PropertyBindingMixins.OneWayBind does not show a nullable warning when using a selector #4009
Description
Describe the bug 🐞
Basically it's the opposite of #2913
When the object you select is actually nullable, there is no warning for dereferencing it without nullcheck.
If I understand correctly, before the fix for issue 2913, TProp was always considered nullable (Both in Expression<Func<TViewModel, TProp?>> and in Func<TProp?, TOut>) because every TProp was nullable annotated, which caused issue 2913.
The fix removed the nullable annotation in the Func, so now TProp is explicitely considered not nullable in the selector, which causes the current behavior.
If we want to fix both issues, TProp should never be nullable annotated. Then, if TProp is detected as class?, TProp will actually be nullable, and if TProp is detected as class, it will be not nullable.
Step to reproduce
See screenshot
Reproduction repository
https://github.com/reactiveui/ReactiveUI
Expected behavior
When the object you select is nullable, there is a warning for dereferencing it without nullcheck. If the object is not nullable, there is no warning.
Screenshots 🖼️
IDE
Rider Windows
Operating system
Windows
Version
11
Device
No response
ReactiveUI Version
20.2.45
Additional information ℹ️
I have a PR available at https://github.com/elem-74/ReactiveUI/tree/fixOneWayBindAnnotations but your contributing guidelines said to open an issue before a PR, so here it is.