public void GetAverageDentistRating_WithValidDentistIdAndNoRatings_ShouldReturnNotRated() { var options = new DbContextOptionsBuilder <DentHubContext>() .UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString()) // Give a Unique name to the DB .Options; var dbContext = new DentHubContext(options); var rating1 = new Rating { Id = 1, PatientId = "1", DentistId = "2", RatingByPatient = 6 }; var rating2 = new Rating { Id = 2, PatientId = "1", DentistId = "3", RatingByPatient = 10 }; var rating3 = new Rating { Id = 3, PatientId = "1", DentistId = "4", RatingByPatient = 8 }; var rating4 = new Rating { Id = 4, PatientId = "1", DentistId = "5", RatingByPatient = 6 }; dbContext.Ratings.Add(rating1); dbContext.Ratings.Add(rating2); dbContext.Ratings.Add(rating3); dbContext.Ratings.Add(rating4); dbContext.SaveChanges(); var ratingRepository = new DbRepository <Rating>(dbContext); var service = new RatingService(ratingRepository); var result = service.GetAverageDentistRating("1"); Assert.Equal("Not Rated", result); }