flutter_flutter/packages/flutter/test/widgets/snapshot_widget_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.

// This file is run as part of a reduced test set in CI on Mac and Windows
// machines.
@Tags(<String>['reduced-test-set'])
library;

import 'dart:ui' as ui;

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:leak_tracker_flutter_testing/leak_tracker_flutter_testing.dart';

import '../impeller_test_helpers.dart';

void main() {
  testWidgets('SnapshotWidget can rasterize child', (WidgetTester tester) async {
    final controller = SnapshotController(allowSnapshotting: true);
    addTearDown(controller.dispose);
    final Key key = UniqueKey();

    await tester.pumpWidget(
      RepaintBoundary(
        key: key,
        child: TestDependencies(
          child: SnapshotWidget(
            controller: controller,
            child: Container(width: 100, height: 100, color: const Color(0xFFAABB11)),
          ),
        ),
      ),
    );
    await expectLater(find.byKey(key), matchesGoldenFile('raster_widget.yellow.png'));

    // Now change the color and assert the old snapshot still matches.
    await tester.pumpWidget(
      RepaintBoundary(
        key: key,
        child: TestDependencies(
          child: SnapshotWidget(
            controller: controller,
            child: Container(width: 100, height: 100, color: const Color(0xFFAA0000)),
          ),
        ),
      ),
    );
    await expectLater(find.byKey(key), matchesGoldenFile('raster_widget.yellow.png'));

    // Now invoke clear and the raster is re-generated.
    controller.clear();
    await tester.pump();

    await expectLater(find.byKey(key), matchesGoldenFile('raster_widget.red.png'));
  }, skip: kIsWeb); // TODO(jonahwilliams): https://github.com/flutter/flutter/issues/106689

  testWidgets('Changing devicePixelRatio does not repaint if snapshotting is not enabled', (
    WidgetTester tester,
  ) async {
    final controller = SnapshotController();
    addTearDown(controller.dispose);
    final painter = TestPainter();
    addTearDown(painter.dispose);
    var devicePixelRatio = 1.0;
    late StateSetter localSetState;

    await tester.pumpWidget(
      StatefulBuilder(
        builder: (BuildContext context, StateSetter setState) {
          localSetState = setState;
          return Center(
            child: TestDependencies(
              devicePixelRatio: devicePixelRatio,
              child: SnapshotWidget(
                controller: controller,
                painter: painter,
                child: const SizedBox(width: 100, height: 100),
              ),
            ),
          );
        },
      ),
    );

    expect(painter.count, 1);

    localSetState(() {
      devicePixelRatio = 2.0;
    });
    await tester.pump();

    // Not repainted as dpr was not used.
    expect(painter.count, 1);
  }, skip: kIsWeb); // TODO(jonahwilliams): https://github.com/flutter/flutter/issues/106689

  testWidgets('Changing devicePixelRatio forces raster regeneration', (WidgetTester tester) async {
    final controller = SnapshotController(allowSnapshotting: true);
    addTearDown(controller.dispose);
    final painter = TestPainter();
    addTearDown(painter.dispose);
    var devicePixelRatio = 1.0;
    late StateSetter localSetState;

    await tester.pumpWidget(
      StatefulBuilder(
        builder: (BuildContext context, StateSetter setState) {
          localSetState = setState;
          return Center(
            child: TestDependencies(
              devicePixelRatio: devicePixelRatio,
              child: SnapshotWidget(
                controller: controller,
                painter: painter,
                child: const SizedBox(width: 100, height: 100),
              ),
            ),
          );
        },
      ),
    );
    final ui.Image? raster = painter.lastImage;

    expect(raster, isNotNull);
    expect(painter.count, 1);

    localSetState(() {
      devicePixelRatio = 2.0;
    });
    await tester.pump();

    final ui.Image? newRaster = painter.lastImage;

    expect(painter.count, 2);
    expect(raster, isNot(newRaster));
  }, skip: kIsWeb); // TODO(jonahwilliams): https://github.com/flutter/flutter/issues/106689

  testWidgets('SnapshotWidget paints its child as a single picture layer', (
    WidgetTester tester,
  ) async {
    final controller = SnapshotController(allowSnapshotting: true);
    addTearDown(controller.dispose);

    await tester.pumpWidget(
      RepaintBoundary(
        child: Center(
          child: TestDependencies(
            child: SnapshotWidget(
              controller: controller,
              child: Container(width: 100, height: 100, color: const Color(0xFFAABB11)),
            ),
          ),
        ),
      ),
    );

    expect(tester.layers, hasLength(3));
    expect(tester.layers.last, isA<PictureLayer>());

    controller.allowSnapshotting = false;
    await tester.pump();

    expect(tester.layers, hasLength(3));
    expect(tester.layers.last, isA<PictureLayer>());
  }, skip: kIsWeb); // TODO(jonahwilliams): https://github.com/flutter/flutter/issues/106689

  testWidgets('SnapshotWidget can update the painter type', (WidgetTester tester) async {
    final controller = SnapshotController(allowSnapshotting: true);
    addTearDown(controller.dispose);
    final painter1 = TestPainter();
    addTearDown(painter1.dispose);
    final painter2 = TestPainter2();
    addTearDown(painter2.dispose);

    await tester.pumpWidget(
      Center(
        child: TestDependencies(
          child: SnapshotWidget(controller: controller, painter: painter1, child: const SizedBox()),
        ),
      ),
    );

    await tester.pumpWidget(
      Center(
        child: TestDependencies(
          child: SnapshotWidget(controller: controller, painter: painter2, child: const SizedBox()),
        ),
      ),
    );

    expect(tester.takeException(), isNull);
  }, skip: kIsWeb); // TODO(jonahwilliams): https://github.com/flutter/flutter/issues/106689

  testWidgets('RenderSnapshotWidget does not error on rasterization of child with empty size', (
    WidgetTester tester,
  ) async {
    final controller = SnapshotController(allowSnapshotting: true);
    addTearDown(controller.dispose);

    await tester.pumpWidget(
      Center(
        child: TestDependencies(
          child: SnapshotWidget(controller: controller, child: const SizedBox()),
        ),
      ),
    );

    expect(tester.takeException(), isNull);
  }, skip: kIsWeb); // TODO(jonahwilliams): https://github.com/flutter/flutter/issues/106689

  testWidgets('RenderSnapshotWidget throws assertion if platform view is encountered', (
    WidgetTester tester,
  ) async {
    final controller = SnapshotController(allowSnapshotting: true);
    addTearDown(controller.dispose);

    await tester.pumpWidget(
      Center(
        child: TestDependencies(
          child: SnapshotWidget(
            controller: controller,
            child: const SizedBox(width: 100, height: 100, child: TestPlatformView()),
          ),
        ),
      ),
    );

    expect(
      tester.takeException(),
      isA<FlutterError>().having(
        (FlutterError error) => error.message,
        'message',
        contains('SnapshotWidget used with a child that contains a PlatformView'),
      ),
    );
  }, skip: kIsWeb); // TODO(jonahwilliams): https://github.com/flutter/flutter/issues/106689

  testWidgets('RenderSnapshotWidget does not assert if SnapshotMode.forced', (
    WidgetTester tester,
  ) async {
    final controller = SnapshotController(allowSnapshotting: true);
    addTearDown(controller.dispose);

    await tester.pumpWidget(
      Center(
        child: TestDependencies(
          child: SnapshotWidget(
            controller: controller,
            mode: SnapshotMode.forced,
            child: const SizedBox(width: 100, height: 100, child: TestPlatformView()),
          ),
        ),
      ),
    );

    expect(tester.takeException(), isNull);
  }, skip: kIsWeb); // TODO(jonahwilliams): https://github.com/flutter/flutter/issues/106689

  testWidgets(
    'RenderSnapshotWidget does not take a snapshot if a platform view is encountered with SnapshotMode.permissive',
    (WidgetTester tester) async {
      final controller = SnapshotController(allowSnapshotting: true);
      addTearDown(controller.dispose);

      await tester.pumpWidget(
        Center(
          child: TestDependencies(
            child: SnapshotWidget(
              controller: controller,
              mode: SnapshotMode.permissive,
              child: const SizedBox(width: 100, height: 100, child: TestPlatformView()),
            ),
          ),
        ),
      );

      expect(tester.takeException(), isNull);
      expect(tester.layers.last, isA<PlatformViewLayer>());
    },
    skip: kIsWeb, // TODO(jonahwilliams): https://github.com/flutter/flutter/issues/106689
  );

  testWidgets(
    'SnapshotWidget should have same result when enabled',
    (WidgetTester tester) async {
      addTearDown(tester.view.reset);

      tester.view
        ..physicalSize = const Size(10, 10)
        ..devicePixelRatio = 1;

      const repaintBoundaryKey = ValueKey<String>('boundary');
      final controller = SnapshotController();
      addTearDown(controller.dispose);

      await tester.pumpWidget(
        RepaintBoundary(
          key: repaintBoundaryKey,
          child: MaterialApp(
            debugShowCheckedModeBanner: false,
            home: Container(
              color: Colors.black,
              padding: const EdgeInsets.only(right: 0.6, bottom: 0.6),
              child: SnapshotWidget(
                controller: controller,
                child: Container(
                  margin: const EdgeInsets.only(right: 0.4, bottom: 0.4),
                  color: Colors.blue,
                ),
              ),
            ),
          ),
        ),
      );

      final ui.Image imageWhenDisabled =
          (tester.renderObject(find.byKey(repaintBoundaryKey)) as RenderRepaintBoundary)
              .toImageSync();
      addTearDown(imageWhenDisabled.dispose);

      controller.allowSnapshotting = true;
      await tester.pump();

      await expectLater(find.byKey(repaintBoundaryKey), matchesReferenceImage(imageWhenDisabled));
    },
    // TODO(jonahwilliams): https://github.com/flutter/flutter/issues/106689
    skip: kIsWeb || impellerEnabled,
  );

  test('SnapshotPainter dispatches memory events', () async {
    await expectLater(
      await memoryEvents(() => TestPainter().dispose(), TestPainter),
      areCreateAndDispose,
    );
  });
}

class TestPlatformView extends SingleChildRenderObjectWidget {
  const TestPlatformView({super.key});

  @override
  RenderObject createRenderObject(BuildContext context) {
    return RenderTestPlatformView();
  }
}

class RenderTestPlatformView extends RenderProxyBox {
  @override
  void paint(PaintingContext context, ui.Offset offset) {
    context.addLayer(PlatformViewLayer(rect: offset & size, viewId: 1));
  }
}

class TestPainter extends SnapshotPainter {
  int count = 0;
  bool shouldRepaintValue = false;
  ui.Image? lastImage;

  int addedListenerCount = 0;
  int removedListenerCount = 0;

  @override
  void addListener(ui.VoidCallback listener) {
    addedListenerCount += 1;
    super.addListener(listener);
  }

  @override
  void removeListener(ui.VoidCallback listener) {
    removedListenerCount += 1;
    super.removeListener(listener);
  }

  @override
  void paintSnapshot(
    PaintingContext context,
    Offset offset,
    Size size,
    ui.Image image,
    Size sourceSize,
    double pixelRatio,
  ) {
    count += 1;
    lastImage = image;
  }

  @override
  void paint(
    PaintingContext context,
    ui.Offset offset,
    ui.Size size,
    PaintingContextCallback painter,
  ) {
    count += 1;
  }

  @override
  bool shouldRepaint(covariant TestPainter oldDelegate) => shouldRepaintValue;
}

class TestPainter2 extends TestPainter {
  @override
  bool shouldRepaint(covariant TestPainter2 oldDelegate) => shouldRepaintValue;
}

class TestDependencies extends StatelessWidget {
  const TestDependencies({required this.child, super.key, this.devicePixelRatio});

  final Widget child;
  final double? devicePixelRatio;

  @override
  Widget build(BuildContext context) {
    return Directionality(
      textDirection: TextDirection.ltr,
      child: MediaQuery(
        data: const MediaQueryData().copyWith(devicePixelRatio: devicePixelRatio),
        child: child,
      ),
    );
  }
}