AutoMapper catches and ignores NullReferenceException

As written in:

http://stackoverflow.com/questions/7332426/automapper-catches-and-ignores-nullreferenceexception

Maybe this is by design, but we initially did not expect automapper to catch and ignore all NullReferenceExceptions in our mappings. We mostly use the MapFrom and create sometimes complex expressions. We want these mappings to fail if there’s any exception, even a NullReferenceException, but we cant get AutoMapper to do that. Is there any way to make automapper not ignore all these exceptions without having to write a custom value resolver for every case? This would mean alot of extra code for us, so much in fact that it probably would be less code without using automapper in the first place.

These are the test that we would expect to all pass:

[TestFixture] public class Tests { [SetUp] public void Setup() { Mapper.Reset(); }

[Test]
public void ShouldThrowMappingExceptionUsingMapFromExpression()
{
    Mapper.CreateMap<Source, Destination>()
        .ForMember(d => d.DestinationMember, o => o.MapFrom(s => s.SourceMember.SourceProperty))
        ;

    Assert.Throws<AutoMapperMappingException>(() => Mapper.Map<Source, Destination>(new Source()));
}

[Test]
public void ShouldThrowMappingExceptionUsingResolveUsingExpression()
{
    Mapper.CreateMap<Source, Destination>()
        .ForMember(d => d.DestinationMember, o => o.ResolveUsing(s => s.SourceMember.SourceProperty))
        ;

    Assert.Throws<AutoMapperMappingException>(() => Mapper.Map<Source, Destination>(new Source()));
}

[Test]
public void ShouldThrowMappingExceptionUsingResolverInstance()
{
    Mapper.CreateMap<Source, Destination>()
        .ForMember(d => d.DestinationMember, o => o.ResolveUsing(new TestValueResolver()).FromMember(s => s.SourceMember))
        ;

    Assert.Throws<AutoMapperMappingException>(() => Mapper.Map<Source, Destination>(new Source()));
}

[Test]
public void ShouldThrowMappingExceptionUsingResolverType()
{
    Mapper.CreateMap<Source, Destination>()
        .ForMember(d => d.DestinationMember, o => o.ResolveUsing<TestValueResolver>().FromMember(s => s.SourceMember))
        ;

    Assert.Throws<AutoMapperMappingException>(() => Mapper.Map<Source, Destination>(new Source()));
}

}

public class Destination { public string DestinationMember { get; set; } }

public class Source { public SourceChild SourceMember { get; set; } }

public class SourceChild { public string SourceProperty { get; set; } }

public class TestValueResolver : ValueResolver<SourceChild, string> { protected override string ResolveCore(SourceChild source) { return source.SourceProperty; } }

[jacob-ewald]

Ah, sorry, I see what happened. When reading the docs it seemed like all one had to do was replace ResolveUsing with MapFrom, but that’s only part of it. You also need to switch how you’re passing arguments to it if you have lambdas. I see that now in the documentation, thanks @lbargaoanu.

[lock[bot]]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.