Section 2.1: Synchronous ESM Support

Node.js 22 introduces the capability to use require() for synchronous ES Module (ESM) graphs, which facilitates a smoother integration of modern JavaScript standards. Traditionally, the CommonJS (CJS) system relied on require() for importing modules, while ESM utilizes the import syntax for static imports, resolving dependencies at compile time.

To enable ESM in a Node.js project, you can either set "type": "module" in the package.json file or change the file extension to .mjs. Here’s an example of how to create an ESM file:

// server/util.mjs

export const add = (a, b) => a + b;

Next, you can create a main.js file to import this ESM module using require():

// server/main.js

const { add } = require('./util.mjs');

console.log(1 + 2 = ${add(1, 2)});

Running this will initially yield an error, as require() does not support importing ES modules. However, with the --experimental-require-module flag enabled, you can seamlessly integrate ESM in a CJS context, provided that the modules execute synchronously.

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In this video, the speaker shares their excitement about the new features in Node.js 22.

Section 2.2: Establishing a Stable Watch Mode

Node.js 22 stabilizes the watch mode feature that was introduced as experimental in Node.js 19. This mode is beneficial during development, allowing automatic restarts of the Node.js application whenever changes are made, which enhances productivity.

Section 2.3: Default WebSocket Client

With the release of Node.js 22, the WebSocket client is now enabled by default, simplifying the process of establishing communication channels. This integration reduces the need for third-party libraries and streamlines coding practices.

Section 2.4: Running Scripts from package.json

A new experimental feature in Node.js 22 allows for executing scripts defined in the package.json file directly via the command line using the node --run command. This improvement enhances efficiency by reducing overhead when running scripts, particularly in development environments.

Section 2.5: Upgrading to V8 JavaScript Engine Version 12.4

Node.js 22 upgrades to V8 JavaScript Engine Version 12.4, which introduces new features such as the asynchronous Array.fromAsync() method, enhancing the array manipulation capabilities of JavaScript.