test: Add a test for TimeSpan properties

test/Extensionsions.Configuration.Object.UnitTests/TimeSpanTest.cs

@@ -0,0 +1,20 @@
+using AutoFixture.Xunit2;
+using FluentAssertions;
+using Microsoft.Extensions.Configuration;
+using System;
+using Xunit;
+
+namespace Extensions.Configuration.Object.UnitTests;
+
+public class TimeSpanTest
+{
+    [Theory, AutoData]
+    public void AddObject_WithTimeSpan_ShouldLoadFieldsIntoConfiguration(TimeSpan expected)
+    {
+        var configuration = new ConfigurationBuilder()
+            .AddObject(new { MyTimeSpan = expected })
+            .Build();
+
+        configuration[$"MyTimeSpan"].Should().Be(expected.ToString());
+    }
+}