Correct merge for references

Indemos · May 13, 2023 · 6f50383 · 6f50383
1 parent ceb81b3
commit 6f50383
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Showing 3 changed files with 11 additions and 5 deletions.
diff --git a/Libs/ExpressionMapper.csproj b/Libs/ExpressionMapper.csproj
@@ -9,7 +9,7 @@
   <PropertyGroup>
     <IsPackable>true</IsPackable>
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
-    <Version>1.0.0</Version>
+    <Version>1.0.1</Version>
     <Description>Simpler alternative to Automapper.</Description>
     <Authors>artemiusgreat</Authors>
     <Copyright>indemos.com</Copyright>

diff --git a/Libs/Mapper.cs b/Libs/Mapper.cs
@@ -59,9 +59,12 @@ private static Func<TI, TO, TO> CreateMerge()
       {
         if (sourceMembers.TryGetValue(o.Name, out var sourceProperty))
         {
-          return sourceProperty.Type.IsValueType ?
-            Expression.Bind(o, sourceProperty) :
-            Expression.Bind(o, Expression.Coalesce(sourceProperty, Expression.Property(output, o)));
+          var isValue = sourceProperty.Type.IsValueType;
+          var isNullable = Nullable.GetUnderlyingType(sourceProperty.Type);
+
+          return isNullable is not null || isValue is false ?
+            Expression.Bind(o, Expression.Coalesce(sourceProperty, Expression.Property(output, o))) :
+            Expression.Bind(o, sourceProperty);
         }
 
         return Expression.Bind(o, Expression.Property(output, o));

diff --git a/Tests/Maps.cs b/Tests/Maps.cs
@@ -7,12 +7,14 @@ public class Maps
     public class A
     {
       public int Id { get; set; }
+      public int? Count { get; set; }
       public string Name { get; set; }
     }
 
     public class B
     {
       public int Id { get; set; }
+      public int? Count { get; set; }
       public string Name { get; set; }
       public string Description { get; set; }
       public A Link { get; set; }
@@ -35,11 +37,12 @@ public void MergeSameTypes()
     public void Merge()
     {
       var source = new A { Id = 1 };
-      var destination = new B { Id = 2, Name = "2", Link = new A { Id = 3 }};
+      var destination = new B { Id = 2, Count = 5, Name = "2", Link = new A { Id = 3 }};
 
       var merge = Mapper<A, B>.Merge(source, destination);
 
       Assert.Equal(1, merge.Id);
+      Assert.Equal(5, merge.Count);
       Assert.Equal("2", merge.Name);
       Assert.Equal(3, merge.Link.Id);
       Assert.Equal(destination.Link, merge.Link);