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

import 'semantics_tester.dart';

void main() {
  testWidgets('SemanticNode.rect is clipped', (WidgetTester tester) async {
    final SemanticsTester semantics = SemanticsTester(tester);

    await tester.pumpWidget(
      const Directionality(
        textDirection: TextDirection.ltr,
        child: Center(
          child: SizedBox(
            width: 100.0,
            child: Flex(
              clipBehavior: Clip.hardEdge,
              direction: Axis.horizontal,
              children: <Widget>[
                SizedBox(width: 75.0, child: Text('1')),
                SizedBox(width: 75.0, child: Text('2')),
                SizedBox(width: 75.0, child: Text('3')),
              ],
            ),
          ),
        ),
      ),
    );

    final dynamic exception = tester.takeException();
    expect(exception, isFlutterError);
    // ignore: avoid_dynamic_calls
    expect(exception.diagnostics.first.level, DiagnosticLevel.summary);
    // ignore: avoid_dynamic_calls
    expect(exception.diagnostics.first.toString(), contains('overflowed'));

    expect(
      semantics,
      hasSemantics(
        TestSemantics.root(
          children: <TestSemantics>[
            TestSemantics(label: '1', rect: const Rect.fromLTRB(0.0, 0.0, 75.0, 14.0)),
            TestSemantics(
              label: '2',
              rect: const Rect.fromLTRB(0.0, 0.0, 25.0, 14.0), // clipped form original 75.0 to 25.0
            ),
            // node with Text 3 not present.
          ],
        ),
        ignoreTransform: true,
        ignoreId: true,
      ),
    );

    semantics.dispose();
  });

  testWidgets(
    'SemanticsNode is not removed if out of bounds and merged into something within bounds',
    (WidgetTester tester) async {
      final SemanticsTester semantics = SemanticsTester(tester);

      await tester.pumpWidget(
        const Directionality(
          textDirection: TextDirection.ltr,
          child: Center(
            child: SizedBox(
              width: 100.0,
              child: Flex(
                clipBehavior: Clip.hardEdge,
                direction: Axis.horizontal,
                children: <Widget>[
                  SizedBox(width: 75.0, child: Text('1')),
                  MergeSemantics(
                    child: Flex(
                      direction: Axis.horizontal,
                      children: <Widget>[
                        SizedBox(width: 75.0, child: Text('2')),
                        SizedBox(width: 75.0, child: Text('3')),
                      ],
                    ),
                  ),
                ],
              ),
            ),
          ),
        ),
      );

      final dynamic exception = tester.takeException();
      expect(exception, isFlutterError);
      // ignore: avoid_dynamic_calls
      expect(exception.diagnostics.first.level, DiagnosticLevel.summary);
      // ignore: avoid_dynamic_calls
      expect(exception.diagnostics.first.toString(), contains('overflowed'));

      expect(
        semantics,
        hasSemantics(
          TestSemantics.root(
            children: <TestSemantics>[
              TestSemantics(label: '1', rect: const Rect.fromLTRB(0.0, 0.0, 75.0, 14.0)),
              TestSemantics(
                label: '2\n3',
                rect: const Rect.fromLTRB(
                  0.0,
                  0.0,
                  25.0,
                  14.0,
                ), // clipped form original 75.0 to 25.0
              ),
            ],
          ),
          ignoreTransform: true,
          ignoreId: true,
        ),
      );

      semantics.dispose();
    },
  );
}