Exit the tool if a DevTools subprocess fails when running on a bot (#97613)

packages/flutter_tools/lib/executable.dart

@@ -112,6 +112,7 @@ Future<void> main(List<String> args) async {
         processManager: globals.processManager,
         dartExecutable: globals.artifacts.getHostArtifact(HostArtifact.engineDartBinary).path,
         logger: globals.logger,
+        botDetector: globals.botDetector,
       ),
       Logger: () {
         final LoggerFactory loggerFactory = LoggerFactory(

packages/flutter_tools/lib/src/context_runner.dart

@@ -218,6 +218,7 @@ Future<T> runInContext<T>(
         processManager: globals.processManager,
         dartExecutable: globals.artifacts.getHostArtifact(HostArtifact.engineDartBinary).path,
         logger: globals.logger,
+        botDetector: globals.botDetector,
       ),
       Doctor: () => Doctor(logger: globals.logger),
       DoctorValidatorsProvider: () => DoctorValidatorsProvider.defaultInstance,

packages/flutter_tools/lib/src/devtools_launcher.dart

@@ -9,6 +9,8 @@ import 'dart:async';
 import 'package:meta/meta.dart';
 import 'package:process/process.dart';
 
+import 'base/bot_detector.dart';
+import 'base/common.dart';
 import 'base/io.dart' as io;
 import 'base/logger.dart';
 import 'convert.dart';
@@ -21,16 +23,22 @@ class DevtoolsServerLauncher extends DevtoolsLauncher {
     @required ProcessManager processManager,
     @required String dartExecutable,
     @required Logger logger,
+    @required BotDetector botDetector,
   })  : _processManager = processManager,
         _dartExecutable = dartExecutable,
-        _logger = logger;
+        _logger = logger,
+        _botDetector = botDetector;
 
   final ProcessManager _processManager;
   final String _dartExecutable;
   final Logger _logger;
+  final BotDetector _botDetector;
   final Completer<void> _processStartCompleter = Completer<void>();
 
   io.Process _devToolsProcess;
+  bool _devToolsProcessKilled = false;
+  @visibleForTesting
+  Future<void> devToolsProcessExit;
 
   static final RegExp _serveDevToolsPattern =
       RegExp(r'Serving DevTools at ((http|//)[a-zA-Z0-9:/=_\-\.\[\]]+?)\.?$');
@@ -66,6 +74,16 @@ class DevtoolsServerLauncher extends DevtoolsLauncher {
           .transform(utf8.decoder)
           .transform(const LineSplitter())
           .listen(_logger.printError);
+
+      final bool runningOnBot = await _botDetector.isRunningOnBot;
+      devToolsProcessExit = _devToolsProcess.exitCode.then(
+        (int exitCode) {
+          if (!_devToolsProcessKilled && runningOnBot) {
+            throwToolExit('DevTools process failed: exitCode=$exitCode');
+          }
+        }
+      );
+
       devToolsUrl = await completer.future;
     } on Exception catch (e, st) {
       _logger.printError('Failed to launch DevTools: $e', stackTrace: st);
@@ -86,8 +104,8 @@ class DevtoolsServerLauncher extends DevtoolsLauncher {
       devToolsUrl = null;
     }
     if (_devToolsProcess != null) {
+      _devToolsProcessKilled = true;
       _devToolsProcess.kill();
-      await _devToolsProcess.exitCode;
     }
   }
 }

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

@@ -14,6 +14,7 @@ import 'package:flutter_tools/src/resident_runner.dart';
 
 import '../src/common.dart';
 import '../src/fake_process_manager.dart';
+import '../src/fakes.dart';
 
 void main() {
   BufferLogger logger;
@@ -29,6 +30,7 @@ void main() {
     final DevtoolsLauncher launcher = DevtoolsServerLauncher(
       dartExecutable: 'dart',
       logger: logger,
+      botDetector: const FakeBotDetector(false),
       processManager: FakeProcessManager.list(<FakeCommand>[
         FakeCommand(
           command: const <String>[
@@ -52,6 +54,7 @@ void main() {
     final DevtoolsLauncher launcher = DevtoolsServerLauncher(
       dartExecutable: 'dart',
       logger: logger,
+      botDetector: const FakeBotDetector(false),
       processManager: FakeProcessManager.list(<FakeCommand>[
         FakeCommand(
           command: const <String>[
@@ -91,6 +94,7 @@ void main() {
     final DevtoolsLauncher launcher = DevtoolsServerLauncher(
       dartExecutable: 'dart',
       logger: logger,
+      botDetector: const FakeBotDetector(false),
       processManager: processManager,
     );
 
@@ -104,6 +108,7 @@ void main() {
     final DevtoolsLauncher launcher = DevtoolsServerLauncher(
       dartExecutable: 'dart',
       logger: logger,
+      botDetector: const FakeBotDetector(false),
       processManager: FakeProcessManager.list(<FakeCommand>[
         const FakeCommand(
           command: <String>[
@@ -121,4 +126,29 @@ void main() {
 
     expect(logger.errorText, contains('Failed to launch DevTools: ProcessException'));
   });
+
+  testWithoutContext('DevtoolsLauncher handles failure of DevTools process on a bot', () async {
+    final Completer<void> completer = Completer<void>();
+    final DevtoolsServerLauncher launcher = DevtoolsServerLauncher(
+      dartExecutable: 'dart',
+      logger: logger,
+      botDetector: const FakeBotDetector(true),
+      processManager: FakeProcessManager.list(<FakeCommand>[
+        FakeCommand(
+          command: const <String>[
+            'dart',
+            'devtools',
+            '--no-launch-browser',
+          ],
+          stdout: 'Serving DevTools at http://127.0.0.1:9100\n',
+          completer: completer,
+          exitCode: 255,
+        ),
+      ]),
+    );
+
+    await launcher.launch(null);
+    completer.complete();
+    expect(launcher.devToolsProcessExit, throwsToolExit());
+  });
 }

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

@@ -20,6 +20,7 @@ import 'package:vm_service/vm_service.dart' as vm_service;
 import '../src/common.dart';
 import '../src/fake_process_manager.dart';
 import '../src/fake_vm_services.dart';
+import '../src/fakes.dart';
 
 final vm_service.Isolate isolate = vm_service.Isolate(
   id: '1',
@@ -106,6 +107,7 @@ void main() {
       processManager: FakeProcessManager.empty(),
       dartExecutable: 'dart',
       logger: BufferLogger.test(),
+      botDetector: const FakeBotDetector(false),
     );
     final ResidentDevtoolsHandler handler = FlutterResidentDevtoolsHandler(
       // Uses real devtools instance which should be a no-op if