Null safety migration (#48)

Co-authored-by: German Saprykin <german.saprykin@it-nomads.com>

example/chat_app/ios/Flutter/Debug.xcconfig

@@ -1 +1,2 @@
+#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
 #include "Generated.xcconfig"

example/chat_app/ios/Flutter/Release.xcconfig

@@ -1 +1,2 @@
+#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "Generated.xcconfig"

example/chat_app/lib/chat.dart

@@ -8,7 +8,7 @@ import 'state.dart' as state;
 
 class _ChatPageState extends State<ChatPage> {
   final _msgs = <ChatMessage>[];
-  StreamSubscription<ChatMessage> _sub;
+  late StreamSubscription<ChatMessage> _sub;
 
   @override
   void initState() {

example/chat_app/lib/client/client.dart

@@ -3,20 +3,21 @@ import 'dart:convert';
 
 import 'package:centrifuge/centrifuge.dart';
 import 'package:dash_chat/dash_chat.dart';
-import 'package:fluttertoast/fluttertoast.dart';
 import 'package:flutter/material.dart';
+import 'package:fluttertoast/fluttertoast.dart';
 
 import '../conf.dart' as conf;
 import '../state.dart' as state;
 
 class ChatClient {
-  Client _client;
+  late Client _client;
 
-  StreamSubscription<ConnectEvent> _connSub;
-  StreamSubscription<DisconnectEvent> _disconnSub;
-  StreamSubscription<MessageEvent> _msgSub;
+  StreamSubscription<ConnectEvent>? _connSub;
+  StreamSubscription<DisconnectEvent>? _disconnSub;
 
-  Subscription subscription;
+  late StreamSubscription<MessageEvent> _msgSub;
+
+  late Subscription? subscription;
   final _chatMsgController = StreamController<ChatMessage>();
 
   Stream<ChatMessage> get messages => _chatMsgController.stream;
@@ -56,7 +57,7 @@ class ChatClient {
 
   void subscribe(String channel) {
     print("Subscribing to channel $channel");
-    subscription = _client.getSubscription(channel);
+    final subscription = _client.getSubscription(channel);
     subscription.publishStream
         .map<String>((e) => utf8.decode(e.data))
         .listen((data) {
@@ -78,11 +79,13 @@ class ChatClient {
     subscription.subscribeErrorStream.listen(print);
     subscription.unsubscribeStream.listen(print);
     subscription.subscribe();
+
+    this.subscription = subscription;
   }
 
   void dispose() {
-    _connSub.cancel();
-    _disconnSub.cancel();
+    _connSub?.cancel();
+    _disconnSub?.cancel();
     _msgSub.cancel();
     _chatMsgController.close();
   }
@@ -92,7 +95,7 @@ class ChatClient {
     print("Sending msg : $output");
     final data = utf8.encode(output);
     try {
-      await subscription.publish(data);
+      await subscription?.publish(data);
     } catch (e) {
       rethrow;
     }

example/chat_app/lib/state.dart

@@ -1 +1 @@
-String username;
+String username = 'A User';

example/chat_app/lib/widgets/login.dart

@@ -12,7 +12,7 @@ class _LoginFormState extends State<LoginForm> {
       const Text("Choose a username", textScaleFactor: 1.8),
       const Padding(padding: EdgeInsets.only(top: 35.0)),
       Row(mainAxisAlignment: MainAxisAlignment.center, children: <Widget>[
-        Icon(Icons.person),
+        const Icon(Icons.person),
         const Padding(padding: EdgeInsets.only(right: 10.0)),
         Container(
             width: 250.0,
@@ -24,20 +24,22 @@ class _LoginFormState extends State<LoginForm> {
             )),
       ]),
       const Padding(padding: EdgeInsets.only(top: 35.0)),
-      OutlineButton(
-          child: const Text("Login"),
-          onPressed: () {
-            state.username = _controller.text;
-            widget.onLoggedIn();
-          },
-          shape:
-              RoundedRectangleBorder(borderRadius: BorderRadius.circular(30.0)))
+      ElevatedButton(
+        child: const Text("Login"),
+        onPressed: () {
+          state.username = _controller.text;
+          widget.onLoggedIn();
+        },
+        style: ButtonStyle(
+            shape: MaterialStateProperty.all(RoundedRectangleBorder(
+                borderRadius: BorderRadius.circular(30.0)))),
+      )
     ]);
   }
 }
 
 class LoginForm extends StatefulWidget {
-  const LoginForm({@required this.onLoggedIn});
+  const LoginForm({required this.onLoggedIn});
 
   final VoidCallback onLoggedIn;
 

example/chat_app/pubspec.yaml

@@ -8,23 +8,22 @@ publish_to: "none" # Remove this line if you wish to publish to pub.dev
 version: 0.1.0
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: ">=2.12.0 <3.0.0"
 
 dependencies:
+  centrifuge:
+    path: ../../
+  dash_chat: ^1.1.15-nullsafety
+  extra_pedantic: ^1.1.1+3
   flutter:
     sdk: flutter
+  fluttertoast: ^8.0.6
   pedantic: ^1.8.0
-  extra_pedantic: ^1.1.1+3
   responsive_builder: ^0.1.5
-  dash_chat: ^1.0.18
-  corsac_jwt: ^0.2.1
-  fluttertoast: ^4.0.0
-  centrifuge:
-    path: ../../
 
-  # The following adds the Cupertino Icons font to your application.
-  # Use with the CupertinoIcons class for iOS style icons.
-  cupertino_icons: ^0.1.3
+dependency_overrides:
+  dash_chat:
+    git: git@github.com:fayeed/dash_chat.git
 
 dev_dependencies:
   flutter_test:

example/flutter_app/lib/main.dart

@@ -21,7 +21,7 @@ class MyApp extends StatelessWidget {
 }
 
 class MyHomePage extends StatefulWidget {
-  MyHomePage({Key key, this.title}) : super(key: key);
+  MyHomePage({Key? key, required this.title}) : super(key: key);
 
   final String title;
 
@@ -30,9 +30,9 @@ class MyHomePage extends StatefulWidget {
 }
 
 class _MyHomePageState extends State<MyHomePage> {
-  centrifuge.Client _centrifuge;
-  centrifuge.Subscription _subscription;
-  ScrollController _controller;
+  late centrifuge.Client _centrifuge;
+  late centrifuge.Subscription _subscription;
+  late ScrollController _controller;
 
   final _items = <_ChatItem>[];
 
@@ -151,7 +151,7 @@ class _MyHomePageState extends State<MyHomePage> {
 }
 
 class _ChatItem {
-  _ChatItem({this.title, this.subtitle});
+  _ChatItem({required this.title, required this.subtitle});
 
   final String title;
   final String subtitle;

example/flutter_app/pubspec.yaml

@@ -2,7 +2,7 @@ name: centrifuge_app
 description: A new Flutter project.
 
 environment:
- sdk: '>=2.0.0  <3.0.0'
+ sdk: '>=2.12.0  <3.0.0'
 
 dependencies:
   flutter:
@@ -17,7 +17,6 @@ dev_dependencies:
   flutter_test:
     sdk: flutter
 
-
 # For information on the generic Dart part of this file, see the
 # following page: https://www.dartlang.org/tools/pub/pubspec
 

lib/src/client.dart

@@ -10,7 +10,7 @@ import 'proto/client.pb.dart';
 import 'subscription.dart';
 import 'transport.dart';
 
-Client createClient(String url, {ClientConfig config}) => ClientImpl(
+Client createClient(String url, {ClientConfig? config}) => ClientImpl(
       url,
       config ?? ClientConfig(),
       protobufTransportBuilder,
@@ -79,15 +79,15 @@ class ClientImpl implements Client, GeneratedMessageSender {
   final TransportBuilder _transportBuilder;
   final _subscriptions = <String, SubscriptionImpl>{};
 
-  Transport _transport;
-  String _token;
+  late Transport _transport;
+  String? _token;
 
   final String _url;
   ClientConfig _config;
 
-  ClientConfig get config => _config;
-  List<int> _connectData;
-  String _clientID;
+  ClientConfig? get config => _config;
+  List<int>? _connectData;
+  String? _clientID;
 
   final _connectController = StreamController<ConnectEvent>.broadcast();
   final _disconnectController = StreamController<DisconnectEvent>.broadcast();
@@ -152,7 +152,7 @@ class ClientImpl implements Client, GeneratedMessageSender {
   @override
   Subscription getSubscription(String channel) {
     if (hasSubscription(channel)) {
-      return _subscriptions[channel];
+      return _subscriptions[channel]!;
     }
 
     final subscription = SubscriptionImpl(channel, this);
@@ -164,11 +164,9 @@ class ClientImpl implements Client, GeneratedMessageSender {
 
   @override
   Future<void> removeSubscription(Subscription subscription) async {
-    if (subscription != null) {
-      final String channel = subscription.channel;
-      subscription.unsubscribe();
-      _subscriptions.remove(channel);
-    }
+    final String channel = subscription.channel;
+    subscription.unsubscribe();
+    _subscriptions.remove(channel);
   }
 
   Future<UnsubscribeEvent> unsubscribe(String channel) async {
@@ -185,7 +183,8 @@ class ClientImpl implements Client, GeneratedMessageSender {
 
   int _retryCount = 0;
 
-  void _processDisconnect({@required String reason, bool reconnect}) async {
+  void _processDisconnect(
+      {required String reason, required bool reconnect}) async {
     if (_state == _ClientState.disconnected) {
       return;
     }
@@ -227,11 +226,11 @@ class ClientImpl implements Client, GeneratedMessageSender {
 
       final request = ConnectRequest();
       if (_token != null) {
-        request.token = _token;
+        request.token = _token!;
       }
 
       if (_connectData != null) {
-        request.data = _connectData;
+        request.data = _connectData!;
       }
 
       final result = await _transport.sendMessage(
@@ -294,9 +293,9 @@ class ClientImpl implements Client, GeneratedMessageSender {
     }
   }
 
-  Future<String> getToken(String channel) async {
-    if (_isPrivateChannel(channel)) {
-      final event = PrivateSubEvent(_clientID, channel);
+  Future<String?> getToken(String channel) async {
+    if (_clientID != null && _isPrivateChannel(channel)) {
+      final event = PrivateSubEvent(_clientID!, channel);
       return _onPrivateSub(event);
     }
     return null;

lib/src/client_config.dart

@@ -14,7 +14,7 @@ class ClientConfig {
       this.privateChannelPrefix = "\$",
       this.pingInterval = const Duration(seconds: 25),
       this.onPrivateSub = _defaultPrivateSubCallback,
-      WaitRetry retry})
+      WaitRetry? retry})
       : retry = retry ?? _defaultRetry(maxReconnectDelay.inSeconds);
 
   final Duration timeout;
@@ -27,10 +27,10 @@ class ClientConfig {
   final String privateChannelPrefix;
   final Duration pingInterval;
   final PrivateSubCallback onPrivateSub;
-  final Future Function(int) retry;
+  final Future? Function(int) retry;
 }
 
-typedef WaitRetry = Future Function(int);
+typedef WaitRetry = Future? Function(int);
 
 typedef PrivateSubCallback = Future<String> Function(PrivateSubEvent);
 

lib/src/error.dart

@@ -3,7 +3,7 @@ class Error {
   final String message;
 
   /// Custom error code.
-  Error.custom(this.code, [this.message]);
+  Error.custom(this.code, this.message);
 
   @override
   String toString() {

lib/src/subscription.dart

@@ -1,7 +1,5 @@
 import 'dart:async';
 
-import 'package:meta/meta.dart';
-
 import 'client.dart';
 import 'error.dart' as errors;
 import 'events.dart';
@@ -137,7 +135,7 @@ class SubscriptionImpl implements Subscription {
   void addUnsubscribe(UnsubscribeEvent event) =>
       _unsubscribeController.add(event);
 
-  Future _resubscribe({@required bool isResubscribed}) async {
+  Future _resubscribe({required bool isResubscribed}) async {
     try {
       final token = await _client.getToken(channel);
       final request = SubscribeRequest()