Sealed private classes to fix Sonar smells (#5189)

Author: snakefoot

src/NLog/Config/LoggingConfigurationParser.cs

@@ -1433,7 +1433,7 @@ private static string GetName(Target target)
         /// <summary>
         /// Config element that's validated and having extra context
         /// </summary>
-        private class ValidatedConfigurationElement : ILoggingConfigurationElement
+        private sealed class ValidatedConfigurationElement : ILoggingConfigurationElement
         {
             private static readonly IDictionary<string, string> EmptyDefaultDictionary = new SortHelpers.ReadOnlySingleBucketDictionary<string, string>();
 

src/NLog/Filters/WhenRepeatedFilter.cs

@@ -301,7 +301,7 @@ private FilterResult RefreshFilterInfo(LogEventInfo logEvent, FilterInfo filterI
         /// <summary>
         /// Filter Value State (mutable)
         /// </summary>
-        private class FilterInfo
+        private sealed class FilterInfo
         {
             public FilterInfo(StringBuilder stringBuilder)
             {

src/NLog/Internal/Collections/PropertiesDictionary.cs

@@ -605,7 +605,7 @@ public void Reset()
             }
         }
 
-        private class ParameterEnumerator : DictionaryEnumeratorBase, IEnumerator<MessageTemplateParameter>
+        private sealed class ParameterEnumerator : DictionaryEnumeratorBase, IEnumerator<MessageTemplateParameter>
         {
             /// <inheritDoc/>
             public MessageTemplateParameter Current => CurrentParameter;
@@ -619,7 +619,7 @@ public ParameterEnumerator(PropertiesDictionary dictionary)
             }
         }
 
-        private class DictionaryEnumerator : DictionaryEnumeratorBase, IEnumerator<KeyValuePair<object, object>>
+        private sealed class DictionaryEnumerator : DictionaryEnumeratorBase, IEnumerator<KeyValuePair<object, object>>
         {
             /// <inheritDoc/>
             public KeyValuePair<object, object> Current => CurrentProperty;
@@ -634,7 +634,7 @@ public DictionaryEnumerator(PropertiesDictionary dictionary)
         }
 
         [DebuggerDisplay("Count = {Count}")]
-        private class DictionaryCollection : ICollection<object>
+        private sealed class DictionaryCollection : ICollection<object>
         {
             private readonly PropertiesDictionary _dictionary;
             private readonly bool _keyCollection;
@@ -708,7 +708,7 @@ IEnumerator IEnumerable.GetEnumerator()
                 return GetEnumerator();
             }
 
-            private class DictionaryCollectionEnumerator : DictionaryEnumeratorBase, IEnumerator<object>
+            private sealed class DictionaryCollectionEnumerator : DictionaryEnumeratorBase, IEnumerator<object>
             {
                 private readonly bool _keyCollection;
 
@@ -769,7 +769,7 @@ internal static bool Equals(string x, string y)
         /// Property-Key equality-comparer that uses string-hashcode from OrdinalIgnoreCase
         /// Enables case-insensitive lookup using <see cref="IgnoreCasePropertyKey"/>
         /// </summary>
-        private class PropertyKeyComparer : IEqualityComparer<object>
+        private sealed class PropertyKeyComparer : IEqualityComparer<object>
         {
             public static readonly PropertyKeyComparer Default = new PropertyKeyComparer();
 

src/NLog/Layouts/CSV/CsvLayout.cs

@@ -251,7 +251,7 @@ private bool ColumnValueRequiresQuotes(CsvQuotingMode quoting, StringBuilder sb,
         /// </summary>
         [ThreadAgnostic]
         [AppDomainFixedOutput]
-        private class CsvHeaderLayout : Layout
+        private sealed class CsvHeaderLayout : Layout
         {
             private readonly CsvLayout _parent;
             private string _headerOutput;

src/NLog/SetupSerializationBuilderExtensions.cs

@@ -88,7 +88,7 @@ public static ISetupSerializationBuilder RegisterObjectTransformation(this ISetu
             return setupBuilder;
         }
 
-        private class ObjectTypeTransformation<T> : IObjectTypeTransformer
+        private sealed class ObjectTypeTransformation<T> : IObjectTypeTransformer
         {
             private readonly IObjectTypeTransformer _original;
             private readonly Func<T, object> _transformer;
@@ -111,7 +111,7 @@ public object TryTransformObject(object obj)
             }
         }
 
-        private class ObjectTypeTransformation : IObjectTypeTransformer
+        private sealed class ObjectTypeTransformation : IObjectTypeTransformer
         {
             private readonly IObjectTypeTransformer _original;
             private readonly Func<object, object> _transformer;

tests/PackageLoaderTestAssembly/NLogPackageLoaders.cs

@@ -33,17 +33,16 @@
 
 using System;
 using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
 using NLog;
 using NLog.Config;
 
 namespace LoaderTestPublic
 {
-    public class NLogPackageLoader
+    public sealed class NLogPackageLoader
     {
         public static void Preload()
         {
-
+            // Nothing to do
         }
     }
 }
@@ -53,7 +52,7 @@ namespace LoaderTestInternal
     /// <summary>
     /// private
     /// </summary>
-    internal class NLogPackageLoader
+    internal sealed class NLogPackageLoader
     {
         public static void Preload()
         {
@@ -66,8 +65,7 @@ namespace LoaderTestPrivateNested
 {
     internal class SomeType
     {
-        [SuppressMessage("ReSharper", "UnusedMember.Local")]
-        private class NLogPackageLoader
+        private sealed class NLogPackageLoader
         {
             public static void Preload(ConfigurationItemFactory fact)
             {
@@ -82,9 +80,8 @@ public static void Preload(ConfigurationItemFactory fact)
 
 namespace LoaderTestPrivateNestedStatic
 {
-    internal class SomeType
+    internal sealed class SomeType
     {
-        [SuppressMessage("ReSharper", "UnusedMember.Local")]
         private static class NLogPackageLoader
         {
             public static void Preload()
@@ -97,7 +94,7 @@ public static void Preload()
 
 namespace LoaderTestWrong1
 {
-    public class NLogPackageLoader
+    public sealed class NLogPackageLoader
     {
         [DebuggerStepThrough]
         public static void Preload()
@@ -109,7 +106,7 @@ public static void Preload()
 
 namespace LoaderTestWrong2
 {
-    public class NLogPackageLoader
+    public sealed class NLogPackageLoader
     {
         public void Preload()
         {
@@ -120,7 +117,7 @@ public void Preload()
 
 namespace LoaderTestWrong3
 {
-    public class NLogPackageLoader
+    public sealed class NLogPackageLoader
     {
         public static void Preload(int arg1, int arg2)
         {