How to use netServerPrototypeListenApply method in Cypress

1const fs = require('fs')2const debug = require('debug')('net-profiler')3function getCaller (level = 5) {4  try {5    return new Error().stack.split('\n')[level].slice(7)6  } catch (e) {7    return 'unknown'8  }9}10function getLogPath (logPath) {11  if (!logPath) {12    const os = require('os')13    const dirName = fs.mkdtempSync(`${os.tmpdir()}/net-profiler-`)14    logPath = `${dirName}/timeline.txt`15  }16  return logPath17}18function Connection (host, port, type = 'connection', toHost, toPort) {19  this.type = type20  this.host = host || 'localhost'21  this.port = port22  this.toHost = toHost || 'localhost'23  this.toPort = toPort24}25Connection.prototype.beginning = function () {26  switch (this.type) {27    case 'server':28      return `O server began listening on ${this.host}:${this.port} at ${getCaller()}`29    case 'client':30      return `C client connected from ${this.host}:${this.port} to server on ${this.toHost}:${this.toPort}`31    default:32      return `X connection opened to ${this.host}:${this.port} by ${getCaller()}`33  }34}35Connection.prototype.ending = function () {36  switch (this.type) {37    case 'server':38      return 'O server closed'39    case 'client':40      return 'C client disconnected'41    default:42      return 'X connection closed'43  }44}45/**46 * Tracks all incoming and outgoing network connections and logs a timeline of network traffic to a file.47 *48 * @param options.net the `net` object to stub, default: nodejs net object49 * @param options.tickMs the number of milliseconds between ticks in the profile, default: 100050 * @param options.tickWhenNoneActive should ticks be recorded when no connections are active, default: false51 * @param options.logPath path to the file to append to, default: new file in your temp directory52 */53function NetProfiler (options = {}) {54  if (!(this instanceof NetProfiler)) return new NetProfiler(options)55  if (!options.net) {56    options.net = require('net')57  }58  this.net = options.net59  this.proxies = {}60  this.activeConnections = []61  this.startTs = new Date() / 100062  this.tickMs = options.tickMs || 100063  this.tickWhenNoneActive = options.tickWhenNoneActive || false64  this.logPath = getLogPath(options.logPath)65  debug('logging to ', this.logPath)66  this.startProfiling()67}68NetProfiler.prototype.install = function () {69  const net = this.net70  const self = this71  function netSocketPrototypeConnectApply (target, thisArg, args) {72    const client = target.bind(thisArg)(...args)73    let options = self.net._normalizeArgs(args)[0]74    if (Array.isArray(options)) {75      options = options[0]76    }77    options.host = options.host || 'localhost'78    const connection = new Connection(options.host, options.port)79    client.on('close', () => {80      self.removeActiveConnection(connection)81    })82    self.addActiveConnection(connection)83    return client84  }85  function netServerPrototypeListenApply (target, thisArg, args) {86    const server = thisArg87    server.on('listening', () => {88      const { host, port } = server.address()89      const connection = new Connection(host, port, 'server')90      self.addActiveConnection(connection)91      server.on('close', () => {92        self.removeActiveConnection(connection)93      })94      server.on('connection', (client) => {95        const clientConn = new Connection(client.remoteAddress, client.remotePort, 'client', host, port)96        self.addActiveConnection(clientConn)97        client.on('close', () => {98          self.removeActiveConnection(clientConn)99        })100      })101    })102    const listener = target.bind(thisArg)(...args)103    return listener104  }105  this.proxies['net.Socket.prototype.connect'] = Proxy.revocable(net.Socket.prototype.connect, {106    apply: netSocketPrototypeConnectApply,107  })108  this.proxies['net.Server.prototype.listen'] = Proxy.revocable(net.Server.prototype.listen, {109    apply: netServerPrototypeListenApply,110  })111  net.Socket.prototype.connect = this.proxies['net.Socket.prototype.connect'].proxy112  net.Server.prototype.listen = this.proxies['net.Server.prototype.listen'].proxy113}114NetProfiler.prototype.uninstall = function () {115  const net = this.net116  net.Socket.prototype.connect = this.proxies['net.Socket.prototype.connect'].proxy['[[Target]]']117  net.Server.prototype.listen = this.proxies['net.Server.prototype.listen'].proxy['[[Target]]']118  this.proxies.forEach((proxy) => {119    proxy.revoke()120  })121}122NetProfiler.prototype.startProfiling = function () {123  this.install()124  debug('profiling started')125  this.logStream = fs.openSync(this.logPath, 'a')126  this.writeTimeline('Profiling started!')127  this.startTimer()128}129NetProfiler.prototype.startTimer = function () {130  if (!this.tickMs) {131    return132  }133  this.timer = setInterval(() => {134    const tick = this.tickWhenNoneActive || this.activeConnections.find((x) => {135      return !!x136    })137    if (tick) {138      this.writeTimeline()139    }140  }, this.tickMs)141}142NetProfiler.prototype.stopTimer = function () {143  clearInterval(this.timer)144}145NetProfiler.prototype.stopProfiling = function () {146  this.writeTimeline('Profiling stopped!')147  this.stopTimer()148  fs.closeSync(this.logStream)149  debug('profiling ended')150  this.uninstall()151}152NetProfiler.prototype.addActiveConnection = function (connection) {153  let index = this.activeConnections.findIndex((x) => {154    return typeof x === 'undefined'155  })156  if (index === -1) {157    index = this.activeConnections.length158    this.activeConnections.push(connection)159  } else {160    this.activeConnections[index] = connection161  }162  this.writeTimeline(index, connection.beginning())163}164NetProfiler.prototype.removeActiveConnection = function (connection) {165  let index = this.activeConnections.findIndex((x) => {166    return x === connection167  })168  this.writeTimeline(index, connection.ending())169  this.activeConnections[index] = undefined170}171NetProfiler.prototype.getTimestamp = function () {172  let elapsed = (new Date() / 1000 - this.startTs).toString()173  const parts = elapsed.split('.', 2)174  if (!parts[1]) {175    parts[1] = '000'176  }177  while (parts[1].length < 3) {178    parts[1] += '0'179  }180  elapsed = `${parts[0]}.${parts[1] ? parts[1].slice(0, 3) : '000'}`181  while (elapsed.length < 11) {182    elapsed = ` ${elapsed}`183  }184  return elapsed185}186NetProfiler.prototype.writeTimeline = function (index, message) {187  if (!message) {188    message = index || ''189    index = this.activeConnections.length190  }191  let row = `   ${this.activeConnections.map((conn, i) => {192    if (conn) {193      return ['|', '1', 'l', ':'][i % 4]194    }195    return ' '196  }).join('   ')}`197  if (message) {198    const column = 3 + index * 4199    row = `${row.substring(0, column - 2)}[ ${message} ]${row.substring(2 + column + message.length)}`200  }201  row = `${this.getTimestamp()}${row.replace(/\s+$/, '')}\n`202  fs.writeSync(this.logStream, row)203}...