Node.js quick file server (static files over HTTP)

If you do not want to use ready tool, you can use the code below, as demonstrated by me at https://developer.mozilla.org/en-US/docs/Node_server_without_framework:

var http = require('http');
var fs = require('fs');
var path = require('path');

http.createServer(function (request, response) {
    console.log('request starting...');

    var filePath = '.' + request.url;
    if (filePath == './')
        filePath = './index.html';

    var extname = path.extname(filePath);
    var contentType = 'text/html';
    switch (extname) {
        case '.js':
            contentType = 'text/javascript';
            break;
        case '.css':
            contentType = 'text/css';
            break;
        case '.json':
            contentType = 'application/json';
            break;
        case '.png':
            contentType = 'image/png';
            break;      
        case '.jpg':
            contentType = 'image/jpg';
            break;
        case '.wav':
            contentType = 'audio/wav';
            break;
    }

    fs.readFile(filePath, function(error, content) {
        if (error) {
            if(error.code == 'ENOENT'){
                fs.readFile('./404.html', function(error, content) {
                    response.writeHead(200, { 'Content-Type': contentType });
                    response.end(content, 'utf-8');
                });
            }
            else {
                response.writeHead(500);
                response.end('Sorry, check with the site admin for error: '+error.code+' ..\n');
                response.end(); 
            }
        }
        else {
            response.writeHead(200, { 'Content-Type': contentType });
            response.end(content, 'utf-8');
        }
    });

}).listen(8125);
console.log('Server running at http://127.0.0.1:8125/');

UPDATE If you need to access your server from external demand/file, you need to overcome the CORS, in your node.js file by writing the below, as I mentioned in a previous answer here

// Website you wish to allow to connect
response.setHeader('Access-Control-Allow-Origin', '*');

// Request methods you wish to allow
response.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');

// Request headers you wish to allow
response.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');

// Set to true if you need the website to include cookies in the requests sent
// to the API (e.g. in case you use sessions)
response.setHeader('Access-Control-Allow-Credentials', true);

UPDATE

As Adrian mentioned, in the comments, he wrote an ES6 code with full explanation here, I just re-posting his code below, in case the code gone from the original site for any reason:

const http = require('http');
const url = require('url');
const fs = require('fs');
const path = require('path');
const port = process.argv[2] || 9000;

http.createServer(function (req, res) {
  console.log(`${req.method} ${req.url}`);

  // parse URL
  const parsedUrl = url.parse(req.url);
  // extract URL path
  let pathname = `.${parsedUrl.pathname}`;
  // based on the URL path, extract the file extension. e.g. .js, .doc, ...
  const ext = path.parse(pathname).ext;
  // maps file extension to MIME typere
  const map = {
    '.ico': 'image/x-icon',
    '.html': 'text/html',
    '.js': 'text/javascript',
    '.json': 'application/json',
    '.css': 'text/css',
    '.png': 'image/png',
    '.jpg': 'image/jpeg',
    '.wav': 'audio/wav',
    '.mp3': 'audio/mpeg',
    '.svg': 'image/svg+xml',
    '.pdf': 'application/pdf',
    '.doc': 'application/msword'
  };

  fs.exists(pathname, function (exist) {
    if(!exist) {
      // if the file is not found, return 404
      res.statusCode = 404;
      res.end(`File ${pathname} not found!`);
      return;
    }

    // if is a directory search for index file matching the extension
    if (fs.statSync(pathname).isDirectory()) pathname += '/index' + ext;

    // read file from file system
    fs.readFile(pathname, function(err, data){
      if(err){
        res.statusCode = 500;
        res.end(`Error getting the file: ${err}.`);
      } else {
        // if the file is found, set Content-type and send data
        res.setHeader('Content-type', map[ext] || 'text/plain' );
        res.end(data);
      }
    });
  });


}).listen(parseInt(port));

console.log(`Server listening on port ${port}`);

A good "ready-to-use tool" option could be http-server:

npm install http-server -g

To use it:

cd D:\Folder
http-server

Or, like this:

http-server D:\Folder

Check it out: https://github.com/nodeapps/http-server