server.js

const http = require('http')
const fs = require('fs')
const path = require('path')
const { isUtf8 } = require('buffer')



const port = 3000

const server = http.createServer((req,res)=>{
    const filePath = path.join(__dirname, req.url === '/'? "index.html" : req.url)

    const extName = String(path.extname(filePath).toLowerCase())

    const mimeType = {
        '.html':'text/html',
        '.css':'text/css',
        '.js':'text/javascript',
    }

    const contentType = mimeType[extName] || 'application/octet-stream'

    fs.readFile(filePath,(err,content)=>{
        if (err) {
            if(err.code === "ENOENT"){
                res.writeHead(404,{"Content-Type":"text/html"})
                res.end("404: File Not Found")
            }
        } else {
            res.writeHead(200,{'Content-Type':contentType})
            res.end(content,"utf-8")
        }
    })
})

server.listen(port,()=>{
    console.log(`Serving is listening on port : ${port}`)
})