NS3002 false positive

[AdamWillden]

        private IMapper CreateMapperMock()
        {
            var mapper = Substitute.For<IMapper>();

            mapper
                .Map<InvitationDto>(Arg.Any<Invitation>())
                .Returns(_ =>
                {
                    //  NS3002 Can not find an argument of type ... to this call
                    _invitationDto.Roles = _.Arg<Invitation>().IdentityRoles; 

                    return _invitationDto;
                });
        }

[tpodolak]

Hi @AdamWillden thank you for reporting, could you show definition of IMapper interface?

[AdamWillden]

@tpodolak sorry... complete lack of info from me

It is AutoMapper: https://github.com/AutoMapper/AutoMapper/blob/master/src/AutoMapper/IMapper.cs

[AdamWillden]

P.S. thanks for creating this. Well worth the effort :-) and your hard work is appreciated.

[tpodolak]

This bug is caused due to the way we process and compare method arguments. In your case the method is defined as

public TResult Map<TResult>(object input);

When analyzer analyses usage of _.Arg it checks the method parameters of Map definition and it sees object instead of Invitation so it reports types incompatibility.

What analyzer should do is to take parameter type from the invocation rather than from method symbol. In that case it will know that as you used Map with Invitation type and it is fine to do Arg in callback. This should be possible to fix but might be tricky to do correctly for named and optional parameters. I will try to look at this over the weekend

[AdamWillden]

Fantastic, thank you again