IQueryable<T> to IObservable<T>

ToObservable.cs

public static IObservable<T> ToObservable<T>(this IQueryable<T> source)
{
    if (source == null)
        throw new ArgumentNullException(nameof(source));

    IDbAsyncEnumerable<T> dbAsyncSource = source as IDbAsyncEnumerable<T>;
    
    if (dbAsyncSource == null)
        return source.AsEnumerable().ToObservable();
        
    return Observable.Create<T>(async (observer, cancellationToken) =>
    {
        using (var enumerator = dbAsyncSource.GetAsyncEnumerator())
        {
            try
            {
                while (await enumerator.MoveNextAsync(cancellationToken))
                {
                    observer.OnNext(enumerator.Current);
                }
                observer.OnCompleted();
            }
            catch (TaskCanceledException)
            {
            }
            catch (Exception error)
            {
                observer.OnError(error);
            }
        }
    });
}