Add Tests to fix FamilySearch#43 and FamilySearch#48.

- SourceReference.

Gedcomx.Model.Test/SourceReferenceTest.cs

@@ -0,0 +1,66 @@
+using System.Xml.Serialization;
+
+using Gx.Source;
+
+using Newtonsoft.Json;
+
+using NUnit.Framework;
+
+namespace Gedcomx.Model.Test;
+
+/// <summary>
+/// Test calss for <see cref="SourceReference"/>
+/// </summary>
+[TestFixture]
+public class SourceReferenceTest
+{
+    [Test]
+    public void SourceReferenceEmpty()
+    {
+        SourceReference sut = new();
+
+        VerifyXmlSerialization(sut);
+        VerifyJsonSerialization(sut);
+    }
+
+    [Test]
+    public void SourceReferenceObjectInitialization()
+    {
+        SourceReference sut = new()
+        {
+            // ExtensibleData
+            Id = "SR-1",
+            // HypermediaEnabledData
+            Links = { new(), { "rel", new Uri("https://www.familysearch.org/platform/collections/tree") }, { "rel", "template" } },
+            // SourceReference
+            DescriptionRef = "DescriptionRef",
+            Attribution = new(),
+            Qualifiers = { new() },
+            Tags = { new() }
+        };
+
+        VerifyXmlSerialization(sut);
+        VerifyJsonSerialization(sut);
+    }
+
+    private static void VerifyXmlSerialization(SourceReference sut)
+    {
+        XmlSerializer serializer = new(typeof(SourceReference));
+        using MemoryStream stream = new();
+        serializer.Serialize(stream, sut);
+
+        stream.Seek(0, SeekOrigin.Begin);
+        var result = new StreamReader(stream).ReadToEnd();
+        result.ShouldContain(sut);
+    }
+
+    private static void VerifyJsonSerialization(SourceReference sut)
+    {
+        JsonSerializerSettings jsonSettings = new()
+        {
+            NullValueHandling = NullValueHandling.Ignore
+        };
+
+        Assert.DoesNotThrow(() => JsonConvert.DeserializeObject<SourceReference>(JsonConvert.SerializeObject(sut, jsonSettings), jsonSettings));
+    }
+}