diff --git a/packages/flutter_auth_core/lib/src/flutter_auth.dart b/packages/flutter_auth_core/lib/src/flutter_auth.dart
index 6861b72..c02acd1 100644
--- a/packages/flutter_auth_core/lib/src/flutter_auth.dart
+++ b/packages/flutter_auth_core/lib/src/flutter_auth.dart
@@ -1,11 +1,7 @@
-import 'package:flutter_auth_core/src/utils/flutter_auth_exception_code.dart';
-import 'package:flutter_auth_core/src/utils/flutter_auth_exception_message.dart';
 import 'package:flutter_webview_plugin/flutter_webview_plugin.dart';
 
-import 'utils/flutter_auth_webview.dart';
-import 'package:meta/meta.dart' show required, visibleForOverriding;
+import 'package:meta/meta.dart' show visibleForOverriding;
 import 'package:flutter/material.dart';
-import 'package:flutter/widgets.dart';
 import 'package:flutter_auth_core/flutter_auth_core.dart';
 
 // ignore: public_member_api_docs
@@ -14,21 +10,19 @@ class FlutterAuth {
   final String clientSecret;
   final String callbackUrl;
   final bool clearCache;
-  final String userAgent;
+  final String? userAgent;
 
   /// Returns an instance of [FlutterAuth].
-  FlutterAuth(
-      {@required this.clientId,
-      @required this.clientSecret,
-      @required this.callbackUrl,
-      this.clearCache = false,
-      this.userAgent}) {
-    assert(clientId != null && clientId.isNotEmpty,
-        'ClientId may not be null or empty.');
-    assert(clientSecret != null && clientSecret.isNotEmpty,
-        'ClientSecret may not be null or empty.');
-    assert(callbackUrl != null && callbackUrl.isNotEmpty,
-        'CallbackUrl may not be null or empty.');
+  FlutterAuth({
+    required this.clientId,
+    required this.clientSecret,
+    required this.callbackUrl,
+    this.clearCache = false,
+    this.userAgent,
+  }) {
+    assert(clientId.isNotEmpty, 'ClientId may not be empty.');
+    assert(clientSecret.isNotEmpty, 'ClientSecret may not be empty.');
+    assert(callbackUrl.isNotEmpty, 'CallbackUrl may not be empty.');
   }
 
   @visibleForOverriding
@@ -50,8 +44,9 @@ class FlutterAuth {
   @visibleForTesting
   // ignore: public_member_api_docs
   Future<FlutterAuthResult> openLoginPageWithWebview(
-      BuildContext context, String url) async {
-    assert(context != null && url != null && url.isNotEmpty);
+      BuildContext? context, String url) async {
+    assert(context != null);
+    assert(url.isNotEmpty);
     var authorizedResult;
 
     try {
@@ -73,14 +68,17 @@ class FlutterAuth {
 
   @visibleForTesting
   // ignore: public_member_api_docs
-  Future<dynamic> navigateToWebview(BuildContext context, String url) async {
-    return Navigator.of(context).push(MaterialPageRoute(
+  Future<dynamic> navigateToWebview(BuildContext? context, String url) async {
+    return Navigator.of(context!).push(
+      MaterialPageRoute(
         builder: (context) => FlutterAuthWebview(
-              url: url,
-              redirectUrl: callbackUrl,
-              userAgent: userAgent,
-              clearCache: clearCache,
-            )));
+          url: url,
+          redirectUrl: callbackUrl,
+          userAgent: userAgent,
+          clearCache: clearCache,
+        ),
+      ),
+    );
   }
 
   @visibleForTesting
diff --git a/packages/flutter_auth_core/lib/src/flutter_auth_exception.dart b/packages/flutter_auth_core/lib/src/flutter_auth_exception.dart
index 8e282bf..2290b5d 100644
--- a/packages/flutter_auth_core/lib/src/flutter_auth_exception.dart
+++ b/packages/flutter_auth_core/lib/src/flutter_auth_exception.dart
@@ -9,10 +9,10 @@ class FlutterAuthException {
   FlutterAuthException({this.code, this.message, this.details});
 
   /// The error code
-  final FlutterAuthExceptionCode code;
+  final FlutterAuthExceptionCode? code;
 
   /// Description of the error thrown
-  final String message;
+  final String? message;
 
   /// Additional details of the error thrown
   final dynamic details;
diff --git a/packages/flutter_auth_core/lib/src/flutter_auth_result.dart b/packages/flutter_auth_core/lib/src/flutter_auth_result.dart
index 5538f2b..5746674 100644
--- a/packages/flutter_auth_core/lib/src/flutter_auth_result.dart
+++ b/packages/flutter_auth_core/lib/src/flutter_auth_result.dart
@@ -8,10 +8,10 @@ class FlutterAuthResult {
   FlutterAuthResult({this.token, this.secret}) : assert(token != null);
 
   /// The token obtained after the user has successfully logged in.
-  final String token;
+  final String? token;
 
   /// The secret obtained after the user has successfully logged in.
-  final String secret;
+  final String? secret;
 
   /// Returns the current instance as a [Map].
   Map<String, dynamic> get asMap {
diff --git a/packages/flutter_auth_core/lib/src/utils/flutter_auth_webview.dart b/packages/flutter_auth_core/lib/src/utils/flutter_auth_webview.dart
index 01caefc..ada3d04 100644
--- a/packages/flutter_auth_core/lib/src/utils/flutter_auth_webview.dart
+++ b/packages/flutter_auth_core/lib/src/utils/flutter_auth_webview.dart
@@ -9,13 +9,13 @@ class FlutterAuthWebview extends StatefulWidget {
   final String redirectUrl;
   final bool clearCache;
   final String title;
-  final String userAgent;
+  final String? userAgent;
 
   // ignore: public_member_api_docs
   const FlutterAuthWebview(
-      {Key key,
-      @required this.url,
-      @required this.redirectUrl,
+      {Key? key,
+      required this.url,
+      required this.redirectUrl,
       this.userAgent,
       this.clearCache = true,
       this.title = ""})
@@ -29,9 +29,9 @@ class _FlutterAuthWebviewState extends State<FlutterAuthWebview> {
   final FlutterWebviewPlugin _wv = FlutterWebviewPlugin();
 
   // On urlChanged stream
-  StreamSubscription<String> _onUrlChanged;
+  late StreamSubscription<String> _onUrlChanged;
 
-  StreamSubscription<WebViewHttpError> _onHttpError;
+  late StreamSubscription<WebViewHttpError> _onHttpError;
 
   static const String _userAgentMacOSX =
       "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_2) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/79.0.3945.88 Safari/537.36";
diff --git a/packages/flutter_auth_core/pubspec.yaml b/packages/flutter_auth_core/pubspec.yaml
index 939095b..468cc95 100644
--- a/packages/flutter_auth_core/pubspec.yaml
+++ b/packages/flutter_auth_core/pubspec.yaml
@@ -4,19 +4,19 @@ version: 0.0.4
 homepage: https://github.com/StackTiger/flutter_auth/tree/master/packages/flutter_auth_core
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: ">=2.16.0 <3.0.0"
 
 dependencies:
   flutter:
     sdk: flutter
-  quiver: ">=2.0.0 <3.0.0"
-  meta: ^1.1.8
-  url_launcher: ^5.5.0
-  http: ^0.12.2
-  oauth1: ^1.0.4
-  flutter_webview_plugin: ^0.3.11
+  flutter_webview_plugin: ^0.4.0
+  http: ^0.13.4
+  meta: ^1.7.0
+  oauth1: ^2.0.0
+  quiver: ^3.0.1+1
+  url_launcher: ^6.0.20
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  mockito: ^4.1.1
+  mockito: ^5.1.0
diff --git a/packages/flutter_auth_core/test/flutter_auth_test.dart b/packages/flutter_auth_core/test/flutter_auth_test.dart
index b3770f8..379de52 100644
--- a/packages/flutter_auth_core/test/flutter_auth_test.dart
+++ b/packages/flutter_auth_core/test/flutter_auth_test.dart
@@ -14,7 +14,7 @@ const kAuthorizedResultUrl = 'test-authorized-result-url';
 BuildContext kMockBuildContext = MockBuildContext();
 
 void main() {
-  TestFlutterAuth testFlutterAuth;
+  late TestFlutterAuth testFlutterAuth;
   TestWidgetsFlutterBinding.ensureInitialized();
 
   setUp(() {
@@ -45,31 +45,31 @@ void main() {
       try {
         FlutterAuth(
             callbackUrl: kCallbackUrl,
-            clientId: null,
+            clientId: '',
             clientSecret: kClientSecret);
       } on AssertionError catch (e) {
-        expect(e.message, 'ClientId may not be null or empty.');
+        expect(e.message, 'ClientId may not be empty.');
       }
     });
 
     test('throws AssertionError if clientSecret is null', () {
       try {
         FlutterAuth(
-            callbackUrl: kCallbackUrl, clientId: kClientId, clientSecret: null);
+            callbackUrl: kCallbackUrl, clientId: kClientId, clientSecret: '');
       } on AssertionError catch (e) {
-        expect(e.message, 'ClientSecret may not be null or empty.');
+        expect(e.message, 'ClientSecret may not be empty.');
       }
     });
 
     test('throws AssertionError if callbackUrl is null', () {
       try {
         FlutterAuth(
-          callbackUrl: null,
+          callbackUrl: '',
           clientId: kClientId,
           clientSecret: kClientSecret,
         );
       } on AssertionError catch (e) {
-        expect(e.message, 'CallbackUrl may not be null or empty.');
+        expect(e.message, 'CallbackUrl may not be empty.');
       }
     });
   });
@@ -111,7 +111,7 @@ void main() {
     test('throws AssertionError if url is null', () {
       expect(
           () =>
-              testFlutterAuth.openLoginPageWithWebview(kMockBuildContext, null),
+              testFlutterAuth.openLoginPageWithWebview(kMockBuildContext, ''),
           throwsAssertionError);
     });
 
@@ -135,7 +135,7 @@ class TestFlutterAuth extends FlutterAuth {
             userAgent: kUserAgent);
 
   @override
-  navigateToWebview(BuildContext context, String url) {
+  navigateToWebview(BuildContext? context, String url) {
     return Future.value('mock-url');
   }
 
diff --git a/packages/github_auth/example/android/app/src/main/AndroidManifest.xml b/packages/github_auth/example/android/app/src/main/AndroidManifest.xml
index 86fd5aa..926a1e1 100644
--- a/packages/github_auth/example/android/app/src/main/AndroidManifest.xml
+++ b/packages/github_auth/example/android/app/src/main/AndroidManifest.xml
@@ -6,7 +6,7 @@
          additional functionality it is fine to subclass or reimplement
          FlutterApplication and put your custom class here. -->
     <application
-        android:name="io.flutter.app.FlutterApplication"
+        android:name="${applicationName}"
         android:label="github_auth_example"
         android:icon="@mipmap/ic_launcher">
         <activity
diff --git a/packages/github_auth/example/pubspec.yaml b/packages/github_auth/example/pubspec.yaml
index c071704..044125a 100644
--- a/packages/github_auth/example/pubspec.yaml
+++ b/packages/github_auth/example/pubspec.yaml
@@ -23,4 +23,4 @@ flutter:
   uses-material-design: true
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: ">=2.16.0 <3.0.0"
diff --git a/packages/github_auth/example/test_driver/app_test.dart b/packages/github_auth/example/test_driver/app_test.dart
index c1a756d..95780f9 100644
--- a/packages/github_auth/example/test_driver/app_test.dart
+++ b/packages/github_auth/example/test_driver/app_test.dart
@@ -1,9 +1,8 @@
+import 'package:flutter_test/flutter_test.dart';
 import 'package:flutter_driver/flutter_driver.dart';
-import 'package:test/test.dart';
-
 void main() {
   group('Github Auth App', () {
-    final titleTextFinder = find.byValueKey('title');
+    final titleTextFinder = find.text('title');
 
     FlutterDriver driver;
 
diff --git a/packages/github_auth/lib/src/github_api_error.dart b/packages/github_auth/lib/src/github_api_error.dart
index d1b9aa6..0d4758c 100644
--- a/packages/github_auth/lib/src/github_api_error.dart
+++ b/packages/github_auth/lib/src/github_api_error.dart
@@ -1,9 +1,9 @@
 // https://docs.github.com/en/free-pro-team@latest/developers/apps/authorizing-oauth-apps#error-codes-for-the-device-flow
 
 class GithubAPIError {
-  String code;
-  String message;
-  String uri;
+  String? code;
+  String? message;
+  String? uri;
 
   GithubAPIError({this.code, this.message, this.uri});
 
diff --git a/packages/github_auth/lib/src/github_auth.dart b/packages/github_auth/lib/src/github_auth.dart
index 4fef8b7..193be0b 100644
--- a/packages/github_auth/lib/src/github_auth.dart
+++ b/packages/github_auth/lib/src/github_auth.dart
@@ -34,20 +34,25 @@ class GithubAuth extends FlutterAuth {
   final bool clearCache;
 
   /// The user agent to be used for the Webview
-  final String userAgent;
+  final String? userAgent;
 
   @visibleForTesting
   // ignore: public_member_api_docs
   final client = http.Client();
 
   GithubAuth(
-      {@required this.clientId,
-      @required this.clientSecret,
-      @required this.callbackUrl,
+      {required this.clientId,
+      required this.clientSecret,
+      required this.callbackUrl,
       this.scope = "user,gist,user:email",
       this.allowSignUp = true,
       this.clearCache = false,
-      this.userAgent});
+      this.userAgent})
+      : super(
+          clientId: clientId,
+          clientSecret: clientSecret,
+          callbackUrl: callbackUrl,
+        );
 
   @visibleForTesting
   @override
@@ -55,7 +60,7 @@ class GithubAuth extends FlutterAuth {
   Future<FlutterAuthResult> loginComplete(Uri authorizedResultUrl) async {
     FlutterAuthResult result;
     // exchange for access token
-    String code = authorizedResultUrl.queryParameters[kCodeConstant];
+    String? code = authorizedResultUrl.queryParameters[kCodeConstant];
 
     if (code == null || code.isEmpty) {
       throw FlutterAuthException(
@@ -78,7 +83,8 @@ class GithubAuth extends FlutterAuth {
 
   @visibleForTesting
   Future<String> getAccessToken(String code) async {
-    var response = await client.post("$kApiEndpointAccessToken", headers: {
+    http.Response response =
+        await client.post(Uri.parse(kApiEndpointAccessToken), headers: {
       kAcceptConstant: kAcceptJsonConstant,
     }, body: {
       kClientIdConstant: clientId,
@@ -87,7 +93,7 @@ class GithubAuth extends FlutterAuth {
     });
 
     if (response.statusCode == 200) {
-      var body = json.decode(utf8.decode(response.bodyBytes));
+      Map<String, dynamic> body = json.decode(utf8.decode(response.bodyBytes));
       var error = body[kErrorConstant];
       if (error != null) {
         throw GithubAPIError.parse(body);
diff --git a/packages/github_auth/lib/src/utils/constants.dart b/packages/github_auth/lib/src/utils/constants.dart
index d8e873d..fdd0832 100644
--- a/packages/github_auth/lib/src/utils/constants.dart
+++ b/packages/github_auth/lib/src/utils/constants.dart
@@ -1,11 +1,31 @@
-const kApiBaseEndpoint = 'https://github.com/login/oauth';
-const kApiEndpointAccessToken = '$kApiBaseEndpoint/access_token';
-const kApiEndpointAuthorize = '$kApiBaseEndpoint/authorize';
-
-const kCodeConstant = 'code';
-const kAccessTokenConstant = 'access_token';
-const kClientSecretConstant = 'client_secret';
-const kClientIdConstant = "client_id";
-const kAcceptConstant = "Accept";
-const kAcceptJsonConstant = "application/json";
-const kErrorConstant = "error";
+/// Global constant for Github OAuth Login base url
+const String kApiBaseEndpoint = 'https://github.com/login/oauth';
+
+/// Global constant for Github OAuth Login access token endpoint
+const String kApiEndpointAccessToken = '$kApiBaseEndpoint/access_token';
+
+/// Global constant for Github OAuth Login authorize endpoint
+const String kApiEndpointAuthorize = '$kApiBaseEndpoint/authorize';
+
+/// Global key constant for Github OAuth Login that to be
+/// passed to the API call to get the access token
+/// while logging in with [GithubAuth.clientId] and [GithubAuth.clientSecret].
+const String kCodeConstant = 'code';
+
+/// Global key constant for to get the access token from the json response.
+const String kAccessTokenConstant = 'access_token';
+
+/// Global Key constant to put the client secret in the request body.
+const String kClientSecretConstant = 'client_secret';
+
+/// Global Key constant to put the client id in the request body.
+const String kClientIdConstant = "client_id";
+
+/// Global Key constant to put the headers in the request body.
+const String kAcceptConstant = "Accept";
+
+/// Global Value constant to put the headers in the request body.
+const String kAcceptJsonConstant = "application/json";
+
+/// Global Key constant to get the error from the json response.
+const String kErrorConstant = "error";
diff --git a/packages/github_auth/pubspec.yaml b/packages/github_auth/pubspec.yaml
index d3db13b..0077956 100644
--- a/packages/github_auth/pubspec.yaml
+++ b/packages/github_auth/pubspec.yaml
@@ -4,18 +4,19 @@ version: 0.0.4
 homepage: https://github.com/StackTiger/flutter_auth/tree/master/packages/github_auth
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
-  flutter: ">=1.10.0"
+  sdk: ">=2.16.0 <3.0.0"
+  flutter: ">=2.10.0"
 
 dependencies:
-  flutter_auth_core: ^0.0.0
   flutter:
     sdk: flutter
-  quiver: ">=2.0.0 <3.0.0"
-  meta: ^1.1.8
-  http: ^0.12.2
+  flutter_auth_core: 
+    path: ../flutter_auth_core
+  http: ^0.13.4
+  meta: ^1.7.0
+  quiver: ^3.0.1+1
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  mockito: ^4.1.1
+  mockito: ^5.1.0
diff --git a/packages/github_auth/test/github_auth_test.dart b/packages/github_auth/test/github_auth_test.dart
index f3f798d..66b6183 100644
--- a/packages/github_auth/test/github_auth_test.dart
+++ b/packages/github_auth/test/github_auth_test.dart
@@ -1,5 +1,3 @@
-import 'dart:async';
-
 import 'package:flutter/material.dart';
 import 'package:flutter_auth_core/flutter_auth_core.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -9,7 +7,7 @@ import 'package:mockito/mockito.dart';
 import 'package:http/http.dart' as http;
 
 BuildContext kMockBuildContext = MockBuildContext();
-MockHttpClient kClient;
+late MockHttpClient kClient;
 
 const kCallbackUrl = 'githubsdk://';
 const kClientId = 'test-consumer-key';
@@ -21,7 +19,7 @@ const kToken = 'test-token';
 
 void main() {
   TestWidgetsFlutterBinding.ensureInitialized();
-  GithubAuth githubAuth;
+  late GithubAuth githubAuth;
 
   setUp(() {
     githubAuth = TestGithubAuth();
@@ -85,9 +83,9 @@ void main() {
   });
 
   group('loginComplete()', () {
-    String mockCode;
-    String mockAccessToken;
-    Uri mockAuthorizedResultUrl;
+    late String mockCode;
+    late String mockAccessToken;
+    late Uri mockAuthorizedResultUrl;
 
     setUp(() {
       mockCode = 'test-code';
@@ -98,7 +96,7 @@ void main() {
 
     test('return a [FlutterAuthResult] with [FlutterAuthStatus] success',
         () async {
-      when(kClient.post(kApiEndpointAccessToken,
+      when(kClient.post(Uri.parse(kApiEndpointAccessToken),
               headers: anyNamed('headers'), body: anyNamed('body')))
           .thenAnswer((_) async =>
               http.Response('{"access_token": "$mockAccessToken"}', 200));
@@ -128,7 +126,7 @@ void main() {
     test(
         'returns a [FlutterAuthResult] with [FlutterAuthStatus] error if statusCode != 200',
         () async {
-      when(kClient.post(kApiEndpointAccessToken,
+      when(kClient.post(Uri.parse(kApiEndpointAccessToken),
               headers: anyNamed('headers'), body: anyNamed('body')))
           .thenAnswer((_) async => http.Response('mock error', 400));
 
@@ -145,7 +143,7 @@ void main() {
     test(
         'return a [FlutterAuthResult] with FlutterAuthStatus.error if [accessToken] is null ',
         () async {
-      when(kClient.post(kApiEndpointAccessToken,
+      when(kClient.post(Uri.parse(kApiEndpointAccessToken),
               headers: anyNamed('headers'), body: anyNamed('body')))
           .thenAnswer((_) async => http.Response('mock error', 400));
 
diff --git a/packages/twitter_auth/lib/src/twitter_api_error.dart b/packages/twitter_auth/lib/src/twitter_api_error.dart
index 21862ba..9694cab 100644
--- a/packages/twitter_auth/lib/src/twitter_api_error.dart
+++ b/packages/twitter_auth/lib/src/twitter_api_error.dart
@@ -1,8 +1,8 @@
 // https://developer.twitter.com/ja/docs/basics/response-codes
 
 class TwitterAPIError {
-  String code;
-  String message;
+  String? code;
+  String? message;
 
   TwitterAPIError({this.code, this.message});
 
diff --git a/packages/twitter_auth/lib/src/twitter_auth.dart b/packages/twitter_auth/lib/src/twitter_auth.dart
index df50780..f287d57 100644
--- a/packages/twitter_auth/lib/src/twitter_auth.dart
+++ b/packages/twitter_auth/lib/src/twitter_auth.dart
@@ -2,7 +2,6 @@ import 'package:oauth1/oauth1.dart' as oauth1;
 import 'package:flutter/material.dart';
 import 'package:flutter/widgets.dart';
 import 'package:flutter_auth_core/flutter_auth_core.dart';
-import 'package:meta/meta.dart' show required, visibleForTesting;
 import 'package:oauth1/oauth1.dart';
 import 'package:twitter_auth/src/utils/exception.dart';
 import 'utils/constants.dart';
@@ -25,13 +24,13 @@ class TwitterAuth extends FlutterAuth {
   final bool clearCache;
 
   /// The user agent to be used for the Webview
-  final String userAgent;
+  final String? userAgent;
 
-  ClientCredentials _clientCredentials;
+  late ClientCredentials _clientCredentials;
 
   @visibleForTesting
   // ignore: public_member_api_docs
-  Authorization authorization;
+  late Authorization authorization;
 
   static final dynamic _client = oauth1.Platform(
       kApiEndpointRequestToken,
@@ -41,15 +40,18 @@ class TwitterAuth extends FlutterAuth {
 
   /// Returns an instance of [TwitterAuth].
   TwitterAuth(
-      {@required this.clientId,
-      @required this.clientSecret,
-      @required this.callbackUrl,
+      {required this.clientId,
+      required this.clientSecret,
+      required this.callbackUrl,
       this.clearCache = false,
-      this.userAgent}) {
-    assert(clientId != null && clientId.isNotEmpty,
-        'Consumer key may not be null or empty.');
-    assert(clientSecret != null && clientSecret.isNotEmpty,
-        'Consumer secret may not be null or empty.');
+      this.userAgent})
+      : super(
+            clientId: clientId,
+            clientSecret: clientSecret,
+            callbackUrl: callbackUrl) {
+    assert(clientId.isNotEmpty, 'Consumer key may not be null or empty.');
+    assert(
+        clientSecret.isNotEmpty, 'Consumer secret may not be null or empty.');
     _clientCredentials = ClientCredentials(clientId, clientSecret);
   }
 
diff --git a/packages/twitter_auth/lib/src/utils/exception.dart b/packages/twitter_auth/lib/src/utils/exception.dart
index 0fa42cd..59deaa2 100644
--- a/packages/twitter_auth/lib/src/utils/exception.dart
+++ b/packages/twitter_auth/lib/src/utils/exception.dart
@@ -13,14 +13,15 @@ dynamic parseLoginException(error) {
 
   FlutterAuthException exception;
   if (error is SocketException) {
-    if (error.message != null && error.message.contains("Failed host lookup")) {
+    if (error.message.contains("Failed host lookup")) {
       exception = FlutterAuthException(
           code: FlutterAuthExceptionCode.network,
           message: 'No network',
           details: error.toString());
     }
-  } else if (error is StateError) {
-    final apiError = parseTwitterApiError(error);
+  }
+  if (error is StateError) {
+    final apiError = parseTwitterApiError(error as StateError);
 
     exception = FlutterAuthException(
       code: FlutterAuthExceptionCode.login,
@@ -38,7 +39,7 @@ dynamic parseLoginException(error) {
 }
 
 TwitterAPIError parseTwitterApiError(StateError error) {
-  List<XmlElement> errors = XmlElement.parseString(
+  List<XmlElement>? errors = XmlElement.parseString(
     error.message,
     returnElementsNamed: ['error'],
     start: 0,
diff --git a/packages/twitter_auth/pubspec.yaml b/packages/twitter_auth/pubspec.yaml
index d03f060..a30cc46 100644
--- a/packages/twitter_auth/pubspec.yaml
+++ b/packages/twitter_auth/pubspec.yaml
@@ -4,20 +4,21 @@ version: 0.0.4
 homepage: https://github.com/StackTiger/flutter_auth/tree/master/packages/twitter_auth
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
-  flutter: ">=1.10.0"
+  sdk: ">=2.16.0 <3.0.0"
+  flutter: ">=2.10.0"
 
 dependencies:
-  flutter_auth_core: ^0.0.0
   flutter:
     sdk: flutter
-  quiver: ">=2.0.0 <3.0.0"
+  flutter_auth_core:
+    path: packages/flutter_auth_core
+  http: ^0.13.4
   meta: ^1.1.8
-  http: ^0.12.2
-  oauth1: ^1.0.4
-  xml_parser: ^0.1.2
+  oauth1: ^2.0.0
+  quiver: ^3.0.1+1
+  xml_parser: ^1.0.0
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  mockito: ^4.1.1
+  mockito: ^5.1.0
diff --git a/packages/twitter_auth/test/twitter_auth_test.dart b/packages/twitter_auth/test/twitter_auth_test.dart
index 6342fc3..4c3d5bd 100644
--- a/packages/twitter_auth/test/twitter_auth_test.dart
+++ b/packages/twitter_auth/test/twitter_auth_test.dart
@@ -1,5 +1,3 @@
-import 'dart:async';
-
 import 'package:flutter/material.dart';
 import 'package:flutter_auth_core/flutter_auth_core.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -16,10 +14,10 @@ const kToken = 'test-token';
 const kAuthorizedResultUrl = 'test-authorized-result-url';
 
 BuildContext kMockBuildContext = MockBuildContext();
-MockOAuth1 kOauth1;
+late MockOAuth1 kOauth1;
 
 void main() {
-  TwitterAuth twitterAuth;
+  late TwitterAuth twitterAuth;
 
   TestWidgetsFlutterBinding.ensureInitialized();
 
@@ -63,9 +61,10 @@ void main() {
   });
 
   test('login()', () async {
-    when(kOauth1.requestTemporaryCredentials(any)).thenAnswer((_) {
+    when(kOauth1.requestTemporaryCredentials('oob')).thenAnswer((_) {
       return Future<AuthorizationResponse>.value(
-          AuthorizationResponse(Credentials('x', 'x'), null));
+        AuthorizationResponse(Credentials('x', 'x'), {}),
+      );
     });
 
     final result = await twitterAuth.login(kMockBuildContext);
@@ -77,10 +76,10 @@ void main() {
   });
 
   group('loginComplete()', () {
-    String mockOauthToken;
-    String mockOauthVerifier;
-    String mockOauthSecret;
-    Uri mockAuthorizedResultUrl;
+    late String mockOauthToken;
+    late String mockOauthVerifier;
+    late String mockOauthSecret;
+    late Uri mockAuthorizedResultUrl;
 
     setUp(() {
       mockOauthToken = 'test-oauth-token';
@@ -92,15 +91,17 @@ void main() {
 
     test('return a [FlutterAuthResult] with [FlutterAuthStatus] success',
         () async {
-      when(kOauth1.requestTokenCredentials(any, any)).thenAnswer((_) =>
-          Future.value(AuthorizationResponse(
-              Credentials(mockOauthToken, mockOauthSecret), null)));
+      when(kOauth1.requestTokenCredentials(
+              Credentials(any.toString(), any.toString()), any.toString()))
+          .thenAnswer((_) => Future.value(AuthorizationResponse(
+              Credentials(mockOauthToken, mockOauthSecret), {})));
 
       final result = await twitterAuth.loginComplete(mockAuthorizedResultUrl);
 
-      final capturedCredentials =
-          verify(kOauth1.requestTokenCredentials(captureAny, mockOauthVerifier))
-              .captured[0] as Credentials;
+      final capturedCredentials = verify(kOauth1.requestTokenCredentials(
+              Credentials(captureAny.toString(), captureAny.toString()),
+              mockOauthVerifier))
+          .captured[0] as Credentials;
 
       expect(capturedCredentials.token, mockOauthToken);
       expect(capturedCredentials.tokenSecret, '');
@@ -112,14 +113,16 @@ void main() {
     test(
         'returns a [FlutterAuthResult] with [FlutterAuthStatus] error if [requestTokenCredentials] errors',
         () async {
-      when(kOauth1.requestTokenCredentials(any, any))
+      when(kOauth1.requestTokenCredentials(
+              Credentials(any.toString(), any.toString()), any.toString()))
           .thenAnswer((_) => new Future.error('mock error'));
 
       try {
         await twitterAuth.loginComplete(mockAuthorizedResultUrl);
       } on FlutterAuthException catch (e) {
-        final capturedCredentials = verify(
-                kOauth1.requestTokenCredentials(captureAny, mockOauthVerifier))
+        final capturedCredentials = verify(kOauth1.requestTokenCredentials(
+                Credentials(captureAny.toString(), captureAny.toString()),
+                mockOauthVerifier))
             .captured[0] as Credentials;
 
         expect(capturedCredentials.token, mockOauthToken);
@@ -143,7 +146,8 @@ void main() {
         expect(e.code, FlutterAuthExceptionCode.login);
         expect(e.message, 'oauth token is null');
 
-        verifyNever(kOauth1.requestTokenCredentials(any, any));
+        verifyNever(kOauth1.requestTokenCredentials(
+            Credentials(any.toString(), any.toString()), any.toString()));
       } catch (_) {}
     });
   });
@@ -152,8 +156,16 @@ void main() {
 class MockBuildContext extends Mock implements BuildContext {}
 
 class MockOAuth1 extends Mock implements oauth1.Authorization {
+  Platform _platform = Platform(
+      'https://api.twitter.com/oauth/request_token',
+      'https://api.twitter.com/oauth/authorize',
+      'https://api.twitter.com/oauth/access_token',
+      SignatureMethods.hmacSha1);
   MockOAuth1() {
-    Authorization(ClientCredentials(kClientId, kClientSecret), null);
+    Authorization(
+      ClientCredentials(kClientId, kClientSecret),
+      _platform
+    );
   }
 }