enable nullable on BaseClient and SftpClient (#1339)

* enable nullable on BaseClient and SftpClient

* SftpClient: use nameof for ArgumentException

Author: mus65

src/Renci.SshNet/BaseClient.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Net.Sockets;
 using System.Threading;
 using System.Threading.Tasks;
@@ -22,7 +23,7 @@ public abstract class BaseClient : IBaseClient
         private readonly IServiceFactory _serviceFactory;
         private readonly object _keepAliveLock = new object();
         private TimeSpan _keepAliveInterval;
-        private Timer _keepAliveTimer;
+        private Timer? _keepAliveTimer;
         private ConnectionInfo _connectionInfo;
         private bool _isDisposed;
 
@@ -32,7 +33,7 @@ public abstract class BaseClient : IBaseClient
         /// <value>
         /// The current session.
         /// </value>
-        internal ISession Session { get; private set; }
+        internal ISession? Session { get; private set; }
 
         /// <summary>
         /// Gets the factory for creating new services.
@@ -142,17 +143,17 @@ public TimeSpan KeepAliveInterval
         /// <summary>
         /// Occurs when an error occurred.
         /// </summary>
-        public event EventHandler<ExceptionEventArgs> ErrorOccurred;
+        public event EventHandler<ExceptionEventArgs>? ErrorOccurred;
 
         /// <summary>
         /// Occurs when host key received.
         /// </summary>
-        public event EventHandler<HostKeyEventArgs> HostKeyReceived;
+        public event EventHandler<HostKeyEventArgs>? HostKeyReceived;
 
         /// <summary>
         /// Occurs when server identification received.
         /// </summary>
-        public event EventHandler<SshIdentificationEventArgs> ServerIdentificationReceived;
+        public event EventHandler<SshIdentificationEventArgs>? ServerIdentificationReceived;
 
         /// <summary>
         /// Initializes a new instance of the <see cref="BaseClient"/> class.
@@ -193,7 +194,7 @@ private protected BaseClient(ConnectionInfo connectionInfo, bool ownsConnectionI
                 throw new ArgumentNullException(nameof(serviceFactory));
             }
 
-            ConnectionInfo = connectionInfo;
+            _connectionInfo = connectionInfo;
             _ownsConnectionInfo = ownsConnectionInfo;
             _serviceFactory = serviceFactory;
             _keepAliveInterval = Timeout.InfiniteTimeSpan;
@@ -391,17 +392,17 @@ protected virtual void OnDisconnected()
         {
         }
 
-        private void Session_ErrorOccured(object sender, ExceptionEventArgs e)
+        private void Session_ErrorOccured(object? sender, ExceptionEventArgs e)
         {
             ErrorOccurred?.Invoke(this, e);
         }
 
-        private void Session_HostKeyReceived(object sender, HostKeyEventArgs e)
+        private void Session_HostKeyReceived(object? sender, HostKeyEventArgs e)
         {
             HostKeyReceived?.Invoke(this, e);
         }
 
-        private void Session_ServerIdentificationReceived(object sender, SshIdentificationEventArgs e)
+        private void Session_ServerIdentificationReceived(object? sender, SshIdentificationEventArgs e)
         {
             ServerIdentificationReceived?.Invoke(this, e);
         }
@@ -432,14 +433,12 @@ protected virtual void Dispose(bool disposing)
 
                 Disconnect();
 
-                if (_ownsConnectionInfo && _connectionInfo is not null)
+                if (_ownsConnectionInfo)
                 {
                     if (_connectionInfo is IDisposable connectionInfoDisposable)
                     {
                         connectionInfoDisposable.Dispose();
                     }
-
-                    _connectionInfo = null;
                 }
 
                 _isDisposed = true;

src/Renci.SshNet/IBaseClient.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Net.Sockets;
 using System.Threading;
 using System.Threading.Tasks;

src/Renci.SshNet/ISftpClient.cs

@@ -1,4 +1,5 @@
-using System;
+#nullable enable
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Text;
@@ -192,7 +193,7 @@ public interface ISftpClient : IBaseClient
         /// <remarks>
         /// Method calls made by this method to <paramref name="output" />, may under certain conditions result in exceptions thrown by the stream.
         /// </remarks>
-        IAsyncResult BeginDownloadFile(string path, Stream output, AsyncCallback asyncCallback);
+        IAsyncResult BeginDownloadFile(string path, Stream output, AsyncCallback? asyncCallback);
 
         /// <summary>
         /// Begins an asynchronous file downloading into the stream.
@@ -211,7 +212,7 @@ public interface ISftpClient : IBaseClient
         /// <remarks>
         /// Method calls made by this method to <paramref name="output" />, may under certain conditions result in exceptions thrown by the stream.
         /// </remarks>
-        IAsyncResult BeginDownloadFile(string path, Stream output, AsyncCallback asyncCallback, object state, Action<ulong> downloadCallback = null);
+        IAsyncResult BeginDownloadFile(string path, Stream output, AsyncCallback? asyncCallback, object? state, Action<ulong>? downloadCallback = null);
 
         /// <summary>
         /// Begins an asynchronous operation of retrieving list of files in remote directory.
@@ -224,7 +225,7 @@ public interface ISftpClient : IBaseClient
         /// An <see cref="IAsyncResult" /> that references the asynchronous operation.
         /// </returns>
         /// <exception cref="ObjectDisposedException">The method was called after the client was disposed.</exception>
-        IAsyncResult BeginListDirectory(string path, AsyncCallback asyncCallback, object state, Action<int> listCallback = null);
+        IAsyncResult BeginListDirectory(string path, AsyncCallback? asyncCallback, object? state, Action<int>? listCallback = null);
 
         /// <summary>
         /// Begins the synchronize directories.
@@ -240,7 +241,7 @@ public interface ISftpClient : IBaseClient
         /// <exception cref="ArgumentNullException"><paramref name="sourcePath"/> is <see langword="null"/>.</exception>
         /// <exception cref="ArgumentException"><paramref name="destinationPath"/> is <see langword="null"/> or contains only whitespace.</exception>
         /// <exception cref="SshException">If a problem occurs while copying the file.</exception>
-        IAsyncResult BeginSynchronizeDirectories(string sourcePath, string destinationPath, string searchPattern, AsyncCallback asyncCallback, object state);
+        IAsyncResult BeginSynchronizeDirectories(string sourcePath, string destinationPath, string searchPattern, AsyncCallback? asyncCallback, object? state);
 
         /// <summary>
         /// Begins an asynchronous uploading the stream into remote file.
@@ -289,7 +290,7 @@ public interface ISftpClient : IBaseClient
         /// If the remote file already exists, it is overwritten and truncated.
         /// </para>
         /// </remarks>
-        IAsyncResult BeginUploadFile(Stream input, string path, AsyncCallback asyncCallback);
+        IAsyncResult BeginUploadFile(Stream input, string path, AsyncCallback? asyncCallback);
 
         /// <summary>
         /// Begins an asynchronous uploading the stream into remote file.
@@ -316,7 +317,7 @@ public interface ISftpClient : IBaseClient
         /// If the remote file already exists, it is overwritten and truncated.
         /// </para>
         /// </remarks>
-        IAsyncResult BeginUploadFile(Stream input, string path, AsyncCallback asyncCallback, object state, Action<ulong> uploadCallback = null);
+        IAsyncResult BeginUploadFile(Stream input, string path, AsyncCallback? asyncCallback, object? state, Action<ulong>? uploadCallback = null);
 
         /// <summary>
         /// Begins an asynchronous uploading the stream into remote file.
@@ -343,7 +344,7 @@ public interface ISftpClient : IBaseClient
         /// <see cref="SshException"/>.
         /// </para>
         /// </remarks>
-        IAsyncResult BeginUploadFile(Stream input, string path, bool canOverride, AsyncCallback asyncCallback, object state, Action<ulong> uploadCallback = null);
+        IAsyncResult BeginUploadFile(Stream input, string path, bool canOverride, AsyncCallback? asyncCallback, object? state, Action<ulong>? uploadCallback = null);
 
         /// <summary>
         /// Changes remote directory to path.
@@ -522,7 +523,7 @@ public interface ISftpClient : IBaseClient
         /// <remarks>
         /// Method calls made by this method to <paramref name="output" />, may under certain conditions result in exceptions thrown by the stream.
         /// </remarks>
-        void DownloadFile(string path, Stream output, Action<ulong> downloadCallback = null);
+        void DownloadFile(string path, Stream output, Action<ulong>? downloadCallback = null);
 
         /// <summary>
         /// Ends an asynchronous file downloading into the stream.
@@ -698,7 +699,7 @@ public interface ISftpClient : IBaseClient
         /// <exception cref="SftpPermissionDeniedException">Permission to list the contents of the directory was denied by the remote host. <para>-or-</para> A SSH command was denied by the server.</exception>
         /// <exception cref="SshException">A SSH error where <see cref="Exception.Message" /> is the message from the remote host.</exception>
         /// <exception cref="ObjectDisposedException">The method was called after the client was disposed.</exception>
-        IEnumerable<ISftpFile> ListDirectory(string path, Action<int> listCallback = null);
+        IEnumerable<ISftpFile> ListDirectory(string path, Action<int>? listCallback = null);
 
         /// <summary>
         /// Asynchronously enumerates the files in remote directory.
@@ -1004,7 +1005,7 @@ public interface ISftpClient : IBaseClient
         /// <remarks>
         /// Method calls made by this method to <paramref name="input" />, may under certain conditions result in exceptions thrown by the stream.
         /// </remarks>
-        void UploadFile(Stream input, string path, Action<ulong> uploadCallback = null);
+        void UploadFile(Stream input, string path, Action<ulong>? uploadCallback = null);
 
         /// <summary>
         /// Uploads stream into remote file.
@@ -1022,7 +1023,7 @@ public interface ISftpClient : IBaseClient
         /// <remarks>
         /// Method calls made by this method to <paramref name="input" />, may under certain conditions result in exceptions thrown by the stream.
         /// </remarks>
-        void UploadFile(Stream input, string path, bool canOverride, Action<ulong> uploadCallback = null);
+        void UploadFile(Stream input, string path, bool canOverride, Action<ulong>? uploadCallback = null);
 
         /// <summary>
         /// Writes the specified byte array to the specified file, and closes the file.