flutter/examples/flutter_gallery/test_driver/scroll_perf_web_test.dart

// Copyright 2014 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:async';

import 'package:flutter_driver/flutter_driver.dart';
import 'package:test/test.dart' hide TypeMatcher, isInstanceOf;

void main() {
  group('scrolling performance test', () {
    FlutterDriver driver;

    setUpAll(() async {
      driver = await FlutterDriver.connect(browser: true);
    });

    tearDownAll(() async {
      if (driver != null)
        driver.close();
    });

    test('measure', () async {
      final Timeline timeline = await driver.traceAction(() async {
        await driver.tap(find.text('Material'));

        final SerializableFinder demoList = find.byValueKey('GalleryDemoList');

        // TODO(eseidel): These are very artificial scrolls, we should use better
        // https://github.com/flutter/flutter/issues/3316
        // Scroll down
        for (int i = 0; i < 5; i++) {
          await driver.scroll(demoList, 0.0, -300.0, const Duration(milliseconds: 300));
          await Future<void>.delayed(const Duration(milliseconds: 500));
        }

        // Scroll up
        for (int i = 0; i < 5; i++) {
          await driver.scroll(demoList, 0.0, 300.0, const Duration(milliseconds: 300));
          await Future<void>.delayed(const Duration(milliseconds: 500));
        }
      });

      TimelineSummary.summarize(timeline)
        ..writeTimelineToFile('home_scroll_perf', pretty: true);
    });
  });
}