[flutter_tools] migrate web_device.dart to null-safety (#91632)

packages/flutter_tools/lib/src/android/android_device.dart

@@ -541,7 +541,7 @@ class AndroidDevice extends Device {
     String mainPath,
     String route,
     DebuggingOptions debuggingOptions,
-    Map<String, dynamic> platformArgs,
+    Map<String, dynamic> platformArgs = const <String, Object>{},
     bool prebuiltApplication = false,
     bool ipv6 = false,
     String userIdentifier,

packages/flutter_tools/lib/src/device.dart

@@ -468,7 +468,7 @@ abstract class Device {
   /// The ID returned matches that in the output of `flutter emulators`. Fetching
   /// this name may require connecting to the device and if an error occurs null
   /// will be returned.
-  Future<String> get emulatorId;
+  Future<String?> get emulatorId;
 
   /// Whether this device can run the provided [buildMode].
   ///
@@ -501,7 +501,7 @@ abstract class Device {
   /// Specify [userIdentifier] to install for a particular user (Android only).
   Future<bool> installApp(
     covariant ApplicationPackage app, {
-    String userIdentifier,
+    String? userIdentifier,
   });
 
   /// Uninstall an app package from the current device.
@@ -510,7 +510,7 @@ abstract class Device {
   /// defaults to all users (Android only).
   Future<bool> uninstallApp(
     covariant ApplicationPackage app, {
-    String userIdentifier,
+    String? userIdentifier,
   });
 
   /// Check if the device is supported by Flutter.
@@ -550,12 +550,12 @@ abstract class Device {
   /// reader will also include log messages from before the invocation time.
   /// Defaults to false.
   FutureOr<DeviceLogReader> getLogReader({
-    covariant ApplicationPackage app,
+    covariant ApplicationPackage? app,
     bool includePastLogs = false,
   });
 
   /// Get the port forwarder for this device.
-  DevicePortForwarder get portForwarder;
+  DevicePortForwarder? get portForwarder;
 
   /// Get the DDS instance for this device.
   final DartDevelopmentService dds = DartDevelopmentService();
@@ -572,13 +572,13 @@ abstract class Device {
   /// start call. The build mode is not used by all platforms.
   Future<LaunchResult> startApp(
     covariant ApplicationPackage package, {
-    String mainPath,
-    String route,
-    DebuggingOptions debuggingOptions,
+    String? mainPath,
+    String? route,
+    required DebuggingOptions debuggingOptions,
     Map<String, Object?> platformArgs,
     bool prebuiltApplication = false,
     bool ipv6 = false,
-    String userIdentifier,
+    String? userIdentifier,
   });
 
   /// Whether this device implements support for hot reload.
@@ -603,7 +603,7 @@ abstract class Device {
   /// Specify [userIdentifier] to stop app installed to a profile (Android only).
   Future<bool> stopApp(
     covariant ApplicationPackage app, {
-    String userIdentifier,
+    String? userIdentifier,
   });
 
   /// Query the current application memory usage..
@@ -917,7 +917,7 @@ class DiscoveredApp {
 
 // An empty device log reader
 class NoOpDeviceLogReader implements DeviceLogReader {
-  NoOpDeviceLogReader(this.name);
+  NoOpDeviceLogReader(String? nameOrNull) : name = nameOrNull ?? '';
 
   @override
   final String name;

packages/flutter_tools/test/general.shard/web/devices_test.dart

@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// @dart = 2.8
+import 'dart:async';
 
 import 'package:file/memory.dart';
+import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/base/logger.dart';
 import 'package:flutter_tools/src/base/platform.dart';
 import 'package:flutter_tools/src/build_info.dart';
@@ -32,8 +33,10 @@ void main() {
   });
 
   testWithoutContext('GoogleChromeDevice defaults', () async {
+    final TestChromiumLauncher launcher = TestChromiumLauncher();
+
     final GoogleChromeDevice chromeDevice = GoogleChromeDevice(
-      chromiumLauncher: null,
+      chromiumLauncher: launcher,
       fileSystem: MemoryFileSystem.test(),
       logger: BufferLogger.test(),
       platform: FakePlatform(),
@@ -50,7 +53,7 @@ void main() {
     expect(await chromeDevice.isLocalEmulator, false);
     expect(chromeDevice.getLogReader(), isA<NoOpDeviceLogReader>());
     expect(chromeDevice.getLogReader(), isA<NoOpDeviceLogReader>());
-    expect(await chromeDevice.portForwarder.forward(1), 1);
+    expect(await chromeDevice.portForwarder!.forward(1), 1);
 
     expect(chromeDevice.supportsRuntimeMode(BuildMode.debug), true);
     expect(chromeDevice.supportsRuntimeMode(BuildMode.profile), true);
@@ -59,8 +62,10 @@ void main() {
   });
 
   testWithoutContext('MicrosoftEdge defaults', () async {
+    final TestChromiumLauncher launcher = TestChromiumLauncher();
+
     final MicrosoftEdgeDevice chromeDevice = MicrosoftEdgeDevice(
-      chromiumLauncher: null,
+      chromiumLauncher: launcher,
       fileSystem: MemoryFileSystem.test(),
       logger: BufferLogger.test(),
       processManager: FakeProcessManager.any(),
@@ -76,7 +81,7 @@ void main() {
     expect(await chromeDevice.isLocalEmulator, false);
     expect(chromeDevice.getLogReader(), isA<NoOpDeviceLogReader>());
     expect(chromeDevice.getLogReader(), isA<NoOpDeviceLogReader>());
-    expect(await chromeDevice.portForwarder.forward(1), 1);
+    expect(await chromeDevice.portForwarder!.forward(1), 1);
 
     expect(chromeDevice.supportsRuntimeMode(BuildMode.debug), true);
     expect(chromeDevice.supportsRuntimeMode(BuildMode.profile), true);
@@ -99,7 +104,7 @@ void main() {
     expect(await device.isLocalEmulator, false);
     expect(device.getLogReader(), isA<NoOpDeviceLogReader>());
     expect(device.getLogReader(), isA<NoOpDeviceLogReader>());
-    expect(await device.portForwarder.forward(1), 1);
+    expect(await device.portForwarder!.forward(1), 1);
 
     expect(device.supportsRuntimeMode(BuildMode.debug), true);
     expect(device.supportsRuntimeMode(BuildMode.profile), true);
@@ -353,3 +358,38 @@ void main() {
     expect((await macosWebDevices.pollingGetDevices()).whereType<MicrosoftEdgeDevice>(), isEmpty);
   });
 }
+
+/// A test implementation of the [ChromiumLauncher] that launches a fixed instance.
+class TestChromiumLauncher implements ChromiumLauncher {
+  TestChromiumLauncher();
+
+  bool _hasInstance = false;
+  void setInstance(Chromium chromium) {
+    _hasInstance = true;
+    currentCompleter.complete(chromium);
+  }
+
+  @override
+  Completer<Chromium> currentCompleter = Completer<Chromium>();
+
+  @override
+  bool canFindExecutable() {
+    return true;
+  }
+
+  @override
+  Future<Chromium> get connectedInstance => currentCompleter.future;
+
+  @override
+  String findExecutable() {
+    return 'chrome';
+  }
+
+  @override
+  bool get hasChromeInstance => _hasInstance;
+
+  @override
+  Future<Chromium> launch(String url, {bool headless = false, int? debugPort, bool skipCheck = false, Directory? cacheDir}) async {
+    return currentCompleter.future;
+  }
+}