Make the LineEndingExtensions class internal instead of public

Author: 0xced

src/LineEnding.cs

@@ -27,7 +27,7 @@ public enum LineEnding
     /// <summary>
     /// Extensions to the <see cref="LineEnding"/> enum type.
     /// </summary>
-    public static class LineEndingExtensions
+    internal static class LineEndingExtensions
     {
         /// <summary>
         /// Returns a string representation of the specified <paramref name="lineEnding"/>.

tests/LineEndingExtensionsTest.cs

@@ -0,0 +1,18 @@
+using System;
+using FluentAssertions;
+using Xunit;
+
+namespace Serilog.Formatting.Log4Net.Tests
+{
+    public class LineEndingTest
+    {
+        [Fact]
+        public void InvalidLineEnding()
+        {
+            Action action = () => _ = new Log4NetTextFormatter(c => c.UseLineEnding((LineEnding)4));
+
+            action.Should().ThrowExactly<ArgumentOutOfRangeException>()
+                .WithMessage("The value of argument 'lineEnding' (4) is invalid for enum type 'LineEnding'.*");
+        }
+    }
+}

tests/LineEndingTest.cs

@@ -27,10 +27,6 @@ namespace Serilog.Formatting.Log4Net
         LineFeed = 1,
         CarriageReturn = 2,
     }
-    public static class LineEndingExtensions
-    {
-        public static string ToCharacters(this Serilog.Formatting.Log4Net.LineEnding lineEnding) { }
-    }
     public class Log4NetTextFormatter : Serilog.Formatting.ITextFormatter
     {
         public Log4NetTextFormatter() { }