public void Interest() { var account = new CashAccount(); account.InterestPaid(new Date(2000, 01, 01), 100.00m, "test"); var result = account.Transactions.ToArray(); result.Should().BeEquivalentTo(new[] { new { Date = new Date(2000, 01, 01), Description = "test", Amount = 100.00m, Type = BankAccountTransactionType.Interest, Balance = 100.00m } }); }