public Test() { DbContextOptions <ApplicationDbContext> options; var builder = new DbContextOptionsBuilder <ApplicationDbContext>(); builder.UseInMemoryDatabase(); options = builder.Options; ApplicationDbContext _context = new ApplicationDbContext(options); _context.Database.EnsureDeleted(); _context.Database.EnsureCreated(); _context.SaveChanges(); _service = new TestService(_context); var user = new ApplicationUser { UserName = "******", Email = "*****@*****.**" }; var cpu = new CPU { Name = "i5-8400", Manufacturer = "Intel", Series = "i5", Socket = "1151", Cores = "6", TDP = "65", iGPU = 1, Price = "829" }; var mobo = new MOBO { Name = "Z370-A PRO", Manufacturer = "MSI", Standard = "ATX", Chipset = "Z370", Socket = "1151", Ram_type = "DDR4", Price = "519" }; var casePC = new Case { Name = "BIG", Manufacturer = "Corsair", Price = "500" }; var psu = new PSU { Name = "EVGA Supernnova G2", Manufacturer = "EVGA", Wattage = "550", Price = "329" }; var ram = new RAM { Name = "Corsair Vengeance LPX", Manufacturer = "Corsair", Ram_type = "DDR4", Speed = "3000", Price = "619" }; var cooler = new Cooler { Name = "Noctua NH-D15", Socket = "1151", Fans = "2", Price = "400" }; var gpu = new GPU { Name = "MSI GTX 1070TI GAMING", Manufacturer = "MSI", Chipset = "GTX 1070TI", TDP = "200", Price = "2100" }; _service.AddConfiguration(cpu, gpu, mobo, ram, psu, casePC, cooler, user); list = _service.GetPCs(); pcdata = list.FirstOrDefault(); }