clean-up

Author: goderbauer

tictactoe/lib/src/concurrent_game_engine.dart

@@ -6,33 +6,32 @@ import 'package:async/async.dart';
 import 'game_engine.dart';
 
 class ConcurrentGameEngine implements GameEngine {
-  final ReceivePort _receivePort = ReceivePort();
-  late final StreamQueue<Object?> _receiveQueue = StreamQueue<Object?>(
-    _receivePort,
-  );
-  SendPort? _sendPort;
   Isolate? _isolate;
+  SendPort? _sendPort;
+
+  final ReceivePort _receivePort = ReceivePort();
+  late final StreamQueue _receiveQueue = StreamQueue(_receivePort);
 
   @override
   Future<UiState> start() async {
     if (_isolate == null) {
       _isolate = await Isolate.spawn(_isolateEntryPoint, _receivePort.sendPort);
-      _sendPort = await _receiveQueue.next as SendPort;
+      _sendPort = await _receiveQueue.next;
     }
     _sendPort!.send('start');
-    return (await _receiveQueue.next) as UiState;
+    return await _receiveQueue.next;
   }
 
   @override
   Future<UiState> reportMove(int row, int col) async {
     _sendPort!.send([row, col]);
-    return (await _receiveQueue.next) as UiState;
+    return await _receiveQueue.next;
   }
 
   @override
   Future<UiState> makeMove() async {
     _sendPort!.send('makeMove');
-    return (await _receiveQueue.next) as UiState;
+    return await _receiveQueue.next;
   }
 
   @override
@@ -45,22 +44,18 @@ class ConcurrentGameEngine implements GameEngine {
 }
 
 void _isolateEntryPoint(SendPort sendPort) {
-  final ReceivePort receivePort = ReceivePort();
+  final receivePort = ReceivePort();
   sendPort.send(receivePort.sendPort);
 
-  final GameEngine engine = GameEngine();
+  final  engine = GameEngine();
 
   receivePort.listen((Object? message) async {
-    final UiState uiState;
     if (message == 'start') {
-      uiState = await engine.start();
+      sendPort.send(await engine.start());
     } else if (message == 'makeMove') {
-      uiState = await engine.makeMove();
+      sendPort.send(await engine.makeMove());
     } else if (message is List<int> && message.length == 2) {
-      uiState = await engine.reportMove(message.first, message.last);
-    } else {
-      throw Exception('Invalid message sent to isolate: $message');
+      sendPort.send(await engine.reportMove(message.first, message.last));
     }
-    sendPort.send(uiState);
   });
 }