nm_nodejs.js does not work on linux with firefox

[epragalakis]

I posted a similar issue on: mdn/content#36513

although the examples differ from each other.

If this is under active maintenance and you are interested in it I can post more debug info (and also a walthrough of my attempts) later.

[guest271314]

First make sure the file is marked executable.

Then remove this

process.env.UV_THREADPOOL_SIZE = 1;

If you have deno available you can test the nm_nodejs.js outside of a Native Messaging host context with the code here #2 (comment).

Test on Chromium or Chrome to make sure the host works there.

If that doesn't work try using this https://github.com/guest271314/NativeMessagingHosts/blob/main/nm_host.js, which works using node, deno, and/or bun .

[guest271314]

What versions of Firefox and Node.js are you using?

Can you kindly create a gist including all of the code you are using?

BTW, I updated nm_nodejs.js here https://github.com/guest271314/native-messaging-nodejs/blob/main/nm_nodejs.js, though the code on MDN should still work.

@Josh-Cena One of your team mates over in MDN world contacted me by email, we exchanged idea, and they saw fit to ban me from MDN, so if we need to coordinate to publish working code - if we conclude it's the code and not something else that's not working - kindly visit this issue so we have working code published on MDN. Thanks.

[epragalakis]

node 20.17
fedora 40 (sway spin)

BTW, I updated nm_nodejs.js here https://github.com/guest271314/native-messaging-nodejs/blob/main/nm_nodejs.js,

it worked!! (although I dont understand why and also the code looks like its doing way more than using the stdin and stdout as the docs mention)

I will post a follow up message with more debug info on the MDN example when I get some time in the coming days

[guest271314]

@epragalakis

nm_nodejs.js does not work on linux with firefox #3

Cannot reproduce.

Works for me on Linux 5.15.0-43-generic x86_64 x86_64 x86_64 GNU/Linux.

manifest.json

{
  "name": "tab",
  "version": "1.0",
  "manifest_version": 3,
  "chrome_url_overrides": {
    "newtab": "./tab.html"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "newtab@guest271314"
    }
  },
  "background": {
    "scripts": ["background.js"]
  },
  "permissions": ["nativeMessaging"]
}

nm_nodejs.mjs

#!/usr/bin/env -S /home/user/bin/node

import fs from "node:fs/promises";

async function getMessage() {
  const header = new Uint32Array(1);
  await readFullAsync(1, header);
  const message = await readFullAsync(header[0]);
  return message;
}

async function readFullAsync(length, buffer = new Uint8Array(65536)) {
  const data = [];
  while (data.length < length) {
    const input = await fs.open("/dev/stdin");
    const { bytesRead } = await input.read({ buffer });
    await input.close();
    if (bytesRead === 0) {
      break;
    }
    data.push(...buffer.subarray(0, bytesRead));
  }
  return new Uint8Array(data);
}

async function sendMessage(message) {
  const header = new Uint32Array([message.length]);
  const stdout = await fs.open(`/proc/${process.pid}/fd/1`, "w");
  await stdout.write(header);
  await stdout.write(message);
  await stdout.close();
}

while (true) {
  try {
    const message = await getMessage();
    await sendMessage(message);
  } catch (e) {
    console.error(e);
    process.exit(1);
  }
}

From App side.

node version v24.0.0-nightly202410257ddd2c2282.

Make sure the file is executable.

chmod +x nm_nodejs.mjs

nm_nodejs.json

{
  "name": "nm_nodejs",
  "description": "Node.js Native Messaging host",
  "path": "/home/xubuntu/tab-firefox/nm_nodejs.mjs",
  "type": "stdio",
  "allowed_extensions": [ "newtab@guest271314" ]
}

nm_nodejs.json is written to the local filesystem at ~/.mozilla/native-messaging-hosts/nm_nodejs.json, see Manifest location at hLinux.

Firefox Nightly 133.0a1 (2024-10-27) (64-bit).

Code run in DevTools on the Wex extension page

globalThis.port = browser.runtime.connectNative("nm_nodejs");
port.onMessage.addListener((message) => console.log(message));
port.onDisconnect.addListener((p) => console.log(chrome.runtime.lastError));
port.postMessage(new Array(209715));

Message from host

Array(209715) [ null, null, null, null, null, null, null, null, null, null, … ]

Firefox Nightly screenshot

Task Manager screen shot

[guest271314]

@Josh-Cena Cannot reproduce the code on MDN not working. See above. Need more details.

[Josh-Cena]

I know nothing about this area so sorry I can't provide any help in debugging. @guest271314 fully appreciate your effort here. I'm sorry to hear about your situation with MDN, but if someone else has made that decision it's beyond my capability to revert it. I'm happy to credit you on any fix we may reach for the MDN example, though.

[guest271314]

@Josh-Cena I wasn't asking for anything re MDN. I'm just notifying you I'm banned from over there. Any help I can provide from here for Native Messaging that helps the documentation and working code examples I will.

This script, nm_standalone_test.js (nm_standalone_test.js.tar.gz), here How to test the different hosts #2 tests Native Messaging hosts, outside of the browser. So there's really no getting around the question of the protocol and programming language or runtime not working as expected, leaving user or architecture as causes fof issues. C, C++, Rust, WASM, Python, JavaScript (QuickJS, txiki.js, Node.js, Deno, Bun) should all read and write the same output back to the parent process, again, on the commandline. Thanks.

[guest271314]

@epragalakis Re

hey @Josh-Cena
long shot, but do you remember on why you had to do the above (lines 266-271)
instead of doing a console.log or process.stdout.write ?

console.log() doesn't work in JavaScript runtimes for Native Messaging hosts to send a message back to the browser.

[guest271314]

@epragalakis The reason that console lof doesn't work for sending messages from the runtime to the browser is 1. ECMA-262 doesn't specify I/O for "JavaScript", therefore console is not part of ECMA-262, and the implementation thereof, if implemented at all (could be print() in a given JavaScript runtime; I/O might not be possible, e.g., SerentityOS's LibJS js), and console is, in general, expected to be a TTY; the browser is not a TTY.

[guest271314]

@Josh-Cena AN independent Native Messaging hacker verified this https://github.com/guest271314/native-messaging-nodejs/blob/main/nm_nodejs.js works on Apple devices, using node version 18. I'm running node version 24.

Would you mind updating the example on MDN to use the above code?

[guest271314]

@Josh-Cena Re mdn/content#36626 (comment)

Could you make minimal changes required to make it work, rather than copying entire source code over?

I don't understand. Don't you want code that works on Linux, Microsoft products, and Apple products on MDN.

The PR changes one part of one file. What's the blocker?