packages/flutter/test/widgets/annotated_region_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 'package:flutter/rendering.dart';
import 'package:flutter/widgets.dart';
import 'package:flutter_test/flutter_test.dart';

void main() {
  testWidgets('provides a value to the layer tree', (WidgetTester tester) async {
    await tester.pumpWidget(
      const AnnotatedRegion<int>(value: 1, child: SizedBox(width: 100.0, height: 100.0)),
    );
    final List<Layer> layers = tester.layers;
    final AnnotatedRegionLayer<int> layer = layers.whereType<AnnotatedRegionLayer<int>>().first;
    expect(layer.value, 1);
  });

  testWidgets('provides a value to the layer tree in a particular region', (
    WidgetTester tester,
  ) async {
    await tester.pumpWidget(
      Transform.translate(
        offset: const Offset(25.0, 25.0),
        child: const AnnotatedRegion<int>(value: 1, child: SizedBox(width: 100.0, height: 100.0)),
      ),
    );
    int? result = RendererBinding.instance.renderView.debugLayer!.find<int>(
      Offset(10.0 * tester.view.devicePixelRatio, 10.0 * tester.view.devicePixelRatio),
    );
    expect(result, null);
    result = RendererBinding.instance.renderView.debugLayer!.find<int>(
      Offset(50.0 * tester.view.devicePixelRatio, 50.0 * tester.view.devicePixelRatio),
    );
    expect(result, 1);
  });
}