index.js

const {app, BrowserWindow} = require('electron');
const url = require('url');
const http = require('http');
const fs = require('fs');
const path = require('path');

let win = null

function boot() {
  win = new BrowserWindow({
    width:1020,
    height:680,
    resizable:false
  })
  win.loadURL(`http://127.0.0.1:1234`)
}

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 '.svg':
            contentType = 'image/svg+xml';
            break;
        case '.jpg':
            contentType = 'image/jpg';
            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(1234);
app.on('ready', boot);