Automated Testing with Jest: Beginner's Guide

Hello HaWkers! Today, we're going to talk about the importance of automated testing and how you can implement it in your JavaScript code using Jest.

Why Automated Testing?

Automated tests are essential to ensure code quality and prevent the introduction of bugs. They allow you to verify that all of your application's functions are working as expected, even after code changes and additions.

What is Jest?

Jest is a JavaScript testing framework developed by Facebook. It is used to test JavaScript code, including React and Vue code. Jest is known for its speed and flexibility as it has a robust mocking system and an easy-to-use API.

Configuring Jest

To start using Jest, you need to install it in your project. If you are working on a Node.js project, you can install Jest using npm:

npm install --save-dev jest

Then add the following to your package.json file:

"scripts": {  "test": "jest"}

Now you can run your tests with npm test.

Writing Your First Test

Let's create a simple test for a function that adds two numbers. First, create a sum.js file:

function sum(a, b) {  return a + b;}module.exports = sum;

Now, create a sum.test.js file:

const sum = require('./sum');test('add 1 + 2 to 3', () => {  expect(sum(1, 2)).toBe(3);});

Now, if you run npm test, Jest will run the test you just created.

Conclusion

Congratulations! You've just written and run your first test with Jest. Automated testing is an important part of software development that can save you a lot of hassle in the future.

If you want to learn more about JavaScript, check out the article about Clean Code in JavaScript: Best Practices.

Until next time, HaWkers!

Let's go up! 🦅