Add an e2e (host-independent) test demo to testing_app (#515)

testing_app/test/perf_test_e2e.dart

@@ -0,0 +1,87 @@
+// Copyright 2020 The Flutter team. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This file duplicates the behavior of test_driver/perf_test.dart, but uses
+// the e2e package to implement a host-independent test.
+
+import 'dart:convert' show JsonEncoder;
+
+import 'package:e2e/e2e.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:testing_app/main.dart' as app;
+
+import 'e2e_utils.dart';
+
+void main() {
+  final binding =
+      E2EWidgetsFlutterBinding.ensureInitialized() as E2EWidgetsFlutterBinding;
+  // The fullyLive frame policy simulates the way Flutter response to animations.
+  // See https://github.com/flutter/flutter/issues/60237
+  binding.framePolicy = LiveTestWidgetsFlutterBindingFramePolicy.fullyLive;
+
+  group('Testing App Performance Tests on e2e', () {
+    testWidgets('Scrolling test', (tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+      await watchPerformance(binding, () async {
+        final listFinder = find.byType(ListView);
+        final scroller = tester.widget<ListView>(listFinder).controller;
+        await scroller.animateTo(
+          7000,
+          duration: const Duration(seconds: 1),
+          curve: Curves.linear,
+        );
+        await tester.pumpAndSettle();
+
+        await scroller.animateTo(
+          -7000,
+          duration: const Duration(seconds: 1),
+          curve: Curves.linear,
+        );
+        await tester.pumpAndSettle();
+      }, reportKey: 'scrolling');
+      // The performance result is reported to `data['scrolling']`.
+      // See `e2e_test.dart` for detail.
+      print('scrolling performance test result:');
+      print(JsonEncoder.withIndent('  ')
+          .convert(binding.reportData['scrolling']));
+    }, semanticsEnabled: false);
+
+    testWidgets('Favorites operations test', (tester) async {
+      app.main();
+      await tester.pumpAndSettle();
+      await watchPerformance(binding, () async {
+        final iconKeys = [
+          'icon_0',
+          'icon_1',
+          'icon_2',
+        ];
+        for (var icon in iconKeys) {
+          await tester.tap(find.byKey(ValueKey<String>(icon)));
+          await tester.pumpAndSettle();
+        }
+
+        await tester.tap(find.text('Favorites'));
+        await tester.pumpAndSettle();
+
+        final removeIconKeys = [
+          'remove_icon_0',
+          'remove_icon_1',
+          'remove_icon_2',
+        ];
+
+        for (final iconKey in removeIconKeys) {
+          await tester.tap(find.byKey(ValueKey<String>(iconKey)));
+          await tester.pumpAndSettle();
+        }
+      }, reportKey: 'favorites_operations');
+      // The performance result is reported to `data['favorites_operations']`.
+      // See `e2e_test.dart` for detail.
+      print('favorites_operations performance test result:');
+      print(JsonEncoder.withIndent('  ')
+          .convert(binding.reportData['favorites_operations']));
+    }, semanticsEnabled: false);
+  });
+}