a simple example of a web server in express js that supports both http and https. es6 and es5 javascript compatible source codes are provided.

app-es5.js

"use strict";
var fs = require('fs');
var http = require('http');
var https = require('https');
var express = require('express');
var app = express();
app.get('/', function (req, res) {
  void req;
  res.send("Date: ".concat(new Date()));
});
var credentials;
try {
  credentials = {
    cert: fs.readFileSync('server.crt', 'utf8'),
    key: fs.readFileSync('server.key', 'utf8'),
  };
}
catch (err) {
  console.error('Failed reading SSL certificates:', err.message);
  process.exit(1);
}
var httpServer = http.createServer(app);
var httpsServer = https.createServer(credentials, app);
var address = 'www1.localhost.test';
var httpPort = 80;
var httpsPort = 443;
httpServer.listen(httpPort, address, function () {
  console.log("HTTP server on http://".concat(address, ":").concat(httpPort, "/"));
});
httpsServer.listen(httpsPort, address, function () {
  console.log("HTTPS server on https://".concat(address, ":").concat(httpsPort, "/"));
});
process.on('uncaughtException', function (err) {
  console.error('Uncaught exception:', err);
});
process.on('unhandledRejection', function (reason, promise) {
  console.error('Unhandled Rejection at:', promise, 'reason:', reason);
});

app.js

const fs = require('fs');
const http = require('http');
const https = require('https');
const express = require('express');

const app = express();

app.get('/', (req, res) => {
  void req;
  res.send(`The date today is: ${new Date()}`);
});

let credentials;
try {
  credentials = {
    cert: fs.readFileSync('server.crt', 'utf8'),
    key: fs.readFileSync('server.key', 'utf8'),
  };
} catch (err) {
  console.error(`Failed reading SSL certificates: ${err.message}`);
  process.exit(1);
}

const httpServer = http.createServer(app);
const httpsServer = https.createServer(credentials, app);

const address = 'www1.localhost.test';
const httpPort = 80;
const httpsPort = 443;

httpServer.listen(httpPort, address, () => {
  console.log(`HTTP server on http://${address}:${httpPort}/`);
});
httpsServer.listen(httpsPort, address, () => {
  console.log(`HTTPS server on https://${address}:${httpsPort}/`);
});

process.on('uncaughtException', (err) => {
  console.error('Uncaught exception:', err);
});
process.on('unhandledRejection', (reason, promise) => {
  console.error('Unhandled Rejection at:', promise, 'reason:', reason);
});