public void CurrentMonthTotalExpenses_Works_Correctly() { var controller = new ExpenseController(_mockExpenseService.Object); var apiCallValue = controller.CurrentMonthTotalExpenses(sampleEmployee.Id); _mockExpenseService.Verify(x => x.StaffTotalExpensesForThisMonth(It.Is <string>(input => input == sampleEmployee.Id))); Assert.IsInstanceOfType(apiCallValue, typeof(OkNegotiatedContentResult <int>)); }