Configure a mapper from string to List<string> and from List<string> to string

I am trying to configure Napster of these two entities to pass from List to string but it gives me an error. any ideas. Thank you

public class  EntidadVM 
     { public List<string> CCC}

public class  EntidadDto 
     { public string CCC}

I’m doing them like this, but it gives me an error

TypeAdapterConfig<MailingDto, MailingVM>.NewConfig()
 .Map(dest => dest.CCC, src => new List<string>(src.CCC.Split(',')).ToList() );

TypeAdapterConfig<MailingDto, MailingVM>.NewConfig()
 .Map(dest => dest.CCC, src => src.CCC.Split(',').ToList() );

[devbased]

@ascariz

[TestMethod]
public void MapToTarget()
{
    var dto = new EntidadDto { CCC = "one,two,three", };

    // expression tree cannot contain call which contains optional arguments, so specify explicitly
    var config = TypeAdapterConfig<EntidadDto, EntidadVM>.NewConfig()
        .Map(dest => dest.CCC, src => new List<string>(src.CCC.Split(',', StringSplitOptions.None)).ToList());
    var vm = dto.Adapt<EntidadVM>(config.Config);
    vm.CCC.ShouldBe(new[] { "one", "two", "three" });

    config = TypeAdapterConfig<EntidadDto, EntidadVM>.NewConfig()
        .Map(dest => dest.CCC, src => src.CCC.Split(',', StringSplitOptions.None).ToList());
    vm = dto.Adapt<EntidadVM>(config.Config);
    vm.CCC.ShouldBe(new[] { "one", "two", "three" });

    // or use after mapping
    config = TypeAdapterConfig<EntidadDto, EntidadVM>.NewConfig()
        .Ignore(x => x.CCC)
        .AfterMapping((src, dest) => dest.CCC = src.CCC.Split(',').ToList());
    vm = dto.Adapt<EntidadVM>(config.Config);
    vm.CCC.ShouldBe(new[] { "one", "two", "three" });

    config = TypeAdapterConfig<EntidadDto, EntidadVM>.NewConfig()
        .Ignore(x => x.CCC)
        .AfterMapping((src, dest) => dest.CCC = new List<string>(src.CCC.Split(',')).ToList());
    vm = dto.Adapt<EntidadVM>(config.Config);
    vm.CCC.ShouldBe(new[] { "one", "two", "three" });
}

[devbased]

@ignacioerrico I don’t have the right to manage the issue 😅 It just turned out that I’m subscribed to this topic, so I quickly replied to you 😊