Using Raw Node JS to send data to a http server

RequestNode.js

const http = require('http')

const HOSTNAME = 'localhost'
const PORT = 3000

const client = () => {
  const bodyString = JSON.stringify({
    username: 'foobar',
    password: 'Password1'
  })
  
  const headers = {
    'Content-Type': 'application/json',
    'Content-Length': bodyString.length
  }
  
  const options = {
    host: HOSTNAME,
    path: '/users/1',
    port: PORT,
    method: 'PUT',
    headers
  }
  
  const callback = (response) => {
    let str = ''
    response.on('data', (chunk) => str += chunk)
    response.on('end', () => console.log(str))
  }
  
  console.log('sending request')
  http.request(options, callback).write(bodyString)
}

const server = http.createServer((req, res) => {
  console.log('received request')
  res.statusCode = 200
  res.setHeader('Content-Type', 'text/plain')
  let str = ''
  res.on('data', (chunk) => str += chunk)
  res.on('end', () => {
    console.log(str)
    res.send(`method ${req.method}, url ${req.url}`)
  })
})

setTimeout(client, 2000)

server.listen(PORT, HOSTNAME, () => {
  console.log(`Server running at http://${HOSTNAME}:${PORT}`)
})