change list to UseTargetValue on mapping to target

src/Mapster.Tests/Mapster.Tests.csproj

@@ -9,7 +9,7 @@
  <PublicSign Condition=" '$(OS)' != 'Windows_NT' ">true</PublicSign>
  </PropertyGroup>
  <ItemGroup>
- <PackageReference Include="ExpressionDebugger" Version="2.0.0" />
+ <PackageReference Include="ExpressionDebugger" Version="2.1.2" />
  <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.9.0" />
  <PackageReference Include="MSTest.TestAdapter" Version="1.4.0" />
  <PackageReference Include="MSTest.TestFramework" Version="1.4.0" />

src/Mapster.Tests/WhenMappingToTarget.cs

@@ -1,4 +1,5 @@
 using System.Collections.Generic;
+using System.Linq.Expressions;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Shouldly;
 
@@ -18,13 +19,13 @@ public void MappingToTarget_With_SameList()
  b.List.ShouldBe(new List<int>{1,2,3});
  }
 
- internal class Foo
+ public class Foo
  {
  public double A { get; set; }
  public List<int> List { get; set; }
  }
 
- internal class Bar
+ public class Bar
  {
  public double A { get; set; }
  public List<int> List { get; set; }

src/Mapster/Adapters/ArrayAdapter.cs

@@ -9,6 +9,7 @@ namespace Mapster.Adapters
  public class ArrayAdapter : BaseAdapter
  {
  protected override int Score => -123;
+ protected override ObjectType ObjectType => ObjectType.Collection;
 
  protected override bool CanMap(PreCompileArgument arg)
  {

src/Mapster/Adapters/BaseAdapter.cs

@@ -188,9 +188,19 @@ protected Expression CreateBlockExpressionBody(Expression source, Expression? de
  );
  }
 
- var result = Expression.Variable(arg.DestinationType, "result");
+ //if (object.ReferenceEquals(source, destination))
+ // return destination;
+ if (destination != null && 
+ !source.Type.GetTypeInfo().IsValueType &&
+ !destination.Type.GetTypeInfo().IsValueType &&
+ (source.Type.IsAssignableFrom(destination.Type) || destination.Type.IsAssignableFrom(source.Type)))
+ {
+ var refEquals = Expression.Call(typeof(object), nameof(ReferenceEquals), null, source, destination);
+ blocks.Add(Expression.IfThen(refEquals, Expression.Return(label, destination)));
+ }
 
  //var result = new TDest();
+ var result = Expression.Variable(arg.DestinationType, "result");
  var assign = Expression.Assign(result, set);
  var assignActions = new List<Expression> {assign};
 

src/Mapster/Adapters/CollectionAdapter.cs

@@ -11,7 +11,7 @@ namespace Mapster.Adapters
  internal class CollectionAdapter : BaseAdapter
  {
  protected override int Score => -125;
- protected override bool UseTargetValue => false;
+ protected override bool UseTargetValue => true;
  protected override ObjectType ObjectType => ObjectType.Collection;
 
  protected override bool CanMap(PreCompileArgument arg)
@@ -76,20 +76,32 @@ protected override Expression CreateInstantiationExpression(Expression source, E
  protected override Expression CreateBlockExpression(Expression source, Expression destination, CompileArgument arg)
  {
  var destinationElementType = destination.Type.ExtractCollectionType();
- var listType = destination.Type.GetGenericEnumerableType() != null
- ? typeof(ICollection<>).MakeGenericType(destinationElementType)
- : typeof(IList);
+ var shouldConvert = destination.Type.GetMethod("Add", new[] { destinationElementType }) == null;
 
- if (listType == destination.Type)
- return CreateListSet(source, destination, arg);
+ //var list = (ICollection<>)dest;
+ var actions = new List<Expression>();
+ var list = destination;
+ if (shouldConvert)
+ {
+ var listType = destination.Type.GetGenericEnumerableType() != null
+ ? typeof(ICollection<>).MakeGenericType(destinationElementType)
+ : typeof(IList);
+ list = Expression.Variable(listType, "list");
+ actions.Add(ExpressionEx.Assign(list, destination)); //convert to list type
+ }
 
- var tmp = Expression.Variable(listType, "list");
- var actions = new List<Expression>
+ //list.Clear();
+ if (arg.MapType == MapType.MapToTarget)
  {
- ExpressionEx.Assign(tmp, destination), //convert to list type
- CreateListSet(source, tmp, arg)
- };
- return Expression.Block(new[] { tmp }, actions);
+ var clear = list.Type.GetMethod("Clear", Type.EmptyTypes);
+ actions.Add(Expression.Call(list, clear));
+ }
+
+ actions.Add(CreateListSet(source, list, arg));
+
+ if (shouldConvert)
+ return Expression.Block(new[] { (ParameterExpression)list }, actions);
+ return Expression.Block(actions);
  }
 
  protected override Expression CreateInlineExpression(Expression source, CompileArgument arg)

src/Mapster/Adapters/DictionaryAdapter.cs

@@ -11,8 +11,8 @@ namespace Mapster.Adapters
  internal class DictionaryAdapter : ClassAdapter
  {
  public static int DefaultScore { get; } = -124;
-
  protected override int Score => DefaultScore; //must do before CollectionAdapter
+ protected override ObjectType ObjectType => ObjectType.Collection;
 
  protected override bool CanMap(PreCompileArgument arg)
  {

src/Mapster/Adapters/MultiDimensionalArrayAdapter.cs

@@ -10,6 +10,7 @@ namespace Mapster.Adapters
  public class MultiDimensionalArrayAdapter : BaseAdapter
  {
  protected override int Score => -122;
+ protected override ObjectType ObjectType => ObjectType.Collection;
 
  protected override bool CanMap(PreCompileArgument arg)
  {