vscode npm nodejs: cannot find module 'serialport' error-CodePudding

I started using vscode (on windows10) a few months ago to develop nodejs server rest services and everything ran smoothly. Later, I started to use vscode also for my ESP32 C program using PlatformIO and I'm very pleased I did. The problem is that now that I returned to my nodejs program, I run into errors, mainly because nodejs cannot find the 'serialport' module. I suspect the problem has to do with the paths and the particular way the 'serialport' module has been implemented (as a C source code, as I read somewhere ???). The /server/node_modules directory contains a directory '@serialport'. The 'index.js' program starts running but I get the following error. Please help.

console.log("server running");

var serialPORT = 'COM10';             //  WINDOWS 10 VERSION
//var serialPORT = '/dev/ttyS0';      // LINUX SERVER


var serialport = require("serialport");

console.log("serialport module loaded");     // NEVER REACHES HERE

var port = new serialport(serialPORT, { baudRate:38400, }, (err)=>{
        if(err) console.log("Serialport Error, line #11", err.message);
        else console.log("\r\n\nserial port /dev/serial0 on pins #8: TXD, #10 RXD is open\r\n\n");
        return;
    }
);

const Readline = serialport.parsers.Readline;
const parser = new Readline();
port.pipe(parser);


parser.on('data', onData);

//  REST OF SERVER ...

The printout and error are as follows:

server running
internal/modules/cjs/loader.js:883
  throw err;
  ^

Error: Cannot find module 'serialport'
Require stack:
- C:\Users\Panos\Documents\node_js projects\server\index.js
    at Function.Module._resolveFilename (internal/modules/cjs/loader.js:880:15)
    at Function.Module._load (internal/modules/cjs/loader.js:725:27)
    at Module.require (internal/modules/cjs/loader.js:952:19)
    at require (internal/modules/cjs/helpers.js:88:18)
    at Object.<anonymous> (C:\Users\Panos\Documents\node_js projects\server\index.js:8:18)
    at Module._compile (internal/modules/cjs/loader.js:1063:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:1092:10)
    at Module.load (internal/modules/cjs/loader.js:928:32)
    at Function.Module._load (internal/modules/cjs/loader.js:769:14)
    at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:72:12) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [
    'C:\\Users\\Panos\\Documents\\node_js projects\\server\\index.js'
  ]
}

The package.json is as follows:

{
  "name": "server",
  "version": "1.0.0",
  "description": "node.js version of esp32 web server running on raspberry pi 4",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "author": "panos",
  "license": "ISC",
  "dependencies": {
    "url": "^0.11.0"
  }
}

CodePudding user response：

You haven't installed the package because it isn't listed in the package.json. Run this to install serial port with the cmd console in your project directory

npm i serialport

CodePudding user response：

The answer is in the manual of course:

Local install (default): puts stuff in ./node_modules of the current package root.
Global install (with -g): puts stuff in /usr/local or wherever node is installed.
Install it locally if you're going to require() it.
Install it globally if you're going to run it on the command line.
If you need both, then install it in both places, or use npm link.