public void CheckIfThereIsAorderInTheReports() { //Arange var reportService = new ReportsService(db); var firstOrder = new Order { Id = "1", Name = "Test1" }; var secondOrder = new Order { Id = "2", Name = "Test2" }; var thirdOrder = new Order { Id = "3", Name = "Test3" }; var firstReport = new Report { Id = "1", OrderId = firstOrder.Id, Order = firstOrder }; var secondReport = new Report { Id = "2", OrderId = secondOrder.Id, Order = secondOrder }; var thirdReport = new Report { Id = "3", OrderId = thirdOrder.Id, Order = thirdOrder }; db.Order.AddRange(firstOrder, secondOrder, thirdOrder); db.Report.AddRange(firstReport, secondReport, thirdReport); db.SaveChanges(); //Act var positiveResult = reportService.CheckForOrderId("1"); var negativeResult = reportService.CheckForOrderId("11"); //Assert var expectedPositive = true; var expectedNegative = false; Assert.Equal(expectedPositive, positiveResult); Assert.Equal(expectedNegative, negativeResult); }