[dotnet] Annotate Nullable Reference Types on OpenQA.Selenium.Internal

dotnet/src/webdriver/ICapabilities.cs

@@ -19,6 +19,8 @@
 
 using System;
 
+#nullable enable
+
 namespace OpenQA.Selenium
 {
     /// <summary>
@@ -49,6 +51,6 @@ public interface ICapabilities
         /// <param name="capability">The capability to get.</param>
         /// <returns>An object associated with the capability, or <see langword="null"/>
         /// if the capability is not set on the browser.</returns>
-        object GetCapability(string capability);
+        object? GetCapability(string capability);
     }
 }

dotnet/src/webdriver/Internal/AndroidOptions.cs

@@ -19,55 +19,43 @@
 
 using System;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal
 {
     /// <summary>
     /// Provides a base class for options for browsers to be automated on Android.
     /// </summary>
     public class AndroidOptions
     {
-        private string androidPackage;
-        private string androidDeviceSerial;
-        private string androidActivity;
-
         /// <summary>
         /// Initializes a new instance of the <see cref="AndroidOptions"/> class.
         /// </summary>
         /// <param name="androidPackage"></param>
+        /// <exception cref="ArgumentException">If <paramref name="androidPackage"/> is <see langword="null"/> or <see cref="string.Empty"/>.</exception>
         protected AndroidOptions(string androidPackage)
         {
             if (string.IsNullOrEmpty(androidPackage))
             {
                 throw new ArgumentException("The Android package cannot be null or the empty string", nameof(androidPackage));
             }
 
-            this.androidPackage = androidPackage;
+            this.AndroidPackage = androidPackage;
         }
 
         /// <summary>
         /// The package name of the application to automate.
         /// </summary>
-        public string AndroidPackage
-        {
-            get { return this.androidPackage; }
-        }
+        public string AndroidPackage { get; }
 
         /// <summary>
         /// The serial number of the device on which to launch the application.
         /// </summary>
-        public string AndroidDeviceSerial
-        {
-            get { return this.androidDeviceSerial; }
-            set { this.androidDeviceSerial = value; }
-        }
+        public string? AndroidDeviceSerial { get; set; }
 
         /// <summary>
         /// Gets or sets the name of the Activity hosting the app.
         /// </summary>
-        public string AndroidActivity
-        {
-            get { return this.androidActivity; }
-            set { this.androidActivity = value; }
-        }
+        public string? AndroidActivity { get; set; }
     }
 }

dotnet/src/webdriver/Internal/FileUtilities.cs

@@ -23,6 +23,8 @@
 using System.IO;
 using System.Reflection;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal
 {
     /// <summary>
@@ -40,7 +42,7 @@ internal static class FileUtilities
         /// <returns><see langword="true"/> if the copy is completed; otherwise <see langword="false"/>.</returns>
         public static bool CopyDirectory(string sourceDirectory, string destinationDirectory)
         {
-            bool copyComplete = false;
+            bool copyComplete;
             DirectoryInfo sourceDirectoryInfo = new DirectoryInfo(sourceDirectory);
             DirectoryInfo destinationDirectoryInfo = new DirectoryInfo(destinationDirectory);
 
@@ -132,7 +134,7 @@ public static string FindFile(string fileName)
 
             // If it's not in the same directory as the executing assembly,
             // try looking in the system path.
-            string systemPath = Environment.GetEnvironmentVariable("PATH");
+            string? systemPath = Environment.GetEnvironmentVariable("PATH");
             if (!string.IsNullOrEmpty(systemPath))
             {
                 string expandedPath = Environment.ExpandEnvironmentVariables(systemPath);
@@ -165,7 +167,7 @@ public static string FindFile(string fileName)
         public static string GetCurrentDirectory()
         {
             Assembly executingAssembly = typeof(FileUtilities).Assembly;
-            string location = null;
+            string? location = null;
 
             // Make sure not to call Path.GetDirectoryName if assembly location is null or empty
             if (!string.IsNullOrEmpty(executingAssembly.Location))
@@ -184,13 +186,13 @@ public static string GetCurrentDirectory()
                 location = Directory.GetCurrentDirectory();
             }
 
-            string currentDirectory = location;
+            string currentDirectory = location!;
 
             // If we're shadow copying, get the directory from the codebase instead
             if (AppDomain.CurrentDomain.ShadowCopyFiles)
             {
                 Uri uri = new Uri(executingAssembly.CodeBase);
-                currentDirectory = Path.GetDirectoryName(uri.LocalPath);
+                currentDirectory = Path.GetDirectoryName(uri.LocalPath)!;
             }
 
             return currentDirectory;

dotnet/src/webdriver/Internal/IFindsElement.cs

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

dotnet/src/webdriver/Internal/IHasCapabilitiesDictionary.cs

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

dotnet/src/webdriver/Internal/ResourceUtilities.cs

@@ -22,15 +22,17 @@
 using System.Reflection;
 using System.Runtime.InteropServices;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal
 {
     /// <summary>
     /// Encapsulates methods for finding and extracting WebDriver resources.
     /// </summary>
     internal static class ResourceUtilities
     {
-        private static string productVersion;
-        private static string platformFamily;
+        private static string? productVersion;
+        private static string? platformFamily;
 
         /// <summary>
         /// Gets a string representing the informational version of the Selenium product.
@@ -60,18 +62,7 @@ public static string ProductVersion
         /// <summary>
         /// Gets a string representing the platform family on which the Selenium assembly is executing.
         /// </summary>
-        public static string PlatformFamily
-        {
-            get
-            {
-                if (string.IsNullOrEmpty(platformFamily))
-                {
-                    platformFamily = GetPlatformString();
-                }
-
-                return platformFamily;
-            }
-        }
+        public static string PlatformFamily => platformFamily ??= GetPlatformString();
 
         /// <summary>
         /// Gets a <see cref="Stream"/> that contains the resource to use.
@@ -94,7 +85,7 @@ public static string PlatformFamily
         /// </remarks>
         public static Stream GetResourceStream(string fileName, string resourceId)
         {
-            Stream resourceStream = null;
+            Stream? resourceStream;
             string resourceFilePath = Path.Combine(FileUtilities.GetCurrentDirectory(), Path.GetFileName(fileName));
             if (File.Exists(resourceFilePath))
             {
@@ -125,20 +116,22 @@ public static Stream GetResourceStream(string fileName, string resourceId)
 
         private static string GetPlatformString()
         {
-            string platformName = "unknown";
             if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
             {
-                platformName = "windows";
+                return "windows";
             }
             else if (RuntimeInformation.IsOSPlatform(OSPlatform.Linux))
             {
-                platformName = "linux";
+                return "linux";
             }
             else if (RuntimeInformation.IsOSPlatform(OSPlatform.OSX))
             {
-                platformName = "mac";
+                return "mac";
+            }
+            else
+            {
+                return "unknown";
             }
-            return platformName;
         }
     }
 }

dotnet/src/webdriver/Internal/ResponseValueJsonConverter.cs

@@ -22,14 +22,16 @@
 using System.Text.Json;
 using System.Text.Json.Serialization;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal
 {
     /// <summary>
     /// Converts the response to JSON
     /// </summary>
     internal class ResponseValueJsonConverter : JsonConverter<object>
     {
-        public override object Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+        public override object? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
         {
             return ProcessReadToken(ref reader, options);
         }
@@ -67,19 +69,19 @@ public override void Write(Utf8JsonWriter writer, object value, JsonSerializerOp
             }
         }
 
-        private static object ProcessReadToken(ref Utf8JsonReader reader, JsonSerializerOptions options)
+        private static object? ProcessReadToken(ref Utf8JsonReader reader, JsonSerializerOptions options)
         {
             // Recursively processes a token. This is required for elements that next other elements.
-            object processedObject;
+            object? processedObject;
 
             switch (reader.TokenType)
             {
                 case JsonTokenType.StartObject:
                     {
-                        Dictionary<string, object> dictionaryValue = [];
+                        Dictionary<string, object?> dictionaryValue = [];
                         while (reader.Read() && reader.TokenType != JsonTokenType.EndObject)
                         {
-                            string elementKey = reader.GetString();
+                            string elementKey = reader.GetString()!;
                             reader.Read();
                             dictionaryValue.Add(elementKey, ProcessReadToken(ref reader, options));
                         }
@@ -90,7 +92,7 @@ private static object ProcessReadToken(ref Utf8JsonReader reader, JsonSerializer
 
                 case JsonTokenType.StartArray:
                     {
-                        List<object> arrayValue = [];
+                        List<object?> arrayValue = [];
                         while (reader.Read() && reader.TokenType != JsonTokenType.EndArray)
                         {
                             arrayValue.Add(ProcessReadToken(ref reader, options));

dotnet/src/webdriver/Internal/ReturnedCapabilities.cs

@@ -22,13 +22,15 @@
 using System.Collections.ObjectModel;
 using System.Globalization;
 
+#nullable enable
+
 namespace OpenQA.Selenium.Internal
 {
     /// <summary>
     /// Class to Create the capabilities of the browser you require for <see cref="IWebDriver"/>.
     /// If you wish to use default values use the static methods
     /// </summary>
-    internal class ReturnedCapabilities : ICapabilities, IHasCapabilitiesDictionary
+    internal sealed class ReturnedCapabilities : ICapabilities, IHasCapabilitiesDictionary
     {
         private readonly Dictionary<string, object> capabilities = new Dictionary<string, object>();
 
@@ -43,32 +45,26 @@ public ReturnedCapabilities()
         /// Initializes a new instance of the <see cref="ReturnedCapabilities"/> class
         /// </summary>
         /// <param name="rawMap">Dictionary of items for the remote driver</param>
-        public ReturnedCapabilities(Dictionary<string, object> rawMap)
+        public ReturnedCapabilities(Dictionary<string, object>? rawMap)
         {
             if (rawMap != null)
             {
-                foreach (string key in rawMap.Keys)
+                foreach (KeyValuePair<string, object> rawItem in rawMap)
                 {
-                    this.capabilities[key] = rawMap[key];
+                    this.capabilities[rawItem.Key] = rawItem.Value;
                 }
             }
         }
 
         /// <summary>
-        /// Gets the browser name
+        /// Gets the browser name, or <see cref="string.Empty"/> if not specified.
         /// </summary>
         public string BrowserName
         {
             get
             {
-                string name = string.Empty;
-                object capabilityValue = this.GetCapability(CapabilityType.BrowserName);
-                if (capabilityValue != null)
-                {
-                    name = capabilityValue.ToString();
-                }
-
-                return name;
+                object? capabilityValue = this.GetCapability(CapabilityType.BrowserName);
+                return capabilityValue?.ToString() ?? string.Empty;
             }
         }
 
@@ -84,30 +80,24 @@ public object this[string capabilityName]
         {
             get
             {
-                if (!this.capabilities.ContainsKey(capabilityName))
+                if (!this.capabilities.TryGetValue(capabilityName, out object? capabilityValue))
                 {
                     throw new ArgumentException(string.Format(CultureInfo.InvariantCulture, "The capability {0} is not present in this set of capabilities", capabilityName));
                 }
 
-                return this.capabilities[capabilityName];
+                return capabilityValue;
             }
         }
 
         /// <summary>
         /// Gets the underlying Dictionary for a given set of capabilities.
         /// </summary>
-        IDictionary<string, object> IHasCapabilitiesDictionary.CapabilitiesDictionary
-        {
-            get { return this.CapabilitiesDictionary; }
-        }
+        IDictionary<string, object> IHasCapabilitiesDictionary.CapabilitiesDictionary => this.CapabilitiesDictionary;
 
         /// <summary>
         /// Gets the internal capabilities dictionary.
         /// </summary>
-        internal IDictionary<string, object> CapabilitiesDictionary
-        {
-            get { return new ReadOnlyDictionary<string, object>(this.capabilities); }
-        }
+        internal IDictionary<string, object> CapabilitiesDictionary => new ReadOnlyDictionary<string, object>(this.capabilities);
 
         /// <summary>
         /// Gets a value indicating whether the browser has a given capability.
@@ -125,15 +115,14 @@ public bool HasCapability(string capability)
         /// <param name="capability">The capability to get.</param>
         /// <returns>An object associated with the capability, or <see langword="null"/>
         /// if the capability is not set on the browser.</returns>
-        public object GetCapability(string capability)
+        public object? GetCapability(string capability)
         {
-            object capabilityValue = null;
-            if (this.capabilities.ContainsKey(capability))
+            if (this.capabilities.TryGetValue(capability, out object? capabilityValue))
             {
-                capabilityValue = this.capabilities[capability];
+                return capabilityValue;
             }
 
-            return capabilityValue;
+            return null;
         }
 
         /// <summary>