How to Run Typescript Tests With Nodejs Test Runner

#nodejs #typescript #dev

Pre-requirement

(Installing the correct version of nodejs)
In order to run Typescript tests with nodejs test runner as described in this tutorial, you need to have nodejs v22.6.0+. If you dont want to install a different version of nodejs to break your other projects, you can install this version via nvm only into this project by running: nvm install v22.7.0 (- this is a current version at the time writing of this blog post), and creating .nvmrc file with following content

v22.7.0
Why do we need nodejs v21+?

  1. Since v21 nodejs supports glob patterns which we need for executing all test files in codebase.
  2. Since v22.6 nodejs supports native typescript. More about it here: The Easier Way To Setup Nodejs App Written in Typescrips - 5 Steps Needed#^b5567d

Installing Dependencies

The one and only dependency we need is TypeScript Execute (tsx) | tsx. Which can we easily add via command:

yarn add --dev tsx
# replace "yarn" with any package manager you use

Setup Command to Run Tests

Adjust your package.json file to add the command test:

{
	...
	"scripts": {
	    "test": "node --import tsx --test 'src/**/__tests__/*.spec.ts'"
	  },
}

This command expects to load and execute test files inside src, and part of __tests__ folder. You can adjust this glob pattern to your liking.

Creating First Test

import assert from 'assert/strict'
import { describe, it } from 'node:test'

describe('bogus tests', () => {
  it('passes', () => {
    assert.ok(true)
  })
})

Nodejs test runner is super easy, and follows the testing conventions of any other runner.

Running Tests

With this simple yarn command, all tests located in your codebase will be executed 🎉:

yarn test

Producing the following result:
result of test runner on nodejs
And this is it! Easy right?