test.dart

testWidgets('Bottom sheet should appear and show correct icon',
      (WidgetTester tester) async {
    BuildContext savedContext;

    await tester
        .pumpWidget(MaterialApp(home: Builder(builder: (BuildContext context) {
      savedContext = context;
      return Container();
    })));

    await tester.pump();

    expect(find.byIcon(Icons.add_photo_alternate), findsNothing);
    expect(find.byIcon(Icons.add_a_photo), findsNothing);

    ImagePickerBottomSheet.showImagePickerBottomSheet(savedContext);

    await tester.pump(); // Bottom sheet show animation starts
    await tester.pump(const Duration(seconds: 2)); // animation done

    expect(find.byIcon(Icons.add_photo_alternate), findsOneWidget);
    expect(find.byIcon(Icons.add_a_photo), findsOneWidget);
  });