reactive/Ix.NET/Source/System.Interactive.Async.Tests/System/Linq/Operators/Never.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;
using System.Linq;
using System.Threading.Tasks;
using Xunit;

namespace Tests
{
    public class Never : AsyncEnumerableExTests
    {
        [Fact]
        public async Task Never1()
        {
            var xs = AsyncEnumerableEx.Never<int>();

            var e = xs.GetAsyncEnumerator();
            Assert.False(e.MoveNextAsync().IsCompleted); // Very rudimentary check
            AssertThrows<InvalidOperationException>(() => Nop(e.Current));
            await e.DisposeAsync();
        }

        private void Nop(object o)
        {
        }
    }
}