POC-NODE-22

This project is a poc for testing the new feature of Node 22. The new version has been released in avril 2024 and will become the new LTS soon. In this project, I implemented ad put some clarity on the new features. In addition to what is under, we can also point the javascript version that has been upgraded to V8.

Plan of the presentation

I explain with all the details how I build the project and my way of working.

• Support require()ing synchronous ESM graphs
• Running package.json scripts
• Stream default High Water Mark
• Watch Mode
• Websocket Client
• Glob/GlobSync
• Improve performance of AbortSignal creation
• Link

Support require()ing synchronous ESM graphs

You can now use module and mjs module using the "--experimental-require-module":

Run the following command:

$ node --run module

Running package.json scripts

No need to use the following command npm run watch, you can use node directly:

$ node --run watch

It will run the watch script located in the package.json.

Stream default High Water Mark

The high water mark is a parameter that sets a limit on the amount of data that can be stored in the internal stream buffer. When the limit is reached, Node stops reading more data until the buffer is emptied. This process is a security to limit the memory usage and prevent your application from crashing. This limit is a threshold, not a hard limit!

This parameter is tricky. If set too low, the program might take a while to execute very long process requiring a log of information from a stream. If set too high, you might crash your application with a java heap limit exception.

The default value of stream has been increased by default from 16kiB to 64KiB.

In order to see this, just run the following command:

$ node --run highWaterMark

As you can see, it is way faster with the new high water mark limit but also consume obviously more memory.

In order to see the problem that you might encountered, you can limit the max memory allocated to the heap by playwing with the max_old_space_size:

$ node --run highWaterMark-limited

Watch Mode

Run the following command:

$ npm run watch

If you modify the index.js in the watched folder, the node will restart with the new code automatically.

You can test the performance between the two version with this:

$ hyperfine --warmup 3 'node --run performance' 'npm run performance'

Websocket Client

No need of dependencies for connection a node script to a websocket server.

$ cd websocket/server
$ npm run dev

You can now connect to the websocket server without any dependencies in the file index.js in the folder websocket.

const socket = new WebSocket("ws://localhost:8080");

// Connection opened
socket.addEventListener("open", () => {
  socket.send("Hello Server!");
});

Glob/GlobSync

No need to import the glob function from Glob npm. You can use it directly from node:fs directly. Run the following command and check the content of the file index.js in the directory glob.

$ npm run glob

Improve performance of AbortSignal creation

Run the bun server, I am using for the test with the following command:

$ cd abort-signal/server
$ npm run dev

Node v22 improve the api abort on the fetch:

const resp = await fetch("http://localhost:3000", {
    signal: AbortSignal.timeout(2000),
});

You can see the result in the file ``fetch.jsin the folderabort-signal`. Run the following command:

$ npm run abort-signal

Link

Node 22 Node 22 - Testing AbortSignal Explanation deep