public void Count_ReturnsCorrectCount() { var options = new DbContextOptionsBuilder <ApplicationDbContext>().UseInMemoryDatabase(Guid.NewGuid().ToString()).Options; using (var dbContext = new ApplicationDbContext(options)) { Employee employee = new Employee() { FirstName = "Ivan", MiddleName = "Ivanov", LastName = "Ivanov", PhoneNumber = "0897924218", Email = "*****@*****.**", Town = "Sofia", Address = "address 1", }; dbContext.Employees.Add(employee); dbContext.SaveChanges(); var employeesService = new EmployeesService(dbContext); int employeesCount = employeesService.Count(); Assert.Equal(1, employeesCount); } }