public async Task DepositAsync_WithAmountMoreThanZero_ReturnTransactionsResult() { // Arrange var depositRequest = new DepositRequest { AccountIban = "TH123456", Amount = 1000, }; var account = new Account { AccountId = Guid.NewGuid(), AccountIban = "TH123456", Balance = 1000, }; accountRepository.GetByAccountIbanAsync(Arg.Any <string>()).Returns(Task.FromResult(account)); accountRepository.UpdateAccountAsync(Arg.Any <Account>()).Returns(Task.FromResult(new Account())); depositRepository.AddDepositAsync(Arg.Any <Deposit>()).Returns(Task.FromResult(new Deposit())); // Act var transactionsResult = await transactionsService.DepositAsync(depositRequest); // Assert Assert.True(transactionsResult.Success); Assert.Equal(1999, transactionsResult.Balance); }