How to parse AutoMapper exceptions for error logs table?

[frankhaugen]

Sorry for a clumsy title, but it's descriptive.

I am mapping a single object/record at a time to ensure I get the exception, but exploring the AutoMapperMappingException type, it's a jungle of information.

What I want is a simple one row per property/field when something goes wrong, that can be customer readable. I would have expected there to be a ton of libraries to facilitate this, or some docs but I can't find anything.

Here's my little extension method to extract the exception:

        public static AutoMapperResult<T> TryMap<T, TValue>(this IMapper mapper, TValue value)
        {
            var output = new AutoMapperResult<T>();

            try
            {
                output.Data = mapper.Map<TValue, T>(value);
                output.Success = true;
            }
            catch (AutoMapperMappingException mappingException)
            {
                output.MappingException = mappingException;
            }

            return output;
        }

here's how I map it to my internal entity, (or rather two of the lines referencing the type name works fine, but I want member/property names, and those examples only return "null"):

    public class MappingExceptionProfile : Profile
    {
        public MappingExceptionProfile()
        {
            CreateMap<AutoMapperMappingException, MappingException>()
                .ForMember(x => x.DestinationProperty, opt => opt.MapFrom(y => y.Types.Value.GetRelatedTypePairs().FirstOrDefault().DestinationType.Name))
                .ForMember(x => x.DestinationProperty, opt => opt.MapFrom(y => y.MemberMap.DestinationName))
                .ForMember(x => x.SourceProperty, opt => opt.MapFrom(y => y.Types.Value.GetRelatedTypePairs().FirstOrDefault().SourceType.Name))
                .ForMember(x => x.SourceProperty, opt => opt.MapFrom(y => y.MemberMap.SourceMember.Name))
                .ForMember(x => x.ErrorMessage, opt => opt.MapFrom(y => y.Message))
                .ForMember(x => x.DateTime, opt => opt.MapFrom(y => DateTime.UtcNow))
                .ForMember(x => x.Severity, opt => opt.MapFrom(y => Severity.Error))
                ;
        }
    }

[lbargaoanu]

You should look at how the error message is composed. And write some tests :) These are internal details that we're not going to document.