[e2e] Add new e2e_driver for handling response data and performance watcher

packages/e2e/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.6.3
+
+* Add customizable `flutter_driver` adaptor.
+* Add utilities for tracking frame performance in an e2e test.
+
 ## 0.6.2+1
 
 * Fix incorrect test results when one test passes then another fails

packages/e2e/example/test_driver/example_e2e_test.dart

@@ -2,4 +2,4 @@ import 'dart:async';
 
 import 'package:e2e/e2e_driver.dart' as e2e;
 
-Future<void> main() async => e2e.main();
+Future<void> main() async => e2e.e2eDriver();

packages/e2e/lib/e2e_driver.dart

@@ -1,21 +1,89 @@
+// 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 'dart:convert';
 import 'dart:io';
 
-import 'package:e2e/common.dart' as e2e;
 import 'package:flutter_driver/flutter_driver.dart';
 
-Future<void> main() async {
+import 'package:e2e/common.dart' as e2e;
+import 'package:path/path.dart' as path;
+
+/// This method remains for backword compatibility.
+Future<void> main() => e2eDriver();
+
+/// Flutter Driver test output directory.
+///
+/// Tests should write any output files to this directory. Defaults to the path
+/// set in the FLUTTER_TEST_OUTPUTS_DIR environment variable, or `build` if
+/// unset.
+String testOutputsDirectory =
+    Platform.environment['FLUTTER_TEST_OUTPUTS_DIR'] ?? 'build';
+
+/// The callback type to handle [e2e.Response.data] after the test succcess.
+typedef ResponseDataCallback = FutureOr<void> Function(Map<String, dynamic>);
+
+/// Writes a json-serializable json data to to
+/// [testOutputsDirectory]/`testOutputFilename.json`.
+///
+/// This is the default `responseDataCallback` in [e2eDriver].
+Future<void> writeResponseData(
+  Map<String, dynamic> data, {
+  String testOutputFilename = 'e2e_perf_summary',
+}) async {
+  assert(testOutputFilename != null);
+  await fs.directory(testOutputsDirectory).create(recursive: true);
+  final File file = fs.file(path.join(
+    testOutputsDirectory,
+    '$testOutputFilename.json',
+  ));
+  final String resultString = _encodeJson(data, true);
+  await file.writeAsString(resultString);
+}
+
+/// Adaptor to run E2E test using `flutter drive`.
+///
+/// `timeout` controls the longest time waited before the test ends.
+/// It is not necessarily the execution time for the test app: the test may
+/// finish sooner than the `timeout`.
+///
+/// `responseDataCallback` is the handler for processing [e2e.Response.data].
+/// The default value is `writeResponseData`.
+///
+/// To an E2E test `<test_name>.dart` using `flutter drive`, put a file named
+/// `<test_name>_test.dart` in the app's `test_driver` directory:
+///
+/// ```dart
+/// import 'dart:async';
+///
+/// import 'package:e2e/e2e_driver.dart' as e2e;
+///
+/// Future<void> main() async => e2e.e2eDriver();
+///
+/// ```
+Future<void> e2eDriver({
+  Duration timeout = const Duration(minutes: 1),
+  ResponseDataCallback responseDataCallback = writeResponseData,
+}) async {
   final FlutterDriver driver = await FlutterDriver.connect();
-  final String jsonResult =
-      await driver.requestData(null, timeout: const Duration(minutes: 1));
+  final String jsonResult = await driver.requestData(null, timeout: timeout);
   final e2e.Response response = e2e.Response.fromJson(jsonResult);
   await driver.close();
 
   if (response.allTestsPassed) {
     print('All tests passed.');
+    await responseDataCallback(response.data);
     exit(0);
   } else {
     print('Failure Details:\n${response.formattedFailureDetails}');
     exit(1);
   }
 }
+
+const JsonEncoder _prettyEncoder = JsonEncoder.withIndent('  ');
+
+String _encodeJson(Map<String, dynamic> jsonObject, bool pretty) {
+  return pretty ? _prettyEncoder.convert(jsonObject) : json.encode(jsonObject);
+}

packages/e2e/lib/e2e_perf.dart

@@ -0,0 +1,199 @@
+// 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 'dart:ui';
+
+import 'package:flutter/scheduler.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:flutter/widgets.dart';
+
+import 'package:e2e/e2e.dart';
+
+/// The maximum amount of time considered safe to spend for a frame's build
+/// phase. Anything past that is in the danger of missing the frame as 60FPS.
+///
+/// Changing this doesn't re-evaluate existing summary.
+Duration kBuildBudget = const Duration(milliseconds: 16);
+// TODO(CareF): Automatically calculate the refresh budget (#61958)
+
+bool _firstRun = true;
+
+/// The warning message to show when a benchmark is performed with assert on.
+/// TODO(CareF) remove this and update pubspect when flutter/flutter#61509 is
+/// in released version.
+const String kDebugWarning = '''
+┏╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍┓
+┇ ⚠    THIS BENCHMARK IS BEING RUN IN DEBUG MODE     ⚠  ┇
+┡╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍╍┦
+│                                                       │
+│  Numbers obtained from a benchmark while asserts are  │
+│  enabled will not accurately reflect the performance  │
+│  that will be experienced by end users using release  ╎
+│  builds. Benchmarks should be run using this command  ╎
+│  line:  "flutter run --profile test.dart" or          ┊
+│  or "flutter drive --profile -t test.dart".           ┊
+│                                                       ┊
+└─────────────────────────────────────────────────╌┄┈  🐢
+''';
+
+/// watches the [FrameTiming] of `action` and report it to the e2e binding.
+Future<void> watchPerformance(
+  E2EWidgetsFlutterBinding binding,
+  Future<void> action(),
+) async {
+  assert(() {
+    if (_firstRun) {
+      debugPrint(kDebugWarning);
+      _firstRun = false;
+    }
+    return true;
+  }());
+  final List<FrameTiming> frameTimings = <FrameTiming>[];
+  final TimingsCallback watcher = frameTimings.addAll;
+  binding.addTimingsCallback(watcher);
+  await action();
+  binding.removeTimingsCallback(watcher);
+  // TODO(CareF): determine if it's running on firebase and report metric online
+  final FrameTimingSummarizer frameTimes = FrameTimingSummarizer(frameTimings);
+  binding.reportData = <String, dynamic>{'performance': frameTimes.summary};
+}
+
+/// This class and summarizes a list of [FrameTiming] for the performance
+/// metrics.
+class FrameTimingSummarizer {
+  /// Summarize `data` to frame build time and frame rasterizer time statistics.
+  ///
+  /// See [TimelineSummary.summaryJson] for detail.
+  factory FrameTimingSummarizer(List<FrameTiming> data) {
+    assert(data != null);
+    assert(data.isNotEmpty);
+    final List<Duration> frameBuildTime = List<Duration>.unmodifiable(
+      data.map<Duration>((FrameTiming datum) => datum.buildDuration),
+    );
+    final List<Duration> frameBuildTimeSorted =
+        List<Duration>.from(frameBuildTime)..sort();
+    final List<Duration> frameRasterizerTime = List<Duration>.unmodifiable(
+      data.map<Duration>((FrameTiming datum) => datum.rasterDuration),
+    );
+    final List<Duration> frameRasterizerTimeSorted =
+        List<Duration>.from(frameRasterizerTime)..sort();
+    final Duration Function(Duration, Duration) add =
+        (Duration a, Duration b) => a + b;
+    return FrameTimingSummarizer._(
+      frameBuildTime: frameBuildTime,
+      frameRasterizerTime: frameRasterizerTime,
+      // This avarage calculation is microsecond precision, which is fine
+      // because typical values of these times are milliseconds.
+      averageFrameBuildTime: frameBuildTime.reduce(add) ~/ data.length,
+      p90FrameBuildTime: _findPercentile(frameBuildTimeSorted, 0.90),
+      p99FrameBuildTime: _findPercentile(frameBuildTimeSorted, 0.99),
+      worstFrameBuildTime: frameBuildTimeSorted.last,
+      missedFrameBuildBudget: _countExceed(frameBuildTimeSorted, kBuildBudget),
+      averageFrameRasterizerTime:
+          frameRasterizerTime.reduce(add) ~/ data.length,
+      p90FrameRasterizerTime: _findPercentile(frameRasterizerTimeSorted, 0.90),
+      p99FrameRasterizerTime: _findPercentile(frameRasterizerTimeSorted, 0.99),
+      worstFrameRasterizerTime: frameRasterizerTimeSorted.last,
+      missedFrameRasterizerBudget:
+          _countExceed(frameRasterizerTimeSorted, kBuildBudget),
+    );
+  }
+
+  const FrameTimingSummarizer._({
+    @required this.frameBuildTime,
+    @required this.frameRasterizerTime,
+    @required this.averageFrameBuildTime,
+    @required this.p90FrameBuildTime,
+    @required this.p99FrameBuildTime,
+    @required this.worstFrameBuildTime,
+    @required this.missedFrameBuildBudget,
+    @required this.averageFrameRasterizerTime,
+    @required this.p90FrameRasterizerTime,
+    @required this.p99FrameRasterizerTime,
+    @required this.worstFrameRasterizerTime,
+    @required this.missedFrameRasterizerBudget,
+  });
+
+  /// List of frame build time in microseconds
+  final List<Duration> frameBuildTime;
+
+  /// List of frame rasterizer time in microseconds
+  final List<Duration> frameRasterizerTime;
+
+  /// The average value of [frameBuildTime] in milliseconds.
+  final Duration averageFrameBuildTime;
+
+  /// The 90-th percentile value of [frameBuildTime] in milliseconds
+  final Duration p90FrameBuildTime;
+
+  /// The 99-th percentile value of [frameBuildTime] in milliseconds
+  final Duration p99FrameBuildTime;
+
+  /// The largest value of [frameBuildTime] in milliseconds
+  final Duration worstFrameBuildTime;
+
+  /// Number of items in [frameBuildTime] that's greater than [kBuildBudget]
+  final int missedFrameBuildBudget;
+
+  /// The average value of [frameRasterizerTime] in milliseconds.
+  final Duration averageFrameRasterizerTime;
+
+  /// The 90-th percentile value of [frameRasterizerTime] in milliseconds.
+  final Duration p90FrameRasterizerTime;
+
+  /// The 99-th percentile value of [frameRasterizerTime] in milliseconds.
+  final Duration p99FrameRasterizerTime;
+
+  /// The largest value of [frameRasterizerTime] in milliseconds.
+  final Duration worstFrameRasterizerTime;
+
+  /// Number of items in [frameRasterizerTime] that's greater than [kBuildBudget]
+  final int missedFrameRasterizerBudget;
+
+  /// Convert the summary result to a json object.
+  ///
+  /// See [TimelineSummary.summaryJson] for detail.
+  Map<String, dynamic> get summary => <String, dynamic>{
+        'average_frame_build_time_millis':
+            averageFrameBuildTime.inMicroseconds / 1E3,
+        '90th_percentile_frame_build_time_millis':
+            p90FrameBuildTime.inMicroseconds / 1E3,
+        '99th_percentile_frame_build_time_millis':
+            p99FrameBuildTime.inMicroseconds / 1E3,
+        'worst_frame_build_time_millis':
+            worstFrameBuildTime.inMicroseconds / 1E3,
+        'missed_frame_build_budget_count': missedFrameBuildBudget,
+        'average_frame_rasterizer_time_millis':
+            averageFrameRasterizerTime.inMicroseconds / 1E3,
+        '90th_percentile_frame_rasterizer_time_millis':
+            p90FrameRasterizerTime.inMicroseconds / 1E3,
+        '99th_percentile_frame_rasterizer_time_millis':
+            p99FrameRasterizerTime.inMicroseconds / 1E3,
+        'worst_frame_rasterizer_time_millis':
+            worstFrameRasterizerTime.inMicroseconds / 1E3,
+        'missed_frame_rasterizer_budget_count': missedFrameRasterizerBudget,
+        'frame_count': frameBuildTime.length,
+        'frame_build_times': frameBuildTime
+            .map<int>((Duration datum) => datum.inMicroseconds)
+            .toList(),
+        'frame_rasterizer_times': frameRasterizerTime
+            .map<int>((Duration datum) => datum.inMicroseconds)
+            .toList(),
+      };
+}
+
+// The following helper functions require data sorted
+
+// return the 100*p-th percentile of the data
+T _findPercentile<T>(List<T> data, double p) {
+  assert(p >= 0 && p <= 1);
+  return data[((data.length - 1) * p).round()];
+}
+
+// return the number of items in data that > threshold
+int _countExceed<T extends Comparable<T>>(List<T> data, T threshold) {
+  return data.length -
+      data.indexWhere((T datum) => datum.compareTo(threshold) > 0);
+}

packages/e2e/pubspec.yaml

@@ -1,6 +1,6 @@
 name: e2e
 description: Runs tests that use the flutter_test API as integration tests.
-version: 0.6.2+1
+version: 0.6.3
 homepage: https://github.com/flutter/plugins/tree/master/packages/e2e
 
 environment:
@@ -14,6 +14,7 @@ dependencies:
     sdk: flutter
   flutter_test:
     sdk: flutter
+  path: ^1.6.4
 
 dev_dependencies:
   pedantic: ^1.8.0

packages/e2e/test/frame_timing_summarizer_test.dart

@@ -0,0 +1,35 @@
+import 'dart:ui';
+
+import 'package:flutter_test/flutter_test.dart';
+
+import 'package:e2e/e2e_perf.dart';
+
+void main() {
+  test('Test FrameTimingSummarizer', () {
+    List<int> buildTimes = <int>[
+      for (int i = 1; i <= 100; i += 1) 1000 * i,
+    ];
+    buildTimes = buildTimes.reversed.toList();
+    List<int> rasterTimes = <int>[
+      for (int i = 1; i <= 100; i += 1) 1000 * i + 1000,
+    ];
+    rasterTimes = rasterTimes.reversed.toList();
+    List<FrameTiming> inputData = <FrameTiming>[
+      for (int i = 0; i < 100; i += 1)
+        FrameTiming(<int>[0, buildTimes[i], 500, rasterTimes[i]]),
+    ];
+    FrameTimingSummarizer summary = FrameTimingSummarizer(inputData);
+    expect(summary.averageFrameBuildTime.inMicroseconds, 50500);
+    expect(summary.p90FrameBuildTime.inMicroseconds, 90000);
+    expect(summary.p99FrameBuildTime.inMicroseconds, 99000);
+    expect(summary.worstFrameBuildTime.inMicroseconds, 100000);
+    expect(summary.missedFrameBuildBudget, 84);
+
+    expect(summary.averageFrameRasterizerTime.inMicroseconds, 51000);
+    expect(summary.p90FrameRasterizerTime.inMicroseconds, 90500);
+    expect(summary.p99FrameRasterizerTime.inMicroseconds, 99500);
+    expect(summary.worstFrameRasterizerTime.inMicroseconds, 100500);
+    expect(summary.missedFrameRasterizerBudget, 85);
+    expect(summary.frameBuildTime.length, 100);
+  });
+}