheme: darkTheme,
-              themeMode: _.themeMode ?? themeMode ?? ThemeMode.system,
+              themeMode: _.themeMode ?? themeMode,
               locale: Get.locale ?? locale,
               localizationsDelegates: localizationsDelegates,
               localeListResolutionCallback: localeListResolutionCallback,
               localeResolutionCallback: localeResolutionCallback,
-              supportedLocales:
-                  supportedLocales ?? const <Locale>[Locale('en', 'US')],
-              debugShowMaterialGrid: debugShowMaterialGrid ?? false,
-              showPerformanceOverlay: showPerformanceOverlay ?? false,
-              checkerboardRasterCacheImages:
-                  checkerboardRasterCacheImages ?? false,
-              checkerboardOffscreenLayers: checkerboardOffscreenLayers ?? false,
-              showSemanticsDebugger: showSemanticsDebugger ?? false,
-              debugShowCheckedModeBanner: debugShowCheckedModeBanner ?? true,
+              supportedLocales: supportedLocales,
+              debugShowMaterialGrid: debugShowMaterialGrid,
+              showPerformanceOverlay: showPerformanceOverlay,
+              checkerboardRasterCacheImages: checkerboardRasterCacheImages,
+              checkerboardOffscreenLayers: checkerboardOffscreenLayers,
+              showSemanticsDebugger: showSemanticsDebugger,
+              debugShowCheckedModeBanner: debugShowCheckedModeBanner,
               shortcuts: shortcuts,
               //   actions: actions,
             ));

 import '../../../get_core/src/get_main.dart';
-
 import '../../get_navigation.dart';
 import '../routes/get_route.dart';
 
 class RouteDecoder {
-  final GetPage route;
-  final Map<String, String> parameters;
+  final GetPage? route;
+  final Map<String, String?> parameters;
   const RouteDecoder(this.route, this.parameters);
 }
 
@@ -15,10 +14,10 @@ class ParseRouteTree {
   RouteDecoder matchRoute(String name) {
     final uri = Uri.parse(name);
     final route = _findRoute(uri.path);
-    final params = Map<String, String>.from(uri.queryParameters);
+    final params = Map<String, String?>.from(uri.queryParameters);
     if (route != null) {
       final parsedParams = _parseParams(name, route.path);
-      if (parsedParams != null && parsedParams.isNotEmpty) {
+      if (parsedParams.isNotEmpty) {
         params.addAll(parsedParams);
       }
     } else {
@@ -45,12 +44,12 @@ class ParseRouteTree {
 
   List<GetPage> _flattenPage(GetPage route) {
     final result = <GetPage>[];
-    if (route.children == null || route.children.isEmpty) {
+    if (route.children == null || route.children!.isEmpty) {
       return result;
     }
 
     final parentPath = route.name;
-    for (var page in route.children) {
+    for (var page in route.children!) {
       // Add Parent middlewares to children
       final pageMiddlewares = page.middlewares ?? <GetMiddleware>[];
       pageMiddlewares.addAll(route.middlewares ?? <GetMiddleware>[]);
@@ -88,15 +87,15 @@ class ParseRouteTree {
         middlewares: middlewares,
       );
 
-  GetPage _findRoute(String name) {
-    return _routes.firstWhere(
+  GetPage? _findRoute(String name) {
+    return _routes.firstWhereOrNull(
       (route) => route.path.regex.hasMatch(name),
-      orElse: () => null,
     );
   }
 
-  Map<String, String> _parseParams(String path, PathDecoded routePath) {
-    final params = <String, String>{};
+
+  Map<String, String?> _parseParams(String path, PathDecoded routePath) {
+    final params = <String, String?>{};
     var idx = path.indexOf('?');
     if (idx > -1) {
       path = path.substring(0, idx);
@@ -104,10 +103,21 @@ class ParseRouteTree {
       params.addAll(uri.queryParameters);
     }
     Match paramsMatch = routePath.regex.firstMatch(path);
+
     for (var i = 0; i < routePath.keys.length; i++) {
-      var param = Uri.decodeQueryComponent(paramsMatch[i + 1]);
-      params[routePath.keys[i]] = param;
+      var param = Uri.decodeQueryComponent(paramsMatch![i + 1]!);
+      params[routePath.keys[i]!] = param;
     }
     return params;
   }
 }
+
+extension FirstWhereExt<T> on List<T> {
+  /// The first element satisfying [test], or `null` if there are none.
+  T? firstWhereOrNull(bool Function(T element) test) {
+    for (var element in this) {
+      if (test(element)) return element;
+    }
+    return null;
+  }
+}

@@ -8,14 +8,14 @@ import 'parse_route.dart';
 
 class GetMaterialController extends GetxController {
   bool testMode = false;
-  Key unikey;
-  ThemeData theme;
-  ThemeMode themeMode;
+  Key? unikey;
+  ThemeData? theme;
+  ThemeMode? themeMode;
 
   bool defaultPopGesture = GetPlatform.isIOS;
   bool defaultOpaqueRoute = true;
 
-  Transition defaultTransition;
+  Transition? defaultTransition;
   Duration defaultTransitionDuration = Duration(milliseconds: 300);
   Curve defaultTransitionCurve = Curves.easeOutQuad;
 
@@ -25,13 +25,13 @@ class GetMaterialController extends GetxController {
 
   final routing = Routing();
 
-  Map<String, String> parameters = {};
+  Map<String, String?> parameters = {};
 
-  ParseRouteTree routeTree;
+  late ParseRouteTree routeTree;
 
-  CustomTransition customTransition;
+  CustomTransition? customTransition;
 
-  GlobalKey<NavigatorState> key = GlobalKey<NavigatorState>();
+  GlobalKey<NavigatorState>? key = GlobalKey<NavigatorState>();
 
   Map<int, GlobalKey<NavigatorState>> keys = {};
 

@@ -4,8 +4,8 @@ import 'package:flutter/widgets.dart';
 abstract class CustomTransition {
   Widget buildTransition(
     BuildContext context,
-    Curve curve,
-    Alignment alignment,
+    Curve? curve,
+    Alignment? alignment,
     Animation<double> animation,
     Animation<double> secondaryAnimation,
     Widget child,

@@ -12,7 +12,7 @@ import 'transitions_type.dart';
 
 class GetPageRoute<T> extends PageRoute<T> {
   GetPageRoute({
-    RouteSettings settings,
+    RouteSettings? settings,
     this.transitionDuration = const Duration(milliseconds: 300),
     this.opaque = true,
     this.parameter,
@@ -31,51 +31,47 @@ class GetPageRoute<T> extends PageRoute<T> {
     this.maintainState = true,
     bool fullscreenDialog = false,
     this.middlewares,
-  })  : assert(opaque != null),
-        assert(barrierDismissible != null),
-        assert(maintainState != null),
-        assert(fullscreenDialog != null),
-        reference = "$routeName: ${page.hashCode}",
+  })  : reference = "$routeName: ${page.hashCode}",
         super(settings: settings, fullscreenDialog: fullscreenDialog);
 
   @override
   final Duration transitionDuration;
 
-  final GetPageBuilder page;
+  final GetPageBuilder? page;
 
-  final String routeName;
+  final String? routeName;
 
   final String reference;
 
-  final CustomTransition customTransition;
+  final CustomTransition? customTransition;
 
-  final Bindings binding;
+  final Bindings? binding;
 
-  final Map<String, String> parameter;
+  final Map<String, String>? parameter;
 
-  final List<Bindings> bindings;
+  final List<Bindings>? bindings;
 
   @override
   final bool opaque;
 
-  final bool popGesture;
+  final bool? popGesture;
 
   @override
   final bool barrierDismissible;
 
-  final Transition transition;
+  final Transition? transition;
 
-  final Curve curve;
+  final Curve? curve;
 
-  final Alignment alignment;
+  final Alignment? alignment;
 
-  final List<GetMiddleware> middlewares;
+  final List<GetMiddleware>? middlewares;
 
   @override
-  final Color barrierColor;
+  final Color? barrierColor;
 
   @override
-  final String barrierLabel;
+  final String? barrierLabel;
 
   @override
   final bool maintainState;
@@ -93,8 +89,8 @@ class GetPageRoute<T> extends PageRoute<T> {
         route.willHandlePopInternally ||
         route.hasScopedWillPopCallback ||
         route.fullscreenDialog ||
-        route.animation.status != AnimationStatus.completed ||
-        route.secondaryAnimation.status != AnimationStatus.dismissed ||
+        route.animation!.status != AnimationStatus.completed ||
+        route.secondaryAnimation!.status != AnimationStatus.dismissed ||
         isPopGestureInProgress(route)) return false;
 
     return true;
@@ -105,8 +101,8 @@ class GetPageRoute<T> extends PageRoute<T> {
     assert(_isPopGestureEnabled(route));
 
     return _CupertinoBackGestureController<T>(
-      navigator: route.navigator,
-      controller: route.controller,
+      navigator: route.navigator!,
+      controller: route.controller!,
     );
   }
 
@@ -129,12 +125,12 @@ class GetPageRoute<T> extends PageRoute<T> {
       }
     }
 
-    final pageToBuild = middlewareRunner.runOnPageBuildStart(page);
+    final pageToBuild = middlewareRunner.runOnPageBuildStart(page)!;
     return middlewareRunner.runOnPageBuilt(pageToBuild());
   }
 
   static bool isPopGestureInProgress(PageRoute<dynamic> route) {
-    return route.navigator.userGestureInProgress;
+    return route.navigator!.userGestureInProgress;
   }
 
   bool get popGestureInProgress => isPopGestureInProgress(this);
@@ -156,7 +152,7 @@ class GetPageRoute<T> extends PageRoute<T> {
           linearTransition: hasCurve);
     }
     if (customTransition != null) {
-      return customTransition.buildTransition(
+      return customTransition!.buildTransition(
         context,
         finalCurve,
         alignment,
@@ -312,7 +308,7 @@ class GetPageRoute<T> extends PageRoute<T> {
       case Transition.size:
         return SizeTransitions().buildTransitions(
             context,
-            curve,
+            curve!,
             alignment,
             animation,
             secondaryAnimation,
@@ -364,7 +360,7 @@ class GetPageRoute<T> extends PageRoute<T> {
 
       default:
         if (Get.customTransition != null) {
-          return Get.customTransition.buildTransition(
+          return Get.customTransition!.buildTransition(
               context, curve, alignment, animation, secondaryAnimation, child);
         }
 
@@ -386,7 +382,7 @@ class GetPageRoute<T> extends PageRoute<T> {
   void dispose() {
     super.dispose();
     if (Get.smartManagement != SmartManagement.onlyBuilder) {
-      WidgetsBinding.instance.addPostFrameCallback((_) {
+      WidgetsBinding.instance!.addPostFrameCallback((_) {
         if (Get.reference != reference) {
           GetInstance().removeDependencyByRoute("$reference");
         }
@@ -412,14 +408,11 @@ const int _kMaxPageBackAnimationTime = 300;
 
 class _CupertinoBackGestureDetector<T> extends StatefulWidget {
   const _CupertinoBackGestureDetector({
-    Key key,
-    @required this.enabledCallback,
-    @required this.onStartPopGesture,
-    @required this.child,
-  })  : assert(enabledCallback != null),
-        assert(onStartPopGesture != null),
-        assert(child != null),
-        super(key: key);
+    Key? key,
+    required this.enabledCallback,
+    required this.onStartPopGesture,
+    required this.child,
+  }) : super(key: key);
 
   final Widget child;
 
@@ -434,9 +427,9 @@ class _CupertinoBackGestureDetector<T> extends StatefulWidget {
 
 class _CupertinoBackGestureDetectorState<T>
     extends State<_CupertinoBackGestureDetector<T>> {
-  _CupertinoBackGestureController<T> _backGestureController;
+  _CupertinoBackGestureController<T>? _backGestureController;
 
-  HorizontalDragGestureRecognizer _recognizer;
+  late HorizontalDragGestureRecognizer _recognizer;
 
   @override
   void initState() {
@@ -463,15 +456,15 @@ class _CupertinoBackGestureDetectorState<T>
   void _handleDragUpdate(DragUpdateDetails details) {
     assert(mounted);
     assert(_backGestureController != null);
-    _backGestureController.dragUpdate(
-        _convertToLogical(details.primaryDelta / context.size.width));
+    _backGestureController!.dragUpdate(
+        _convertToLogical(details.primaryDelta! / context.size!.width)!);
   }
 
   void _handleDragEnd(DragEndDetails details) {
     assert(mounted);
     assert(_backGestureController != null);
-    _backGestureController.dragEnd(_convertToLogical(
-        details.velocity.pixelsPerSecond.dx / context.size.width));
+    _backGestureController!.dragEnd(_convertToLogical(
+        details.velocity.pixelsPerSecond.dx / context.size!.width)!);
     _backGestureController = null;
   }
 
@@ -487,17 +480,15 @@ class _CupertinoBackGestureDetectorState<T>
     if (widget.enabledCallback()) _recognizer.addPointer(event);
   }
 
-  double _convertToLogical(double value) {
+  double? _convertToLogical(double value) {
     switch (Directionality.of(context)) {
       case TextDirection.rtl:
         return -value;
       case TextDirection.ltr:
         return value;
+      default:
+        return value;
     }
-    // FIXME: shouldn't we return a default here?
-    //  or perhaps throw error
-    // ignore: avoid_returning_null
-    return null;
   }
 
   @override
@@ -533,10 +524,9 @@ class _CupertinoBackGestureController<T> {
   ///
   /// The [navigator] and [controller] arguments must not be null.
   _CupertinoBackGestureController({
-    @required this.navigator,
-    @required this.controller,
-  })  : assert(navigator != null),
-        assert(controller != null) {
+    required this.navigator,
+    required this.controller,
+  }) {
     navigator.didStartUserGesture();
   }
 
@@ -579,7 +569,8 @@ class _CupertinoBackGestureController<T> {
           _kMaxDroppedSwipePageForwardAnimationTime,
           0,
           controller.value,
-        ).floor(),
+        )!
+            .floor(),
         _kMaxPageBackAnimationTime,
       );
       controller.animateTo(1.0,
@@ -597,7 +588,8 @@ class _CupertinoBackGestureController<T> {
           0,
           _kMaxDroppedSwipePageForwardAnimationTime,
           controller.value,
-        ).floor();
+        )!
+            .floor();
         controller.animateBack(
           0.0,
           duration: Duration(milliseconds: droppedPageBackAnimationTime),
@@ -610,7 +602,7 @@ class _CupertinoBackGestureController<T> {
       // Keep the userGestureInProgress in true state so we don't change the
       // curve of the page transition mid-flight since CupertinoPageTransition
       // depends on userGestureInProgress.
-      AnimationStatusListener animationStatusCallback;
+      late AnimationStatusListener animationStatusCallback;
       animationStatusCallback = (status) {
         navigator.didStopUserGesture();
         controller.removeStatusListener(animationStatusCallback);

@@ -4,8 +4,8 @@ import 'package:flutter/material.dart';
 class LeftToRightFadeTransition {
   Widget buildTransitions(
       BuildContext context,
-      Curve curve,
-      Alignment alignment,
+      Curve? curve,
+      Alignment? alignment,
       Animation<double> animation,
       Animation<double> secondaryAnimation,
       Widget child) {
@@ -30,8 +30,8 @@ class LeftToRightFadeTransition {
 class RightToLeftFadeTransition {
   Widget buildTransitions(
       BuildContext context,
-      Curve curve,
-      Alignment alignment,
+      Curve? curve,
+      Alignment? alignment,
       Animation<double> animation,
       Animation<double> secondaryAnimation,
       Widget child) {
@@ -68,8 +68,8 @@ class NoTransition {
 class FadeInTransition {
   Widget buildTransitions(
       BuildContext context,
-      Curve curve,
-      Alignment alignment,
+      Curve? curve,
+      Alignment? alignment,
       Animation<double> animation,
       Animation<double> secondaryAnimation,
       Widget child) {
@@ -80,8 +80,8 @@ class FadeInTransition {
 class SlideDownTransition {
   Widget buildTransitions(
       BuildContext context,
-      Curve curve,
-      Alignment alignment,
+      Curve? curve,
+      Alignment? alignment,
       Animation<double> animation,
       Animation<double> secondaryAnimation,
       Widget child) {
@@ -98,8 +98,8 @@ class SlideDownTransition {
 class SlideLeftTransition {
   Widget buildTransitions(
       BuildContext context,
-      Curve curve,
-      Alignment alignment,
+      Curve? curve,
+      Alignment? alignment,
       Animation<double> animation,
       Animation<double> secondaryAnimation,
       Widget child) {
@@ -116,8 +116,8 @@ class SlideLeftTransition {
 class SlideRightTransition {
   Widget buildTransitions(
       BuildContext context,
-      Curve curve,
-      Alignment alignment,
+      Curve? curve,
+      Alignment? alignment,
       Animation<double> animation,
       Animation<double> secondaryAnimation,
       Widget child) {
@@ -134,8 +134,8 @@ class SlideRightTransition {
 class SlideTopTransition {
   Widget buildTransitions(
       BuildContext context,
-      Curve curve,
-      Alignment alignment,
+      Curve? curve,
+      Alignment? alignment,
       Animation<double> animation,
       Animation<double> secondaryAnimation,
       Widget child) {
@@ -152,8 +152,8 @@ class SlideTopTransition {
 class ZoomInTransition {
   Widget buildTransitions(
       BuildContext context,
-      Curve curve,
-      Alignment alignment,
+      Curve? curve,
+      Alignment? alignment,
       Animation<double> animation,
       Animation<double> secondaryAnimation,
       Widget child) {
@@ -168,7 +168,7 @@ class SizeTransitions {
   Widget buildTransitions(
       BuildContext context,
       Curve curve,
-      Alignment alignment,
+      Alignment? alignment,
       Animation<double> animation,
       Animation<double> secondaryAnimation,
       Widget child) {

@@ -8,33 +8,33 @@ import 'transitions_type.dart';
 class PathDecoded {
   const PathDecoded(this.regex, this.keys);
   final RegExp regex;
-  final List<String> keys;
+  final List<String?> keys;
 }
 
 class GetPage {
   final String name;
   final GetPageBuilder page;
-  final bool popGesture;
-  final Map<String, String> parameter;
-  final String title;
-  final Transition transition;
+  final bool? popGesture;
+  final Map<String, String>? parameter;
+  final String? title;
+  final Transition? transition;
   final Curve curve;
-  final Alignment alignment;
+  final Alignment? alignment;
   final bool maintainState;
   final bool opaque;
-  final Bindings binding;
+  final Bindings? binding;
   final List<Bindings> bindings;
-  final CustomTransition customTransition;
-  final Duration transitionDuration;
+  final CustomTransition? customTransition;
+  final Duration? transitionDuration;
   final bool fullscreenDialog;
-  final RouteSettings settings;
-  final List<GetPage> children;
-  final List<GetMiddleware> middlewares;
+  final RouteSettings? settings;
+  final List<GetPage>? children;
+  final List<GetMiddleware>? middlewares;
   final PathDecoded path;
 
   GetPage({
-    @required this.name,
-    @required this.page,
+    required this.name,
+    required this.page,
     this.title,
     this.settings,
     this.maintainState = true,
@@ -51,14 +51,10 @@ class GetPage {
     this.fullscreenDialog = false,
     this.children,
     this.middlewares,
-  })  : path = _nameToRegex(name),
-        assert(page != null),
-        assert(name != null),
-        assert(maintainState != null),
-        assert(fullscreenDialog != null);
+  }) : path = _nameToRegex(name);
 
   static PathDecoded _nameToRegex(String path) {
-    var keys = <String>[];
+    var keys = <String?>[];
 
     String _replace(Match pattern) {
       var buffer = StringBuffer('(?:');
@@ -79,24 +75,24 @@ class GetPage {
   }
 
   GetPage copyWith({
-    String name,
-    GetPageBuilder page,
-    bool popGesture,
-    Map<String, String> parameter,
-    String title,
-    Transition transition,
-    Curve curve,
-    Alignment alignment,
-    bool maintainState,
-    bool opaque,
-    Bindings binding,
-    List<Bindings> bindings,
-    CustomTransition customTransition,
-    Duration transitionDuration,
-    bool fullscreenDialog,
-    RouteSettings settings,
-    List<GetPage> children,
-    List<GetMiddleware> middlewares,
+    String? name,
+    GetPageBuilder? page,
+    bool? popGesture,
+    Map<String, String>? parameter,
+    String? title,
+    Transition? transition,
+    Curve? curve,
+    Alignment? alignment,
+    bool? maintainState,
+    bool? opaque,
+    Bindings? binding,
+    List<Bindings>? bindings,
+    CustomTransition? customTransition,
+    Duration? transitionDuration,
+    bool? fullscreenDialog,
+    RouteSettings? settings,
+    List<GetPage>? children,
+    List<GetMiddleware>? middlewares,
   }) {
     return GetPage(
       name: name ?? this.name,

@@ -10,11 +10,11 @@ class Routing {
   String previous;
   dynamic args;
   String removed;
-  Route<dynamic> route;
-  bool isBack;
-  bool isSnackbar;
-  bool isBottomSheet;
-  bool isDialog;
+  Route<dynamic>? route;
+  bool? isBack;
+  bool? isSnackbar;
+  bool? isBottomSheet;
+  bool? isDialog;
 
   Routing({
     this.current = '',
@@ -35,9 +35,9 @@ class Routing {
 
 /// Extracts the name of a route based on it's instance type
 /// or null if not possible.
-String _extractRouteName(Route route) {
-  if (route?.settings?.name != null) {
-    return route.settings.name;
+String? _extractRouteName(Route? route) {
+  if (route?.settings.name != null) {
+    return route!.settings.name;
   }
 
   if (route is GetPageRoute) {
@@ -61,17 +61,17 @@ class _RouteData {
   final bool isSnackbar;
   final bool isBottomSheet;
   final bool isDialog;
-  final String name;
+  final String? name;
 
   _RouteData({
-    @required this.name,
-    @required this.isGetPageRoute,
-    @required this.isSnackbar,
-    @required this.isBottomSheet,
-    @required this.isDialog,
+    required this.name,
+    required this.isGetPageRoute,
+    required this.isSnackbar,
+    required this.isBottomSheet,
+    required this.isDialog,
   });
 
-  factory _RouteData.ofRoute(Route route) {
+  factory _RouteData.ofRoute(Route? route) {
     return _RouteData(
       name: _extractRouteName(route),
       isGetPageRoute: route is GetPageRoute,
@@ -83,14 +83,14 @@ class _RouteData {
 }
 
 class GetObserver extends NavigatorObserver {
-  final Function(Routing) routing;
+  final Function(Routing?)? routing;
 
   GetObserver([this.routing, this._routeSend]);
 
-  final Routing _routeSend;
+  final Routing? _routeSend;
 
   @override
-  void didPush(Route route, Route previousRoute) {
+  void didPush(Route route, Route? previousRoute) {
     super.didPush(route, previousRoute);
     final newRoute = _RouteData.ofRoute(route);
 
@@ -110,7 +110,7 @@ class GetObserver extends NavigatorObserver {
         value.current = newRoute.name ?? '';
       }
 
-      value.args = route?.settings?.arguments;
+      value.args = route.settings.arguments;
       value.route = route;
       value.isBack = false;
       value.removed = '';
@@ -122,12 +122,12 @@ class GetObserver extends NavigatorObserver {
     });
 
     if (routing != null) {
-      routing(_routeSend);
+      routing!(_routeSend);
     }
   }
 
   @override
-  void didPop(Route route, Route previousRoute) {
+  void didPop(Route route, Route? previousRoute) {
     super.didPop(route, previousRoute);
     final currentRoute = _RouteData.ofRoute(route);
     final newRoute = _RouteData.ofRoute(previousRoute);
@@ -151,7 +151,7 @@ class GetObserver extends NavigatorObserver {
         value.current = _extractRouteName(previousRoute) ?? '';
       }
 
-      value.args = route?.settings?.arguments;
+      value.args = route.settings.arguments;
       value.route = previousRoute;
       value.isBack = true;
       value.removed = '';
@@ -167,7 +167,7 @@ class GetObserver extends NavigatorObserver {
   }
 
   @override
-  void didReplace({Route newRoute, Route oldRoute}) {
+  void didReplace({Route? newRoute, Route? oldRoute}) {
     super.didReplace(newRoute: newRoute, oldRoute: oldRoute);
     final newName = _extractRouteName(newRoute);
     final oldName = _extractRouteName(oldRoute);
@@ -183,7 +183,7 @@ class GetObserver extends NavigatorObserver {
         value.current = newName ?? '';
       }
 
-      value.args = newRoute?.settings?.arguments;
+      value.args = newRoute?.settings.arguments;
       value.route = newRoute;
       value.isBack = false;
       value.removed = '';
@@ -198,7 +198,7 @@ class GetObserver extends NavigatorObserver {
   }
 
   @override
-  void didRemove(Route route, Route previousRoute) {
+  void didRemove(Route route, Route? previousRoute) {
     super.didRemove(route, previousRoute);
     final routeName = _extractRouteName(route);
     final currentRoute = _RouteData.ofRoute(route);