/// Rebuild the widget after 'refresh' or 'loadmore' is completed, check
/// their callbaks can get a correct timestamp(defined in 'builder').
/// If get a wrong timestamp, consider memory leak.
testWidgets("test memory leak", (tester) async {
  final controller = RefreshController();
  int currentTimestamp = 0;
  await tester.pumpWidget(MaterialApp(
    home: Directionality(
      textDirection: TextDirection.ltr,
      child: Builder(
          key: Key('builder'),
          builder: (context) {
            int timestamp = DateTime.now().millisecondsSinceEpoch;
            currentTimestamp = timestamp;
            print('$timestamp ---- build');
            return SmartRefresher(
              controller: controller,
              enablePullUp: true,
              onLoading: () {
                controller.loadComplete();
                print('$timestamp --- onLoading');
                expect(timestamp, currentTimestamp);
                tester
                    .firstElement(find.byKey(Key('builder')))
                    .markNeedsBuild();
              },
              onRefresh: () {
                controller.refreshCompleted();
                print('$timestamp --- onRefresh');
                expect(timestamp, currentTimestamp);
                tester
                    .firstElement(find.byKey(Key('builder')))
                    .markNeedsBuild();
              },
              child: ListView(
                children: List<Widget>.generate(20, (index) {
                  return Container(height: 50, child: Text('Item: $index'));
                }),
              ),
            );
          }),
    ),
  ));

  // test pull refresh
  await tester.drag(find.byType(Scrollable), const Offset(0, 100.0),
      touchSlopY: 0.0);
  await tester.pumpAndSettle();
  await tester.drag(find.byType(Scrollable), const Offset(0, 100.0),
      touchSlopY: 0.0);
  await tester.pumpAndSettle();

  // test load more
  controller.position!.jumpTo(controller.position!.maxScrollExtent - 30.0);
  await tester.drag(find.byType(Scrollable), const Offset(0, -30.0));
  await tester.pumpAndSettle();
  await tester.drag(find.byType(Scrollable), const Offset(0, -30.0));
  await tester.pumpAndSettle();
});

class SmartRefresherState extends State<SmartRefresher> {

  final RefreshIndicator defaultHeader =
      defaultTargetPlatform == TargetPlatform.iOS
          ? ClassicHeader()
          : MaterialClassicHeader();

  final LoadIndicator defaultFooter = ClassicFooter();
}