Bank Tech Test

This is a little program I wrote in node.js to practise and demonstrate writing high quality code.

It simulates a bank account and keeps track of your balance, deposits and withdrawals.

Here is a screenshot of the program in action.

Usage:

Download a copy of this repository, then, in the directory, run

npm install

To run the tests, run

jest

To see the coverage, run

jest --coverage

Use the node REPL to run the program (by running node).

Run these lines first to import the classes and create instances of them:

const Account = require('./src/account');
const TransactionMaker = require('./src/transactionMaker');
const Statement = require('./src/statement');

const account = new Account;
const transactionMaker = new TransactionMaker(account);
const statement = new Statement(account);

Then you can run

transactionMaker.deposit(amount);
transactionMaker.withdraw(amount);
statement.printStatement();

to interact with the program.

You can also enter node run.js to see an example of how the program runs.

My Approach:

I thought about the different classes and drew a diagram on how they should interact.

There are 3 classes:

• Account - keeps track of all transactions along with the balance
• Statement - gets transactions from account to print a statement for the user to see
• TransactionMaker - handles deposits and withdrawals and sends them to the Account for storing.

I wrote the programm following Test Driven Development (TDD), always starting with a test and then writing code to implement that feature. Each test increased the complexity of the program incrementally.

After all the main features were implemented I tested for lots of edge cases on the user input, when calling the deposit and withdraw function.