NullPropagate property path

src/.editorconfig

@@ -0,0 +1,10 @@
+[*.cs]
+
+# S3220: Method calls should not resolve ambiguously to overloads with "params"
+dotnet_diagnostic.S3220.severity = suggestion
+
+# RCS1238: Avoid nested ?: operators.
+dotnet_diagnostic.RCS1238.severity = suggestion
+
+# S3358: Ternary operators should not be nested
+dotnet_diagnostic.S3358.severity = suggestion

src/Mapster.Tests/WhenMappingWithPath.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Linq.Expressions;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Shouldly;
 
@@ -42,6 +43,23 @@ public void MapPath()
  dto2.Address.Number.ShouldBe(poco.Child.Address.Number + "test");
  }
 
+ [TestMethod]
+ public void MapPath_AllowNull()
+ {
+ TypeAdapterConfig.GlobalSettings.Compiler = exp => exp.CompileWithDebugInfo();
+ TypeAdapterConfig<Poco, Dto>.NewConfig()
+ .Map(dest => dest.Location, src => src.Child.Address.Location);
+
+ var poco = new Poco
+ {
+ Id = Guid.NewGuid(),
+ Child = new ChildPoco()
+ };
+ var dto = poco.Adapt<Dto>();
+ dto.Id.ShouldBe(poco.Id);
+ dto.Location.ShouldBeNull();
+ }
+
  [TestMethod]
  public void MapPath_Condition()
  {
@@ -156,6 +174,7 @@ public class Dto
  {
  public Guid Id { get; set; }
  public Address Address { get; set; }
+ public string Location { get; set; }
  }
  }
 }

src/Mapster.sln

@@ -1,10 +1,11 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 15
-VisualStudioVersion = 15.0.26228.4
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.29709.97
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Solution Items", "Solution Items", "{A5580F9D-0F5F-4224-980F-7824536A627D}"
  ProjectSection(SolutionItems) = preProject
+ .editorconfig = .editorconfig
  ..\LICENSE = ..\LICENSE
  ..\README.md = ..\README.md
  EndProjectSection

src/Mapster/Adapters/ClassAdapter.cs

@@ -108,7 +108,7 @@ protected override Expression CreateBlockExpression(Expression source, Expressio
  var destMember = arg.MapType == MapType.MapToTarget || member.UseDestinationValue
  ? member.DestinationMember.GetExpression(destination)
  : null;
- 
+
  var adapt = CreateAdaptExpression(member.Getter, member.DestinationMember.Type, arg, member, destMember);
  if (!member.UseDestinationValue)
  {
@@ -192,7 +192,7 @@ protected override Expression CreateBlockExpression(Expression source, Expressio
  {
  value = member.Getter.NullPropagate(value);
  }
- var bind = Expression.Bind((MemberInfo)member.DestinationMember.Info, value);
+ var bind = Expression.Bind((MemberInfo)member.DestinationMember.Info!, value);
  lines.Add(bind);
  }
 

src/Mapster/Adapters/MultiDimensionalArrayAdapter.cs

@@ -38,7 +38,7 @@ private static IEnumerable<Expression> GetArrayBounds(Expression source, Type de
  {
  yield return Expression.Constant(1);
  }
- yield return ExpressionEx.CreateCountExpression(source, true);
+ yield return ExpressionEx.CreateCountExpression(source, true)!;
  }
  else
  {
@@ -66,8 +66,8 @@ protected override Expression CreateBlockExpression(Expression source, Expressio
  var method = typeof(Array).GetMethod("Copy", new[] { typeof(Array), typeof(int), typeof(Array), typeof(int), typeof(int) });
  return Expression.Call(method, source, Expression.Constant(0), destination, Expression.Constant(0), ExpressionEx.CreateCountExpression(source, true));
  }
- else
-  return CreateArraySet(source, destination, arg);
+
+ return CreateArraySet(source, destination, arg);
  }
 
  protected override Expression CreateInlineExpression(Expression source, CompileArgument arg)
@@ -103,7 +103,7 @@ private Expression CreateArraySet(Expression source, Expression destination, Com
 
  var method = typeof(Array).GetMethod("GetLength", new[] { typeof(int) });
  block.AddRange(
- vlenx.Select((vlen, i) => 
+ vlenx.Select((vlen, i) =>
  Expression.Assign(
  vlen,
  Expression.Call(destination, method, Expression.Constant(i)))));

src/Mapster/Mapster.csproj

@@ -19,7 +19,7 @@
  <RootNamespace>Mapster</RootNamespace>
  <Version>5.0.0-PRE4</Version>
  <LangVersion>8.0</LangVersion>
- <Nullable Condition="'$(TargetFramework)' == 'netcoreapp3.0'">enable</Nullable>
+ <Nullable>enable</Nullable>
  </PropertyGroup>
  <ItemGroup Condition="'$(TargetFramework)' == 'net40'">
  <Reference Include="Microsoft.CSharp" />
@@ -37,4 +37,7 @@
  <PackageReference Include="Microsoft.CSharp" Version="4.3.0" />
  <PackageReference Include="System.Reflection.Emit" Version="4.3.0" />
  </ItemGroup>
+ <ItemGroup>
+ <None Include="..\.editorconfig" Link=".editorconfig" />
+ </ItemGroup>
 </Project>

src/Mapster/Models/InvokerModel.cs

@@ -6,7 +6,7 @@ namespace Mapster.Models
  public class InvokerModel
  {
  public string DestinationMemberName { get; set; }
- public LambdaExpression Invoker { get; set; }
+ public LambdaExpression? Invoker { get; set; }
  public string? SourceMemberName { get; set; }
  public LambdaExpression? Condition { get; set; }
  public bool IsChildPath { get; set; }
@@ -24,10 +24,26 @@ public class InvokerModel
  : Expression.Lambda(this.Condition.Apply(source), source),
  Invoker = this.IsChildPath
  ? this.Invoker
- : Expression.Lambda(this.Invoker?.Apply(source) ?? ExpressionEx.PropertyOrField(source, this.SourceMemberName!), source),
+ : Expression.Lambda(this.GetInvokingExpression(source), source),
  SourceMemberName = this.SourceMemberName,
  IsChildPath = true,
  };
  }
+
+ public Expression GetInvokingExpression(Expression exp, MapType mapType = MapType.Map)
+ {
+ if (this.IsChildPath)
+ return this.Invoker!.Body;
+ return this.SourceMemberName != null
+ ? ExpressionEx.PropertyOrFieldPath(exp, this.SourceMemberName)
+ : this.Invoker!.Apply(mapType, exp);
+ }
+
+ public Expression? GetConditionExpression(Expression exp, MapType mapType = MapType.Map)
+ {
+ return this.IsChildPath
+ ? this.Condition?.Body
+ : this.Condition?.Apply(mapType, exp);
+ }
  }
 }

src/Mapster/Settings/ValueAccessingStrategy.cs

@@ -28,7 +28,7 @@ public static class ValueAccessingStrategy
  {
  var config = arg.Settings;
  var resolvers = config.Resolvers;
- if (resolvers == null || resolvers.Count <= 0)
+ if (resolvers == null || resolvers.Count == 0)
  return null;
 
  var invokes = new List<Tuple<Expression, Expression>>();
@@ -38,21 +38,15 @@ public static class ValueAccessingStrategy
  {
  if (!destinationMember.Name.Equals(resolver.DestinationMemberName))
  continue;
- var invoke = resolver.Invoker == null
- ? ExpressionEx.PropertyOrField(source, resolver.SourceMemberName)
- : resolver.IsChildPath
- ? resolver.Invoker.Body
- : resolver.Invoker.Apply(arg.MapType, source);
 
- if (resolver.Condition == null)
+ var invoke = resolver.GetInvokingExpression(source, arg.MapType);
+ var condition = resolver.GetConditionExpression(source, arg.MapType);
+ if (condition == null)
  {
  getter = invoke;
  break;
  }
 
- var condition = resolver.IsChildPath
- ? resolver.Condition.Body
- : resolver.Condition.Apply(arg.MapType, source);
  invokes.Add(Tuple.Create(condition, invoke));
  }
 
@@ -208,7 +202,7 @@ private static IEnumerable<string> GetDeepUnflattening(IMemberModel destinationM
  {
  var config = arg.Settings;
  var resolvers = config.Resolvers;
- if (resolvers == null || resolvers.Count <= 0)
+ if (resolvers == null || resolvers.Count == 0)
  return null;
  var dictType = source.Type.GetDictionaryType();
  if (dictType == null)
@@ -217,24 +211,24 @@ private static IEnumerable<string> GetDeepUnflattening(IMemberModel destinationM
  var method = typeof(MapsterHelper).GetMethods().First(m => m.Name == nameof(MapsterHelper.GetValueOrDefault)).MakeGenericMethod(args);
 
  Expression? getter = null;
- LambdaExpression? lastCondition = null;
+ Expression? lastCondition = null;
  foreach (var resolver in resolvers)
  {
  if (!destinationMember.Name.Equals(resolver.DestinationMemberName))
  continue;
 
  Expression invoke = resolver.Invoker == null
  ? Expression.Call(method, source.To(dictType), Expression.Constant(resolver.SourceMemberName))
- : resolver.Invoker.Apply(arg.MapType, source);
+ : resolver.GetInvokingExpression(source, arg.MapType);
  getter = lastCondition != null
- ? Expression.Condition(lastCondition.Apply(arg.MapType, source), getter, invoke)
+ ? Expression.Condition(lastCondition, getter, invoke)
  : invoke;
- lastCondition = resolver.Condition;
- if (resolver.Condition == null)
+ lastCondition = resolver.GetConditionExpression(source, arg.MapType);
+ if (lastCondition == null)
  break;
  }
  if (lastCondition != null)
- getter = Expression.Condition(lastCondition.Apply(arg.MapType, source), getter!, getter!.Type.CreateDefault());
+ getter = Expression.Condition(lastCondition, getter!, getter!.Type.CreateDefault());
  return getter;
  }
  }

src/Mapster/TypeAdapterConfig.cs

@@ -4,9 +4,9 @@
 using System.Linq;
 using System.Linq.Expressions;
 using System.Reflection;
+using System.Runtime.CompilerServices;
 using Mapster.Adapters;
 using Mapster.Utils;
-using System.Runtime.CompilerServices;
 
 namespace Mapster
 {

src/Mapster/Utils/CoreExtensions.cs

@@ -9,7 +9,7 @@ public static string ToPascalCase(this string name)
  return NameMatchingStrategy.PascalCase(name);
  }
 
-#if !NETCOREAPP3_0
+#if !NETCOREAPP
  public static HashSet<T> ToHashSet<T>(this IEnumerable<T> source)
  {
  return new HashSet<T>(source);

src/Mapster/Utils/Enum.cs

@@ -6,7 +6,7 @@
 
 namespace Mapster.Utils
 {
- public static class Enum<TEnum> where TEnum : struct 
+ public static class Enum<TEnum> where TEnum : struct
  {
  private static readonly Dictionary<string, TEnum> _lookup = ((TEnum[])Enum.GetValues(typeof(TEnum))).ToDictionary(x => x.ToString().ToUpperInvariant(), y => y);
  private static readonly Dictionary<TEnum, string> _reverseLookup = ((TEnum[])Enum.GetValues(typeof(TEnum))).ToDictionary(x => x, y => y.ToString());

src/Mapster/Utils/ExpressionEx.cs

@@ -17,10 +17,10 @@ public static Expression Assign(Expression left, Expression right)
  return Expression.Assign(left, middle);
  }
 
- public static Expression PropertyOrField(Expression expr, string path)
+ public static Expression PropertyOrFieldPath(Expression expr, string path)
  {
  var props = path.Split('.');
- return props.Aggregate(expr, Expression.PropertyOrField);
+ return expr.NullPropagate(props);
  }
 
  private static bool IsReferenceAssignableFrom(this Type destType, Type srcType)
@@ -46,19 +46,14 @@ public static Expression Apply(this LambdaExpression lambda, MapType mapType, pa
  return lambda.Apply(mapType != MapType.Projection, exps);
  }
 
- public static Expression Apply(this LambdaExpression lambda, ParameterExpression p1, ParameterExpression? p2)
+ public static Expression Apply(this LambdaExpression lambda, ParameterExpression p1, ParameterExpression? p2 = null)
  {
  if (p2 == null)
  return lambda.Apply(false, p1);
  else
  return lambda.Apply(false, p1, p2);
  }
 
- public static Expression Apply(this LambdaExpression lambda, params ParameterExpression[] exps)
- {
- return lambda.Apply(false, exps.Cast<Expression>().ToArray());
- }
-
  private static Expression Apply(this LambdaExpression lambda, bool allowInvoke, params Expression[] exps)
  {
  var replacer = new ParameterExpressionReplacer(lambda.Parameters, exps);
@@ -243,7 +238,7 @@ public static bool CanBeNull(this Expression exp)
  {
  if (!exp.Type.CanBeNull())
  return false;
- 
+
  var visitor = new NullableExpressionVisitor();
  visitor.Visit(exp);
  return visitor.CanBeNull.GetValueOrDefault();
@@ -287,5 +282,21 @@ public static Expression NullPropagate(this Expression exp, Expression value)
  value.Type.CreateDefault(),
  value);
  }
+
+ public static Expression NullPropagate(this Expression exp, string[] props, int i = 0)
+ {
+ if (props.Length <= i)
+ return exp;
+ var head = Expression.PropertyOrField(exp, props[i]);
+ var tail = NullPropagate(head, props, i + 1);
+ if (!exp.CanBeNull())
+ return tail;
+
+ var compareNull = Expression.Equal(exp, Expression.Constant(null, exp.Type));
+ return Expression.Condition(
+ compareNull,
+ tail.Type.CreateDefault(),
+ tail);
+ }
  }
 }

src/Mapster/Utils/NullableExpressionVisitor.cs

@@ -1,6 +1,4 @@
-using System;
-using System.Collections;
-using System.Collections.Generic;
+using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using System.Linq;
 using System.Linq.Expressions;