Rx.NET 6.1 now available

[idg10]

A new minor version of Rx.NET is now available. You can get System.Reactive v6.1.0 from NuGet today.

We've bumped the minor version number because this release has new features.

DisposeWith extension method

Thanks to Chris Pulman for implementing this.

This simplifies the use of CompositeDisposable when using a 'fluent' coding style. When subscribing to some observable source, you can append a call to this, e.g.: src.Subscribe(observer).DisposeWith(d); (where d is a CompositeDisposable).

See this video for more details: https://www.youtube.com/watch?v=6wQVb8iyLFU

TakeUntil(CancellationToken)

Thanks to Nils Aufschläger for the initial suggestion, and for implementing the operator. Thanks to Daniel Weber for proposing the design we ultimately chose.

As with the existing TakeUntil overloads, this provides a way to cause a source to complete early. With this new overload, you can trigger completion with any CancellationToken. The original motivation for this was to be able to take 'infinite' sources (e.g., an IObservable<T> produced by adapting a .NET event) and provide a way to make them complete.

See this video for more details: https://www.youtube.com/watch?v=-ivFY_Hv89Y

ResetExceptionDispatchInfo

Thanks to Adam Jones for the initial issue report, and for reviewing our work on this.

The .NET runtime's machinery for rethrowing exceptions from some context other than the one in which the exception was first caught assumes that the exception was initially thrown in the conventional way. If it wasn't, and if you reuse the same exception object, its stack trace can grow over time. This is just part of the .NET runtime's behaviour, but it's quite easy to run into this by accident with Rx, because in Rx, exceptions are typically reported not with throw but with a call to OnError. So if you use Rx's mechanisms for adapting this to a normal throw (e.g. if you await an IObservable<T>) you can run into this issue.

We've added a new operator, ResetExceptionDispatchInfo, that enables you to avoid running into this behaviour if you have set up an Rx observable that might end up causing the same exception to be rethrown multiple times.

See this video for more details: https://www.youtube.com/watch?v=_4BVPQit6EM

Intro to Rx updated

We've also published an updated edition of the Intro to Rx book to cover these changes, which you can find at https://introtorx.com/