Non-fatal null check operator issue

[Cee-Ng]

Using fading_edge_scrollview 2.0.0, and I found this issue being reported quite often in our crashlytics console, which seems to point to an issue with the fact _isScrolledToEnd can be null based off the line it points to.
`

Non-fatal Exception: io.flutter.plugins.firebase.crashlytics.FlutterError: Null check operator used on a null value. Error thrown Instance of 'ErrorDescription'.
at ScrollPosition.maxScrollExtent(ScrollPosition.java:140)
at _FadingEdgeScrollViewState._postFrameCallback(_FadingEdgeScrollViewState.java:206)
at SchedulerBinding._invokeFrameCallback(SchedulerBinding.java:1144)
at SchedulerBinding.handleDrawFrame(SchedulerBinding.java:1090)
at SchedulerBinding._handleDrawFrame(SchedulerBinding.java:998)

[alex-myznikov]

I have the same issue. It turns to be that the issue originates from the ScrollPosition.maxScrollExtent, which is declared as a non-nullable in scroll_position.dart, while it still can be null in some cases. It can be fixed for now by checking _controller.position.hasContentDimensions each time before _controller.position.maxScrollExtent in fading_edge_scrollview.dart.

@mponkin Can we expect this issue to be checked and fixed any time soon? Shall I submit a pull request for it?

[mponkin]

Published version 2.0.1 with fix
@alex-myznikov Thanks for explanation. I was unable to understand the problem at first glance.
I was unable to test if fix is working, because I've never reproduced original issue, so please report if it still happen

[alex-myznikov]

Hi, thank you! I've tested the fix and it seems to work well in my case.