Release Notes for Node.js 22

This release includes an upgrade of the V8 JavaScript engine to v12.4, which is part of Chromium 124.

The upgraded V8 JavaScript engine includes the following new features and enhancements:

For more information about the changes that are available in the V8 JavaScript Engine, see the V8 blog.

Red Hat build of Node.js 22 increases the default high water mark for Node.js streams from 16 KB to 65 KB. This enhancement helps to improve the general performance of Node.js streams.

For more information, see the Node.js new stream.Writable and new stream.Readable documentation.

Red Hat build of Node.js 22 provides more efficient creation of AbortSignal instances. This enhancement greatly improves the performance of the fetch() API and the test runner module.

For more information, see the Node.js AbortSignal documentation.

Red Hat build of Node.js 22 enhances the writeFileSync() method by including a highly efficient fast path for UTF-8-encoded string data. This release also uses the improved writeFileSync() functionality to help optimize the appendFileSync() method. This enhancement focuses specifically on maximizing the efficiency of string data operations.

For more information, see the Node.js fs.writeFileSync and fs.appendFileSync documentation.

From the Node.js 17 release onward, Node.js no longer prefers IPv4 addresses over IPv6 addresses. Node.js adheres to the order that is returned based on the domain name search (DNS) entries. This behavior does not typically affect properly configured hosts. However, this behavior might cause issues for hosts that have a partially or incorrectly configured IPv6 stack. Recent releases have aimed to improve the user experience with incorrectly configured IPv6 stacks, by including an implementation of the Happy Eyeballs algorithm and by fixing edge cases.

Red Hat build of Node.js 22 includes three new events for connection attempts in the net.createConnection flow:

Additionally, Red Hat build of Node.js 22 resolves an issue where a new connection attempt could start after a previous attempt failed and the user had already destroyed the connection. This issue caused a failed assertion in earlier releases.

For more information, see the Node.js net.Socket documentation.

Red Hat build of Node.js 22 adds support for the deflate-raw parameter in both CompressionStream and DecompressionSteam constructors. The deflate-raw parameter compresses or decompresses the stream by using the DEFLATE algorithm without a header and trailing checksum. This enhancement ensures consistency with the web-streams compression that modern browsers support.

For more information, see the Node.js CompressionStream and DecompressionStream documentation.

Red Hat build of Node.js 22 provides watch mode as a stable feature that you can use in production environments. In earlier releases, watch mode was available as an experimental feature only.

You can run Node.js applications in watch mode by using the node --watch CLI option. Running an application in watch mode means that the process restarts if you modify an imported file, which offers the core benefit of a faster inner loop development cycle.

Watch mode includes the following options:

For more information, see the Node.js --watch documentation.

This release removes support for import assertions that use the assert keyword. Import assertions are now superseded by import attributes that use the with keyword. From Red Hat build of Node.js 22 onward, ensure that any occurrences of the assert keyword are replaced by the with keyword.

For example, consider the following statement, where <module_name> represents the name of the module that you want to import:

import "<module_name>" assert { ... }

Replace the preceding example with the following statement:

import "<module_name>" with { ... }

For more information, see the Node.js Import attributes documentation.

This release includes the runtime deprecation of the following util APIs:

For more information, see the Node.js Utilities: Deprecated APIs documentation.

Red Hat build of Node.js 22 includes an experimental built-in browser-compatible implementation of the WebSocket API. This enhancement provides a WebSocket client without external dependencies.

This feature is enabled by default. If you want to disable this feature, you can use the --no-experimental-websocket CLI flag.

Red Hat build of Node.js 22 includes the following experimental enhancements for ECMAScript Modules (ESM) compatibility.

Red Hat build of Node.js 22 introduces the following experimental features for TypeScript support.

Red Hat build of Node.js 22 introduces an experimental implementation of the Web Storage API that uses SQLite for data storage. You can enable this feature by using the --experimental-webstorage CLI flag.

For more information, see the Node.js --experimental-webstorage documentation.

Red Hat build of Node.js 22 introduces an experimental feature for a built-in node:sqlite module that you can enable by using the --experimental-sqlite CLI flag.

The following example shows how to use the node:sqlite module to open an in-memory database, write data to the database, and read the data back:

import { DatabaseSync } from 'node:sqlite';
const database = new DatabaseSync(':memory:');

// Execute SQL statements from strings.
database.exec(`
  CREATE TABLE data(
    key INTEGER PRIMARY KEY,
    value TEXT
  ) STRICT
`);
// Create a prepared statement to insert data into the database.
const insert = database.prepare('INSERT INTO data (key, value) VALUES (?, ?)');
// Execute the prepared statement with bound values.
insert.run(1, 'hello');
insert.run(2, 'world');
// Create a prepared statement to read data from the database.
const query = database.prepare('SELECT * FROM data ORDER BY key');
// Execute the prepared statement and log the result set.
console.log(query.all());
// Prints: [ { key: 1, value: 'hello' }, { key: 2, value: 'world' } ]

For more information, see the Node.js SQLite documentation.

Red Hat build of Node.js 22 includes an experimental Navigator global object. The Navigator object is a partial implementation of the Navigator API, which is used to represent the identity and state of the user agent.

For more information, see the Node.js Navigator documentation.

Red Hat build of Node.js 22 includes an experimental util.styleText(format, text) function that returns formatted text based on supplied format and text string parameters. You can use this new API to format text in different colors (for example, red, blue, green) and emphasis styles (for example, italic, bold, underline) based on util.inspect.colors.

The following example formats the text Hello World in green font:

const { styleText } = require('node:util');
const myMessage = styleText('green', 'Hello World');
console.log(myMessage);

The following example formats the text Error! in bold red font:

const { styleText } = require('node:util');
const myMessage = styleText(['red', 'bold'], 'Error!');
console.log(myMessage);

For more information, see the Node.js util.styleText documentation.

In addition to the existing experimental support for defining environment variables in files, Red Hat build of Node.js 22 includes the following experimental APIs for the programmatic loading and parsing of environment variables:

Red Hat build of Node.js 22 introduces the following experimental features that offer two alternative solutions for automatic on-disk code caching.