This source code follows Martin Fowler's book "Refactoring, Improving the Design of Existing Code".

When you find you have to add a feature to a program, and the program's code is not structured in a convenient way to add the feature, first refactor the program to make it easy to add the feature, then add the feature.

Whenever you do refactoring, the first step is always the same. You need to build a solid set of tests for that section of code. The tests are essential because even though you follow refactorings structured to avoid most of the opportunities for introducing bugs, you are still human and still make mistakes. Thus you need solid tests.

Actually the statement method prints out a simple text output of a rental statement

Rental Record for martin
  Ran 3.5
  Trois Couleurs: Bleu 2.0
Amount owed is 5.5
You earned 2 frequent renter points

We want to write an HTML version of the statement method :

<h1>Rental Record for <em>martin</em></h1>
<table>
  <tr><td>Ran</td><td>3.5</td></tr>
  <tr><td>Trois Couleurs: Bleu</td><td>2.0</td></tr>
</table>
<p>Amount owed is <em>5.5</em></p>
<p>You earned <em>2</em> frequent renter points</p>

The purpose of this is to provide good examples for the refactoring workshop.

All you need to build this project is Java 17 or later, Maven 3.0 or later.

Unit tests can be run using maven:

$ mvn test

Tests are located in the test directory and run using JUnit 5.