samples/context_menus/test/anywhere_page_test.dart

import 'package:context_menus/anywhere_page.dart';
import 'package:context_menus/main.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';

void main() {
  testWidgets('Right click works outside of text', (tester) async {
    await tester.pumpWidget(const MyApp());

    // Navigate to the AnywherePage example.
    await tester.dragUntilVisible(
      find.text(AnywherePage.title),
      find.byType(ListView),
      const Offset(0.0, -100.0),
    );
    await tester.pumpAndSettle();
    await tester.tap(find.text(AnywherePage.title));
    await tester.pumpAndSettle();

    // Right click on the background of the app to show the context menu.
    final TestGesture gesture = await tester.startGesture(
      const Offset(100.0, 100.0),
      kind: PointerDeviceKind.mouse,
      buttons: kSecondaryMouseButton,
    );
    await tester.pump();
    await gesture.up();
    await gesture.removePointer();
    await tester.pumpAndSettle();

    // The context menu is shown, with a custom back button.
    expect(find.byType(AdaptiveTextSelectionToolbar), findsOneWidget);
    expect(find.text('Back'), findsOneWidget);
  });
}