public void DuplicateOfferingExists_WithNoDuplicates_ShouldReturnFalse() { var options = new DbContextOptionsBuilder <DentHubContext>() .UseInMemoryDatabase(databaseName: Guid.NewGuid().ToString()) // Give a Unique name to the DB .Options; var dbContext = new DentHubContext(options); var repository = new DbRepository <Appointment>(dbContext); var ratingRepository = new DbRepository <Rating>(dbContext); var service = new AppointmentService(repository, ratingRepository); var user = new DentHubUser() { Id = "2", FirstName = "Test2", LastName = "Dentist", }; var appointment = new Appointment { Id = 31, ClinicId = 1, DentistID = "2", TimeStart = new DateTime(2019, 05, 05, 10, 0, 0), TimeEnd = new DateTime(2019, 05, 05, 10, 30, 0), Status = Status.Offering, }; dbContext.Appointments.Add(appointment); dbContext.DentHubUsers.Add(user); dbContext.SaveChanges(); var timeStart = new DateTime(2019, 05, 05, 10, 30, 0); var timeEnd = new DateTime(2019, 05, 05, 11, 00, 0); var result = service.DuplicateOfferingExists (user, timeStart, timeEnd); Assert.False(result); }