Added comment & style fix & new unit test for issue #82

Author: fubar-coder

src/FubarDev.FtpServer/Networking/StreamPipeWriterService.cs

@@ -39,6 +39,10 @@ public StreamPipeWriterService(
             Stream = stream;
             _pipeReader = pipeReader;
         }
+
+        /// <summary>
+        /// Gets the stream used to write the output.
+        /// </summary>
         protected Stream Stream { get; }
 
         /// <inheritdoc />

test/FubarDev.FtpServer.Tests/Issues/Issue82ProtocolViolation.cs

@@ -0,0 +1,63 @@
+// <copyright file="Issue82ProtocolViolation.cs" company="Fubar Development Junker">
+// Copyright (c) Fubar Development Junker. All rights reserved.
+// </copyright>
+
+using System.Collections.Generic;
+using System.IO;
+using System.Net;
+using System.Threading.Tasks;
+
+using Xunit;
+
+namespace FubarDev.FtpServer.Tests.Issues
+{
+    public class Issue82ProtocolViolation : IClassFixture<FtpServerFixture>
+    {
+        private readonly IFtpServer _server;
+
+        public Issue82ProtocolViolation(FtpServerFixture ftpServerFixture)
+        {
+            _server = ftpServerFixture.Server;
+        }
+
+        [Fact]
+        public async Task TestParallelRequests()
+        {
+            var tasks = new List<Task>();
+            var maxTasks = 100;
+            for (var i = 0; i != maxTasks; i++)
+            {
+                var task = Task.Run(GetFilesAsync);
+                tasks.Add(task);
+            }
+
+            await Task.WhenAll(tasks).ConfigureAwait(false);
+        }
+
+        private async Task<IList<string>> GetFilesAsync()
+        {
+            var requestUri = $"ftp://127.0.0.1:{_server.Port}";
+            var request = (FtpWebRequest)WebRequest.Create(requestUri);
+            request.Method = WebRequestMethods.Ftp.ListDirectory;
+            request.Credentials = new NetworkCredential("anonymous", "foo@bar.com");
+            request.KeepAlive = false;
+
+            var files = new List<string>();
+            using (var response = await request.GetResponseAsync().ConfigureAwait(false))
+            {
+                using var responseStream = response.GetResponseStream();
+                using var reader = new StreamReader(responseStream);
+                string line;
+                while ((line = reader.ReadLine()) != null)
+                {
+                    files.Add(Path.GetFileName(line));
+                }
+
+                reader.Close();
+                responseStream.Close();
+            }
+
+            return files;
+        }
+    }
+}