Mock AutoMapper Mapper.Map call using Moq

Question

Whats the best way to setup a mock expection for the Map function in AutoMapper.

I extract the IMapper interface so I can setup expects for that interface. My mapper has dependencies, so I have to pass those in to the mapper.

What happens when I create 2 instances of my mapper class, with 2 different dependency implementations? I asume that both mappers will use the same dependency instance, since the AutoMapper map is static. Or AutoMapper might even throw an exception because I try to setup 2 different maps with the same objects.?

Whats the best way to solve this?

public interface IMapper {
    TTarget Map<TSource, TTarget>(TSource source);
    void ValidateMappingConfiguration();
}

public class MyMapper : IMapper {
    private readonly IMyService service;

    public MyMapper(IMyService service) {
        this.service = service
        Mapper.CreateMap<MyModelClass, MyDTO>()
            .ForMember(d => d.RelatedData, o => o.MapFrom(s =>
                service.getData(s.id).RelatedData))
    }

    public void ValidateMappingConfiguration() {
        Mapper.AssertConfigurationIsValid();
    }

    public TTarget Map<TSource, TTarget>(TSource source) {
        return Mapper.Map<TSource, TTarget>(source);
    }
}

Answer 1

Whats the best way to setup a mock expection for the Map function in AutoMapper[?]

Here's one way:

var mapperMock = new Mock<IMapper>();
mapperMock.Setup(m => m.Map<Foo, Bar>(It.IsAny<Foo>())).Returns(new Bar());