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)