From 6252b87c1a6b9d63c9868a2535cd9ae181f9bafc Mon Sep 17 00:00:00 2001
From: Sebastian Krysmanski <noreply@manski.net>
Date: Tue, 25 Jun 2024 10:42:34 +0200
Subject: [PATCH] Fix Type.GetDefaultValue() for nullable value types

---
 src/AppMotor.Core/Extensions/TypeExtensions.cs       |  5 +++++
 .../Tests/Extensions/TypeExtensionsTests.cs          | 12 ++++++++++++
 2 files changed, 17 insertions(+)

diff --git a/src/AppMotor.Core/Extensions/TypeExtensions.cs b/src/AppMotor.Core/Extensions/TypeExtensions.cs
index 0a8ff35d..46d497fe 100644
--- a/src/AppMotor.Core/Extensions/TypeExtensions.cs
+++ b/src/AppMotor.Core/Extensions/TypeExtensions.cs
@@ -43,6 +43,11 @@ public static string GetCSharpName(this Type type, bool includeNamespaces = fals
     {
         if (type.IsValueType)
         {
+            if (type.IsNullableValueType())
+            {
+                return null;
+            }
+
             return RuntimeHelpers.GetUninitializedObject(type);
         }
         else
diff --git a/tests/AppMotor.Core.Tests/Tests/Extensions/TypeExtensionsTests.cs b/tests/AppMotor.Core.Tests/Tests/Extensions/TypeExtensionsTests.cs
index 42a6c4f5..d53d5ba5 100644
--- a/tests/AppMotor.Core.Tests/Tests/Extensions/TypeExtensionsTests.cs
+++ b/tests/AppMotor.Core.Tests/Tests/Extensions/TypeExtensionsTests.cs
@@ -37,6 +37,18 @@ public void Test_GetDefaultValue()
         typeof(bool).GetDefaultValue().ShouldBe(false);
     }
 
+    [Fact]
+    public void Test_GetDefaultValue_NullableValueTypes()
+    {
+        // Verify assumptions
+        default(bool?).ShouldBe(null);
+        default(int?).ShouldBe(null);
+
+        // Tests
+        typeof(bool?).GetDefaultValue().ShouldBe(null);
+        typeof(int?).GetDefaultValue().ShouldBe(null);
+    }
+
     /// <summary>
     /// Tests that mutating the default value of a mutable struct doesn't mutate the default value itself.
     /// This version works with regular C# (where such a thing isn't possible - see <see cref="Test_GetDefaultValue_MutableStruct_Reflection"/>).