Add tests for deserializing guids

tests/Jellyfin.Common.Tests/Json/JsonGuidConverterTests.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Text.Json;
+using MediaBrowser.Common.Json.Converters;
+using Xunit;
+
+namespace Jellyfin.Common.Tests.Extensions
+{
+    public static class JsonGuidConverterTests
+    {
+        [Fact]
+        public static void Deserialize_Valid_Success()
+        {
+            var options = new JsonSerializerOptions();
+            options.Converters.Add(new JsonGuidConverter());
+            Guid value = JsonSerializer.Deserialize<Guid>(@"""a852a27afe324084ae66db579ee3ee18""", options);
+            Assert.Equal(new Guid("a852a27afe324084ae66db579ee3ee18"), value);
+
+            value = JsonSerializer.Deserialize<Guid>(@"""e9b2dcaa-529c-426e-9433-5e9981f27f2e""", options);
+            Assert.Equal(new Guid("e9b2dcaa-529c-426e-9433-5e9981f27f2e"), value);
+        }
+    }
+}