Node.js Native Messaging Host Memory Usage

background.js

/*
port = chrome.runtime.connectNative('node_native_messaging_host_memory_usage');
port.onMessage.addListener((message)=>{
  console.log(message);
});

port.onDisconnect.addListener(()=>{
  if (chrome.runtime.lastError) {
    console.log(chrome.runtime.lastError.message)
  }
  console.log('Disconnected')
});

port.postMessage('test');
*/

example.js

#!node
// https://github.com/simov/native-messaging/blob/master/protocol.js
// https://github.com/simov/native-messaging/blob/master/nodejs/example.js
// Might be good to use an explicit path to node on the shebang line
// in case it isn't in PATH when launched by Chrome
// let sendMessage = require('./protocol')(handleMessage);
process.stdin.on('readable', () => {
  let input = [];
  let chunk;
  while ((chunk = process.stdin.read())) {
    input.push(chunk);
  }
  input = Buffer.concat(input);

  let msgLen = input.readUInt32LE(0);
  let dataLen = msgLen + 4;

  if (input.length >= dataLen) {
    let content = input.slice(4, dataLen);
    let json = JSON.parse(content.toString());
    handleMessage(json);
  }
});

function sendMessage(msg) {

  let buffer = Buffer.from(JSON.stringify(msg));

  let header = Buffer.alloc(4);
  header.writeUInt32LE(buffer.length, 0);

  let data = Buffer.concat([header, buffer]);
  process.stdout.write(data);
}

process.on('uncaughtException', (err) => {
  sendMessage({ error: err.toString() });
});

function handleMessage(input) {
  while (true) {
    sendMessage([...new Uint8Array(1764).fill(255)]);
  }
}

manifest.json

{
  "name": "node-native-messaging-host-memory-usage",
  "version": "1.0",
  "manifest_version": 3,
  "permissions": [ 
    "nativeMessaging"
  ],
  "background": {
    "service_worker": "background.js"
  },
  "action": {}
}

node_native_messaging_host_memory_usage.json

{
  "name": "node_native_messaging_host_memory_usage",
  "description": "Node.js Native Messaging Host Memory Usage",
  "path": "/path/to/node-native-messaging-host-memory-usage/example.js",
  "type": "stdio",
  "allowed_origins": [
    "chrome-extension://<id>/"
  ]
}