packages/flutter/test/widgets/multi_view_parent_data_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/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';

import 'multi_view_testing.dart';

void main() {
  testWidgets('Hot reload does not crash if ViewAnchor is used between ParentDataWidget and the render object it is applied to', (WidgetTester tester) async {
    // Regression test for https://github.com/flutter/flutter/issues/142480.
    Widget buildTest(String string) {
      return Directionality(
        textDirection: TextDirection.ltr,
        child: Stack(
          children: <Widget>[
            Positioned( // ParentDataWidget
              right: 0,
              bottom: 0,
              child: ViewAnchor(
                view: View(
                  view: FakeView(tester.view),
                  child: const Text('Side-view'),
                ),
                child: Text(string), // Text's RenderObject is the target for the ParentDataWidget above.
              ),
            ),
          ],
        ),
      );
    }

    await tester.pumpWidget(buildTest('bottom-right'));
    expect(tester.getBottomRight(find.text('bottom-right')), const Offset(800, 600));
    // Rebuild with a slightly different string to simulate a hot reload.
    await tester.pumpWidget(buildTest('bottom-right-again'));
    expect(find.text('bottom-right'), findsNothing);
    expect(tester.getBottomRight(find.text('bottom-right-again')), const Offset(800, 600));
  });
}