examples/server-sent-events/benchmark.js

const http = require('http')

const n = 120
let connected = 0
let messages = 0
let start = Date.now()
let phase = 'connecting'
let connection_time
let broadcast_time

let message = process.argv[2] || 'msg'
let expected_data = 'data: ' + message

for (let i = 0; i < n; i++) {
  http
    .get(
      {
        host: '127.0.0.1',
        port: 8080,
        path: '/events',
      },
      (response) => {
        response.on('data', (data) => {
          if (data.includes(expected_data)) {
            messages += 1
          } else if (data.includes('data: connected\n')) {
            connected += 1
          }
        })
      }
    )
    .on('error', (_) => {})
}

setInterval(() => {
  if (phase === 'connecting' && connected === n) {
    // done connecting
    phase = 'messaging'
    connection_time = Date.now() - start
  }

  if (phase === 'messaging') {
    phase = 'waiting'
    start = Date.now()

    http
      .request(
        {
          method: 'POST',
          host: '127.0.0.1',
          port: 8080,
          path: '/broadcast/' + message,
        },
        (response) => {
          response.on('data', (_) => {})
        }
      )
      .end()
  }

  if (phase === 'waiting' && messages >= n) {
    // all messages received
    broadcast_time = Date.now() - start
    phase = 'paused'
    messages = 0
    phase = 'messaging'
  }

  process.stdout.write('\r\x1b[K')
  process.stdout.write(
    `Connected: ${connected}, connection time: ${connection_time} ms, total broadcast time: ${broadcast_time} ms`
  )
}, 20)