Account statement printing application that tracks transactions and outputs a statement showing balance and transaction history.

1. Clone this repo
2. Install pipenv with brew install pipenv
3. Nagivate to the project repo
4. Run pipenv install to install project dependencies.
5. See the How to use section on how to run the code as an application.

Via your machine's CLI in the interactive Python3 REPL:

>>> from src.account import Account
>>> from src.printer import Printer
>>> from src.transaction import Transaction
>>> printer = Printer()
>>> account = Account(0, Transaction, printer)
>>> account.deposit(200)
>>> account.deposit(50)
>>> account.withdraw(100)
>>> account.print_statement()
date       || credit  || debit   || balance
16/06/2020 ||         || 200.00  || 0.00   
16/06/2020 ||         || 50.00   || 200.00 
16/06/2020 || 100.00  ||         || 250.00 

To run all tests:

pipenv run test

To run only unit tests:

pipenv run test_unit

To run only integrations tests:

pipenv run test_integration

To run tests with coverage report bundled:

pipenv run test_coverage

Tests are structured into two modules spec for unit tests and integration for feature tests.

• User can deposit money
• User can withdraw money
• User can print a statement:

date       || credit  || debit   || balance
14/01/2012 ||         || 500.00  || 2500.00
13/01/2012 || 2000.00 ||         || 3000.00
10/01/2012 || 1000.00 ||         || 1000.00

AS A conscientious saver
SO THAT I can save for the future
I NEED to be able deposit funds into my account

AS A reckless spender
SO THAT I can take buy the things I want
I NEED to be able to withdraw funds from my account

AS A careful money manager
SO THAT I know what's going on with my account
I NEED to able to see a printed account statement

Account statement printing is achieved using three objects:

• an Account object which tracks the a list of the users transactions.
• a Transaction object which is stored inside the Account object and tracks information about individual transactions.
• a Printer object as utility dependency of the Account object which accepts an array of transactions and prints a formatted statement using them.

Below is the object domain model for the three objects:

I explored using separate withdraw and deposit methods but settled on using a single transact method on the Account object as it was clearer and cut down on repeated code.

Furthermore, I also went back and forth on whether to directly submit a new transaction object to the Account object's transact method. Initially I decided that it was more user friendly to be able to simply specify the amount of a transaction that took place and then dependency inject the Transaction class into the Account object where it could then be used to dynamically created new instances of Transaction when required.

While this worked ok, it didn't fit well with the user stories being able to withdraw and deposit so I refactored to add this methods and changed the transact method to be private instead calling it via the withdraw and deposit methods to keep the code DRY and still present a nice interface for users.