chrishuffman5/cli-nodejs-22

Node.js 22 LTS Version Expert

Node 22 LTS (codename Jod). Released April 2024, EOL April 2027. Second-latest LTS.

Key Features

| Feature | Status | |---|---| | require() for ES modules | Experimental (no flag needed from 22.12+) | | WebSocket client built-in | Stable | | glob / globSync in node:fs | Stable | | --watch mode improvements | Stable | | node:test snapshot testing | Added | | V8 12.4, Promise.withResolvers() | Included | | util.parseEnv() | Added |

Built-in WebSocket Client

No need to install the ws package for basic WebSocket usage.

// Built-in WebSocket (no import needed, global)
const socket = new WebSocket('wss://echo.websocket.org');

socket.addEventListener('open', () => {
  console.log('Connected');
  socket.send('Hello from Node 22!');
});

socket.addEventListener('message', (event) => {
  console.log('Received:', event.data);
  socket.close();
});

socket.addEventListener('close', () => {
  console.log('Disconnected');
});

socket.addEventListener('error', (event) => {
  console.error('WebSocket error:', event);
});

Built-in Glob (node:fs)

import { glob, globSync } from 'node:fs/promises';

// Async glob (returns AsyncIterable)
const jsFiles = await Array.fromAsync(glob('**/*.js'));
console.log(jsFiles);

// With options
const tsFiles = await Array.fromAsync(glob('**/*.ts', {
  cwd: '/project/src',
  exclude: (name) => name.includes('node_modules'),
}));

// For-await iteration (memory efficient for large trees)
for await (const file of glob('**/*.json', { cwd: '/data' })) {
  console.log(file);
}

// Sync version (for startup/config loading)
import { globSync as globSyncFs } from 'node:fs';
const configs = globSyncFs('*.config.{js,ts,json}');

require() for ESM (Experimental)

CJS code can now require() ES modules that meet certain constraints (no top-level await, synchronous).

// In a CJS file (no flag needed from Node 22.12+):
const { helper } = require('./esm-module.mjs');

// Restrictions:
// - The ESM module must not use top-level await
// - Works for most pure-function ESM libraries
// - Enables gradual ESM migration

Snapshot Testing (node:test)

import { test } from 'node:test';

test('snapshot test', (t) => {
  const result = generateReport();
  // First run: creates snapshot. Subsequent runs: compares.
  t.assert.snapshot(result);
});

test('named snapshot', (t) => {
  t.assert.snapshot(JSON.stringify(data, null, 2), 'report-data');
});

# Update snapshots
node --test --test-update-snapshots

util.parseEnv()

import { parseEnv } from 'node:util';

const envContent = `
DB_HOST=localhost
DB_PORT=5432
# This is a comment
SECRET="my secret value"
`;

const parsed = parseEnv(envContent);
// { DB_HOST: 'localhost', DB_PORT: '5432', SECRET: 'my secret value' }

V8 12.4 Highlights

• Promise.withResolvers() -- returns { promise, resolve, reject } in one call
• Object.groupBy() / Map.groupBy() -- native grouping
• ArrayBuffer.prototype.transfer() stable

// Promise.withResolvers
const { promise, resolve, reject } = Promise.withResolvers();
setTimeout(() => resolve('done'), 1000);
const result = await promise;

// Object.groupBy
const people = [{ name: 'Alice', dept: 'eng' }, { name: 'Bob', dept: 'sales' }];
const byDept = Object.groupBy(people, p => p.dept);
// { eng: [{ name: 'Alice', ... }], sales: [{ name: 'Bob', ... }] }

Migration Notes

When migrating from Node 20 to Node 22:

• Built-in glob eliminates need for fast-glob/globby in many cases
• Built-in WebSocket eliminates need for ws package (basic usage)
• require() ESM support enables gradual migration of CJS codebases
• parseEnv() can replace dotenv for simple .env parsing
• Snapshot testing reduces need for external snapshot libraries