replace no-op log reader with real implementation (#31526)

packages/flutter_tools/lib/src/desktop.dart

@@ -2,9 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:async';
+
 import 'base/io.dart';
 import 'base/platform.dart';
 import 'base/process_manager.dart';
+import 'convert.dart';
+import 'device.dart';
 import 'version.dart';
 
 // Only launch or display desktop embedding devices if
@@ -47,3 +51,21 @@ Future<bool> killProcess(String executable) async {
   }
   return succeeded;
 }
+
+class DesktopLogReader extends DeviceLogReader {
+  final StreamController<String> _inputController = StreamController<String>.broadcast();
+
+  void initializeProcess(Process process) {
+    _inputController.addStream(process.stdout
+      .transform(utf8.decoder)
+      .transform(const LineSplitter()));
+  }
+
+  @override
+  Stream<String> get logLines {
+    return _inputController.stream;
+  }
+
+  @override
+  String get name => 'desktop';
+}

packages/flutter_tools/lib/src/linux/linux_device.dart

@@ -8,7 +8,6 @@ import '../base/os.dart';
 import '../base/platform.dart';
 import '../base/process_manager.dart';
 import '../build_info.dart';
-import '../convert.dart';
 import '../desktop.dart';
 import '../device.dart';
 import '../globals.dart';
@@ -26,7 +25,10 @@ class LinuxDevice extends Device {
   void clearLogs() { }
 
   @override
-  DeviceLogReader getLogReader({ ApplicationPackage app }) => NoOpDeviceLogReader('linux');
+  DeviceLogReader getLogReader({ ApplicationPackage app }) {
+    return _logReader;
+  }
+  final DesktopLogReader _logReader = DesktopLogReader();
 
   // Since the host and target devices are the same, no work needs to be done
   // to install the application.
@@ -79,8 +81,8 @@ class LinuxDevice extends Device {
     if (debuggingOptions?.buildInfo?.isRelease == true) {
       return LaunchResult.succeeded();
     }
-    final LinuxLogReader logReader = LinuxLogReader(package, process);
-    final ProtocolDiscovery observatoryDiscovery = ProtocolDiscovery.observatory(logReader);
+    _logReader.initializeProcess(process);
+    final ProtocolDiscovery observatoryDiscovery = ProtocolDiscovery.observatory(_logReader);
     try {
       final Uri observatoryUri = await observatoryDiscovery.uri;
       return LaunchResult.succeeded(observatoryUri: observatoryUri);
@@ -129,18 +131,3 @@ class LinuxDevices extends PollingDeviceDiscovery {
   @override
   Future<List<String>> getDiagnostics() async => const <String>[];
 }
-
-class LinuxLogReader extends DeviceLogReader {
-  LinuxLogReader(this.linuxApp, this.process);
-
-  final LinuxApp linuxApp;
-  final Process process;
-
-  @override
-  Stream<String> get logLines {
-    return process.stdout.transform(utf8.decoder);
-  }
-
-  @override
-  String get name => linuxApp.displayName;
-}

packages/flutter_tools/lib/src/macos/macos_device.dart

@@ -9,7 +9,6 @@ import '../base/platform.dart';
 import '../base/process_manager.dart';
 import '../build_info.dart';
 import '../cache.dart';
-import '../convert.dart';
 import '../desktop.dart';
 import '../device.dart';
 import '../globals.dart';
@@ -27,7 +26,10 @@ class MacOSDevice extends Device {
   void clearLogs() { }
 
   @override
-  DeviceLogReader getLogReader({ ApplicationPackage app }) => NoOpDeviceLogReader('macos');
+  DeviceLogReader getLogReader({ ApplicationPackage app }) {
+    return _deviceLogReader;
+  }
+  final DesktopLogReader _deviceLogReader = DesktopLogReader();
 
   // Since the host and target devices are the same, no work needs to be done
   // to install the application.
@@ -83,8 +85,8 @@ class MacOSDevice extends Device {
     if (debuggingOptions?.buildInfo?.isRelease == true) {
       return LaunchResult.succeeded();
     }
-    final MacOSLogReader logReader = MacOSLogReader(package, process);
-    final ProtocolDiscovery observatoryDiscovery = ProtocolDiscovery.observatory(logReader);
+    _deviceLogReader.initializeProcess(process);
+    final ProtocolDiscovery observatoryDiscovery = ProtocolDiscovery.observatory(_deviceLogReader);
     try {
       final Uri observatoryUri = await observatoryDiscovery.uri;
       // Bring app to foreground.
@@ -139,18 +141,3 @@ class MacOSDevices extends PollingDeviceDiscovery {
   @override
   Future<List<String>> getDiagnostics() async => const <String>[];
 }
-
-class MacOSLogReader extends DeviceLogReader {
-  MacOSLogReader(this.macOSApp, this.process);
-
-  final MacOSApp macOSApp;
-  final Process process;
-
-  @override
-  Stream<String> get logLines {
-    return process.stdout.transform(utf8.decoder);
-  }
-
-  @override
-  String get name => macOSApp.displayName;
-}

packages/flutter_tools/lib/src/windows/windows_device.dart

@@ -10,7 +10,7 @@ import '../base/os.dart';
 import '../base/platform.dart';
 import '../base/process_manager.dart';
 import '../build_info.dart';
-import '../convert.dart';
+import '../desktop.dart';
 import '../device.dart';
 import '../globals.dart';
 import '../project.dart';
@@ -27,7 +27,10 @@ class WindowsDevice extends Device {
   void clearLogs() { }
 
   @override
-  DeviceLogReader getLogReader({ ApplicationPackage app }) => NoOpDeviceLogReader('windows');
+  DeviceLogReader getLogReader({ ApplicationPackage app }) {
+    return _logReader;
+  }
+  final DesktopLogReader _logReader = DesktopLogReader();
 
   // Since the host and target devices are the same, no work needs to be done
   // to install the application.
@@ -80,8 +83,8 @@ class WindowsDevice extends Device {
     if (debuggingOptions?.buildInfo?.isRelease == true) {
       return LaunchResult.succeeded();
     }
-    final WindowsLogReader logReader = WindowsLogReader(package, process);
-    final ProtocolDiscovery observatoryDiscovery = ProtocolDiscovery.observatory(logReader);
+    _logReader.initializeProcess(process);
+    final ProtocolDiscovery observatoryDiscovery = ProtocolDiscovery.observatory(_logReader);
     try {
       final Uri observatoryUri = await observatoryDiscovery.uri;
       return LaunchResult.succeeded(observatoryUri: observatoryUri);
@@ -162,18 +165,3 @@ List<String> runningProcess(String processName) {
   }
   return null;
 }
-
-class WindowsLogReader extends DeviceLogReader {
-  WindowsLogReader(this.windowsApp, this.process);
-
-  final WindowsApp windowsApp;
-  final Process process;
-
-  @override
-  Stream<String> get logLines {
-    return process.stdout.transform(utf8.decoder);
-  }
-
-  @override
-  String get name => windowsApp.displayName;
-}