server.js

const express = require("express");
const path = require("path");
const fs = require("fs");

const app = express();
const port = process.env.PORT || 8080;

var cors = require("cors");
app.use(cors());

// sendFile will go here
app.get("/", cors(), function (req, res) {
  res.sendFile(path.join(__dirname, "/index.html"));
});

app.get("/video.mp4", cors(), function (req, res) {
  const path = "small.mp4";

  const stat = fs.statSync(path);
  const fileSize = stat.size;
  const range = req.headers.range;
  if (range) {
    const parts = range.replace(/bytes=/, "").split("-");
    const start = parseInt(parts[0], 10);
    const end = parts[1] ? parseInt(parts[1], 10) : fileSize - 1;
    const chunksize = end - start + 1;
    const file = fs.createReadStream(path, { start, end });
    const head = {
      "Content-Range": `bytes ${start}-${end}/${fileSize}`,
      "Accept-Ranges": "bytes",
      "Content-Length": chunksize,
      "Content-Type": "video/mp4",
    };
    res.writeHead(206, head);
    file.pipe(res);
  } else {
    const head = {
      "Content-Length": fileSize,
      "Content-Type": "video/mp4",
    };
    res.writeHead(200, head);
    fs.createReadStream(path).pipe(res);
  }
});
app.listen(port);
console.log("Server started at http://localhost:" + port);