Remotely/Tests/Shared.Tests/StreamExtensionsTests.cs

using System.Security.Cryptography;
using Remotely.Shared.Extensions;

namespace Remotely.Shared.Tests
{
    [TestClass]
    public class StreamExtensionsTests
    {
        [TestMethod]
        public async Task CopyToAsyncTest()
        {
            var bufferSize = 500_000;
            var srcBuffer = new byte[bufferSize];
            RandomNumberGenerator.Fill(srcBuffer);

            using var src = new MemoryStream(srcBuffer);
            using var dst = new MemoryStream();

            var amounts = new List<int>();

            await src.CopyToAsync(dst, bytesRead =>
            {
                amounts.Add(bytesRead);
            });

            Assert.IsTrue(amounts.Any());
            Assert.AreEqual(bufferSize, amounts.Last());
        }
    }
}