[dotnet] Annotate nullable reference types in internal logging

dotnet/src/webdriver/Internal/Logging/ConsoleLogHandler.cs

@@ -19,6 +19,8 @@
 
 using System;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     /// <summary>

dotnet/src/webdriver/Internal/Logging/FileLogHandler.cs

@@ -20,6 +20,8 @@
 using System;
 using System.IO;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     /// <summary>
@@ -40,6 +42,7 @@ public class FileLogHandler : ILogHandler, IDisposable
         /// Initializes a new instance of the <see cref="FileLogHandler"/> class with the specified file path.
         /// </summary>
         /// <param name="filePath">The path of the log file.</param>
+        /// <exception cref="ArgumentException">If <paramref name="filePath"/> is <see langword="null"/> or <see cref="string.Empty"/>.</exception>
         public FileLogHandler(string filePath)
             : this(filePath, overwrite: true)
         {
@@ -51,6 +54,7 @@ public FileLogHandler(string filePath)
         /// </summary>
         /// <param name="filePath">The path of the log file.</param>
         /// <param name="overwrite">Specifies whether the file should be overwritten if it exists on the disk.</param>
+        /// <exception cref="ArgumentException">If <paramref name="filePath"/> is <see langword="null"/> or <see cref="string.Empty"/>.</exception>
         public FileLogHandler(string filePath, bool overwrite)
         {
             if (string.IsNullOrEmpty(filePath)) throw new ArgumentException("File log path cannot be null or empty.", nameof(filePath));
@@ -76,9 +80,14 @@ public FileLogHandler(string filePath, bool overwrite)
         /// <param name="logEvent">The log event to handle.</param>
         public void Handle(LogEvent logEvent)
         {
+            if (_streamWriter is not { } writer)
+            {
+                throw new ObjectDisposedException(nameof(FileLogHandler));
+            }
+
             lock (_lockObj)
             {
-                _streamWriter.WriteLine($"{logEvent.Timestamp:yyyy-MM-dd HH:mm:ss.fff} {_levels[(int)logEvent.Level]} {logEvent.IssuedBy.Name}: {logEvent.Message}");
+                writer.WriteLine($"{logEvent.Timestamp:yyyy-MM-dd HH:mm:ss.fff} {_levels[(int)logEvent.Level]} {logEvent.IssuedBy.Name}: {logEvent.Message}");
             }
         }
 
@@ -112,9 +121,9 @@ protected virtual void Dispose(bool disposing)
                     if (disposing)
                     {
                         _streamWriter?.Dispose();
-                        _streamWriter = null;
+                        _streamWriter = null!;
                         _fileStream?.Dispose();
-                        _fileStream = null;
+                        _fileStream = null!;
                     }
 
                     _isDisposed = true;

dotnet/src/webdriver/Internal/Logging/ILogContext.cs

@@ -19,6 +19,8 @@
 
 using System;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     /// <summary>

dotnet/src/webdriver/Internal/Logging/ILogHandler.cs

@@ -17,6 +17,8 @@
 // under the License.
 // </copyright>
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     /// <summary>

dotnet/src/webdriver/Internal/Logging/ILogHandlerList.cs

@@ -19,6 +19,8 @@
 
 using System.Collections.Generic;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     /// <summary>

dotnet/src/webdriver/Internal/Logging/ILogger.cs

@@ -19,6 +19,8 @@
 
 using System;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     /// <summary>

dotnet/src/webdriver/Internal/Logging/Log.cs

@@ -18,6 +18,9 @@
 // </copyright>
 
 using System;
+using System.Diagnostics.CodeAnalysis;
+
+#nullable enable
 
 namespace OpenQA.Selenium.Internal.Logging
 {
@@ -65,16 +68,11 @@ public static ILogContext CreateContext(LogEventLevel minimumLevel)
         /// <summary>
         /// Gets or sets the current log context.
         /// </summary>
+        [AllowNull]
         internal static ILogContext CurrentContext
         {
-            get
-            {
-                return _logContextManager.CurrentContext;
-            }
-            set
-            {
-                _logContextManager.CurrentContext = value;
-            }
+            get => _logContextManager.CurrentContext;
+            set => _logContextManager.CurrentContext = value;
         }
 
         /// <summary>

dotnet/src/webdriver/Internal/Logging/LogContext.cs

@@ -22,6 +22,8 @@
 using System.Collections.Generic;
 using System.Linq;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     /// <summary>
@@ -30,15 +32,15 @@ namespace OpenQA.Selenium.Internal.Logging
     /// <inheritdoc cref="ILogContext"/>
     internal class LogContext : ILogContext
     {
-        private ConcurrentDictionary<Type, ILogger> _loggers;
+        private ConcurrentDictionary<Type, ILogger>? _loggers;
 
         private LogEventLevel _level;
 
-        private readonly ILogContext _parentLogContext;
+        private readonly ILogContext? _parentLogContext;
 
         private readonly Lazy<LogHandlerList> _lazyLogHandlerList;
 
-        public LogContext(LogEventLevel level, ILogContext parentLogContext, ConcurrentDictionary<Type, ILogger> loggers, IEnumerable<ILogHandler> handlers)
+        public LogContext(LogEventLevel level, ILogContext? parentLogContext, ConcurrentDictionary<Type, ILogger>? loggers, IEnumerable<ILogHandler>? handlers)
         {
             _level = level;
 
@@ -56,14 +58,11 @@ public LogContext(LogEventLevel level, ILogContext parentLogContext, ConcurrentD
             }
         }
 
-        public ILogContext CreateContext()
-        {
-            return CreateContext(_level);
-        }
+        public ILogContext CreateContext() => CreateContext(_level);
 
         public ILogContext CreateContext(LogEventLevel minimumLevel)
         {
-            ConcurrentDictionary<Type, ILogger> loggers = null;
+            ConcurrentDictionary<Type, ILogger>? loggers = null;
 
             if (_loggers != null)
             {
@@ -77,10 +76,7 @@ public ILogContext CreateContext(LogEventLevel minimumLevel)
             return context;
         }
 
-        public ILogger GetLogger<T>()
-        {
-            return GetLogger(typeof(T));
-        }
+        public ILogger GetLogger<T>() => GetLogger(typeof(T));
 
         public ILogger GetLogger(Type type)
         {
@@ -89,12 +85,9 @@ public ILogger GetLogger(Type type)
                 throw new ArgumentNullException(nameof(type));
             }
 
-            if (_loggers is null)
-            {
-                _loggers = new ConcurrentDictionary<Type, ILogger>();
-            }
+            _loggers ??= new ConcurrentDictionary<Type, ILogger>();
 
-            return _loggers.GetOrAdd(type, _ => new Logger(type, _level));
+            return _loggers.GetOrAdd(type, type => new Logger(type, _level));
         }
 
         public bool IsEnabled(ILogger logger, LogEventLevel level)

dotnet/src/webdriver/Internal/Logging/LogContextManager.cs

@@ -17,45 +17,31 @@
 // under the License.
 // </copyright>
 
+using System.Diagnostics.CodeAnalysis;
 using System.Threading;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     internal class LogContextManager
     {
-        private readonly ILogContext _globalLogContext;
-
-        private readonly AsyncLocal<ILogContext> _currentAmbientLogContext = new AsyncLocal<ILogContext>();
+        private readonly AsyncLocal<ILogContext?> _currentAmbientLogContext = new AsyncLocal<ILogContext?>();
 
         public LogContextManager()
         {
             var defaulConsoleLogHandler = new ConsoleLogHandler();
 
-            _globalLogContext = new LogContext(LogEventLevel.Info, null, null, new[] { defaulConsoleLogHandler });
+            GlobalContext = new LogContext(LogEventLevel.Info, null, null, new[] { defaulConsoleLogHandler });
         }
 
-        public ILogContext GlobalContext
-        {
-            get { return _globalLogContext; }
-        }
+        public ILogContext GlobalContext { get; }
 
+        [AllowNull]
         public ILogContext CurrentContext
         {
-            get
-            {
-                if (_currentAmbientLogContext.Value is null)
-                {
-                    return _globalLogContext;
-                }
-                else
-                {
-                    return _currentAmbientLogContext.Value;
-                }
-            }
-            set
-            {
-                _currentAmbientLogContext.Value = value;
-            }
+            get => _currentAmbientLogContext.Value ?? GlobalContext;
+            set => _currentAmbientLogContext.Value = value;
         }
     }
 }

dotnet/src/webdriver/Internal/Logging/LogEvent.cs

@@ -19,6 +19,8 @@
 
 using System;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     /// <summary>
@@ -33,12 +35,13 @@ public sealed class LogEvent
         /// <param name="timestamp">The timestamp of the log event.</param>
         /// <param name="level">The level of the log event.</param>
         /// <param name="message">The message of the log event.</param>
+        /// <exception cref="ArgumentNullException">If <paramref name="issuedBy"/> or <paramref name="message"/> are <see langword="null"/>.</exception>
         public LogEvent(Type issuedBy, DateTimeOffset timestamp, LogEventLevel level, string message)
         {
-            IssuedBy = issuedBy;
+            IssuedBy = issuedBy ?? throw new ArgumentNullException(nameof(issuedBy));
             Timestamp = timestamp;
             Level = level;
-            Message = message;
+            Message = message ?? throw new ArgumentNullException(nameof(message));
         }
 
         /// <summary>

dotnet/src/webdriver/Internal/Logging/LogEventLevel.cs

@@ -17,6 +17,8 @@
 // under the License.
 // </copyright>
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     /// <summary>

dotnet/src/webdriver/Internal/Logging/LogHandlerList.cs

@@ -19,13 +19,15 @@
 
 using System.Collections.Generic;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     /// <summary>
     /// Represents a list of log handlers.
     /// </summary>
     /// <inheritdoc cref="ILogHandlerList"/>
-    internal class LogHandlerList : List<ILogHandler>, ILogHandlerList
+    internal sealed class LogHandlerList : List<ILogHandler>, ILogHandlerList
     {
         private readonly ILogContext _logContext;
 

dotnet/src/webdriver/Internal/Logging/Logger.cs

@@ -19,13 +19,15 @@
 
 using System;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal.Logging
 {
     /// <summary>
     /// The implementation of the <see cref="ILogger"/> interface through which log messages are emitted.
     /// </summary>
     /// <inheritdoc cref="ILogger"/>
-    internal class Logger : ILogger
+    internal sealed class Logger : ILogger
     {
         public Logger(Type issuer, LogEventLevel level)
         {