Refactoring Workshop

This workshop will focus on the basics of refactoring code. You will gain the skills to use and apply common refactoring patterns. These will aid you as you write code, review pull requests and discuss code with others.

The examples in this workshop are simplified to fit within the time limit but are designed to give you the dialect and tools you need to slot these skills into your toolbelt.

Also we will be discussing and mentioning SOLID object oriented principles. I gave a presentation on the topic some time ago, if you need to brush up on the topic.

Skill Level

This workshop will be presenting fundamentals.

• Fundamentals
• Intermediate

Prerequisites

• Light Javascript Knowledge (ES6), no typescript knowledge required.
• Bare minimum you will need node and npm installed.
• Come prepared to do some coding, only your editor of choice and a terminal will be required.

I recommend you install nvm. If you would like a more complete setup script for you computer that installs a bunch of useful development tools and makes your environment more productive, I highly recommend using our Shift3 Laptop setup scripts which will install nvm as well as some other helpful tools.

Install

# Clone the repo then cd to directory
cd /path/to/refactoring-workshop

# install the node version for the repo
nvm install

# install required packages.
npm install

# install test runner globally
npm install -g mocha

How to Work on the Exercises

The exercises are numbered, the first one is 01-extract-method, you will cd into that directory in your terminal and can run the test file at any time.

# change directory to first exercise
cd 01-extract-method

# run the tests
mocha order-printer.tests.js

Now you can open this folder up in your editor and start the exercise.

• A solution directory is provided with each exercise if you are stuck and need a nudge in the right direction, use this as a last resort. If you are in the workshop ask a question instead if you can.
• Run the tests frequently as you change the code, the tests are there to help make sure you are working in small steps, and that the code still works as intended.

Post Workshop Takeaways

No pattern is a panacea, these refactorings are designed to put more tools in your toolbox and give you a wider set of tools to use in your discussions in pull requests, your musings about code, and refactorings as your code base grows.

The important part of each pattern is understanding why and when to apply it, and what problems you are solving. We will discuss these concept more during the workshop. No pattern is meant to be used as a bludgeon and no design pattern solves all problems.

In the real world you should write the simplest code first, don't be afraid of duplication, and abstract once the correct abstractions become clear, no sooner.