What To Expect When You're Expecting

This repository holds all materials for the PyCon 2019 workshop presented by Emily Morehouse.

Summary

We all know we should be testing our applications, but testing is hard and great testing is even harder.

Take a deep dive into what types of things to test and how to approach testing them in your Django apps, plus learn how to leverage modern headless browser libraries and automated visual diff-ing to get (and keep) pixel-perfect apps.

We'll cover types of testing as a whole, plus practical applications and deep dives for testing in Django and visual regression testing with Javascript (whether for templates rendered by Django or for a standalone Javascript client application).

Audience Expectations

A foundational knowledge of Python and a web framework of choice is beneficial, as we'll dive right into testing an existing application. Starter code and code progressions will be provided, so you don't have to be a Django expert to grasp the content! Whether you love, hate, or have never used Javascript, you'll feel at home; our use of JS will be limited to leveraging libraries to gather data and screenshots for visual regression testing, whether for a JS client or a Django web app.

💅🏻 Pre-Workshop Prep

To start, you'll want to clone the repository to your local machine. Though there is an option to download a zipfile of the contents, it is recommended to clone using Git so you can navigate to different branches and commits in the code.

If you need to install Git, please see: Getting Started Installing Git

Clone the repository:

git clone git@github.com:emilyemorehouse/what-to-expect-when-youre-expecting-workshop.git

Next, you should install dependencies for the two applications we'll be working on. Make sure you set up both per the instructions below:

Install dependencies for our React app

If you don't have Node installed, you should install that first: https://nodejs.org/en/download/

This repository is tested with Node v.8.12, so use other versions at your own risk.

git checkout visual-init
cd agnostic-visual-regression-testing/code
npm install
npm run start

Install dependencies for our Django app

You'll need Python 3.6+ installed. If you don't have that set up, see: https://www.python.org/downloads/

git checkout django-init
cd regression-testing-in-django/code

See Step 0 for full instructions on installing dependencies, configuration, and running the app.

👩🏻‍🏫 How To Use This Repository

There are branches for each type of testing that we will cover:

"Regression Testing in Django" uses branch django-walkthrough
"Visual Regression Testing with Javascript" uses branch visual-tests-walkthrough

Each branch has commits per-step, which means that you'll want to checkout a previous version if you want to follow along.

Here's a sample workflow for navigating through the repo:

# Check out to final step on `django-walkthrough` branch
git checkout django-walkthrough

# List commits to go back to a specific step, or get the commit hash (id) from
# https://github.com/emilyemorehouse/what-to-expect-when-youre-expecting-pycon-workshop/commits/django-walkthrough
git log

# Checkout the specific commit you want to work from
git checkout <commit-hash>

You can opt to start from the initial step and work through implementing all of the changes on your own using the committed steps to follow along if you get lost, or you can checkout each step along the way to ensure that you understand each step. It really depends on your comfort level with the material and how you learn best!

📽 Slides

Online: Link

📝 Content and Notes

Introduction
Foundational Knowledge for Testing
Walkthrough - Regression Testing in Django
Walkthrough - Visual Regression Testing Powered By Javascript
Conclusion - Suggested tools and resources

📚 References

"If I have seen further it is by standing on ye sholders of Giants." -- Sir Isaac Newton

Django's Testing Documentation

🧠 Resources

🦄 Additional Resources

🏅 Contributing

Feel free to open an issue or PR. Please read CONTRIBUTING.md for details on the code of conduct, as well as PyCon's Code of Conduct.

If you have feedback or questions, you can contact me:

Email: emily [at] cuttlesoft [dot] com
Twitter: @emilyemorehouse

emilyemorehouse / what-to-expect-when-youre-expecting-workshop