index.js

const serialport = require('serialport');
const SerialPort = serialport.SerialPort;
const PORT = "/dev/ttyUSB0";

serialPort = new SerialPort({
    path: PORT,
    baudRate: 115200,
});

serialPort.on("open", () => {
    console.log("-- Connection opened --");
    serialPort.on("data", (data) => {
        const SERIAL_IN = data.toString();
        const [from, command] = SERIAL_IN.split("::").filter(Boolean);
        console.log(`from: \t\t${from}`);
        console.log(`command: \t${command}`);
    });
});

package.json

{
  "name": "serial",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "serialport": "^10.5.0"
  }
}