[NODE-REALOAD] Update node dependencies without close running server

index.js

// On this example i can add or remove routes and no need to stop ou restart the server

const http = require('http');

// nothing before will be updated if there are changes
require('./node-reload') // Does not change the caller file, requiring on the start is best
// any require from here will be updated if there are changes

// Criando o servidor HTTP
const server = http.createServer((req, res) => {
  const { routes } = require('./routes/index')

  routes(req, res)
});

// Iniciando o servidor na porta 3000
server.listen(3000, () => {
  console.log('Server is running on http://localhost:3000 !');
});

node-reload.js

const Module = require('module');
const fs = require('fs');
const path = require('path');

const originalRequire = Module.prototype.require;
const watchers = new Map();

function clearCache(filename) {
  const resolvedPath = path.resolve(filename);
  delete require.cache[resolvedPath];
}

function watchFile(filename) {
  const resolvedPath = path.resolve(filename);

  if (watchers.has(resolvedPath)) return;

  if (fs.existsSync(resolvedPath)) {
    const watcher = fs.watch(resolvedPath, (eventType) => {
      if (eventType === 'change' || eventType === 'rename') {
        // console.log(`Detected change in ${resolvedPath}, reloading...`);
        clearCache(resolvedPath);
        originalRequire.call(module, resolvedPath);
      }
    });

    watchers.set(resolvedPath, watcher);
  }
}

Module.prototype.require = function (filename) {
  const resolvedPath = Module._resolveFilename(filename, this);
  const req = originalRequire.call(this, filename);

  if (![ // Add here if you have any files or folders that you don't want updated
    /[\/\\]node_modules[\/\\]/
  ].some(e => e.test(resolvedPath))) {
    watchFile(resolvedPath);
    clearCache(resolvedPath);
  }

  // console.log(`Requiring module: ${resolvedPath}`);
  return req;
};

routes.js

// any update to this file will auto update on server with out closing
const routes = (req, res) => {
  if (req.url === '/hello') {
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.end('Hello, World!');
  } else if (req.url === '/new') {
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.end('New route!');
  } else {
    res.writeHead(404, { 'Content-Type': 'text/plain' });
    res.end('Not Found');
  }
}

module.exports = { routes }