If a property in the source list does not exists its value is set null in the destination

[cam92yz]

Hello

We updated AutoMapper to version 11. After the upgrade we faced the problem that the AutoMapper sets a property to null if it does not exist in the source class. The behavior was only recognized in lists.

`

    var mapper = new AutoMapper.Mapper(mapperConfig);

    var destination = new Destination();
    destination.Group = new Group();
    destination.Definitions = new List<Definition>();
    destination.Definitions.Add(new Definition() { Group = new Group() });

    var source = new Source();
    source.Definitions = new List<BusinessDefinition>();
    source.Definitions.Add(new BusinessDefinition());
    mapper.Map(source, destination);

    var x = destination.Definitions[0].Group; // The property does not exist on the BusinessDefinition class. After mapping the "Group" property is null, i expect that the property keeps its value. 
    var z = destination.Group; // This property does not exist in the "Source" class. After mapping the value did not change in this case.

`

ConsoleApp7.zip

[lbargaoanu]

https://docs.automapper.org/en/latest/11.0-Upgrade-Guide.html#mapping-into-existing-collections

[cam92yz]

Thank you

It might be, that i understand something wrong from the upgrade guide, but my collections are not readonly therefore i think that is not
the problem.

`

public class Destination
{
    public Group Group { get; set; }
    public IList<Definition> Definitions { get; set; }
}

public class Definition
{
    public Group Group { get; set; }
}

public class Group
{
    public string Name { get; set; } = "blaaaaa";
}

public class Source
{
    public IList<BusinessDefinition> Definitions { get; set; }
}

public class BusinessDefinition
{
}

`

[lbargaoanu]

Then your code has nothing to do with the 11 release. Whatever it is, 10.1.1 does the same, and you should just fix your code.

[cam92yz]

You are right. Although the described behavior is strange. It's my mistake, i noticed that nothing chaged with the Automapper. The problem that i had in the code, looked like that something has changed with the Automapper.

Thanks

You can close it.