Fixed uses of nullable reference types

OBD.NET/ConsoleClient/Program.cs

@@ -21,9 +21,7 @@ public class Program
             Console.WriteLine("\nAvailable ports:");
 
             foreach (string port in availablePorts)
-            {
                 Console.WriteLine(port);
-            }
 
             return;
         }
@@ -33,10 +31,10 @@ public class Program
         using SerialConnection connection = new(comPort);
         using ELM327 dev = new(connection, new OBDConsoleLogger(OBDLogLevel.Debug));
 
-        dev.SubscribeDataReceived<EngineRPM>((sender, data) => Console.WriteLine("EngineRPM: " + data.Data.Rpm));
+        dev.SubscribeDataReceived<EngineRPM>((_, data) => Console.WriteLine("EngineRPM: " + data.Data.Rpm));
-        dev.SubscribeDataReceived<EngineFuelRate>((sender, data) => Console.WriteLine("VehicleSpeed: " + data.Data));
+        dev.SubscribeDataReceived<EngineFuelRate>((_, data) => Console.WriteLine("VehicleSpeed: " + data.Data));
 
-        dev.SubscribeDataReceived<IOBDData>((sender, data) => Console.WriteLine($"PID {data.Data.PID.ToHexString()}: {data.Data}"));
+        dev.SubscribeDataReceived<IOBDData>((_, data) => Console.WriteLine($"PID {data.Data.PID.ToHexString()}: {data.Data}"));
 
         dev.Initialize();
         dev.RequestData<FuelType>();
@@ -66,18 +64,18 @@ public class Program
         using SerialConnection connection = new(comPort);
         using ELM327 dev = new(connection, new OBDConsoleLogger(OBDLogLevel.Debug));
 
-        dev.Initialize();
+        await dev.InitializeAsync();
 
-        EngineRPM engineRpm = await dev.RequestDataAsync<EngineRPM>();
+        EngineRPM? engineRpm = await dev.RequestDataAsync<EngineRPM>();
-        Console.WriteLine("Data: " + engineRpm.Rpm);
+        Console.WriteLine("Data: " + (engineRpm?.Rpm.ToString() ?? "-"));
 
         engineRpm = await dev.RequestDataAsync<EngineRPM>();
-        Console.WriteLine("Data: " + engineRpm.Rpm);
+        Console.WriteLine("Data: " + (engineRpm?.Rpm.ToString() ?? "-"));
 
-        VehicleSpeed vehicleSpeed = await dev.RequestDataAsync<VehicleSpeed>();
+        VehicleSpeed? vehicleSpeed = await dev.RequestDataAsync<VehicleSpeed>();
-        Console.WriteLine("Data: " + vehicleSpeed.Speed);
+        Console.WriteLine("Data: " + (vehicleSpeed?.Speed.ToString() ?? "-"));
 
         engineRpm = await dev.RequestDataAsync<EngineRPM>();
-        Console.WriteLine("Data: " + engineRpm.Rpm);
+        Console.WriteLine("Data: " + (engineRpm?.Rpm.ToString() ?? "-"));
     }
 }

OBD.NET/OBD.NET.Universal/Communication/BluetoothSerialConnection.cs

@@ -46,7 +46,6 @@ namespace OBD.NET.Communication
         /// Initializes a new instance of the <see cref="BluetoothSerialConnection"/> class.
         /// </summary>
         /// <param name="deviceName">Name of the _device.</param>
-        /// <param name="logger">The logger.</param>
         public BluetoothSerialConnection(string deviceName)
         {
             this._device = deviceName;

OBD.NET/OBD.NET.Universal/Properties/AssemblyInfo.cs

@@ -1,5 +1,4 @@
 using System.Reflection;
-using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 // General Information about an assembly is controlled through the following 

OBD.NET/OBD.NET/Commands/ATCommand.cs

@@ -28,13 +28,13 @@ public class ATCommand
     #region Properties & Fields
 
     public string Command { get; }
-    public string ExpectedResult { get; }
+    public string? ExpectedResult { get; }
 
     #endregion
 
     #region Constructors
 
-    private ATCommand(string command, string expectedResult = null)
+    private ATCommand(string command, string? expectedResult = null)
     {
         this.Command = command;
         this.ExpectedResult = expectedResult;

OBD.NET/OBD.NET/Communication/SerialConnection.cs

@@ -1,7 +1,6 @@
 #if NET5_0_OR_GREATER
 
 using System.IO.Ports;
-using System.Text;
 using OBD.NET.Communication.EventArgs;
 
 namespace OBD.NET.Communication;
@@ -12,19 +11,16 @@ public class SerialConnection : ISerialConnection
 
     private readonly SerialPort _serialPort;
 
-    public bool IsOpen => _serialPort?.IsOpen ?? false;
+    public bool IsOpen => _serialPort.IsOpen;
     public bool IsAsync => false;
 
     private readonly byte[] _readBuffer = new byte[1024];
-    private readonly StringBuilder _lineBuffer = new();
-
-    private readonly AutoResetEvent _hasPrompt = new(true);
 
     #endregion
 
     #region Events
 
-    public event EventHandler<DataReceivedEventArgs> DataReceived = delegate {  };
+    public event EventHandler<DataReceivedEventArgs>? DataReceived = delegate {  };
 
     #endregion
 
@@ -61,7 +57,7 @@ public class SerialConnection : ISerialConnection
         DataReceived?.Invoke(this, new DataReceivedEventArgs(count, _readBuffer));
     }
 
-    public void Dispose() => _serialPort?.Dispose();
+    public void Dispose() => _serialPort.Dispose();
 
     public Task ConnectAsync() => throw new NotSupportedException("Asynchronous operations not supported");
 

OBD.NET/OBD.NET/DataTypes/Count.cs

@@ -4,7 +4,7 @@ public class Count : GenericData
 {
     #region Properties & Fields
 
-    protected override string Unit => null;
+    protected override string? Unit => null;
 
     #endregion
 

OBD.NET/OBD.NET/DataTypes/Degree.cs

@@ -22,7 +22,7 @@ public class Degree : GenericData
 
     #region Methods
 
-    public override string ToString() => (IsFloatingPointValue ? Value.ToString("0.00") : Value.ToString()) + (Unit ?? string.Empty);
+    public override string ToString() => (IsFloatingPointValue ? Value.ToString("0.00") : Value.ToString()) + Unit;
 
     #endregion
 }

OBD.NET/OBD.NET/DataTypes/DegreeCelsius.cs

@@ -22,7 +22,7 @@ public class DegreeCelsius : GenericData
 
     #region Methods
 
-    public override string ToString() => (IsFloatingPointValue ? Value.ToString("0.00") : Value.ToString()) + (Unit ?? string.Empty);
+    public override string ToString() => (IsFloatingPointValue ? Value.ToString("0.00") : Value.ToString()) + Unit;
 
     #endregion
 }

OBD.NET/OBD.NET/DataTypes/GenericData.cs

@@ -9,7 +9,7 @@ public abstract class GenericData
     public double MaxValue { get; }
     public bool IsFloatingPointValue { get; }
 
-    protected abstract string Unit { get; }
+    protected abstract string? Unit { get; }
 
     #endregion
 

OBD.NET/OBD.NET/DataTypes/Ratio.cs

@@ -4,7 +4,7 @@ public class Ratio : GenericData
 {
     #region Properties & Fields
 
-    protected override string Unit => null;
+    protected override string? Unit => null;
 
     #endregion
 

OBD.NET/OBD.NET/Devices/CommandResult.cs

@@ -6,7 +6,7 @@ public class CommandResult
 {
     #region Properties & Fields
 
-    public object Result { get; set; }
+    public object? Result { get; set; }
     public AsyncManualResetEvent WaitHandle { get; }
 
     #endregion

OBD.NET/OBD.NET/Devices/ELM327.cs

@@ -21,7 +21,7 @@ public class ELM327 : SerialDevice
 
     protected Mode Mode { get; set; } = Mode.ShowCurrentData; //TODO DarthAffe 26.06.2016: Implement different modes
 
-    protected string MessageChunk { get; set; }
+    protected string MessageChunk { get; set; } = string.Empty;
 
     #endregion
 
@@ -30,13 +30,13 @@ public class ELM327 : SerialDevice
     public delegate void DataReceivedEventHandler<T>(object sender, DataReceivedEventArgs<T> args) where T : IOBDData;
 
     public delegate void RawDataReceivedEventHandler(object sender, RawDataReceivedEventArgs args);
-    public event RawDataReceivedEventHandler RawDataReceived;
+    public event RawDataReceivedEventHandler? RawDataReceived;
 
     #endregion
 
     #region Constructors
 
-    public ELM327(ISerialConnection connection, IOBDLogger logger = null)
+    public ELM327(ISerialConnection connection, IOBDLogger? logger = null)
         : base(connection, logger: logger)
     { }
 
@@ -124,7 +124,7 @@ public class ELM327 : SerialDevice
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <returns></returns>
-    public virtual async Task<T> RequestDataAsync<T>()
+    public virtual async Task<T?> RequestDataAsync<T>()
         where T : class, IOBDData, new()
     {
         Logger?.WriteLine("Requesting Type " + typeof(T).Name + " ...", OBDLogLevel.Debug);
@@ -135,9 +135,8 @@ public class ELM327 : SerialDevice
     /// <summary>
     /// Requests the data asynchronous and return the data when available
     /// </summary>
-    /// <typeparam name="T"></typeparam>
     /// <returns></returns>
-    public virtual async Task<IOBDData> RequestDataAsync(Type type)
+    public virtual async Task<IOBDData?> RequestDataAsync(Type type)
     {
         Logger?.WriteLine("Requesting Type " + type.Name + " ...", OBDLogLevel.Debug);
         byte pid = ResolvePid(type);
@@ -148,7 +147,7 @@ public class ELM327 : SerialDevice
     /// Request data based on a pid
     /// </summary>
     /// <param name="pid">The pid of the requested data</param>
-    public virtual async Task<object> RequestDataAsync(byte pid)
+    public virtual async Task<object?> RequestDataAsync(byte pid)
     {
         Logger?.WriteLine("Requesting PID " + pid.ToString("X2") + " ...", OBDLogLevel.Debug);
         CommandResult result = SendCommand(((byte)Mode).ToString("X2") + pid.ToString("X2"));
@@ -157,10 +156,8 @@ public class ELM327 : SerialDevice
         return result.Result;
     }
 
-    protected override object ProcessMessage(string message)
+    protected override object? ProcessMessage(string message)
     {
-        if (message == null) return null;
-
         DateTime timestamp = DateTime.Now;
 
         RawDataReceived?.Invoke(this, new RawDataReceivedEventArgs(message, timestamp));
@@ -177,7 +174,7 @@ public class ELM327 : SerialDevice
                 else if (message[0] == '1')
                 {
                     string fullMessage = MessageChunk + message.Substring(2, message.Length - 2);
-                    MessageChunk = null;
+                    MessageChunk = string.Empty;
                     return ProcessMessage(fullMessage);
                 }
             }
@@ -187,15 +184,15 @@ public class ELM327 : SerialDevice
                 if (mode == (byte)Mode)
                 {
                     byte pid = (byte)message.Substring(2, 2).GetHexVal();
-                    if (DataTypeCache.TryGetValue(pid, out Type dataType))
+                    if (DataTypeCache.TryGetValue(pid, out Type? dataType))
                     {
-                        IOBDData obdData = (IOBDData)Activator.CreateInstance(dataType);
+                        IOBDData obdData = (IOBDData)Activator.CreateInstance(dataType)!;
                         obdData.Load(message.Substring(4, message.Length - 4));
 
-                        if (DataReceivedEventHandlers.TryGetValue(dataType, out IDataEventManager dataEventManager))
+                        if (DataReceivedEventHandlers.TryGetValue(dataType, out IDataEventManager? dataEventManager))
                             dataEventManager.RaiseEvent(this, obdData, timestamp);
 
-                        if (DataReceivedEventHandlers.TryGetValue(typeof(IOBDData), out IDataEventManager genericDataEventManager))
+                        if (DataReceivedEventHandlers.TryGetValue(typeof(IOBDData), out IDataEventManager? genericDataEventManager))
                             genericDataEventManager.RaiseEvent(this, obdData, timestamp);
 
                         return obdData;
@@ -223,8 +220,7 @@ public class ELM327 : SerialDevice
 
     protected virtual byte AddToPidCache(Type obdDataType)
     {
-        IOBDData data = (IOBDData)Activator.CreateInstance(obdDataType);
+        if (Activator.CreateInstance(obdDataType) is not IOBDData data) throw new ArgumentException("Has to implement IOBDData", nameof(obdDataType));
-        if (data == null) throw new ArgumentException("Has to implement IOBDData", nameof(obdDataType));
 
         byte pid = data.PID;
 
@@ -267,7 +263,7 @@ public class ELM327 : SerialDevice
 
     public void SubscribeDataReceived<T>(DataReceivedEventHandler<T> eventHandler) where T : IOBDData
     {
-        if (!DataReceivedEventHandlers.TryGetValue(typeof(T), out IDataEventManager eventManager))
+        if (!DataReceivedEventHandlers.TryGetValue(typeof(T), out IDataEventManager? eventManager))
             DataReceivedEventHandlers.Add(typeof(T), (eventManager = new GenericDataEventManager<T>()));
 
         ((GenericDataEventManager<T>)eventManager).DataReceived += eventHandler;
@@ -275,7 +271,7 @@ public class ELM327 : SerialDevice
 
     public void UnsubscribeDataReceived<T>(DataReceivedEventHandler<T> eventHandler) where T : IOBDData
     {
-        if (DataReceivedEventHandlers.TryGetValue(typeof(T), out IDataEventManager eventManager))
+        if (DataReceivedEventHandlers.TryGetValue(typeof(T), out IDataEventManager? eventManager))
             ((GenericDataEventManager<T>)eventManager).DataReceived -= eventHandler;
     }
 

OBD.NET/OBD.NET/Devices/STN1170.cs

@@ -8,7 +8,7 @@ public class STN1170 : ELM327 // Fully compatible device
 {
     #region Constructors
 
-    public STN1170(ISerialConnection connection, IOBDLogger logger = null)
+    public STN1170(ISerialConnection connection, IOBDLogger? logger = null)
         : base(connection, logger)
     { }
 

OBD.NET/OBD.NET/Devices/SerialDevice.cs

@@ -17,16 +17,16 @@ public abstract class SerialDevice : IDisposable
     private readonly BlockingCollection<QueuedCommand> _commandQueue = new();
     private readonly StringBuilder _lineBuffer = new();
     private readonly AutoResetEvent _commandFinishedEvent = new(false);
-    private Task _commandWorkerTask;
+    private Task? _commandWorkerTask;
-    private CancellationTokenSource _commandCancellationToken;
+    private CancellationTokenSource? _commandCancellationToken;
 
     private volatile int _queueSize = 0;
     private readonly ManualResetEvent _queueEmptyEvent = new(true);
 
     public int QueueSize => _queueSize;
 
-    protected QueuedCommand CurrentCommand;
+    protected QueuedCommand? CurrentCommand;
-    protected IOBDLogger Logger { get; }
+    protected IOBDLogger? Logger { get; }
     protected ISerialConnection Connection { get; }
     protected char Terminator { get; set; }
 
@@ -40,7 +40,7 @@ public abstract class SerialDevice : IDisposable
     /// <param name="connection">connection.</param>
     /// <param name="terminator">terminator used for terminating the command message</param>
     /// <param name="logger">logger instance</param>
-    protected SerialDevice(ISerialConnection connection, char terminator = '\r', IOBDLogger logger = null)
+    protected SerialDevice(ISerialConnection connection, char terminator = '\r', IOBDLogger? logger = null)
     {
         this.Connection = connection;
         this.Terminator = terminator;
@@ -88,8 +88,7 @@ public abstract class SerialDevice : IDisposable
         _commandCancellationToken = new CancellationTokenSource();
         _commandWorkerTask = Task.Factory.StartNew(CommandWorker);
     }
-
+    
-
     /// <summary>
     /// Sends the command.
     /// </summary>
@@ -105,7 +104,7 @@ public abstract class SerialDevice : IDisposable
 
         QueuedCommand cmd = new(command);
         _queueEmptyEvent.Reset();
-        _queueSize++;
+        Interlocked.Increment(ref _queueSize);
         _commandQueue.Add(cmd);
 
         return cmd.CommandResult;
@@ -131,7 +130,7 @@ public abstract class SerialDevice : IDisposable
     /// </summary>
     /// <param name="sender">The sender.</param>
     /// <param name="e">The <see cref="DataReceivedEventArgs"/> instance containing the event data.</param>
-    private void OnDataReceived(object sender, DataReceivedEventArgs e)
+    private void OnDataReceived(object? sender, DataReceivedEventArgs e)
     {
         for (int i = 0; i < e.Count; i++)
         {
@@ -143,7 +142,7 @@ public abstract class SerialDevice : IDisposable
                     break;
 
                 case '>':
-                    CurrentCommand.CommandResult.WaitHandle.Set();
+                    CurrentCommand?.CommandResult.WaitHandle.Set();
                     _commandFinishedEvent.Set();
                     break;
 
@@ -178,8 +177,9 @@ public abstract class SerialDevice : IDisposable
     /// <param name="message">The message.</param>
     private void InternalProcessMessage(string message)
     {
-        object data = ProcessMessage(message);
+        object? data = ProcessMessage(message);
-        CurrentCommand.CommandResult.Result = data;
+        if (CurrentCommand != null)
+            CurrentCommand.CommandResult.Result = data;
     }
 
     /// <summary>
@@ -187,13 +187,15 @@ public abstract class SerialDevice : IDisposable
     /// </summary>
     /// <param name="message">message received</param>
     /// <returns>result data</returns>
-    protected abstract object ProcessMessage(string message);
+    protected abstract object? ProcessMessage(string message);
 
     /// <summary>
     /// Worker method for sending commands
     /// </summary>
     private async void CommandWorker()
     {
+        if (_commandCancellationToken == null) return;
+
         CancellationToken cancellationToken = _commandCancellationToken.Token;
 
         while (!_commandCancellationToken.IsCancellationRequested)
@@ -207,13 +209,14 @@ public abstract class SerialDevice : IDisposable
             {
                 if (_commandQueue.TryTake(out CurrentCommand, 10, cancellationToken))
                 {
-                    _queueSize--;
+                    Interlocked.Decrement(ref _queueSize);
 
                     Logger?.WriteLine("Writing Command: '" + CurrentCommand.CommandText.Replace('\r', '\'') + "'", OBDLogLevel.Verbose);
 
                     if (Connection.IsAsync)
                         await Connection.WriteAsync(Encoding.ASCII.GetBytes(CurrentCommand.CommandText));
                     else
+                        // ReSharper disable once MethodHasAsyncOverload
                         Connection.Write(Encoding.ASCII.GetBytes(CurrentCommand.CommandText));
 
                     // wait for command to finish or command canceled
@@ -233,7 +236,7 @@ public abstract class SerialDevice : IDisposable
 
     public void WaitQueue() => _queueEmptyEvent.WaitOne();
 
-    public async Task WaitQueueAsync() => await Task.Run(() => WaitQueue());
+    public async Task WaitQueueAsync() => await Task.Run(WaitQueue);
 
     /// <summary>
     /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
@@ -243,7 +246,7 @@ public abstract class SerialDevice : IDisposable
         _commandQueue.CompleteAdding();
         _commandCancellationToken?.Cancel();
         _commandWorkerTask?.Wait();
-        Connection?.Dispose();
+        Connection.Dispose();
     }
 
     #endregion

OBD.NET/OBD.NET/Events/GenericDataEventManager.cs

@@ -9,7 +9,7 @@ public class GenericDataEventManager<T> : IDataEventManager
 {
     #region Events
 
-    internal event ELM327.DataReceivedEventHandler<T> DataReceived;
+    internal event ELM327.DataReceivedEventHandler<T>? DataReceived;
 
     #endregion
 

OBD.NET/OBD.NET/OBDData/00-1F/CalculatedEngineLoad.cs

@@ -6,7 +6,7 @@ public class CalculatedEngineLoad : AbstractOBDData
 {
     #region Properties & Fields
 
-    public Percent Load => new(A / 2.55, 0, 100);
+    public new Percent Load => new(A / 2.55, 0, 100);
 
     #endregion
 

OBD.NET/OBD.NET/OBDData/40-5F/AbsoluteLoadValue.cs

@@ -6,7 +6,7 @@ public class AbsoluteLoadValue : AbstractOBDData
 {
     #region Properties & Fields
 
-    public Percent Load => new(((256 * A) + B) / 2.55, 0, 25700);
+    public new Percent Load => new(((256 * A) + B) / 2.55, 0, 25700);
 
     #endregion
 

OBD.NET/OBD.NET/OBDData/AbstractOBDData.cs

@@ -9,7 +9,7 @@ public abstract class AbstractOBDData : IOBDData
     public byte PID { get; }
     private readonly int _length;
 
-    private byte[] _rawData;
+    private byte[] _rawData = Array.Empty<byte>();
     public byte[] RawData
     {
         get => _rawData;

OBD.NET/OBD.NET/Util/AsyncManulResetEvent.cs

@@ -26,8 +26,8 @@ public class AsyncManualResetEvent
     public void Set()
     {
         TaskCompletionSource<bool> tcs = _tcs;
-        Task.Factory.StartNew(s => ((TaskCompletionSource<bool>)s).TrySetResult(true),
+        Task.Factory.StartNew(s => ((TaskCompletionSource<bool>)s!).TrySetResult(true),
-            tcs, CancellationToken.None, TaskCreationOptions.PreferFairness, TaskScheduler.Default);
+                              tcs, CancellationToken.None, TaskCreationOptions.PreferFairness, TaskScheduler.Default);
 
         tcs.Task.Wait();
     }
@@ -40,8 +40,7 @@ public class AsyncManualResetEvent
         while (true)
         {
             TaskCompletionSource<bool> tcs = _tcs;
-            if (!tcs.Task.IsCompleted ||
+            if (!tcs.Task.IsCompleted || (Interlocked.CompareExchange(ref _tcs, new TaskCompletionSource<bool>(), tcs) == tcs))
-                (Interlocked.CompareExchange(ref _tcs, new TaskCompletionSource<bool>(), tcs) == tcs))
                 return;
         }
     }