Refactor `TryToMapCollection` method.

framework/src/Volo.Abp.ObjectMapping/Volo/Abp/ObjectMapping/DefaultObjectMapper.cs

@@ -55,13 +55,9 @@ public class DefaultObjectMapper : IObjectMapper, ITransientDependency
                 return specificMapper.Map(source);
             }
 
-            if (!(typeof(TSource).IsEnum || typeof(TSource).IsPrimitive))
+            if (TryToMapCollection<TSource, TDestination>(scope, source, default, out var collectionResult))
             {
-                var result = TryToMapCollection<TSource, TDestination>(scope, source, default);
-                if (result != null)
-                {
-                    return result;
-                }
+                return collectionResult;
             }
         }
 
@@ -103,10 +99,9 @@ public class DefaultObjectMapper : IObjectMapper, ITransientDependency
                 return specificMapper.Map(source, destination);
             }
 
-            var result = TryToMapCollection(scope, source, destination);
-            if (result != null)
+            if (TryToMapCollection(scope, source, destination, out var collectionResult))
             {
-                return result;
+                return collectionResult;
             }
         }
 
@@ -125,11 +120,12 @@ public class DefaultObjectMapper : IObjectMapper, ITransientDependency
         return AutoMap(source, destination);
     }
 
-    protected virtual TDestination? TryToMapCollection<TSource, TDestination>(IServiceScope serviceScope, TSource source, TDestination? destination)
+    protected virtual bool TryToMapCollection<TSource, TDestination>(IServiceScope serviceScope, TSource source, TDestination? destination, out TDestination collectionResult)
     {
         if (!IsCollectionGenericType<TSource, TDestination>(out var sourceArgumentType, out var destinationArgumentType, out var definitionGenericType))
         {
-            return default;
+            collectionResult = default!;
+            return false;
         }
 
         var mapperType = typeof(IObjectMapper<,>).MakeGenericType(sourceArgumentType, destinationArgumentType);
@@ -137,7 +133,8 @@ public class DefaultObjectMapper : IObjectMapper, ITransientDependency
         if (specificMapper == null)
         {
             //skip, no specific mapper
-            return default;
+            collectionResult = default!;
+            return false;
         }
 
         var cacheKey = $"{mapperType.FullName}_{(destination == null ? "MapMethodWithSingleParameter" : "MapMethodWithDoubleParameters")}";
@@ -212,11 +209,13 @@ public class DefaultObjectMapper : IObjectMapper, ITransientDependency
         if (destination != null && destination.GetType().IsArray)
         {
             //Return the new collection if destination is an array,  We won't change array just same behavior as AutoMapper.
-            return (TDestination)result;
+            collectionResult = (TDestination)result;
+            return true;
         }
 
         //Return the destination if destination exists. The parameter reference equals with return object.
-        return destination ?? (TDestination)result;
+        collectionResult = destination ?? (TDestination)result;
+        return true;
     }
 
     protected virtual bool IsCollectionGenericType<TSource, TDestination>(out Type sourceArgumentType, out Type destinationArgumentType, out Type definitionGenericType)

framework/test/Volo.Abp.AutoMapper.Tests/Volo/Abp/AutoMapper/AbpAutoMapperModule_Basic_Tests.cs

@@ -41,7 +41,7 @@ public class AbpAutoMapperModule_Basic_Tests : AbpIntegratedTest<AutoMapperTestM
     public void Should_Map_Enum()
     {
         var dto = _objectMapper.Map<MyEnum, MyEnumDto>(MyEnum.Value3);
-        dto.ShouldBe(MyEnumDto.Value3);
+        dto.ShouldBe(MyEnumDto.Value2); //Value2 is same as Value3
     }
 
     //[Fact] TODO: Disabled because of https://github.com/AutoMapper/AutoMapper/pull/2379#issuecomment-355899664

framework/test/Volo.Abp.AutoMapper.Tests/Volo/Abp/AutoMapper/SampleClasses/MyEnum.cs

@@ -1,8 +1,8 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+namespace Volo.Abp.AutoMapper.SampleClasses;
 
-namespace Volo.Abp.AutoMapper.SampleClasses;
-public enum MyEnum { Value1, Value2, Value3 };
+public enum MyEnum
+{
+    Value1 = 1,
+    Value2,
+    Value3
+}

framework/test/Volo.Abp.AutoMapper.Tests/Volo/Abp/AutoMapper/SampleClasses/MyEnumDto.cs

@@ -1,8 +1,8 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
+namespace Volo.Abp.AutoMapper.SampleClasses;
 
-namespace Volo.Abp.AutoMapper.SampleClasses;
-public enum MyEnumDto { Value1, Value2, Value3 };
+public enum MyEnumDto
+{
+    Value1 = 2,
+    Value2,
+    Value3
+}