public void Update_Existing() { var expenses = TestExpensesFactory.GetTestExpenses(1); sut.Insert(expenses); expenses = sut.GetAll(); var firstExpense = expenses.First(); var details = Guid.NewGuid().ToString(); firstExpense.Details = details; sut.Update(new Transaction[] { firstExpense }); expenses = sut.GetAll(); Assert.AreEqual(details, expenses.First().Details); }