AutoMapper+xUnit: Missing type map configuration or unsupported mapping - asp.net-mvc

Question

I cannot figure this one out. I have a N-Tier ASP.MVC application and I am writing my first Unit Test and it seems to fail on my AutoMapper configuration. I have used AutoMapper a million times and never had any problems using it.
I'm sure I am missing something simple, but I have been staring at this for 24 hours now.
Class Library: APP.DOMAIN
public class User : IEntity<int>
{
public int Id { get; set; }
[StringLength(20), Required]
public string UserName { get; set; }
}
Class Library: APP.SERVICE
References App.Domain
public class UserViewModel
{
public int Id { get; set; }
public string UserName { get; set; }
}
I have my AutoMapper bootstrapper in the service layer.
public static class AutoMapperBootstrapper
{
public static void RegisterMappings()
{
Mapper.CreateMap<User, UserViewModel>();
}
}
UserService.cs
public class UserService : IUserService
{
private readonly IUserRepository _userRepository;
public UserService(IUserRepository userRepository)
{
_userRepository = userRepository;
}
public List<UserViewModel> GetUsers()
{
var users = _userRepository.GetAll();
if (users == null)
{
throw new Exception("No users found.");
}
return Mapper.Map<List<UserViewModel>>(users); // FAILS ON AUTOMAPPER
}
}
ASP.MVC Layer: APP.WEB
References App.Service
private void Application_Start(object sender, EventArgs e)
{
// Register AutoMapper
AutoMapperBootstrapper.RegisterMappings();
Mapper.AssertConfigurationIsValid();
// Code that runs on application startup
AreaRegistration.RegisterAllAreas();
GlobalConfiguration.Configure(WebApiConfig.Register);
RouteConfig.RegisterRoutes(RouteTable.Routes);
}
Unit Test Layer:
public class TestUserRepository :IUserRepository
{
public IEnumerable<User> GetAll()
{
var users = new List<User>()
{
new User { Id = 1, UserName = "Mary"},
new User { Id = 2, UserName = "Joe"}
};
return users;
}
}
public class UserServiceTest
{
private IUserService _userService;
private readonly IUserRepository _userRepository;
public UserServiceTest()
{
_userRepository = new TestUserRepository();
}
[Fact]
public void GetUsers_Should_Return_Correct_Number_Of_Users()
{
// Arrange
_userService = new UserService(_userRepository);
// Act
var result = _userService.GetUsers(); // FAILS ON AUTOMAPPER
// Assert
Assert.True(result.Any(u => u.UserName == "Mary"));
}
}
Failing Test Message:
*** Failures ***
Exception
AutoMapper.AutoMapperMappingException: AutoMapper.AutoMapperMappingException : Missing type map configuration or unsupported mapping.
Mapping types:
User -> UserViewModel
App.Data.Model.User -> App.Service.ViewModels.UserViewModel
Destination path:
List`1[0]
Source value:
App.Data.Model.User
at App.Service.Services.UserService.GetUsers() in D:\Repositories\App\App.Service\Services\UserService.cs:line 36
at App.Tests.Service.Tests.UserServiceTest.GetUsers_Should_Return_Correct_Number_Of_Users() in D:\Repositories\App\App.Tests\Service.Tests\UserServiceTest.cs:line 34

Answer 1

A little late to the party but have you tried setting the mapping before running the test?
public class UserServiceTest
{
public UserServiceTest()
{
// register the mappings before running the test
AutoMapperBootstrapper.RegisterMappings();
}
...
}

Answer 2

What we would need to do is Inject Custom Mapper Mock as given below. Add all those custom profiles that you have used for that particular class that you are unit testing and inject ConfigureMapper() in the Constructor of that class which is expecting IMapper Object
public IMapper ConfigureMapper()
{
var config = new MapperConfiguration(cfg =>
{
cfg.AddProfile<CustomProfile>();
cfg.AddProfile<UserCustomProfile>();
cfg.AddProfile<UserWorkProfile>();
});
return config.CreateMapper();
}
Hope this solves the issue.

Answer 3

I'm not sure what the problem is, it's been a while since I've last used AutoMapper, but I'm quite sure that the following will work:
return users.Select(Mapper.Map<UserViewModel>);

Answer 4

I have a problem with this line:
var authorDTO = mapper.Map<AuthorCreationDTO>(AuthorinsideDB);
So I change the version of Autormapper
from:
<PackageReference Include="AutoMapper.Extensions.Microsoft.DependencyInjection" Version="7.0.0" />
to
Version="6.0.0"
and it worked.