[flutter_driver] support log communication for WebFlutterDriver (#81150)

packages/flutter_driver/lib/src/driver/driver.dart

@@ -147,7 +147,12 @@ abstract class FlutterDriver {
     Map<String, dynamic>? headers,
   }) async {
     if (Platform.environment['FLUTTER_WEB_TEST'] != null) {
-      return WebFlutterDriver.connectWeb(hostUrl: dartVmServiceUrl, timeout: timeout);
+      return WebFlutterDriver.connectWeb(
+        hostUrl: dartVmServiceUrl,
+        timeout: timeout,
+        printCommunication: printCommunication,
+        logCommunicationToFile: logCommunicationToFile,
+      );
     }
     return VMServiceFlutterDriver.connect(
       dartVmServiceUrl: dartVmServiceUrl,

packages/flutter_driver/lib/src/driver/web_driver.dart

@@ -4,15 +4,19 @@
 
 import 'dart:convert';
 import 'dart:io';
-
+import 'package:file/file.dart';
 import 'package:matcher/matcher.dart';
 import 'package:meta/meta.dart';
+
+import 'package:path/path.dart' as path;
 import 'package:vm_service/vm_service.dart' as vms;
 import 'package:webdriver/async_io.dart' as async_io;
 import 'package:webdriver/support/async.dart';
 
 import '../common/error.dart';
 import '../common/message.dart';
+
+import 'common.dart';
 import 'driver.dart';
 import 'timeline.dart';
 
@@ -24,12 +28,22 @@ import 'timeline.dart';
 class WebFlutterDriver extends FlutterDriver {
   /// Creates a driver that uses a connection provided by the given
   /// [_connection].
-  WebFlutterDriver.connectedTo(this._connection) :
-        _startTime = DateTime.now();
+  WebFlutterDriver.connectedTo(
+    this._connection, {
+    bool printCommunication = false,
+    bool logCommunicationToFile = true,
+  })  : _printCommunication = printCommunication,
+        _logCommunicationToFile = logCommunicationToFile,
+        _startTime = DateTime.now(),
+        _driverId = _nextDriverId++;
 
   final FlutterWebConnection _connection;
   DateTime _startTime;
   bool _accessibilityEnabled = false;
+  static int _nextDriverId = 0;
+
+  /// The unique ID of this driver instance.
+  final int _driverId;
 
   /// Start time for tracing.
   @visibleForTesting
@@ -44,14 +58,26 @@ class WebFlutterDriver extends FlutterDriver {
   @override
   async_io.WebDriver get webDriver => _connection._driver;
 
+  /// Whether to print communication between host and app to `stdout`.
+  final bool _printCommunication;
+
+  /// Whether to log communication between host and app to `flutter_driver_commands.log`.
+  final bool _logCommunicationToFile;
+
   /// Creates a driver that uses a connection provided by the given
   /// [hostUrl] which would fallback to environment variable VM_SERVICE_URL.
   /// Driver also depends on environment variables DRIVER_SESSION_ID,
   /// BROWSER_SUPPORTS_TIMELINE, DRIVER_SESSION_URI, DRIVER_SESSION_SPEC,
   /// DRIVER_SESSION_CAPABILITIES and ANDROID_CHROME_ON_EMULATOR for
   /// configurations.
-  static Future<FlutterDriver> connectWeb(
-      {String? hostUrl, Duration? timeout}) async {
+  ///
+  /// See [FlutterDriver.connect] for more documentation.
+  static Future<FlutterDriver> connectWeb({
+    String? hostUrl,
+    bool printCommunication = false,
+    bool logCommunicationToFile = true,
+    Duration? timeout,
+  }) async {
     hostUrl ??= Platform.environment['VM_SERVICE_URL'];
     final Map<String, dynamic> settings = <String, dynamic>{
       'support-timeline-action': Platform.environment['SUPPORT_TIMELINE_ACTION'] == 'true',
@@ -63,7 +89,11 @@ class WebFlutterDriver extends FlutterDriver {
     };
     final FlutterWebConnection connection = await FlutterWebConnection.connect
       (hostUrl!, settings, timeout: timeout);
-    return WebFlutterDriver.connectedTo(connection);
+    return WebFlutterDriver.connectedTo(
+      connection,
+      printCommunication: printCommunication,
+      logCommunicationToFile: logCommunicationToFile,
+    );
   }
 
   @override
@@ -86,9 +116,11 @@ class WebFlutterDriver extends FlutterDriver {
   Future<Map<String, dynamic>> sendCommand(Command command) async {
     Map<String, dynamic> response;
     final Map<String, String> serialized = command.serialize();
+    _logCommunication('>>> $serialized');
     try {
       final dynamic data = await _connection.sendCommand("window.\$flutterDriver('${jsonEncode(serialized)}')", command.timeout);
       response = data != null ? (json.decode(data as String) as Map<String, dynamic>?)! : <String, dynamic>{};
+      _logCommunication('<<< $response');
     } catch (error, stackTrace) {
       throw DriverError("Failed to respond to $command due to remote error\n : \$flutterDriver('${jsonEncode(serialized)}')",
           error,
@@ -108,6 +140,17 @@ class WebFlutterDriver extends FlutterDriver {
     throw UnimplementedError();
   }
 
+  void _logCommunication(String message) {
+    if (_printCommunication) {
+      driverLog('WebFlutterDriver', message);
+    }
+    if (_logCommunicationToFile) {
+      final File file = fs.file(path.join(testOutputsDirectory, 'flutter_driver_commands_$_driverId.log'));
+      file.createSync(recursive: true); // no-op if file exists
+      file.writeAsStringSync('${DateTime.now()} $message\n', mode: FileMode.append, flush: true);
+    }
+  }
+
   @override
   Future<List<int>> screenshot() async {
     await Future<void>.delayed(const Duration(seconds: 2));

packages/flutter_driver/test/src/real_tests/flutter_driver_test.dart

@@ -4,14 +4,17 @@
 
 import 'dart:async';
 import 'dart:convert';
+import 'dart:io';
 
 import 'package:fake_async/fake_async.dart';
 import 'package:flutter_driver/src/common/error.dart';
 import 'package:flutter_driver/src/common/health.dart';
 import 'package:flutter_driver/src/common/layer_tree.dart';
 import 'package:flutter_driver/src/common/wait.dart';
+import 'package:flutter_driver/src/driver/common.dart';
 import 'package:flutter_driver/src/driver/driver.dart';
 import 'package:flutter_driver/src/driver/timeline.dart';
+import 'package:path/path.dart' as path;
 import 'package:vm_service/vm_service.dart' as vms;
 
 import '../../common.dart';
@@ -24,10 +27,87 @@ const String _kWebScriptSuffix = "')";
 
 void main() {
   final List<String> log = <String>[];
+
   driverLog = (String source, String message) {
     log.add('$source: $message');
   };
 
+  group('VMServiceFlutterDriver with logCommunicationToFile', () {
+    late FakeVmService fakeClient;
+    late FakeVM fakeVM;
+    late FakeIsolate fakeIsolate;
+    late VMServiceFlutterDriver driver;
+    int driverId = -1;
+
+    setUp(() {
+      fakeIsolate = FakeIsolate();
+      fakeVM = FakeVM(fakeIsolate);
+      fakeClient = FakeVmService(fakeVM);
+      fakeClient.responses['waitFor'] = makeFakeResponse(<String, dynamic>{'status':'ok'});
+      driverId += 1;
+    });
+
+
+    group('logCommunicationToFile', () {
+      test('logCommunicationToFile = true', () async {
+        driver = VMServiceFlutterDriver.connectedTo(fakeClient, fakeIsolate);
+
+        await driver.waitFor(find.byTooltip('foo'), timeout: _kTestTimeout);
+
+        final File file = File(path.join(testOutputsDirectory, 'flutter_driver_commands_$driverId.log'));
+        final bool exists = file.existsSync();
+        expect(exists, true, reason: 'Not found ${file.path}');
+
+        final String commandLog = await file.readAsString();
+        const String waitForCommandLog = '>>> {command: waitFor, timeout: $_kSerializedTestTimeout, finderType: ByTooltipMessage, text: foo}';
+        const String responseLog = '<<< {isError: false, response: {status: ok}}';
+
+        expect(commandLog.contains(waitForCommandLog), true, reason: '$commandLog not contains $waitForCommandLog');
+        expect(commandLog.contains(responseLog), true, reason: '$commandLog not contains $responseLog');
+      });
+
+      test('logCommunicationToFile = false', () async {
+        driver = VMServiceFlutterDriver.connectedTo(fakeClient, fakeIsolate, logCommunicationToFile: false);
+
+        await driver.waitFor(find.byTooltip('foo'), timeout: _kTestTimeout);
+
+        final File file = File(path.join(testOutputsDirectory, 'flutter_driver_commands_$driverId.log'));
+        final bool exists = file.existsSync();
+        expect(exists, false, reason: 'because ${file.path} exists');
+      });
+    });
+  });
+
+  group('VMServiceFlutterDriver with printCommunication', () {
+    late FakeVmService fakeClient;
+    late FakeVM fakeVM;
+    late FakeIsolate fakeIsolate;
+    late VMServiceFlutterDriver driver;
+
+    setUp(() async {
+      log.clear();
+      fakeIsolate = FakeIsolate();
+      fakeVM = FakeVM(fakeIsolate);
+      fakeClient = FakeVmService(fakeVM);
+      fakeClient.responses['waitFor'] = makeFakeResponse(<String, dynamic>{'status':'ok'});
+    });
+
+    test('printCommunication = true', () async {
+      driver = VMServiceFlutterDriver.connectedTo(fakeClient, fakeIsolate, printCommunication: true);
+      await driver.waitFor(find.byTooltip('foo'), timeout: _kTestTimeout);
+      expect(log, <String>[
+        'VMServiceFlutterDriver: >>> {command: waitFor, timeout: $_kSerializedTestTimeout, finderType: ByTooltipMessage, text: foo}',
+        'VMServiceFlutterDriver: <<< {isError: false, response: {status: ok}}'
+      ]);
+    });
+
+    test('printCommunication = false', () async {
+      driver = VMServiceFlutterDriver.connectedTo(fakeClient, fakeIsolate, printCommunication: false);
+      await driver.waitFor(find.byTooltip('foo'), timeout: _kTestTimeout);
+      expect(log, <String>[]);
+    });
+  });
+
   group('VMServiceFlutterDriver.connect', () {
     late FakeVmService fakeClient;
     late FakeVM fakeVM;
@@ -188,8 +268,8 @@ void main() {
 
   group('VMServiceFlutterDriver', () {
     late FakeVmService fakeClient;
-    FakeVM fakeVM;
-    FakeIsolate fakeIsolate;
+    late FakeVM fakeVM;
+    late FakeIsolate fakeIsolate;
     late VMServiceFlutterDriver driver;
 
     setUp(() {
@@ -563,8 +643,8 @@ void main() {
 
   group('VMServiceFlutterDriver with custom timeout', () {
     late FakeVmService fakeClient;
-    FakeVM fakeVM;
-    FakeIsolate fakeIsolate;
+    late FakeVM fakeVM;
+    late FakeIsolate fakeIsolate;
     late VMServiceFlutterDriver driver;
 
     setUp(() {
@@ -592,6 +672,70 @@ void main() {
     });
   });
 
+  group('WebFlutterDriver with logCommunicationToFile', () {
+    late FakeFlutterWebConnection fakeConnection;
+    late WebFlutterDriver driver;
+    int driverId = -1;
+
+    setUp(() {
+      fakeConnection = FakeFlutterWebConnection();
+      fakeConnection.supportsTimelineAction = true;
+      fakeConnection.responses['waitFor'] = jsonEncode(makeFakeResponse(<String, dynamic>{'status': 'ok'}));
+      driverId += 1;
+    });
+
+    test('logCommunicationToFile = true', () async {
+      driver = WebFlutterDriver.connectedTo(fakeConnection);
+      await driver.waitFor(find.byTooltip('logCommunicationToFile test'), timeout: _kTestTimeout);
+
+      final File file = File(path.join(testOutputsDirectory, 'flutter_driver_commands_$driverId.log'));
+      final bool exists = file.existsSync();
+      expect(exists, true, reason: 'Not found ${file.path}');
+
+      final String commandLog = await file.readAsString();
+      const String waitForCommandLog = '>>> {command: waitFor, timeout: 1234, finderType: ByTooltipMessage, text: logCommunicationToFile test}';
+      const String responseLog = '<<< {isError: false, response: {status: ok}, type: Response}';
+
+      expect(commandLog.contains(waitForCommandLog), true, reason: '$commandLog not contains $waitForCommandLog');
+      expect(commandLog.contains(responseLog), true, reason: '$commandLog not contains $responseLog');
+    });
+
+    test('logCommunicationToFile = false', () async {
+      driver = WebFlutterDriver.connectedTo(fakeConnection, logCommunicationToFile: false);
+      await driver.waitFor(find.byTooltip('logCommunicationToFile test'), timeout: _kTestTimeout);
+      final File file = File(path.join(testOutputsDirectory, 'flutter_driver_commands_$driverId.log'));
+      final bool exists = file.existsSync();
+      expect(exists, false, reason: 'because ${file.path} exists');
+    });
+  });
+
+  group('WebFlutterDriver with printCommunication', () {
+    late FakeFlutterWebConnection fakeConnection;
+    late WebFlutterDriver driver;
+
+    setUp(() {
+      log.clear();
+      fakeConnection = FakeFlutterWebConnection();
+      fakeConnection.supportsTimelineAction = true;
+      fakeConnection.responses['waitFor'] = jsonEncode(makeFakeResponse(<String, dynamic>{'status': 'ok'}));
+    });
+
+    test('printCommunication = true', () async {
+      driver = WebFlutterDriver.connectedTo(fakeConnection, printCommunication: true);
+      await driver.waitFor(find.byTooltip('printCommunication test'), timeout: _kTestTimeout);
+      expect(log, <String>[
+        'WebFlutterDriver: >>> {command: waitFor, timeout: 1234, finderType: ByTooltipMessage, text: printCommunication test}',
+        'WebFlutterDriver: <<< {isError: false, response: {status: ok}, type: Response}',
+      ]);
+    });
+
+    test('printCommunication = false', () async {
+      driver = WebFlutterDriver.connectedTo(fakeConnection, printCommunication: false);
+      await driver.waitFor(find.byTooltip('printCommunication test'), timeout: _kTestTimeout);
+      expect(log, <String>[]);
+    });
+  });
+
   group('WebFlutterDriver', () {
     late FakeFlutterWebConnection fakeConnection;
     late WebFlutterDriver driver;