migrate code to null safety

Author: matehat

lib/src/_stream_router.dart

@@ -35,7 +35,7 @@ class _StreamRouter<T> {
   }
 
   final Stream<T> _incoming;
-  StreamSubscription<T> _subscription;
+  late StreamSubscription<T> _subscription;
 
   final List<_Route<T>> _routes = <_Route<T>>[];
   final StreamController<T> _defaultController =
@@ -44,7 +44,7 @@ class _StreamRouter<T> {
   /// Events that match [predicate] are sent to the stream created by this
   /// method, and not sent to any other router streams.
   Stream<T> route(_Predicate<T> predicate) {
-    _Route route;
+    _Route<T>? route;
     final controller = StreamController<T>.broadcast(onCancel: () {
       _routes.remove(route);
     });
@@ -62,8 +62,7 @@ class _StreamRouter<T> {
   }
 
   void _handle(T event) {
-    final route =
-        _routes.firstWhere((r) => r.predicate(event), orElse: () => null);
+    final route = _routes.firstWhereOrNull((r) => r.predicate(event));
     ((route != null) ? route.controller : _defaultController).add(event);
   }
 }

lib/src/channel.dart

@@ -43,11 +43,12 @@ class PhoenixChannel {
   /// Build a PhoenixChannel from a [PhoenixSocket].
   PhoenixChannel.fromSocket(
     this.socket, {
-    this.topic,
-    this.parameters = const {},
-    Duration timeout,
+    required this.topic,
+    Map<String, dynamic>? parameters,
+    Duration? timeout,
   })  : _controller = StreamController.broadcast(),
         _waiters = {},
+        parameters = parameters ?? {},
         _timeout = timeout ?? socket.defaultTimeout {
     _joinPush = _prepareJoin();
     _logger = Logger('phoenix_socket.channel.$loggerName');
@@ -62,7 +63,7 @@ class PhoenixChannel {
   /// The [PhoenixSocket] through which this channel is established.
   final PhoenixSocket socket;
 
-  final StreamController<Message> _controller;
+  final StreamController<Message > _controller;
   final Map<PhoenixChannelEvent, Completer<Message>> _waiters;
   final List<StreamSubscription> _subscriptions = [];
 
@@ -71,11 +72,11 @@ class PhoenixChannel {
 
   Duration _timeout;
   PhoenixChannelState _state = PhoenixChannelState.closed;
-  Timer _rejoinTimer;
+  Timer? _rejoinTimer;
   bool _joinedOnce = false;
-  String _reference;
-  Push _joinPush;
-  Logger _logger;
+  String? _reference;
+  late Push _joinPush;
+  late Logger _logger;
 
   /// A list of push to be sent out once the channel is joined.
   final List<Push> pushBuffer = [];
@@ -93,7 +94,7 @@ class PhoenixChannel {
   bool get canPush =>
       socket.isConnected && _state == PhoenixChannelState.joined;
 
-  String _loggerName;
+  String? _loggerName;
 
   /// The name of the logger associated to this channel.
   String get loggerName => _loggerName ??= topic.replaceAll(
@@ -103,10 +104,7 @@ class PhoenixChannel {
       '_');
 
   /// This channel's unique numeric reference.
-  String get reference {
-    _reference ??= socket.nextRef;
-    return _reference;
-  }
+  String get reference => _reference ??= socket.nextRef;
 
   /// Returns a future that will complete (or throw) when the provided
   /// reply arrives (or throws).
@@ -143,7 +141,7 @@ class PhoenixChannel {
       sub.cancel();
     }
 
-    _joinPush?.cancelTimeout();
+    _joinPush.cancelTimeout();
 
     _controller.close();
     _waiters.clear();
@@ -161,26 +159,32 @@ class PhoenixChannel {
   void triggerError(PhoenixException error) {
     _logger.fine('Receiving error on channel', error);
     if (!statesIgnoringErrors.contains(_state)) {
-      trigger(error.message);
+      if (error.message != null) {
+        trigger(error.message!);
+      }
+
       _logger.warning('Got error on channel', error);
+
       for (final waiter in _waiters.values) {
         waiter.completeError(error);
       }
       _waiters.clear();
+
       final prevState = _state;
       _state = PhoenixChannelState.errored;
       if (prevState == PhoenixChannelState.joining) {
         _joinPush.reset();
       }
+
       if (socket.isConnected) {
         _startRejoinTimer();
       }
     }
   }
 
   /// Leave this channel.
-  Push leave({Duration timeout}) {
-    _joinPush?.cancelTimeout();
+  Push leave({Duration? timeout}) {
+    _joinPush.cancelTimeout();
     _rejoinTimer?.cancel();
 
     final prevState = _state;
@@ -210,9 +214,10 @@ class PhoenixChannel {
   }
 
   /// Join this channel using the associated [PhoenixSocket].
-  Push join([Duration newTimeout]) {
+  Push join([Duration? newTimeout]) {
     assert(!_joinedOnce);
-    if (newTimeout is Duration) {
+
+    if (newTimeout != null) {
       _timeout = newTimeout;
     }
 
@@ -238,7 +243,7 @@ class PhoenixChannel {
     /// Manually set timeout value for this push.
     ///
     /// If not provided, the default timeout will be used.
-    Duration newTimeout,
+    Duration? newTimeout,
   ]) =>
       pushEvent(
         PhoenixChannelEvent.custom(eventName),
@@ -253,7 +258,7 @@ class PhoenixChannel {
   Push pushEvent(
     PhoenixChannelEvent event,
     Map<String, dynamic> payload, [
-    Duration newTimeout,
+    Duration? newTimeout,
   ]) {
     assert(_joinedOnce);
 
@@ -290,7 +295,7 @@ class PhoenixChannel {
     ];
   }
 
-  Push _prepareJoin([Duration providedTimeout]) {
+  Push _prepareJoin([Duration? providedTimeout]) {
     final push = Push(
       this,
       event: PhoenixChannelEvent.join,
@@ -381,11 +386,12 @@ class PhoenixChannel {
       _controller.add(message.asReplyEvent());
     }
 
-    if (_waiters.containsKey(message.event)) {
+    final waiter = _waiters[message.event];
+    if (waiter != null) {
       _logger.finer(
         () => 'Notifying waiter for ${message.event}',
       );
-      _waiters[message.event].complete(message);
+      waiter.complete(message);
     } else {
       _logger.finer(() => 'No waiter to notify for ${message.event}');
     }

lib/src/events.dart

@@ -18,10 +18,10 @@ class PhoenixSocketCloseEvent extends PhoenixSocketEvent {
   });
 
   /// The reason the socket was closed.
-  final String reason;
+  final String? reason;
 
   /// The code of the socket close.
-  final int code;
+  final int? code;
 }
 
 /// Error event for a [PhoenixSocket].
@@ -99,11 +99,8 @@ class PhoenixChannelEvent extends Equatable {
   /// The constant heartbeat event
   static PhoenixChannelEvent heartbeat = PhoenixChannelEvent._('heartbeat');
 
-  static Set<PhoenixChannelEvent> _statuses;
-
   /// The constant set of possible internal channel event names.
-  static Set<PhoenixChannelEvent> get statuses =>
-      _statuses ??= {close, error, join, reply, leave};
+  static Set<PhoenixChannelEvent> statuses = {close, error, join, reply, leave};
 
   /// Whether the event name is an 'reply' event
   bool get isReply => value.startsWith(__chanReplyEventName);

lib/src/exceptions.dart

@@ -13,28 +13,28 @@ class PhoenixException implements Exception {
   });
 
   /// The associated error event.
-  final PhoenixSocketErrorEvent socketError;
+  final PhoenixSocketErrorEvent? socketError;
 
   /// The associated close event.
-  final PhoenixSocketCloseEvent socketClosed;
+  final PhoenixSocketCloseEvent? socketClosed;
 
   /// The associated channel event.
-  final String channelEvent;
+  final String? channelEvent;
 
   /// The error message for this exception.
-  Message get message {
-    if (socketClosed is PhoenixSocketCloseEvent) {
+  Message? get message {
+    if (socketClosed != null) {
       return Message(event: PhoenixChannelEvent.error);
-    } else if (socketError is PhoenixSocketErrorEvent) {
+    } else if (socketError != null) {
       return Message(event: PhoenixChannelEvent.error);
     }
     return null;
   }
 
   @override
   String toString() {
-    if (socketError is PhoenixSocketErrorEvent) {
-      return socketError.error.toString();
+    if (socketError != null) {
+      return socketError!.error.toString();
     } else {
       return 'PhoenixException: socket closed';
     }

lib/src/message.dart

@@ -50,32 +50,32 @@ class Message implements Equatable {
     this.joinRef,
     this.ref,
     this.topic,
-    this.event,
+    required this.event,
     this.payload,
   }) : assert(event is PhoenixChannelEvent);
 
   /// Reference of the channel on which the message is received.
   ///
   /// Used by the [PhoenixSocket] to route the message on the proper
   /// [PhoenixChannel].
-  final String joinRef;
+  final String? joinRef;
 
   /// The unique identifier for this message.
   ///
   /// This identifier is used in the reply event name, allowing us
   /// to consider a message as a reply to a previous message.
-  final String ref;
+  final String? ref;
 
   /// The topic of the channel on which this message is sent.
-  final String topic;
+  final String? topic;
 
   /// The event name of this message.
   final PhoenixChannelEvent event;
 
   /// The payload of this message.
   ///
   /// This needs to be a JSON-encodable object.
-  final Map<String, dynamic> payload;
+  final Map<String, dynamic>? payload;
 
   /// Encode a message to a JSON-encodable list of values.
   Object encode() {
@@ -91,7 +91,7 @@ class Message implements Equatable {
   }
 
   @override
-  List<Object> get props => [joinRef, ref, topic, event, payload];
+  List<Object?> get props => [joinRef, ref, topic, event, payload];
 
   @override
   bool get stringify => true;
@@ -105,7 +105,7 @@ class Message implements Equatable {
     return Message(
       ref: ref,
       payload: payload,
-      event: PhoenixChannelEvent.replyFor(ref),
+      event: PhoenixChannelEvent.replyFor(ref!),
       topic: topic,
       joinRef: joinRef,
     );

lib/src/message_serializer.dart

@@ -9,7 +9,7 @@ class MessageSerializer {
   /// Default constructor returning the singleton instance of this class.
   factory MessageSerializer() => _instance ??= MessageSerializer._();
 
-  static MessageSerializer _instance;
+  static MessageSerializer? _instance;
 
   /// Yield a [Message] from some raw string arriving from a websocket.
   Message decode(String rawData) {