IAsyncEnumerable Interface Change in .NET 10.0

[TonyValenti]

Hi All,
I noticed that in .NET 10, IAsyncEnumerable's MoveNextAsync now does not accept a cancelation token.

Why was this and what is the right way to cancel/abort moving next?

I did some GROKing but didn't find any clear answers.

[huoyaoyuan]

Nothing has changed. There's never a version that accepts cancellation token: https://github.com/dotnet/runtime/blob/v5.0.0/src/libraries/System.Private.CoreLib/src/System/Collections/Generic/IAsyncEnumerator.cs

Why was this and what is the right way to cancel/abort moving next?

To cancel the consumer, simply cancel the await'd ValueTask. WithCancellation does it for you.
To cancel the producer, the cancellation token needs to be passed when acquiring the IAsyncEnumerable, not consuming.

[TonyValenti]

@huoyaoyuan -
I determined the issue.
When you have:

		<PackageReference Include="System.Linq.Async" Version="6.0.3" />

It exposes:

    //
    // Summary:
    //     Provides a set of extension methods for System.Collections.Generic.IAsyncEnumerator`1.
    public static class AsyncEnumerator {
        public static ValueTask<bool> MoveNextAsync<T>(this IAsyncEnumerator<T> source, CancellationToken cancellationToken);
    }
}

[stephentoub]

Yes. And all it does is:

cancellationToken.ThrowIfCancellationRequested();
return source.MoveNextAsync();