Refactoring journey

Practice refactoring tips to improve your day-to-day efficiency

Objectives

Practice refactoring tips to improve your day-to-day efficiency
Use your IDE features

Before we start

Clone the repository here
Make sure you can run the tests

Connection

Refactoring, you said refactoring ?

Names of Refactorings :

Write down names of refactorings you already know
Write up names on a whiteboard or flipchart

Remind them some they use probably : Rename Variable and Extract Interface.

Concepts

Several ways to write code

What is refactoring ?

Refactoring (noun): a change made to the internal structure of software to make it easier to understand and cheaper to modify without changing its observable behavior.
Refactoring (verb): to restructure software by applying a series of refactorings without changing its observable behavior. - Martin Fowler

Refactoring is a systematic process of improving code without creating new functionality that can transform a mess into clean code and simple design.

The main purpose of refactoring is to fight technical debt

When to refactor ?

When adding a feature

If you must deal with someone else’s dirty code, try to refactor it first
- Clean code is much easier to grasp
Refactoring makes it easier to add new features
- Easier to make changes in clean code

Rule of Three (duplication)

You can copy and paste the code once
BUT when the same code is replicated 3 times, it should be extracted into a new procedure

When fixing a bug

Clean your code and the errors will practically discover themselves.

During a code review

Code review may be the last chance to tidy up the code before it becomes available to the public
Best to perform reviews in a pair with an author : you could fix simple problems quickly

When paying your debt

Dev teams can create technical debt consciously at one time and book some time later to tackle it
See technical debt quadrants

How to ?

There are two cases when tests can break down after refactoring :

You made an error during refactoring
- Go ahead and fix the error
Your tests were too low-level (for example, you were testing private methods of classes)
- In this case : the tests are to blame
- Either refactor the tests themselves or write an entirely new set of higher-level tests