Node v22 Experiments

Pushed along by Deno and Bun, Node have made some really nice strides recently to bring a modern Node experience.

Version 22 has some really nice out of the box features that mean you need a lot less dependencies and get a much more modern coding experience.

This is just some quick notes on the new features based on a video I watched where Matteo Collina chatted with Jason Lengstorf.

TypeScript Support
Working with TypeScript is so much easier, just install TypeScript, tsx and some node types then you’re good to go!

npm i typescript tsx 
npm i --save-dev @types/node

Then it’s as simple as:

node index.ts 

Watch Mode Support
Enabling watch mode in Node (as far as I can recall) has always involved installing a third party package called nodemon. Not anymore!

Simply use the new —watch flag

node --watch index.ts

Environment Variables
Need to use a .env file, well you’d have had to install a third party package like dotenv. No longer!

Out of the box environment variables can be passed in with the —env-file flag

node --env-file=.env index.ts

Styling Text
If you’ve written any kind of CLI or bash script you’ve probably found yourself wanting to colour the text, which meant a third party package like chalk. No more!

Use the in-built styleText util.

import { styleText } from "node:util";

console.log(styleText(["yellow", "underline"], "Yellow underlined text"));

ParseArgs
Similarly if your CLI used args then it was often a pain to read and validate those arguments without a third party package. Now you can use parseArgs

import { parseArgs } from "node:util";

const options = {
  name: {
    type: "string" as const,
  },
};

const args = process.argv.slice(2); // Skip the first two elements (node and script path)
let name = "";

for (let i = 0; i < args.length; i++) {
  if (args[i] === "--name" && i + 1 < args.length) {
    name = args[i + 1];
    break;
  }
}

const { values, positionals } = parseArgs({ args, options });

console.log(values, positionals);
console.log(styleText(["yellow", "underline"], `Yellow underlined text - ${name}`));

Current Directory
Something that used to be fiddly is now a 1 liner

console.log(import.meta.dirname)

Globs & Read Stream
Working with the filesystem using globs and streaming the result to the terminal is now really easy

import { glob } from "node:fs/promises";
import { createReadStream } from "node:fs";

for await (const file of glob(import.meta.dirname + "/*")) {
  console.log(styleText("red", file));
  if (file.endsWith("ts")) {
    const stream = createReadStream(file);

    for await (const chunk of stream) {
      console.log(styleText("green", chunk.toString().toUpperCase()));
    }
  }
}

Test Runner
Running tests used to involve a third party package such as Jest now you can run them out of the box using the new node test runner.

import { test } from "node:test";
import assert from "node:assert/strict";

test("NoJest", function () {
  const res = NoJest();
  assert.equal(res, "Hey no Jest needed!");
});

A code repo where you can run these new features https://github.com/DaveHudson/node-22-experiments