we-kata-bank-account

https://gist.github.com/abachar/d20bdcd07dac589feef8ef21b487648c

Statement

Think of your personal bank account experience When in doubt, go for the simplest solution.

Requirements

• Deposit and Withdrawal
• Account statement (date, amount, balance)
• Statement printing

User Stories

Uer Story 1:

In order to save money
As a bank client
I want to make a deposit in my account

Uer Story 2:

In order to retrieve some or all of my savings
As a bank client
I want to make a withdrawal from my account

Uer Story 3:

In order to check my operations
As a bank client
I want to see the history (operation, date, amount, balance) of my operations

Implementation

By reading the user stories we can see only one pitfall in the scenarios. Users can't withdraw money they don't have. These user stories can be described with the following scenarios:

Scenario I make a deposit 
    Given I have 80 on my bank account
    When I make a deposit of 20
    Then the balance is 100
    
    Given I have 100 on my bank account
    When I make a deposit of -20
    Then I'm notified the operation is impossible

Scenario I make a withdrawal
    Given I have 80 on my bank account
    When I withdraw 20
    Then the balance is 60
    
    Given I have 80 on my bank account
    When I withdraw 100
    Then I'm notified the balance is not sufficient to make the withdrawal

Scenario I check my operations history
    Given I have a bank account
    When I request my operations history
    Then I see my operations history

Important note: Some considerations like authentication, authorization, and account creation are simplified. The database schema is minimal, as well.

The project uses Node.js V14 as a minimum version. It allows us to use ESM modules.

There are several ways to install Node.js:

• You can download it from the website: https://nodejs.org/en/download/
• If you already have a version of Node.js, and you want to manage several versions you can use nvm

The main packages used for this project are:

• Express is an HTTP framework.
• Joi is a schema description language.
• Knex is a query builder, it supports SQLite and MySQL amongst other.
• Ava is used a test runner. It easily works, without any configuration needed.

A collection of "HTTP request in Editor" is provided, as well. It is natively supported by WebStorm and can be run in VS Code with the Rest Client plugin installed.

Run

To run the project you need to open a terminal and go tho the project folder.

Then install its dependencies:

# It uses npm which is installed with Node.js by default
npm i

You can start the project:

# It will start a database, create tables, 
# populate them with data, then start the server 
npm run start:init

You can run all tests:

npm t