How to setup Vitest for Node.js testing

Requirements

Node.js installed with version v14 or higher
Basic Node.js app

Installation

Vitest is super simple to install. It can be installed via any node package manager such as npm, yarn or pnpm. We will install vitest as a devDependency.

npm install --save-dev vitest
# OR
yarn add -D vitest
# OR
pnpm add -D vitest

bash

Configuring the project

We will now add a simple command to our package.json. This will allow us to run npm run test in the command line.

{
  "name": "my-nodejs-app",
  "version": "0.0.0",
  "scripts": {
    "test": "vitest"
  }
}

json

Adding a test file

Once we've updated our configuration, we can start adding test files, for example maths.test.ts. We import test and expect from vitest:

maths.test.ts

import { expect, test } from 'vitest'
 
test('Math.sqrt()', () => {
  expect(Math.sqrt(4)).toBe(2)
  expect(Math.sqrt(144)).toBe(12)
  expect(Math.sqrt(2)).toBe(Math.SQRT2)
})

typescript

Testing the application

To run these tests, simply run the test command we created earlier:

npm run test

bash

This will show all passed and failed tests.

Tip: You can also view those tests in the browser! Simply create a new command shown below:

{
  "scripts": {
    "test": "vitest",
    "test:ui": "vitest --ui"
  }
}

json

Online Example

More from Vitest

You can use Vitest for many more project types, such as: React, Next.js, Vue, Svelte, etc. Read more about the awesomeness Vitest can do at their documentation

Personally, I use Vitest in many of my projects and I absolutely love it! It's simple to setup, fast and has a great community.