add waitUntilNoTransientCallbacks to driver API (#8475)

dev/bots/test.dart

@@ -75,7 +75,7 @@ Future<Null> main() async {
     await _runFlutterTest(p.join(flutterRoot, 'packages', 'flutter'),
       options: coverageFlags,
     );
-    await _runAllDartTests(p.join(flutterRoot, 'packages', 'flutter_driver'));
+    await _runFlutterTest(p.join(flutterRoot, 'packages', 'flutter_driver'));
     await _runFlutterTest(p.join(flutterRoot, 'packages', 'flutter_test'));
     await _runFlutterTest(p.join(flutterRoot, 'packages', 'flutter_markdown'));
     await _runAllDartTests(p.join(flutterRoot, 'packages', 'flutter_tools'),

packages/flutter_driver/lib/src/driver.dart

@@ -339,6 +339,15 @@ class FlutterDriver {
     return null;
   }
 
+  /// Waits until there are no more transient callbacks in the queue.
+  ///
+  /// Use this method when you need to wait for the moment when the application
+  /// becomes "stable", for example, prior to taking a [screenshot].
+  Future<Null> waitUntilNoTransientCallbacks({Duration timeout}) async {
+    await _sendCommand(new WaitUntilNoTransientCallbacks(timeout: timeout));
+    return null;
+  }
+
   /// Tell the driver to perform a scrolling action.
   ///
   /// A scrolling action begins with a "pointer down" event, which commonly maps

packages/flutter_driver/lib/src/extension.dart

@@ -4,6 +4,8 @@
 
 import 'dart:async';
 
+import 'package:meta/meta.dart';
+
 import 'package:flutter/gestures.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/rendering.dart' show RendererBinding;
@@ -27,7 +29,7 @@ class _DriverBinding extends WidgetsFlutterBinding { // TODO(ianh): refactor so
   @override
   void initServiceExtensions() {
     super.initServiceExtensions();
-    _FlutterDriverExtension extension = new _FlutterDriverExtension._();
+    FlutterDriverExtension extension = new FlutterDriverExtension();
     registerServiceExtension(
       name: _extensionMethodName,
       callback: extension.call
@@ -57,10 +59,11 @@ typedef Command CommandDeserializerCallback(Map<String, String> params);
 /// Runs the finder and returns the [Element] found, or `null`.
 typedef Finder FinderConstructor(SerializableFinder finder);
 
-class _FlutterDriverExtension {
+@visibleForTesting
+class FlutterDriverExtension {
   static final Logger _log = new Logger('FlutterDriverExtension');
 
-  _FlutterDriverExtension._() {
+  FlutterDriverExtension() {
     _commandHandlers.addAll(<String, CommandHandlerCallback>{
       'get_health': _getHealth,
       'get_render_tree': _getRenderTree,
@@ -72,6 +75,7 @@ class _FlutterDriverExtension {
       'setInputText': _setInputText,
       'submitInputText': _submitInputText,
       'waitFor': _waitFor,
+      'waitUntilNoTransientCallbacks': _waitUntilNoTransientCallbacks,
     });
 
     _commandDeserializers.addAll(<String, CommandDeserializerCallback>{
@@ -85,6 +89,7 @@ class _FlutterDriverExtension {
       'setInputText': (Map<String, String> params) => new SetInputText.deserialize(params),
       'submitInputText': (Map<String, String> params) => new SubmitInputText.deserialize(params),
       'waitFor': (Map<String, String> params) => new WaitFor.deserialize(params),
+      'waitUntilNoTransientCallbacks': (Map<String, String> params) => new WaitUntilNoTransientCallbacks.deserialize(params),
     });
 
     _finders.addAll(<String, FinderConstructor>{
@@ -123,7 +128,7 @@ class _FlutterDriverExtension {
         throw 'Extension $_extensionMethod does not support command $commandKind';
       Command command = commandDeserializer(params);
       Result response = await commandHandler(command).timeout(command.timeout);
-      return _makeResponse(response.toJson());
+      return _makeResponse(response?.toJson());
     } on TimeoutException catch (error, stackTrace) {
       String msg = 'Timeout while executing $commandKind: $error\n$stackTrace';
       _log.error(msg);
@@ -221,6 +226,11 @@ class _FlutterDriverExtension {
       return null;
   }
 
+  Future<Null> _waitUntilNoTransientCallbacks(Command command) async {
+    if (SchedulerBinding.instance.transientCallbackCount != 0)
+      await _waitUntilFrame(() => SchedulerBinding.instance.transientCallbackCount == 0);
+  }
+
   Future<ScrollResult> _scroll(Command command) async {
     Scroll scrollCommand = command;
     Finder target = await _waitForElement(_createFinder(scrollCommand.finder));

packages/flutter_driver/lib/src/find.dart

@@ -62,6 +62,18 @@ class WaitFor extends CommandWithTarget {
   WaitFor.deserialize(Map<String, String> json) : super.deserialize(json);
 }
 
+/// Waits until there are no more transient callbacks in the queue.
+class WaitUntilNoTransientCallbacks extends Command {
+  @override
+  final String kind = 'waitUntilNoTransientCallbacks';
+
+  WaitUntilNoTransientCallbacks({Duration timeout}) : super(timeout: timeout);
+
+  /// Deserializes the command from JSON generated by [serialize].
+  WaitUntilNoTransientCallbacks.deserialize(Map<String, String> json)
+      : super.deserialize(json);
+}
+
 /// The result of a [WaitFor] command.
 class WaitForResult extends Result {
   /// Deserializes the result from JSON.

packages/flutter_driver/pubspec.yaml

@@ -11,6 +11,7 @@ dependencies:
   file: 2.3.0
   json_rpc_2: '^2.0.0'
   matcher: '>=0.12.0 <1.0.0'
+  meta: ^1.0.4
   path: '^1.4.0'
   web_socket_channel: '^1.0.0'
   vm_service_client: '0.2.2+4'

packages/flutter_driver/test/all.dart

-// Copyright (c) 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-import 'flutter_driver_test.dart' as flutter_driver_test;
-import 'src/retry_test.dart' as retry_test;
-import 'src/timeline_summary_test.dart' as timeline_summary_test;
-import 'src/timeline_test.dart' as timeline_test;
-
-void main() {
-  flutter_driver_test.main();
-  retry_test.main();
-  timeline_summary_test.main();
-  timeline_test.main();
-}

packages/flutter_driver/test/flutter_driver_test.dart

@@ -9,7 +9,7 @@ import 'package:flutter_driver/src/error.dart';
 import 'package:flutter_driver/src/health.dart';
 import 'package:flutter_driver/src/timeline.dart';
 import 'package:json_rpc_2/json_rpc_2.dart' as rpc;
-import 'package:mockito/mockito.dart';
+import 'package:mockito/mockito_no_mirrors.dart';
 import 'package:test/test.dart';
 import 'package:vm_service_client/vm_service_client.dart';
 
@@ -199,6 +199,19 @@ void main() {
       });
     });
 
+    group('waitUntilNoTransientCallbacks', () {
+      test('sends the waitUntilNoTransientCallbacks command', () async {
+        when(mockIsolate.invokeExtension(any, any)).thenAnswer((Invocation i) {
+          expect(i.positionalArguments[1], <String, dynamic>{
+            'command': 'waitUntilNoTransientCallbacks',
+            'timeout': '1000',
+          });
+          return makeMockResponse(<String, dynamic>{});
+        });
+        await driver.waitUntilNoTransientCallbacks(timeout: const Duration(seconds: 1));
+      });
+    });
+
     group('traceAction', () {
       test('traces action', () async {
         bool actionCalled = false;

packages/flutter_driver/test/src/extension_test.dart

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter/scheduler.dart';
+import 'package:flutter_driver/src/extension.dart';
+import 'package:flutter_driver/src/find.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('waitUntilNoTransientCallbacks', () {
+    FlutterDriverExtension extension;
+    Map<String, dynamic> result;
+
+    setUp(() {
+      result = null;
+      extension = new FlutterDriverExtension();
+    });
+
+    testWidgets('returns immediately when transient callback queue is empty', (WidgetTester tester) async {
+      extension.call(new WaitUntilNoTransientCallbacks().serialize())
+          .then<Null>(expectAsync1((Map<String, dynamic> r) {
+        result = r;
+      }));
+
+      await tester.idle();
+      expect(
+          result,
+          <String, dynamic>{
+            'isError': false,
+            'response': null,
+          },
+      );
+    });
+
+    testWidgets('waits until no transient callbacks', (WidgetTester tester) async {
+      SchedulerBinding.instance.scheduleFrameCallback((_) {
+        // Intentionally blank. We only care about existence of a callback.
+      });
+
+      extension.call(new WaitUntilNoTransientCallbacks().serialize())
+          .then<Null>(expectAsync1((Map<String, dynamic> r) {
+        result = r;
+      }));
+
+      // Nothing should happen until the next frame.
+      await tester.idle();
+      expect(result, isNull);
+
+      // NOW we should receive the result.
+      await tester.pump();
+      expect(
+          result,
+          <String, dynamic>{
+            'isError': false,
+            'response': null,
+          },
+      );
+    });
+  });
+}

packages/flutter_tools/test/drive_test.dart

@@ -11,7 +11,7 @@ import 'package:flutter_tools/src/base/platform.dart';
 import 'package:flutter_tools/src/commands/drive.dart';
 import 'package:flutter_tools/src/device.dart';
 import 'package:flutter_tools/src/ios/simulators.dart';
-import 'package:mockito/mockito.dart';
+import 'package:mockito/mockito_no_mirrors.dart';
 import 'package:test/test.dart';
 
 import 'src/common.dart';

packages/flutter_tools/test/install_test.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'package:flutter_tools/src/commands/install.dart';
-import 'package:mockito/mockito.dart';
+import 'package:mockito/mockito_no_mirrors.dart';
 import 'package:test/test.dart';
 
 import 'src/common.dart';

packages/flutter_tools/test/src/context.dart

@@ -20,7 +20,7 @@ import 'package:flutter_tools/src/ios/simulators.dart';
 import 'package:flutter_tools/src/run_hot.dart';
 import 'package:flutter_tools/src/usage.dart';
 
-import 'package:mockito/mockito.dart';
+import 'package:mockito/mockito_no_mirrors.dart';
 import 'package:process/process.dart';
 import 'package:test/test.dart';
 

packages/flutter_tools/test/src/ios/devices_test.dart

@@ -7,7 +7,7 @@ import 'package:file/file.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/ios/devices.dart';
 
-import 'package:mockito/mockito.dart';
+import 'package:mockito/mockito_no_mirrors.dart';
 import 'package:process/process.dart';
 import 'package:test/test.dart';
 

packages/flutter_tools/test/src/ios/ios_workflow_test.dart

@@ -6,7 +6,7 @@ import 'package:flutter_tools/src/doctor.dart';
 import 'package:flutter_tools/src/ios/ios_workflow.dart';
 import 'package:flutter_tools/src/ios/mac.dart';
 
-import 'package:mockito/mockito.dart';
+import 'package:mockito/mockito_no_mirrors.dart';
 import 'package:test/test.dart';
 
 import '../context.dart';

packages/flutter_tools/test/src/ios/simulators_test.dart

@@ -4,7 +4,7 @@ import 'package:file/file.dart';
 import 'package:flutter_tools/src/base/file_system.dart';
 import 'package:flutter_tools/src/ios/mac.dart';
 import 'package:flutter_tools/src/ios/simulators.dart';
-import 'package:mockito/mockito.dart';
+import 'package:mockito/mockito_no_mirrors.dart';
 import 'package:process/process.dart';
 import 'package:test/test.dart';
 

packages/flutter_tools/test/src/mocks.dart

@@ -12,7 +12,7 @@ import 'package:flutter_tools/src/device.dart';
 import 'package:flutter_tools/src/ios/devices.dart';
 import 'package:flutter_tools/src/ios/simulators.dart';
 import 'package:flutter_tools/src/runner/flutter_command.dart';
-import 'package:mockito/mockito.dart';
+import 'package:mockito/mockito_no_mirrors.dart';
 import 'package:test/test.dart';
 
 class MockApplicationPackageStore extends ApplicationPackageStore {

packages/flutter_tools/test/stop_test.dart

@@ -5,7 +5,7 @@
 import 'dart:async';
 
 import 'package:flutter_tools/src/commands/stop.dart';
-import 'package:mockito/mockito.dart';
+import 'package:mockito/mockito_no_mirrors.dart';
 import 'package:test/test.dart';
 
 import 'src/common.dart';