So it's become obvious that having a large, all-encompassing EDMSystem class was probably not the way to go. It did give us a way to express what we wanted our acceptance tests to do, but the time has come to bite the bullet and take a look at where the system is going.

With the ProjectRepository taking care of Create and Find for Project, EDMSystem can be replaced with a combination of UserService and the repository.

[TestFixture]
public class UserServiceFixture
{
  [Test]
  public void OnCreationNoOneIsLoggedIn()
  {
    UserService userService = new UserService();

    UserType currentUser = userService.CurrentUser;

    Assert.Equal<UserType>(UserType.None, currentUser);
  }

  [Test]
  public void CanSuccessfullyLoginAsAdministrator()
  {
    UserService userService = new UserService();

    userService.LoginAs(UserType.Administrator);

    Assert.Equal<UserType>(UserType.Administrator, userService.CurrentUser);
  }

  [Test]
  public void CanSuccessfullyLoginAsNonAdministrator()
  {
    UserService userService = new UserService();

    userService.LoginAs(UserType.Bob);

    Assert.Equal<UserType>(UserType.Bob, userService.CurrentUser);
  }
}

public class UserService : IUserService
{
  public UserType CurrentUser
  {
    get { return currentUser; }
  }

  internal void LoginAs(UserType userType)
  {
    currentUser = userType;
  }

  private UserType currentUser;
}

public interface IUserService
{
  UserType CurrentUser { get; }
}

public enum UserType
{
  None,
  Administrator,
  Bob,
  Joe
}

One small change - I added a UserType of None. With this new class, we can go back and update the acceptance tests. I won't bother pasting them here, but obviously EDMSystem is gone and in its place we have a UserService and ProjectRepository. 10 of the 13 acceptance tests currently pass.