diff --git a/Emby.Naming/AudioBook/AudioBookFilePathParser.cs b/Emby.Naming/AudioBook/AudioBookFilePathParser.cs
index eb9393b0bd..14edd64926 100644
--- a/Emby.Naming/AudioBook/AudioBookFilePathParser.cs
+++ b/Emby.Naming/AudioBook/AudioBookFilePathParser.cs
@@ -1,6 +1,6 @@
+#nullable enable
 #pragma warning disable CS1591
 
-using System;
 using System.Globalization;
 using System.IO;
 using System.Text.RegularExpressions;
@@ -19,12 +19,7 @@ namespace Emby.Naming.AudioBook
 
         public AudioBookFilePathParserResult Parse(string path)
         {
-            if (path == null)
-            {
-                throw new ArgumentNullException(nameof(path));
-            }
-
-            var result = new AudioBookFilePathParserResult();
+            AudioBookFilePathParserResult result = default;
             var fileName = Path.GetFileNameWithoutExtension(path);
             foreach (var expression in _options.AudioBookPartsExpressions)
             {
diff --git a/Emby.Naming/AudioBook/AudioBookFilePathParserResult.cs b/Emby.Naming/AudioBook/AudioBookFilePathParserResult.cs
index e28a58db78..7bfc4479d2 100644
--- a/Emby.Naming/AudioBook/AudioBookFilePathParserResult.cs
+++ b/Emby.Naming/AudioBook/AudioBookFilePathParserResult.cs
@@ -1,8 +1,9 @@
+#nullable enable
 #pragma warning disable CS1591
 
 namespace Emby.Naming.AudioBook
 {
-    public class AudioBookFilePathParserResult
+    public struct AudioBookFilePathParserResult
     {
         public int? PartNumber { get; set; }
 
diff --git a/MediaBrowser.Controller/Extensions/StringExtensions.cs b/MediaBrowser.Controller/Extensions/StringExtensions.cs
index 3cc1f328a9..182c8ef658 100644
--- a/MediaBrowser.Controller/Extensions/StringExtensions.cs
+++ b/MediaBrowser.Controller/Extensions/StringExtensions.cs
@@ -1,3 +1,4 @@
+#nullable enable
 #pragma warning disable CS1591
 
 using System;
@@ -15,11 +16,6 @@ namespace MediaBrowser.Controller.Extensions
     {
         public static string RemoveDiacritics(this string text)
         {
-            if (text == null)
-            {
-                throw new ArgumentNullException(nameof(text));
-            }
-
             var chars = Normalize(text, NormalizationForm.FormD)
                 .Where(ch => CharUnicodeInfo.GetUnicodeCategory(ch) != UnicodeCategory.NonSpacingMark);
 
diff --git a/MediaBrowser.Controller/Library/NameExtensions.cs b/MediaBrowser.Controller/Library/NameExtensions.cs
index 21f33ad190..1c90bb4e02 100644
--- a/MediaBrowser.Controller/Library/NameExtensions.cs
+++ b/MediaBrowser.Controller/Library/NameExtensions.cs
@@ -1,3 +1,4 @@
+#nullable enable
 #pragma warning disable CS1591
 
 using System;
@@ -9,7 +10,7 @@ namespace MediaBrowser.Controller.Library
 {
     public static class NameExtensions
     {
-        private static string RemoveDiacritics(string name)
+        private static string RemoveDiacritics(string? name)
         {
             if (name == null)
             {
diff --git a/tests/Jellyfin.Naming.Tests/AudioBook/AudioBookFileInfoTests.cs b/tests/Jellyfin.Naming.Tests/AudioBook/AudioBookFileInfoTests.cs
new file mode 100644
index 0000000000..a214bc57c4
--- /dev/null
+++ b/tests/Jellyfin.Naming.Tests/AudioBook/AudioBookFileInfoTests.cs
@@ -0,0 +1,30 @@
+using Emby.Naming.AudioBook;
+using Xunit;
+
+namespace Jellyfin.Naming.Tests.AudioBook
+{
+    public class AudioBookFileInfoTests
+    {
+        [Fact]
+        public void CompareTo_Same_Success()
+        {
+            var info = new AudioBookFileInfo();
+            Assert.Equal(0, info.CompareTo(info));
+        }
+
+        [Fact]
+        public void CompareTo_Null_Success()
+        {
+            var info = new AudioBookFileInfo();
+            Assert.Equal(1, info.CompareTo(null));
+        }
+
+        [Fact]
+        public void CompareTo_Empty_Success()
+        {
+            var info1 = new AudioBookFileInfo();
+            var info2 = new AudioBookFileInfo();
+            Assert.Equal(0, info1.CompareTo(info2));
+        }
+    }
+}
diff --git a/tests/Jellyfin.Naming.Tests/Video/ExtraTests.cs b/tests/Jellyfin.Naming.Tests/Video/ExtraTests.cs
index a2722a1753..8dfb8f8591 100644
--- a/tests/Jellyfin.Naming.Tests/Video/ExtraTests.cs
+++ b/tests/Jellyfin.Naming.Tests/Video/ExtraTests.cs
@@ -44,14 +44,14 @@ namespace Jellyfin.Naming.Tests.Video
         }
 
         [Theory]
-        [InlineData(ExtraType.BehindTheScenes, "behind the scenes" )]
-        [InlineData(ExtraType.DeletedScene, "deleted scenes" )]
-        [InlineData(ExtraType.Interview, "interviews" )]
-        [InlineData(ExtraType.Scene, "scenes" )]
-        [InlineData(ExtraType.Sample, "samples" )]
-        [InlineData(ExtraType.Clip, "shorts" )]
-        [InlineData(ExtraType.Clip, "featurettes" )]
-        [InlineData(ExtraType.Unknown, "extras" )]
+        [InlineData(ExtraType.BehindTheScenes, "behind the scenes")]
+        [InlineData(ExtraType.DeletedScene, "deleted scenes")]
+        [InlineData(ExtraType.Interview, "interviews")]
+        [InlineData(ExtraType.Scene, "scenes")]
+        [InlineData(ExtraType.Sample, "samples")]
+        [InlineData(ExtraType.Clip, "shorts")]
+        [InlineData(ExtraType.Clip, "featurettes")]
+        [InlineData(ExtraType.Unknown, "extras")]
         public void TestDirectories(ExtraType type, string dirName)
         {
             Test(dirName + "/300.mp4", type, _videoOptions);
diff --git a/tests/Jellyfin.Server.Implementations.Tests/Library/PathExtensionsTests.cs b/tests/Jellyfin.Server.Implementations.Tests/Library/PathExtensionsTests.cs
index c771f5f4ae..6d768af890 100644
--- a/tests/Jellyfin.Server.Implementations.Tests/Library/PathExtensionsTests.cs
+++ b/tests/Jellyfin.Server.Implementations.Tests/Library/PathExtensionsTests.cs
@@ -10,6 +10,7 @@ namespace Jellyfin.Server.Implementations.Tests.Library
         [InlineData("Superman: Red Son [imdbid=tt10985510]", "imdbid", "tt10985510")]
         [InlineData("Superman: Red Son - tt10985510", "imdbid", "tt10985510")]
         [InlineData("Superman: Red Son", "imdbid", null)]
+        [InlineData("Superman: Red Son", "something", null)]
         public void GetAttributeValue_ValidArgs_Correct(string input, string attribute, string? expectedResult)
         {
             Assert.Equal(expectedResult, PathExtensions.GetAttributeValue(input, attribute));