[web] Fix multi-reply on message channel. Add test

.cirrus.yml

@@ -172,6 +172,7 @@ task:
         - $FRAMEWORK_PATH/flutter/bin/flutter config --local-engine=host_debug_unopt --no-analytics --enable-web
         - $FRAMEWORK_PATH/flutter/bin/flutter pub get --local-engine=host_debug_unopt
         - $FRAMEWORK_PATH/flutter/bin/flutter drive -v --target=test_driver/text_editing_e2e.dart -d web-server --release --browser-name=chrome --local-engine=host_debug_unopt
+        - $FRAMEWORK_PATH/flutter/bin/flutter drive -v --target=test_driver/platform_messages_e2e.dart -d web-server --release --browser-name=chrome --local-engine=host_debug_unopt
         - $FRAMEWORK_PATH/flutter/bin/flutter drive -v --target=test_driver/treeshaking_e2e.dart -d web-server --profile --browser-name=chrome --local-engine=host_debug_unopt
         - $FRAMEWORK_PATH/flutter/bin/flutter drive -v --target=test_driver/image_loading_e2e.dart -d web-server --release --browser-name=chrome --local-engine=host_debug_unopt
 

e2etests/web/regular_integration_tests/lib/platform_messages_main.dart

@@ -0,0 +1,64 @@
+// Copyright 2013 The Flutter 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/material.dart';
+import 'package:flutter/services.dart';
+
+void main() => runApp(MyApp());
+
+Future<ClipboardData> dataFuture;
+
+class MyApp extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+      key: const Key('mainapp'),
+      title: 'Integration Test App For Platform Messages',
+      home: MyHomePage(title: 'Integration Test App For Platform Messages'),
+    );
+  }
+}
+
+class MyHomePage extends StatefulWidget {
+  MyHomePage({Key key, this.title}) : super(key: key);
+
+  final String title;
+
+  @override
+  _MyHomePageState createState() => _MyHomePageState();
+}
+
+class _MyHomePageState extends State<MyHomePage> {
+  final TextEditingController _controller =
+  TextEditingController(text: 'Text1');
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(widget.title),
+      ),
+      body: Center(
+        child: Column(
+          mainAxisAlignment: MainAxisAlignment.center,
+          children: <Widget>[
+              const Text('Hello World',
+            ),
+            // Create a text form field since we can't test clipboard unless
+            // html document has focus.
+            TextFormField(
+              key: const Key('input'),
+              enabled: true,
+              controller: _controller,
+              //initialValue: 'Text1',
+              decoration: const InputDecoration(
+                labelText: 'Text Input Field:',
+              ),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

e2etests/web/regular_integration_tests/test_driver/platform_messages_e2e.dart

@@ -0,0 +1,59 @@
+// Copyright 2013 The Flutter 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 'dart:html' as html;
+// ignore: undefined_shown_name
+import 'dart:ui' as ui show platformViewRegistry;
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:regular_integration_tests/platform_messages_main.dart' as app;
+
+import 'package:e2e/e2e.dart';
+
+void main() async {
+  E2EWidgetsFlutterBinding.ensureInitialized() as E2EWidgetsFlutterBinding;
+
+  testWidgets('platform message for Clipboard.setData reply with future',
+      (WidgetTester tester) async {
+    app.main();
+    await tester.pumpAndSettle();
+
+    // TODO(nurhan): https://github.com/flutter/flutter/issues/51885
+    SystemChannels.textInput.setMockMethodCallHandler(null);
+    // Focus on a TextFormField.
+    final Finder finder = find.byKey(const Key('input'));
+    expect(finder, findsOneWidget);
+    await tester.tap(find.byKey(const Key('input')));
+    // Focus in input, otherwise clipboard will fail with
+    // 'document is not focused' platform exception.
+    html.document.querySelector('input').focus();
+    await Clipboard.setData(const ClipboardData(text: 'sample text'));
+  }, skip: true); // https://github.com/flutter/flutter/issues/54296
+
+  testWidgets('Should create and dispose view embedder',
+      (WidgetTester tester) async {
+    int viewInstanceCount = 0;
+
+    final int currentViewId = platformViewsRegistry.getNextPlatformViewId();
+    // ignore: undefined_prefixed_name
+    ui.platformViewRegistry.registerViewFactory('MyView', (int viewId) {
+      ++viewInstanceCount;
+      return html.DivElement();
+    });
+
+    app.main();
+    await tester.pumpAndSettle();
+    final Map<String, dynamic> createArgs = <String, dynamic>{
+      'id': '567',
+      'viewType': 'MyView',
+    };
+    await SystemChannels.platform_views.invokeMethod<void>('create', createArgs);
+    final Map<String, dynamic> disposeArgs = <String, dynamic>{
+      'id': '567',
+    };
+    await SystemChannels.platform_views.invokeMethod<void>('dispose', disposeArgs);
+    expect(viewInstanceCount, 1);
+  });
+}

e2etests/web/regular_integration_tests/test_driver/platform_messages_e2e_test.dart

@@ -0,0 +1,7 @@
+// Copyright 2013 The Flutter 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:e2e/e2e_driver.dart' as e2e;
+
+Future<void> main() async => e2e.main();

lib/web_ui/lib/src/engine/clipboard.dart

@@ -18,6 +18,7 @@ class ClipboardMessageHandler {
   void setDataMethodCall(
       MethodCall methodCall, ui.PlatformMessageResponseCallback callback) {
     const MethodCodec codec = JSONMethodCodec();
+    bool errorEnvelopeEncoded = false;
     _copyToClipboardStrategy
         .setData(methodCall.arguments['text'])
         .then((bool success) {
@@ -26,10 +27,15 @@ class ClipboardMessageHandler {
       } else {
         callback(codec.encodeErrorEnvelope(
             code: 'copy_fail', message: 'Clipboard.setData failed'));
+        errorEnvelopeEncoded = true;
       }
     }).catchError((dynamic _) {
-      callback(codec.encodeErrorEnvelope(
-          code: 'copy_fail', message: 'Clipboard.setData failed'));
+      // Don't encode a duplicate reply if we already failed and an error
+      // was already encoded.
+      if (!errorEnvelopeEncoded) {
+        callback(codec.encodeErrorEnvelope(
+            code: 'copy_fail', message: 'Clipboard.setData failed'));
+      }
     });
   }
 

lib/web_ui/lib/src/engine/compositor/embedded_views.dart

@@ -69,11 +69,9 @@ class HtmlViewEmbedder {
     switch (decoded.method) {
       case 'create':
         _create(decoded, callback);
-        window._replyToPlatformMessage(callback, codec.encodeSuccessEnvelope(true));
         return;
       case 'dispose':
         _dispose(decoded, callback);
-        window._replyToPlatformMessage(callback, codec.encodeSuccessEnvelope(true));
         return;
     }
     callback(null);

lib/web_ui/lib/src/engine/platform_views.dart

@@ -50,11 +50,9 @@ void handlePlatformViewCall(
   switch (decoded.method) {
     case 'create':
       _createPlatformView(decoded, callback);
-      window._replyToPlatformMessage(callback, codec.encodeSuccessEnvelope(true));
       return;
     case 'dispose':
       _disposePlatformView(decoded, callback);
-      window._replyToPlatformMessage(callback, codec.encodeSuccessEnvelope(true));
       return;
   }
   callback(null);