reactive/Ix.NET/Source/System.Linq.Async/System/Linq/Operators/ToEnumerable.cs

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the Apache 2.0 License.
// See the LICENSE file in the project root for more information. 

using System.Collections.Generic;

namespace System.Linq
{
    public static partial class AsyncEnumerable
    {
        public static IEnumerable<TSource> ToEnumerable<TSource>(this IAsyncEnumerable<TSource> source)
        {
            if (source == null)
                throw Error.ArgumentNull(nameof(source));

            return Core();

            IEnumerable<TSource> Core()
            {
                var e = source.GetAsyncEnumerator(default);

                try
                {
                    while (true)
                    {
                        if (!e.MoveNextAsync().GetAwaiter().GetResult())
                            break;

                        yield return e.Current;
                    }
                }
                finally
                {
                    // Wait
                    e.DisposeAsync().GetAwaiter().GetResult();
                }
            }
        }
    }
}