Testing Node.js Apps

👋 hi there! My name is Kent C. Dodds! This is a workshop repo to teach you how to test your Node.js Apps!

Pre-Workshop Instructions/Requirements

In order for us to maximize our efforts during the workshop, please do the following:

Setup the project (follow the setup instructions below) (~5 minutes)
Install and setup Zoom on the computer you will be using (~5 minutes)
Watch Use Zoom for KCD Workshops (~8 minutes).
Watch Setup and Logistics for KCD Workshops (~24 minutes). Please do NOT skip this step.
Attend my Testing Fundamentals Workshop or have the equivalent fundamental understanding and experience with automated testing and tools. (Additional learning material: But really, what is a JavaScript test? and But really, what is a JavaScript mock?)
Attend my Modern JavaScript Workshop or have the equivalent experience with modern JavaScript APIs.
Attend my Asynchronous JavaScript Workshop or have equivalent experience with asynchronous JavaScript.

The more prepared you are for the workshop, the better it will go for you.

Workshop Outline

Here are the topics we'll be covering:

Testing Pure Functions
Testing Middleware
Testing Controllers
Testing API routes
Mocking third party dependencies
Testing authenticated code

System Requirements

git v2 or greater
NodeJS v10 or greater
yarn v1 or greater (or npm v6 or greater)

All of these must be available in your PATH. To verify things are set up properly, you can run this:

git --version
node --version
yarn --version # or npm --version

If you have trouble with any of these, learn more about the PATH environment variable and how to fix it here for windows or mac/linux.

Setup

You should be able to work through the entire workshop in the browser. This is actually the recommended approach as it requires absolutely no setup whatsoever. Go to this codesandbox and click Fork in the top right corner. Then click the + in the terminal and you can run npm test to get the test watch mode started.

If you'd rather be able to work through the workshop on your own computer, then follow the following instructions.

After you've made sure to have the correct things (and versions) installed, you should be able to just run a few commands to get set up:

git clone https://github.com/kentcdodds/testing-node-apps.git
cd testing-node-apps
npm run setup --silent

This may take a few minutes. It will ask you for your email. This is optional and just automatically adds your email to the links in the project to make filling out some forms easier If you get any errors, please read through them and see if you can find out what the problem is. You may also want to look at Troubleshooting. If you can't work it out on your own then please file an issue and provide all the output from the commands you ran (even if it's a lot).

Running the tests

npm test

This will start Jest in watch mode. Read the output and play around with it.

Your goal will be to go into each test, swap the final version for the exercise version in the import, and make the tests pass

Helpful Emoji 🐨 💰 💯 🦉 📜 💣 🚨

Each exercise has comments in it to help you get through the exercise. These fun emoji characters are here to help you.

Kody the Koala Bear 🐨 will tell you when there's something specific you should do
Marty the Money Bag 💰 will give you specific tips (and sometimes code) along the way
Hannah the Hundred 💯 will give you extra challenges you can do if you finish the exercises early.
Olivia the Owl 🦉 will give you useful tidbits/best practice notes and a link for elaboration and feedback.
Dominic the Document 📜 will give you links to useful documentation
Berry the Bomb 💣 will be hanging around anywhere you need to blow stuff up (delete code)
Alfred the Alert 🚨 will occasionally show up in the test failures with potential explanations for why the tests are failing.

Troubleshooting

"npm run setup" command not working

Here's what the setup script does. If it fails, try doing each of these things individually yourself:

# verify your environment will work with the project
node ./scripts/verify

# install dependencies
npm install

# verify the project is ready to run
npm run build
npm run test:coverage

If any of those scripts fail, please try to work out what went wrong by the error message you get. If you still can't work it out, feel free to open an issue with all the output from that script. I will try to help if I can.

Contributors

Thanks goes to these wonderful people (emoji key):

_{Kent C. Dodds}
💻 📖 🚇

⚠️

This project follows the all-contributors specification. Contributions of any kind welcome!

License

This material is available for private, non-commercial use under the GPL version 3. If you would like to use this material to conduct your own workshop, please contact me at kent@doddsfamily.us

billhimmelsbach/testing-node-apps