C#•16mo ago

✅ AutoMapper - mapping record to a class (.NET 7)

I am using mediatr for my project and I have my command using a sealed record and when I try to map my record to my entity I run into an AutoMapper Extension error. Error: Exception thrown: 'AutoMapper.AutoMapperMappingException' in AutoMapper.dll CODE:

public sealed record CreateProductCommand(string Name, string? Description, string Code, decimal Price);

public class Product : BaseAuditableEntity
{
    public required string Name { get; set; }
    public string? Code { get; set; }
    public string? Description { get; set; }
    public decimal Price { get; set; }
}

public async Task<Result> Handle(CreateProductCommand request, CancellationToken cancellationToken)
{
    var product = _mapper.Map<Product>(request);
    product.AddDomainEvent(new CreatedEvent<Product>(product));
    _unitOfWork.Products.Insert(product);
    await _unitOfWork.SaveChangesAsync(cancellationToken);

    return Result.Success();
}

public sealed record CreateProductCommand(string Name, string? Description, string Code, decimal Price);

public class Product : BaseAuditableEntity
{
    public required string Name { get; set; }
    public string? Code { get; set; }
    public string? Description { get; set; }
    public decimal Price { get; set; }
}

public async Task<Result> Handle(CreateProductCommand request, CancellationToken cancellationToken)
{
    var product = _mapper.Map<Product>(request);
    product.AddDomainEvent(new CreatedEvent<Product>(product));
    _unitOfWork.Products.Insert(product);
    await _unitOfWork.SaveChangesAsync(cancellationToken);

    return Result.Success();
}

When my CreateProductCommand was still a class the mapping worked with no issues.

10 Replies

Omnissiah•16mo ago

aren't there more details in the exception?

Johannes MOP•16mo ago

Unfortunately not. Just that and that's all. But I was able to narrow it down to that it's an issue when I try map a record with a class.

Omnissiah•16mo ago

i guess you ould try explicit construction of the record from automapper? even if just as a test

blueberriesiftheywerecats•16mo ago

the problem is that record wants to get propertys through constructor automapper cant do that by default

Omnissiah•16mo ago

you can try ConstructUsing or the other one

blueberriesiftheywerecats•16mo ago

https://stackoverflow.com/questions/65382286/automapper-problem-with-mapping-records-type

Stack Overflow

AutoMapper: Problem with mapping records type

I am mapping with automapper 10.1.1 in c# 9 from this class public record BFrom { public Guid Id { get; init; } public Guid DbExtraId { get; init; } } into this public record ATo(Guid Id,...

Omnissiah•16mo ago

like ForCtorSomething

Johannes MOP•16mo ago

Would I then have to create a map profile for each and every mapping I will do? Is there a way I can just make it generic to automatically map the properties?

Omnissiah•16mo ago

if it doesn't work without ForCtorParam that's what you have to do i've never searched if there is some source generator or whatever that reduces this effort

Johannes MOP•16mo ago

Shucks that is gonna be a tedious effort for each and everytime a new record is added and a particular mapping is required.

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✅ AutoMapper - mapping record to a class (.NET 7)