Add:创建 flutter go web 版

packages/flutter_web/test/widgets/async_lifecycle_test.dart

@@ -0,0 +1,68 @@
+// Copyright 2018 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_web/widgets.dart';
+import 'package:flutter_web_test/flutter_web_test.dart';
+
+class InvalidOnInitLifecycleWidget extends StatefulWidget {
+  const InvalidOnInitLifecycleWidget({Key key}) : super(key: key);
+
+  @override
+  InvalidOnInitLifecycleWidgetState createState() =>
+      InvalidOnInitLifecycleWidgetState();
+}
+
+class InvalidOnInitLifecycleWidgetState
+    extends State<InvalidOnInitLifecycleWidget> {
+  @override
+  Future<void> initState() async {
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Container();
+  }
+}
+
+class InvalidDidUpdateWidgetLifecycleWidget extends StatefulWidget {
+  const InvalidDidUpdateWidgetLifecycleWidget({Key key, this.id})
+      : super(key: key);
+
+  final int id;
+
+  @override
+  InvalidDidUpdateWidgetLifecycleWidgetState createState() =>
+      InvalidDidUpdateWidgetLifecycleWidgetState();
+}
+
+class InvalidDidUpdateWidgetLifecycleWidgetState
+    extends State<InvalidDidUpdateWidgetLifecycleWidget> {
+  @override
+  Future<void> didUpdateWidget(
+      InvalidDidUpdateWidgetLifecycleWidget oldWidget) async {
+    super.didUpdateWidget(oldWidget);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Container();
+  }
+}
+
+void main() {
+  testWidgets('async onInit throws FlutterError', (WidgetTester tester) async {
+    await tester.pumpWidget(const InvalidOnInitLifecycleWidget());
+
+    expect(tester.takeException(), isFlutterError);
+  });
+
+  testWidgets('async didUpdateWidget throws FlutterError',
+      (WidgetTester tester) async {
+    await tester.pumpWidget(const InvalidDidUpdateWidgetLifecycleWidget(id: 1));
+    await tester.pumpWidget(const InvalidDidUpdateWidgetLifecycleWidget(id: 2));
+
+    expect(tester.takeException(), isFlutterError);
+  });
+}