Add Source test

SabreTools.DatItems.Test/SourceTests.cs

@@ -0,0 +1,23 @@
+using Xunit;
+
+namespace SabreTools.DatItems.Test
+{
+    public class SourceTests
+    {
+        #region Clone
+
+        [Fact]
+        public void CloneTest()
+        {
+            Source item = new Source(1, source: "src");
+
+            object clone = item.Clone();
+            Source? actual = clone as Source;
+            Assert.NotNull(actual);
+            Assert.Equal(1, actual.Index);
+            Assert.Equal("src", actual.Name);
+        }
+
+        #endregion
+    }
+}

SabreTools.DatItems/Source.cs

@@ -10,12 +10,12 @@ namespace SabreTools.DatItems
         /// <summary>
         /// Source index
         /// </summary>
-        public int Index { get; }
+        public readonly int Index;
 
         /// <summary>
         /// Source name
         /// </summary>
-        public string? Name { get; }
+        public readonly string? Name;
 
         /// <summary>
         /// Constructor
@@ -33,10 +33,7 @@ namespace SabreTools.DatItems
         /// <summary>
         /// Clone the current object
         /// </summary>
-        public object Clone()
-        {
-            return new Source(Index, Name);
-        }
+        public object Clone() => new Source(Index, Name);
 
         #endregion
     }