Cannot map properties that have differt names and init access modifier

Hi,
I have a problem with version 7.4. If I want to map two properties with different names and the destination has a different name and the init modifier, Mapster throws a NullReferenceException. This happens when in the configuration of Mapster I set PreserveReference to true.

Here's the code

{
    public Mapper Mapper { get; }

    public MapsterTest()
    {
        var config = new TypeAdapterConfig();
        config.Default.Settings.PreserveReference = true;
        config.Scan(Assembly.GetAssembly(typeof(MapsterTest)));
        config.Compile();
        Mapper = new Mapper(config);
    }
}

internal class MyClass
{
    public int MyProperty { get; set; }
}

internal class DtoClass
{
    public int MyPropertyDto { get; init; }
}
internal class Register : IRegister
{
    void IRegister.Register(TypeAdapterConfig config)
    {
        config.NewConfig<MyClass, DtoClass>()
            .Map(x => x.MyPropertyDto, x=> x.MyProperty);
    }
}

And here's the mapping


var from = new MyClass { MyProperty = 1};

var to = mapster.Mapper.Map<DtoClass>(from);

(The problem does not manifest if the properties have the same name or another modifier (set; or private set;)
This code works fine with version 7.3

@nicoarm93

linked #422

@nicoarm93 @andrerav location of this bug found )

PR with fix is open #658

In my case similar regression between 7.4.0 and 7.3.0 (Mapster throws a NullReferenceException) is not related to PreserveReference. It's about init only properties, when mapping to target object.
Below code works fine with Mapster 7.3.0, but doesn't work with Mapster 7.4.0.

using Mapster;

TypeAdapterConfig<Core.RootSource.NestedSource, Core.RootDestination.NestedDestination>
    .NewConfig()
    .Map(dest => dest.NameDest, src => src.NameSrc);

var dest = new Core.RootDestination { MyProperty = null };

var mapped = Core.RootSource.Create().Adapt(dest);

Console.WriteLine(mapped);

namespace Core
{
    public class RootSource
    {
        public required NestedSource? MyProperty { get; set; }

        public static RootSource Create()
        {
            return new RootSource
            {
                MyProperty = new NestedSource
                {
                    NameSrc = "NotEmptyString"
                }
            };
        }

        public class NestedSource
        {
            public required string NameSrc { get; set; }
        }
    }

    public class RootDestination
    {
        public NestedDestination? MyProperty { get; set; }

        public override string ToString()
        {
            return $"{nameof(RootDestination)}.{nameof(MyProperty)}={MyProperty?.NameDest}";
        }

        public class NestedDestination
        {
            public string? NameDest { get; init; }
        }
    }
}

@Mat3oo

Hello @Mat3oo, @andrerav
I checked my fix. The bug indicated by @Mat3oo persists.
The place of origin itself is most likely identified correctly.
But the created working code and the created non-working code, at first glance, do not make sense and both should not work))

Working Code :

.Lambda #Lambda1<System.Func`3[Core.RootSource+NestedSource,Core.RootDestination+NestedDestination,Core.RootDestination+NestedDestination]>(
    Core.RootSource+NestedSource $var1,
    Core.RootDestination+NestedDestination $var2) {
    .Block(Core.RootDestination+NestedDestination $result) {
        .If ($var1 == null) {
            .Return #Label1 { null }
        } .Else {
            .Default(System.Void)
        };
        $result = ($var2 ?? .New Core.RootDestination+NestedDestination());
        .Block() {
            $result.NameDest = $var1.NameSrc
        };
        .Return #Label1 { $result };
        .Label
            null
        .LabelTarget #Label1:
    }
}

Non-working code (throws a NullReferenceException):

.Lambda #Lambda1<System.Func`3[Core.RootSource+NestedSource,Core.RootDestination+NestedDestination,Core.RootDestination+NestedDestination]>(
    Core.RootSource+NestedSource $var1,
    Core.RootDestination+NestedDestination $var2) {
    .Block(Core.RootDestination+NestedDestination $result) {
        .If ($var1 == null) {
            .Return #Label1 { null }
        } .Else {
            .Default(System.Void)
        };
        $result = ($var2 ?? .New Core.RootDestination+NestedDestination());
        .Block() {
            .Call (.Call .Constant<System.RuntimeType>(Core.RootDestination+NestedDestination).GetProperty("NameSrc")).SetValue(
                $result,
                $var1.NameSrc)
        };
        .Return #Label1 { $result };
        .Label
            null
        .LabelTarget #Label1:
    }
}

fix MapsterMapper#656

Merge pull request #745 from SimTsai/master

In order to identify issues that are still active, we are closing issues that we believe are either resolved or are dormant. If your issue is still active then please reopen. Thanks.

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Cannot map properties that have differt names and init access modifier #656

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Cannot map properties that have differt names and init access modifier #656

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DocSvartz commented on Nov 12, 2023

Mat3oo commented on Dec 8, 2023

DocSvartz commented on Dec 8, 2023

stagep commented on Jan 7, 2025

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