[flutter_tools] enable LocalDevFSWriter for desktop devices, iOS simulator (#66678)

* [flutter_tools] enable LocalDevFSWriter for desktop devices, iOS simulator

* Update device.dart

* Update desktop_device_test.dart

* fix analysis errors

packages/flutter_tools/lib/src/desktop_device.dart

@@ -47,8 +47,10 @@ abstract class DesktopDevice extends Device {
   final Set<Process> _runningProcesses = <Process>{};
   final DesktopLogReader _deviceLogReader = DesktopLogReader();
 
-  DevFSWriter get devFSWriter => _desktopDevFSWriter ??= LocalDevFSWriter(fileSystem: _fileSystem);
-  LocalDevFSWriter _desktopDevFSWriter;
+  @override
+  DevFSWriter createDevFSWriter(covariant ApplicationPackage app, String userIdentifier) {
+    return LocalDevFSWriter(fileSystem: _fileSystem);
+  }
 
   // Since the host and target devices are the same, no work needs to be done
   // to install the application.

packages/flutter_tools/lib/src/device.dart

@@ -27,6 +27,7 @@ import 'base/terminal.dart';
 import 'base/user_messages.dart' hide userMessages;
 import 'base/utils.dart';
 import 'build_info.dart';
+import 'devfs.dart';
 import 'features.dart';
 import 'fuchsia/fuchsia_device.dart';
 import 'fuchsia/fuchsia_sdk.dart';
@@ -622,6 +623,18 @@ abstract class Device {
 
   Future<String> get sdkNameAndVersion;
 
+  /// Create a platform-specific [DevFSWriter] for the given [app], or
+  /// null if the device does not support them.
+  ///
+  /// For example, the destkop device classes can use a writer which
+  /// copies the files across the local file system.
+  DevFSWriter createDevFSWriter(
+    covariant ApplicationPackage app,
+    String userIdentifier,
+  ) {
+    return null;
+  }
+
   /// Get a log reader for this device.
   ///
   /// If `app` is specified, this will return a log reader specific to that

packages/flutter_tools/lib/src/ios/simulators.dart

@@ -296,8 +296,10 @@ class IOSSimulator extends Device {
   final SimControl _simControl;
   final Xcode _xcode;
 
-  DevFSWriter get devFSWriter => _desktopDevFSWriter ??= LocalDevFSWriter(fileSystem: globals.fs);
-  LocalDevFSWriter _desktopDevFSWriter;
+  @override
+  DevFSWriter createDevFSWriter(covariant ApplicationPackage app, String userIdentifier) {
+    return LocalDevFSWriter(fileSystem: globals.fs);
+  }
 
   @override
   Future<bool> get isLocalEmulator async => true;

packages/flutter_tools/lib/src/resident_runner.dart

@@ -185,6 +185,8 @@ class FlutterDevice {
   final ResidentCompiler generator;
   final BuildInfo buildInfo;
   final String userIdentifier;
+
+  DevFSWriter devFSWriter;
   Stream<Uri> observatoryUris;
   vm_service.VmService vmService;
   DevFS devFS;
@@ -573,6 +575,7 @@ class FlutterDevice {
       globals.printError(message);
       return 1;
     }
+    devFSWriter = device.createDevFSWriter(package, userIdentifier);
 
     final Map<String, dynamic> platformArgs = <String, dynamic>{};
 
@@ -620,6 +623,7 @@ class FlutterDevice {
       buildInfo: coldRunner.debuggingOptions.buildInfo,
       applicationBinary: coldRunner.applicationBinary,
     );
+    devFSWriter = device.createDevFSWriter(package, userIdentifier);
 
     final String modeName = coldRunner.debuggingOptions.buildInfo.friendlyModeName;
     final bool prebuiltMode = coldRunner.applicationBinary != null;
@@ -715,7 +719,7 @@ class FlutterDevice {
         pathToReload: pathToReload,
         invalidatedFiles: invalidatedFiles,
         packageConfig: packageConfig,
-        devFSWriter: null,
+        devFSWriter: devFSWriter,
       );
     } on DevFSException {
       devFSStatus.cancel();

packages/flutter_tools/test/general.shard/desktop_device_test.dart

@@ -11,6 +11,7 @@ import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/os.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/desktop_device.dart';
+import 'package:flutter_tools/src/devfs.dart';
 import 'package:flutter_tools/src/device.dart';
 import 'package:flutter_tools/src/project.dart';
 
@@ -242,6 +243,12 @@ void main() {
     expect(result, 2);
     expect(portForwarder.forwardedPorts.isEmpty, true);
   });
+
+  testUsingContext('createDevFSWriter returns a LocalDevFSWriter', () {
+    final FakeDesktopDevice device = setUpDesktopDevice();
+
+    expect(device.createDevFSWriter(null, ''), isA<LocalDevFSWriter>());
+  });
 }
 
 FakeDesktopDevice setUpDesktopDevice({

packages/flutter_tools/test/general.shard/ios/simulators_test.dart

@@ -13,6 +13,7 @@ import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/platform.dart';
 import 'package:flutter_tools/src/build_info.dart';
 import 'package:flutter_tools/src/build_system/build_system.dart';
+import 'package:flutter_tools/src/devfs.dart';
 import 'package:flutter_tools/src/device.dart';
 import 'package:flutter_tools/src/globals.dart' as globals;
 import 'package:flutter_tools/src/ios/mac.dart';
@@ -1000,6 +1001,16 @@ flutter:
       FileSystem: () => MemoryFileSystem.test(),
       ProcessManager: () => FakeProcessManager.any(),
     });
+
+    testUsingContext('createDevFSWriter returns a LocalDevFSWriter', () {
+      final IOSSimulator simulator = IOSSimulator(
+        'test',
+        simControl: mockSimControl,
+        xcode: mockXcode,
+      );
+
+      expect(simulator.createDevFSWriter(null, ''), isA<LocalDevFSWriter>());
+    });
   });
 }