Working with Thread.CurrentPrinciple in unit tests by providing a very thin abstraction layer

gistfile1.cs

    public interface IPrincipalInformationProvider
    {
        bool IsLoggedIn { get; }

        ...
    }
    
    public class ThreadBasedPrincipalInformationProvider : IPrincipalInformationProvider
    {
        public bool IsLoggedIn
        {
            get { return Thread.CurrentPrincipal.Identity.IsAuthenticated; }
        }
        
        ...
    }
    
    public class NotationController : ApiController
    {

        public NotationController(
            IPrincipalInformationProvider principalInformationProvider) //Can inject a fake easily
        {
            _principalInformationProvider = principalInformationProvider;
        }
        
        [HttpGet]
        [Route("Notations", Name = RouteNames.NOTATIONS_SEARCH)]
        public HttpResponseMessage Get([FromUri] MobileSearchFilterParameter filter)
        {
          ...
          var searchResult = _manager.Search(filter, _principalInformationProvider.IsLoggedIn;
          ...
    }