npm init -y
Now, let's install Jest as a development dependency:
bash
Copy
npm install --save-dev jest
Open your package.json and add this test script:
json
Copy
{
  "scripts": {
    "test": "jest"
  }
}
Writing Your First Test

![Abstract waves of light trails forming interconnected networks fluorescent green and black color palette dynamic motion blur effect captured from a side angle with upward tilt high-quality ultra-realistic cinematic 8K UHD high resolution sharp and detail](/image_generation/tillitsdone_Jest_Basic-topic_topics_find_Setting-up-Jest-in-Your-JavaScript-Projectcontent_1732730530541_2.jpeg "Abstract waves of light trails forming interconnected networks fluorescent green and black color palette dynamic motion blur effect captured from a side angle with upward tilt high-quality ultra-realistic cinematic 8K UHD high resolution sharp and detail")

Let's write a simple test to make sure everything's working. Create a new file called sum.js:

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

Then create a test file called sum.test.js:

javascript
Copy
const sum = require('./sum');

test('adds 1 + 2 to equal 3', () => {
  expect(sum(1, 2)).toBe(3);
});

Run your test with:

bash
Copy
npm test

And voilà! You've just written and executed your first Jest test. Pretty straightforward, right?

Best Practices and Tips

Here are some nuggets of wisdom I've learned along the way:

Name your test files with the .test.js or .spec.js suffix
Keep your tests close to the code they're testing
Write descriptive test names that explain the expected behavior
Use Jest's watch mode during development with jest --watch

Remember, testing isn't about achieving 100% coverage from day one. Start small, test the critical parts of your application first, and gradually build up your test suite as you go.

![Macro shot of crystalline structures with intricate patterns sunshine yellow and gray color scheme sharp geometric formations catching light extreme close-up angle with shallow depth of field high-quality ultra-realistic cinematic 8K UHD high resolution sharp and detail](/image_generation/tillitsdone_Jest_Basic-topic_topics_find_Setting-up-Jest-in-Your-JavaScript-Projectcontent_1732730530541_3.jpeg "Macro shot of crystalline structures with intricate patterns sunshine yellow and gray color scheme sharp geometric formations catching light extreme close-up angle with shallow depth of field high-quality ultra-realistic cinematic 8K UHD high resolution sharp and detail")

Copy