refactor: adopt C# 14 language features

JsonApiToolkit/Controllers/JsonApiController.cs

@@ -28,29 +28,23 @@ namespace JsonApiToolkit.Controllers;
 [ServiceFilter(typeof(JsonApiExceptionFilter))]
 public abstract class JsonApiController : ControllerBase
 {
-    private ILogger<JsonApiController>? _logger;
-    private IJsonApiQueryParser? _queryParser;
-    private JsonApiOptions? _options;
-
     /// <summary>
     /// Gets the logger instance.
     /// </summary>
     protected ILogger<JsonApiController> Logger =>
-        _logger ??= HttpContext.RequestServices.GetRequiredService<ILogger<JsonApiController>>();
+        field ??= HttpContext.RequestServices.GetRequiredService<ILogger<JsonApiController>>();
 
     /// <summary>
     /// Gets the query parser service.
     /// </summary>
     protected IJsonApiQueryParser QueryParser =>
-        _queryParser ??= HttpContext.RequestServices.GetRequiredService<IJsonApiQueryParser>();
+        field ??= HttpContext.RequestServices.GetRequiredService<IJsonApiQueryParser>();
 
     /// <summary>
     /// Gets the configured JsonApiOptions.
     /// </summary>
     protected JsonApiOptions Options =>
-        _options ??= HttpContext
-            .RequestServices.GetRequiredService<IOptions<JsonApiOptions>>()
-            .Value;
+        field ??= HttpContext.RequestServices.GetRequiredService<IOptions<JsonApiOptions>>().Value;
 
     /// <summary>
     /// Parses JSON:API query parameters (filter, sort, page, include).

JsonApiToolkit/Extensions/Projection/DynamicTypeBuilder.cs

@@ -9,19 +9,19 @@ namespace JsonApiToolkit.Extensions.Projection;
 /// </summary>
 internal static class DynamicTypeBuilder
 {
-    private static readonly AssemblyBuilder s_assemblyBuilder;
-    private static readonly ModuleBuilder s_moduleBuilder;
-    private static readonly object s_buildLock = new();
-    private static int s_typeCounter;
+    private static readonly AssemblyBuilder _assemblyBuilder;
+    private static readonly ModuleBuilder _moduleBuilder;
+    private static readonly Lock _buildLock = new();
+    private static int _typeCounter;
 
     static DynamicTypeBuilder()
     {
         var assemblyName = new AssemblyName("JsonApiToolkit.Projections");
-        s_assemblyBuilder = AssemblyBuilder.DefineDynamicAssembly(
+        _assemblyBuilder = AssemblyBuilder.DefineDynamicAssembly(
             assemblyName,
             AssemblyBuilderAccess.Run
         );
-        s_moduleBuilder = s_assemblyBuilder.DefineDynamicModule("MainModule");
+        _moduleBuilder = _assemblyBuilder.DefineDynamicModule("MainModule");
     }
 
     /// <summary>
@@ -30,12 +30,12 @@ static DynamicTypeBuilder()
     internal static Type Build(IEnumerable<(string Name, Type PropertyType)> properties)
     {
         // ModuleBuilder is not thread-safe; serialize type creation
-        lock (s_buildLock)
+        lock (_buildLock)
         {
-            int id = ++s_typeCounter;
+            int id = ++_typeCounter;
             string typeName = $"JsonApiProjection_{id}";
 
-            TypeBuilder typeBuilder = s_moduleBuilder.DefineType(
+            TypeBuilder typeBuilder = _moduleBuilder.DefineType(
                 typeName,
                 TypeAttributes.Public
                     | TypeAttributes.Class

JsonApiToolkit/Extensions/StringExtensions.cs

@@ -13,7 +13,7 @@ public static string ToCamelCase(this string str)
         if (string.IsNullOrEmpty(str) || !char.IsUpper(str[0]))
             return str;
 
-        return char.ToLowerInvariant(str[0]) + str.Substring(1);
+        return char.ToLowerInvariant(str[0]) + str[1..];
     }
 
     /// <summary>
@@ -24,6 +24,6 @@ public static string ToPascalCase(this string str)
         if (string.IsNullOrEmpty(str))
             return str;
 
-        return char.ToUpperInvariant(str[0]) + str.Substring(1);
+        return char.ToUpperInvariant(str[0]) + str[1..];
     }
 }