[Bug]: LinqExtensions are sometimes missing equivalent methods from System.Reactive in version 24

[CyLuGh]

Describe the bug 🐞

I'm working on upgrading a project towards version 24 and I thought it could be useful to provide some feedback on the differences I've found.

• CombineLatest in LinqExtensions is missing the override where it would simply return the resulting tuple from all the observables
• [Edit: seems like the IDE was wrongly flagging that] Interactions Handle method isn't awaitable
• I've noticed some crashes when using ObserveOn(RxSchedulers.MainThreadScheduler) :

Works with System.Reactive

 Observable
            .FromEventPattern<EventHandler<SKPaintSurfaceEventArgs>, SKPaintSurfaceEventArgs>(
                _ => async (_, args) => await SkiaElement_PaintSurface(args, viewModel),
                handler => view.SkiaElement.PaintSurface += handler,
                handler => view.SkiaElement.PaintSurface -= handler
            )
            .ObserveOn(RxSchedulers.MainThreadScheduler)
            .Subscribe()
            .DisposeWith(disposables);

Skia crashes as it can't access the canvas for some reason when using ISequencer. It works if I remove the ObserveOn method.

Signal
    .FromEventPattern<SKPaintSurfaceEventArgs>(
        handler => view.SkiaElement.PaintSurface += handler,
        handler => view.SkiaElement.PaintSurface -= handler
    )
    .ObserveOn(RxSchedulers.MainThreadScheduler)
    .Subscribe(t =>
    {
        var args = t.EventArgs;
        SkiaElement_PaintSurface(args, viewModel);
    })
    .DisposeWith(disposables);

Step to reproduce

Switch to version 24 and use ISequencer MainThreadScheduler instead of IScheduler MainThreadScheduler

No response

ReactiveUI Version

24.1

Additional information ℹ️

No response

[glennawatson]

hi @CyLuGh -- Transferred to Primitives since its really gaps in our Primitives layer.

Thanks for the report we'll be adding it soon.

[CyLuGh]

Thanks for moving the issue where it belongs :)

[Edit] I should probably create another issue for the ISequencer?

RxSchedulers.MainThreadScheduler does not work as it was before. It's like it's in a reaaaaaal hurry. It probably reveals some bad design in my code but I get race conditions I hadn't with System.Reactive.

As I'm typing a short tweaked example of my code, I'm starting to wonder if it wouldn't simply be ignoring the Throttle... as it will be calling the command for any value of Scale, without waiting for the auto boundaries adjustment to kick in.

[Reactive]
public partial double Scale { get; set; } = 1d;

/* Don't allow scale < 0.75 */
this.WhenAnyValue(x => x.Scale)
    .Where(x => x < 0.75)
    .SubscribeSafe(_ => Scale = 0.75)
    .DisposeWith(disposables);

/* Don't allow scale > 1 */
this.WhenAnyValue(x => x.Scale)
    .Where(x => x > 1)
    .SubscribeSafe(_ => Scale = 1)
    .DisposeWith(disposables);

/* Redraw grid when scrolling or changing scale */
this.WhenAnyValue( x => x.Scale ).Throttle( TimeSpan.FromMilliseconds( 5 ) )
    .DistinctUntilChanged()
    .Select( _ => false )
    .InvokeCommand( DrawGridCommand );

I should also have been clearer on my previous example: when I said I had no access, it isn't some UI thread lock, the scheduler is working fine on that part, it's more like the UI had no time enough to create the UI fully.

[glennawatson]

@CyLuGh yeah making a new issue for the sequencer would be issue. Sorry for the delay replying.