how-does-one-unit-test

Node Testing for Hacktoberfest 2022

This is a basic group of Node routes and Postgres models setup for testing. You're welcome to create a test suite for the routes and models. Create a issue outlining the tests you aim to complete, then submit a PR that covers it.

Describe basic unit testing in NodeJS. This project is a simple Express server using Jest for testing. This working example has been built for students wanting to write tests on open source projects during Hacktoberfest for practice with testing and contributing.

Table of Contents

• 🔬 NodeJS and Jest Guide to Unit Testing
• ✏️ Steps for Unit Testing
• 🏆 Goals
• 📦 Packages
• 🛠 Tools

🔬 NodeJS and Jest Guide to Unit Testing

The main objective is to explain and use describe(), it(), and before()/etc hooks.

1. describe() is merely for grouping, which you can nest as deep as you need
2. it() is a test case for the feature
3. beforeEach(), afterEach() are hooks to run before/after first/each it() or describe(). Which means, beforeEach() will run before very it()/describe()

✏️ Steps for Unit Testing

• create #feature#.test.js in /test
  • Write describe() block using Jest's BDD style interface | Behavior-driven development (BDD)
  • Write nested it() in the describe() block
    • Use Jest Matcher functions to assert functionality of feature inside it() block | Jest Matches
  • If needed, write your before()/etc hooks. Inside or outside of the describe() block | Setup and Teardown
• To submit your own test cases. If all cases are covered, feel free to create a new Model to test or new Node routes.
  • Write a test suite outlined above
  • Write out comments and steps for your testing as an exmaple to others to see.
  • Create your own feature branch then attach your issue to the pull request.

🏆 Goals:

• Create unit test example in Jest
• Proper Git workflow with feature branches and pull request
• Create intergation test example with Postgres and Supertest
• Add in GitHub Actions for testing code once pushed to Github
• Deploy to AWS if test passes
• Add new test cases for Hacktoberfest

📦 Packages:

You will need Node and Postgres installed. Using Node v18.12.0 and Postgres v15 for this demo. If you don't have these installed follow this guide.

Use yarn or npm to install the following packahes. Testing will require these packages:

• Jest
• Express
• Postgres
• Sequelize
• Docker
• ESlint

TD;LR

npm install jest express sequelize

yarn add jest express sequelize

Guide to Install Node and Postgres

Install NodeJS via nvm

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.2/install.sh | bash

• nvm install stable
• nvm use stable
• which node || node -v should now show your version

Install Postgres via Postgres App for Mac use Postico for GUI.

curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.11/install.sh | bash

• Download Posgresapp and follow install instructions.
• sudo mkdir -p /etc/paths.d && echo /Applications/Postgres.app/Contents/Versions/latest/bin | sudo tee /etc/paths.d/postgresapp

🔑 Keys:

You will need to create dev.js in config/.

module.exports = settings => ({
  postgres: {
    pgUser: 'root',
    pgHost: '127.0.0.1',
    pgDatabase: postgres,
    pgPassword: postgres_password,
  },
  ...settings,
});

Docker Setup

TODO: Outline setting up Docker container

GitHub Actions and Railway Setup

TODO: Outline setting up Github and Railway

🛠 Tools:

These tools are optional but really help with testing and code coverage.

• VSCode
• VSCode Docker extention