Initial commit

node_modules/ws/lib/BufferUtil.js

@@ -0,0 +1,71 @@
+/*!
+ * ws: a node.js websocket client
+ * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
+ * MIT Licensed
+ */
+
+'use strict';
+
+const safeBuffer = require('safe-buffer');
+
+const Buffer = safeBuffer.Buffer;
+
+/**
+ * Merges an array of buffers into a new buffer.
+ *
+ * @param {Buffer[]} list The array of buffers to concat
+ * @param {Number} totalLength The total length of buffers in the list
+ * @return {Buffer} The resulting buffer
+ * @public
+ */
+const concat = (list, totalLength) => {
+  const target = Buffer.allocUnsafe(totalLength);
+  var offset = 0;
+
+  for (var i = 0; i < list.length; i++) {
+    const buf = list[i];
+    buf.copy(target, offset);
+    offset += buf.length;
+  }
+
+  return target;
+};
+
+try {
+  const bufferUtil = require('bufferutil');
+
+  module.exports = Object.assign({ concat }, bufferUtil.BufferUtil || bufferUtil);
+} catch (e) /* istanbul ignore next */ {
+  /**
+   * Masks a buffer using the given mask.
+   *
+   * @param {Buffer} source The buffer to mask
+   * @param {Buffer} mask The mask to use
+   * @param {Buffer} output The buffer where to store the result
+   * @param {Number} offset The offset at which to start writing
+   * @param {Number} length The number of bytes to mask.
+   * @public
+   */
+  const mask = (source, mask, output, offset, length) => {
+    for (var i = 0; i < length; i++) {
+      output[offset + i] = source[i] ^ mask[i & 3];
+    }
+  };
+
+  /**
+   * Unmasks a buffer using the given mask.
+   *
+   * @param {Buffer} buffer The buffer to unmask
+   * @param {Buffer} mask The mask to use
+   * @public
+   */
+  const unmask = (buffer, mask) => {
+    // Required until https://github.com/nodejs/node/issues/9006 is resolved.
+    const length = buffer.length;
+    for (var i = 0; i < length; i++) {
+      buffer[i] ^= mask[i & 3];
+    }
+  };
+
+  module.exports = { concat, mask, unmask };
+}

node_modules/ws/lib/Constants.js

@@ -0,0 +1,10 @@
+'use strict';
+
+const safeBuffer = require('safe-buffer');
+
+const Buffer = safeBuffer.Buffer;
+
+exports.BINARY_TYPES = ['nodebuffer', 'arraybuffer', 'fragments'];
+exports.GUID = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11';
+exports.EMPTY_BUFFER = Buffer.alloc(0);
+exports.NOOP = () => {};

node_modules/ws/lib/ErrorCodes.js

@@ -0,0 +1,28 @@
+/*!
+ * ws: a node.js websocket client
+ * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
+ * MIT Licensed
+ */
+
+'use strict';
+
+module.exports = {
+  isValidErrorCode: function (code) {
+    return (code >= 1000 && code <= 1013 && code !== 1004 && code !== 1005 && code !== 1006) ||
+      (code >= 3000 && code <= 4999);
+  },
+  1000: 'normal',
+  1001: 'going away',
+  1002: 'protocol error',
+  1003: 'unsupported data',
+  1004: 'reserved',
+  1005: 'reserved for extensions',
+  1006: 'reserved for extensions',
+  1007: 'inconsistent or invalid data',
+  1008: 'policy violation',
+  1009: 'message too big',
+  1010: 'extension handshake missing',
+  1011: 'an unexpected condition prevented the request from being fulfilled',
+  1012: 'service restart',
+  1013: 'try again later'
+};

node_modules/ws/lib/EventTarget.js

@@ -0,0 +1,155 @@
+'use strict';
+
+/**
+ * Class representing an event.
+ *
+ * @private
+ */
+class Event {
+  /**
+   * Create a new `Event`.
+   *
+   * @param {String} type The name of the event
+   * @param {Object} target A reference to the target to which the event was dispatched
+   */
+  constructor (type, target) {
+    this.target = target;
+    this.type = type;
+  }
+}
+
+/**
+ * Class representing a message event.
+ *
+ * @extends Event
+ * @private
+ */
+class MessageEvent extends Event {
+  /**
+   * Create a new `MessageEvent`.
+   *
+   * @param {(String|Buffer|ArrayBuffer|Buffer[])} data The received data
+   * @param {Boolean} isBinary Specifies if `data` is binary
+   * @param {WebSocket} target A reference to the target to which the event was dispatched
+   */
+  constructor (data, isBinary, target) {
+    super('message', target);
+
+    this.binary = isBinary; // non-standard.
+    this.data = data;
+  }
+}
+
+/**
+ * Class representing a close event.
+ *
+ * @extends Event
+ * @private
+ */
+class CloseEvent extends Event {
+  /**
+   * Create a new `CloseEvent`.
+   *
+   * @param {Number} code The status code explaining why the connection is being closed
+   * @param {String} reason A human-readable string explaining why the connection is closing
+   * @param {WebSocket} target A reference to the target to which the event was dispatched
+   */
+  constructor (code, reason, target) {
+    super('close', target);
+
+    this.wasClean = code === undefined || code === 1000;
+    this.reason = reason;
+    this.target = target;
+    this.type = 'close';
+    this.code = code;
+  }
+}
+
+/**
+ * Class representing an open event.
+ *
+ * @extends Event
+ * @private
+ */
+class OpenEvent extends Event {
+  /**
+   * Create a new `OpenEvent`.
+   *
+   * @param {WebSocket} target A reference to the target to which the event was dispatched
+   */
+  constructor (target) {
+    super('open', target);
+  }
+}
+
+/**
+ * This provides methods for emulating the `EventTarget` interface. It's not
+ * meant to be used directly.
+ *
+ * @mixin
+ */
+const EventTarget = {
+  /**
+   * Register an event listener.
+   *
+   * @param {String} method A string representing the event type to listen for
+   * @param {Function} listener The listener to add
+   * @public
+   */
+  addEventListener (method, listener) {
+    if (typeof listener !== 'function') return;
+
+    function onMessage (data, flags) {
+      listener.call(this, new MessageEvent(data, !!flags.binary, this));
+    }
+
+    function onClose (code, message) {
+      listener.call(this, new CloseEvent(code, message, this));
+    }
+
+    function onError (event) {
+      event.type = 'error';
+      event.target = this;
+      listener.call(this, event);
+    }
+
+    function onOpen () {
+      listener.call(this, new OpenEvent(this));
+    }
+
+    if (method === 'message') {
+      onMessage._listener = listener;
+      this.on(method, onMessage);
+    } else if (method === 'close') {
+      onClose._listener = listener;
+      this.on(method, onClose);
+    } else if (method === 'error') {
+      onError._listener = listener;
+      this.on(method, onError);
+    } else if (method === 'open') {
+      onOpen._listener = listener;
+      this.on(method, onOpen);
+    } else {
+      this.on(method, listener);
+    }
+  },
+
+  /**
+   * Remove an event listener.
+   *
+   * @param {String} method A string representing the event type to remove
+   * @param {Function} listener The listener to remove
+   * @public
+   */
+  removeEventListener (method, listener) {
+    const listeners = this.listeners(method);
+
+    for (var i = 0; i < listeners.length; i++) {
+      if (listeners[i] === listener || listeners[i]._listener === listener) {
+        this.removeListener(method, listeners[i]);
+      }
+    }
+  }
+};
+
+module.exports = EventTarget;

node_modules/ws/lib/Extensions.js

@@ -0,0 +1,67 @@
+'use strict';
+
+/**
+ * Parse the `Sec-WebSocket-Extensions` header into an object.
+ *
+ * @param {String} value field value of the header
+ * @return {Object} The parsed object
+ * @public
+ */
+const parse = (value) => {
+  value = value || '';
+
+  const extensions = {};
+
+  value.split(',').forEach((v) => {
+    const params = v.split(';');
+    const token = params.shift().trim();
+    const paramsList = extensions[token] = extensions[token] || [];
+    const parsedParams = {};
+
+    params.forEach((param) => {
+      const parts = param.trim().split('=');
+      const key = parts[0];
+      var value = parts[1];
+
+      if (value === undefined) {
+        value = true;
+      } else {
+        // unquote value
+        if (value[0] === '"') {
+          value = value.slice(1);
+        }
+        if (value[value.length - 1] === '"') {
+          value = value.slice(0, value.length - 1);
+        }
+      }
+      (parsedParams[key] = parsedParams[key] || []).push(value);
+    });
+
+    paramsList.push(parsedParams);
+  });
+
+  return extensions;
+};
+
+/**
+ * Serialize a parsed `Sec-WebSocket-Extensions` header to a string.
+ *
+ * @param {Object} value The object to format
+ * @return {String} A string representing the given value
+ * @public
+ */
+const format = (value) => {
+  return Object.keys(value).map((token) => {
+    var paramsList = value[token];
+    if (!Array.isArray(paramsList)) paramsList = [paramsList];
+    return paramsList.map((params) => {
+      return [token].concat(Object.keys(params).map((k) => {
+        var p = params[k];
+        if (!Array.isArray(p)) p = [p];
+        return p.map((v) => v === true ? k : `${k}=${v}`).join('; ');
+      })).join('; ');
+    }).join(', ');
+  }).join(', ');
+};
+
+module.exports = { format, parse };

node_modules/ws/lib/PerMessageDeflate.js

@@ -0,0 +1,384 @@
+'use strict';
+
+const safeBuffer = require('safe-buffer');
+const zlib = require('zlib');
+
+const bufferUtil = require('./BufferUtil');
+
+const Buffer = safeBuffer.Buffer;
+
+const AVAILABLE_WINDOW_BITS = [8, 9, 10, 11, 12, 13, 14, 15];
+const TRAILER = Buffer.from([0x00, 0x00, 0xff, 0xff]);
+const EMPTY_BLOCK = Buffer.from([0x00]);
+const DEFAULT_WINDOW_BITS = 15;
+const DEFAULT_MEM_LEVEL = 8;
+
+/**
+ * Per-message Deflate implementation.
+ */
+class PerMessageDeflate {
+  constructor (options, isServer, maxPayload) {
+    this._options = options || {};
+    this._isServer = !!isServer;
+    this._inflate = null;
+    this._deflate = null;
+    this.params = null;
+    this._maxPayload = maxPayload || 0;
+    this.threshold = this._options.threshold === undefined ? 1024 : this._options.threshold;
+  }
+
+  static get extensionName () {
+    return 'permessage-deflate';
+  }
+
+  /**
+   * Create extension parameters offer.
+   *
+   * @return {Object} Extension parameters
+   * @public
+   */
+  offer () {
+    const params = {};
+
+    if (this._options.serverNoContextTakeover) {
+      params.server_no_context_takeover = true;
+    }
+    if (this._options.clientNoContextTakeover) {
+      params.client_no_context_takeover = true;
+    }
+    if (this._options.serverMaxWindowBits) {
+      params.server_max_window_bits = this._options.serverMaxWindowBits;
+    }
+    if (this._options.clientMaxWindowBits) {
+      params.client_max_window_bits = this._options.clientMaxWindowBits;
+    } else if (this._options.clientMaxWindowBits == null) {
+      params.client_max_window_bits = true;
+    }
+
+    return params;
+  }
+
+  /**
+   * Accept extension offer.
+   *
+   * @param {Array} paramsList Extension parameters
+   * @return {Object} Accepted configuration
+   * @public
+   */
+  accept (paramsList) {
+    paramsList = this.normalizeParams(paramsList);
+
+    var params;
+    if (this._isServer) {
+      params = this.acceptAsServer(paramsList);
+    } else {
+      params = this.acceptAsClient(paramsList);
+    }
+
+    this.params = params;
+    return params;
+  }
+
+  /**
+   * Releases all resources used by the extension.
+   *
+   * @public
+   */
+  cleanup () {
+    if (this._inflate) {
+      if (this._inflate.writeInProgress) {
+        this._inflate.pendingClose = true;
+      } else {
+        this._inflate.close();
+        this._inflate = null;
+      }
+    }
+    if (this._deflate) {
+      if (this._deflate.writeInProgress) {
+        this._deflate.pendingClose = true;
+      } else {
+        this._deflate.close();
+        this._deflate = null;
+      }
+    }
+  }
+
+  /**
+   * Accept extension offer from client.
+   *
+   * @param {Array} paramsList Extension parameters
+   * @return {Object} Accepted configuration
+   * @private
+   */
+  acceptAsServer (paramsList) {
+    const accepted = {};
+    const result = paramsList.some((params) => {
+      if ((
+        this._options.serverNoContextTakeover === false &&
+        params.server_no_context_takeover
+      ) || (
+        this._options.serverMaxWindowBits === false &&
+        params.server_max_window_bits
+      ) || (
+        typeof this._options.serverMaxWindowBits === 'number' &&
+        typeof params.server_max_window_bits === 'number' &&
+        this._options.serverMaxWindowBits > params.server_max_window_bits
+      ) || (
+        typeof this._options.clientMaxWindowBits === 'number' &&
+        !params.client_max_window_bits
+      )) {
+        return;
+      }
+
+      if (
+        this._options.serverNoContextTakeover ||
+        params.server_no_context_takeover
+      ) {
+        accepted.server_no_context_takeover = true;
+      }
+      if (this._options.clientNoContextTakeover) {
+        accepted.client_no_context_takeover = true;
+      }
+      if (
+        this._options.clientNoContextTakeover !== false &&
+        params.client_no_context_takeover
+      ) {
+        accepted.client_no_context_takeover = true;
+      }
+      if (typeof this._options.serverMaxWindowBits === 'number') {
+        accepted.server_max_window_bits = this._options.serverMaxWindowBits;
+      } else if (typeof params.server_max_window_bits === 'number') {
+        accepted.server_max_window_bits = params.server_max_window_bits;
+      }
+      if (typeof this._options.clientMaxWindowBits === 'number') {
+        accepted.client_max_window_bits = this._options.clientMaxWindowBits;
+      } else if (
+        this._options.clientMaxWindowBits !== false &&
+        typeof params.client_max_window_bits === 'number'
+      ) {
+        accepted.client_max_window_bits = params.client_max_window_bits;
+      }
+      return true;
+    });
+
+    if (!result) throw new Error(`Doesn't support the offered configuration`);
+
+    return accepted;
+  }
+
+  /**
+   * Accept extension response from server.
+   *
+   * @param {Array} paramsList Extension parameters
+   * @return {Object} Accepted configuration
+   * @private
+   */
+  acceptAsClient (paramsList) {
+    const params = paramsList[0];
+
+    if (this._options.clientNoContextTakeover != null) {
+      if (
+        this._options.clientNoContextTakeover === false &&
+        params.client_no_context_takeover
+      ) {
+        throw new Error('Invalid value for "client_no_context_takeover"');
+      }
+    }
+    if (this._options.clientMaxWindowBits != null) {
+      if (
+        this._options.clientMaxWindowBits === false &&
+        params.client_max_window_bits
+      ) {
+        throw new Error('Invalid value for "client_max_window_bits"');
+      }
+      if (
+        typeof this._options.clientMaxWindowBits === 'number' && (
+        !params.client_max_window_bits ||
+        params.client_max_window_bits > this._options.clientMaxWindowBits
+      )) {
+        throw new Error('Invalid value for "client_max_window_bits"');
+      }
+    }
+
+    return params;
+  }
+
+  /**
+   * Normalize extensions parameters.
+   *
+   * @param {Array} paramsList Extension parameters
+   * @return {Array} Normalized extensions parameters
+   * @private
+   */
+  normalizeParams (paramsList) {
+    return paramsList.map((params) => {
+      Object.keys(params).forEach((key) => {
+        var value = params[key];
+        if (value.length > 1) {
+          throw new Error(`Multiple extension parameters for ${key}`);
+        }
+
+        value = value[0];
+
+        switch (key) {
+          case 'server_no_context_takeover':
+          case 'client_no_context_takeover':
+            if (value !== true) {
+              throw new Error(`invalid extension parameter value for ${key} (${value})`);
+            }
+            params[key] = true;
+            break;
+          case 'server_max_window_bits':
+          case 'client_max_window_bits':
+            if (typeof value === 'string') {
+              value = parseInt(value, 10);
+              if (!~AVAILABLE_WINDOW_BITS.indexOf(value)) {
+                throw new Error(`invalid extension parameter value for ${key} (${value})`);
+              }
+            }
+            if (!this._isServer && value === true) {
+              throw new Error(`Missing extension parameter value for ${key}`);
+            }
+            params[key] = value;
+            break;
+          default:
+            throw new Error(`Not defined extension parameter (${key})`);
+        }
+      });
+      return params;
+    });
+  }
+
+  /**
+   * Decompress data.
+   *
+   * @param {Buffer} data Compressed data
+   * @param {Boolean} fin Specifies whether or not this is the last fragment
+   * @param {Function} callback Callback
+   * @public
+   */
+  decompress (data, fin, callback) {
+    const endpoint = this._isServer ? 'client' : 'server';
+
+    if (!this._inflate) {
+      const maxWindowBits = this.params[`${endpoint}_max_window_bits`];
+      this._inflate = zlib.createInflateRaw({
+        windowBits: typeof maxWindowBits === 'number' ? maxWindowBits : DEFAULT_WINDOW_BITS
+      });
+    }
+    this._inflate.writeInProgress = true;
+
+    var totalLength = 0;
+    const buffers = [];
+    var err;
+
+    const onData = (data) => {
+      totalLength += data.length;
+      if (this._maxPayload < 1 || totalLength <= this._maxPayload) {
+        return buffers.push(data);
+      }
+
+      err = new Error('max payload size exceeded');
+      err.closeCode = 1009;
+      this._inflate.reset();
+    };
+
+    const onError = (err) => {
+      cleanup();
+      callback(err);
+    };
+
+    const cleanup = () => {
+      if (!this._inflate) return;
+
+      this._inflate.removeListener('error', onError);
+      this._inflate.removeListener('data', onData);
+      this._inflate.writeInProgress = false;
+
+      if (
+        (fin && this.params[`${endpoint}_no_context_takeover`]) ||
+        this._inflate.pendingClose
+      ) {
+        this._inflate.close();
+        this._inflate = null;
+      }
+    };
+
+    this._inflate.on('error', onError).on('data', onData);
+    this._inflate.write(data);
+    if (fin) this._inflate.write(TRAILER);
+
+    this._inflate.flush(() => {
+      cleanup();
+      if (err) callback(err);
+      else callback(null, bufferUtil.concat(buffers, totalLength));
+    });
+  }
+
+  /**
+   * Compress data.
+   *
+   * @param {Buffer} data Data to compress
+   * @param {Boolean} fin Specifies whether or not this is the last fragment
+   * @param {Function} callback Callback
+   * @public
+   */
+  compress (data, fin, callback) {
+    if (!data || data.length === 0) {
+      process.nextTick(callback, null, EMPTY_BLOCK);
+      return;
+    }
+
+    const endpoint = this._isServer ? 'server' : 'client';
+
+    if (!this._deflate) {
+      const maxWindowBits = this.params[`${endpoint}_max_window_bits`];
+      this._deflate = zlib.createDeflateRaw({
+        flush: zlib.Z_SYNC_FLUSH,
+        windowBits: typeof maxWindowBits === 'number' ? maxWindowBits : DEFAULT_WINDOW_BITS,
+        memLevel: this._options.memLevel || DEFAULT_MEM_LEVEL
+      });
+    }
+    this._deflate.writeInProgress = true;
+
+    var totalLength = 0;
+    const buffers = [];
+
+    const onData = (data) => {
+      totalLength += data.length;
+      buffers.push(data);
+    };
+
+    const onError = (err) => {
+      cleanup();
+      callback(err);
+    };
+
+    const cleanup = () => {
+      if (!this._deflate) return;
+
+      this._deflate.removeListener('error', onError);
+      this._deflate.removeListener('data', onData);
+      this._deflate.writeInProgress = false;
+
+      if (
+        (fin && this.params[`${endpoint}_no_context_takeover`]) ||
+        this._deflate.pendingClose
+      ) {
+        this._deflate.close();
+        this._deflate = null;
+      }
+    };
+
+    this._deflate.on('error', onError).on('data', onData);
+    this._deflate.write(data);
+    this._deflate.flush(zlib.Z_SYNC_FLUSH, () => {
+      cleanup();
+      var data = bufferUtil.concat(buffers, totalLength);
+      if (fin) data = data.slice(0, data.length - 4);
+      callback(null, data);
+    });
+  }
+}
+
+module.exports = PerMessageDeflate;

node_modules/ws/lib/Receiver.js

@@ -0,0 +1,555 @@
+/*!
+ * ws: a node.js websocket client
+ * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
+ * MIT Licensed
+ */
+
+'use strict';
+
+const safeBuffer = require('safe-buffer');
+
+const PerMessageDeflate = require('./PerMessageDeflate');
+const isValidUTF8 = require('./Validation');
+const bufferUtil = require('./BufferUtil');
+const ErrorCodes = require('./ErrorCodes');
+const constants = require('./Constants');
+
+const Buffer = safeBuffer.Buffer;
+
+const GET_INFO = 0;
+const GET_PAYLOAD_LENGTH_16 = 1;
+const GET_PAYLOAD_LENGTH_64 = 2;
+const GET_MASK = 3;
+const GET_DATA = 4;
+const INFLATING = 5;
+
+/**
+ * HyBi Receiver implementation.
+ */
+class Receiver {
+  /**
+   * Creates a Receiver instance.
+   *
+   * @param {Object} extensions An object containing the negotiated extensions
+   * @param {Number} maxPayload The maximum allowed message length
+   * @param {String} binaryType The type for binary data
+   */
+  constructor (extensions, maxPayload, binaryType) {
+    this.binaryType = binaryType || constants.BINARY_TYPES[0];
+    this.extensions = extensions || {};
+    this.maxPayload = maxPayload | 0;
+
+    this.bufferedBytes = 0;
+    this.buffers = [];
+
+    this.compressed = false;
+    this.payloadLength = 0;
+    this.fragmented = 0;
+    this.masked = false;
+    this.fin = false;
+    this.mask = null;
+    this.opcode = 0;
+
+    this.totalPayloadLength = 0;
+    this.messageLength = 0;
+    this.fragments = [];
+
+    this.cleanupCallback = null;
+    this.hadError = false;
+    this.dead = false;
+    this.loop = false;
+
+    this.onmessage = null;
+    this.onclose = null;
+    this.onerror = null;
+    this.onping = null;
+    this.onpong = null;
+
+    this.state = GET_INFO;
+  }
+
+  /**
+   * Consumes bytes from the available buffered data.
+   *
+   * @param {Number} bytes The number of bytes to consume
+   * @return {Buffer} Consumed bytes
+   * @private
+   */
+  readBuffer (bytes) {
+    var offset = 0;
+    var dst;
+    var l;
+
+    this.bufferedBytes -= bytes;
+
+    if (bytes === this.buffers[0].length) return this.buffers.shift();
+
+    if (bytes < this.buffers[0].length) {
+      dst = this.buffers[0].slice(0, bytes);
+      this.buffers[0] = this.buffers[0].slice(bytes);
+      return dst;
+    }
+
+    dst = Buffer.allocUnsafe(bytes);
+
+    while (bytes > 0) {
+      l = this.buffers[0].length;
+
+      if (bytes >= l) {
+        this.buffers[0].copy(dst, offset);
+        offset += l;
+        this.buffers.shift();
+      } else {
+        this.buffers[0].copy(dst, offset, 0, bytes);
+        this.buffers[0] = this.buffers[0].slice(bytes);
+      }
+
+      bytes -= l;
+    }
+
+    return dst;
+  }
+
+  /**
+   * Checks if the number of buffered bytes is bigger or equal than `n` and
+   * calls `cleanup` if necessary.
+   *
+   * @param {Number} n The number of bytes to check against
+   * @return {Boolean} `true` if `bufferedBytes >= n`, else `false`
+   * @private
+   */
+  hasBufferedBytes (n) {
+    if (this.bufferedBytes >= n) return true;
+
+    this.loop = false;
+    if (this.dead) this.cleanup(this.cleanupCallback);
+    return false;
+  }
+
+  /**
+   * Adds new data to the parser.
+   *
+   * @public
+   */
+  add (data) {
+    if (this.dead) return;
+
+    this.bufferedBytes += data.length;
+    this.buffers.push(data);
+    this.startLoop();
+  }
+
+  /**
+   * Starts the parsing loop.
+   *
+   * @private
+   */
+  startLoop () {
+    this.loop = true;
+
+    while (this.loop) {
+      switch (this.state) {
+        case GET_INFO:
+          this.getInfo();
+          break;
+        case GET_PAYLOAD_LENGTH_16:
+          this.getPayloadLength16();
+          break;
+        case GET_PAYLOAD_LENGTH_64:
+          this.getPayloadLength64();
+          break;
+        case GET_MASK:
+          this.getMask();
+          break;
+        case GET_DATA:
+          this.getData();
+          break;
+        default: // `INFLATING`
+          this.loop = false;
+      }
+    }
+  }
+
+  /**
+   * Reads the first two bytes of a frame.
+   *
+   * @private
+   */
+  getInfo () {
+    if (!this.hasBufferedBytes(2)) return;
+
+    const buf = this.readBuffer(2);
+
+    if ((buf[0] & 0x30) !== 0x00) {
+      this.error(new Error('RSV2 and RSV3 must be clear'), 1002);
+      return;
+    }
+
+    const compressed = (buf[0] & 0x40) === 0x40;
+
+    if (compressed && !this.extensions[PerMessageDeflate.extensionName]) {
+      this.error(new Error('RSV1 must be clear'), 1002);
+      return;
+    }
+
+    this.fin = (buf[0] & 0x80) === 0x80;
+    this.opcode = buf[0] & 0x0f;
+    this.payloadLength = buf[1] & 0x7f;
+
+    if (this.opcode === 0x00) {
+      if (compressed) {
+        this.error(new Error('RSV1 must be clear'), 1002);
+        return;
+      }
+
+      if (!this.fragmented) {
+        this.error(new Error(`invalid opcode: ${this.opcode}`), 1002);
+        return;
+      } else {
+        this.opcode = this.fragmented;
+      }
+    } else if (this.opcode === 0x01 || this.opcode === 0x02) {
+      if (this.fragmented) {
+        this.error(new Error(`invalid opcode: ${this.opcode}`), 1002);
+        return;
+      }
+
+      this.compressed = compressed;
+    } else if (this.opcode > 0x07 && this.opcode < 0x0b) {
+      if (!this.fin) {
+        this.error(new Error('FIN must be set'), 1002);
+        return;
+      }
+
+      if (compressed) {
+        this.error(new Error('RSV1 must be clear'), 1002);
+        return;
+      }
+
+      if (this.payloadLength > 0x7d) {
+        this.error(new Error('invalid payload length'), 1002);
+        return;
+      }
+    } else {
+      this.error(new Error(`invalid opcode: ${this.opcode}`), 1002);
+      return;
+    }
+
+    if (!this.fin && !this.fragmented) this.fragmented = this.opcode;
+
+    this.masked = (buf[1] & 0x80) === 0x80;
+
+    if (this.payloadLength === 126) this.state = GET_PAYLOAD_LENGTH_16;
+    else if (this.payloadLength === 127) this.state = GET_PAYLOAD_LENGTH_64;
+    else this.haveLength();
+  }
+
+  /**
+   * Gets extended payload length (7+16).
+   *
+   * @private
+   */
+  getPayloadLength16 () {
+    if (!this.hasBufferedBytes(2)) return;
+
+    this.payloadLength = this.readBuffer(2).readUInt16BE(0, true);
+    this.haveLength();
+  }
+
+  /**
+   * Gets extended payload length (7+64).
+   *
+   * @private
+   */
+  getPayloadLength64 () {
+    if (!this.hasBufferedBytes(8)) return;
+
+    const buf = this.readBuffer(8);
+    const num = buf.readUInt32BE(0, true);
+
+    //
+    // The maximum safe integer in JavaScript is 2^53 - 1. An error is returned
+    // if payload length is greater than this number.
+    //
+    if (num > Math.pow(2, 53 - 32) - 1) {
+      this.error(new Error('max payload size exceeded'), 1009);
+      return;
+    }
+
+    this.payloadLength = (num * Math.pow(2, 32)) + buf.readUInt32BE(4, true);
+    this.haveLength();
+  }
+
+  /**
+   * Payload length has been read.
+   *
+   * @private
+   */
+  haveLength () {
+    if (this.opcode < 0x08 && this.maxPayloadExceeded(this.payloadLength)) {
+      return;
+    }
+
+    if (this.masked) this.state = GET_MASK;
+    else this.state = GET_DATA;
+  }
+
+  /**
+   * Reads mask bytes.
+   *
+   * @private
+   */
+  getMask () {
+    if (!this.hasBufferedBytes(4)) return;
+
+    this.mask = this.readBuffer(4);
+    this.state = GET_DATA;
+  }
+
+  /**
+   * Reads data bytes.
+   *
+   * @private
+   */
+  getData () {
+    var data = constants.EMPTY_BUFFER;
+
+    if (this.payloadLength) {
+      if (!this.hasBufferedBytes(this.payloadLength)) return;
+
+      data = this.readBuffer(this.payloadLength);
+      if (this.masked) bufferUtil.unmask(data, this.mask);
+    }
+
+    if (this.opcode > 0x07) {
+      this.controlMessage(data);
+    } else if (this.compressed) {
+      this.state = INFLATING;
+      this.decompress(data);
+    } else if (this.pushFragment(data)) {
+      this.dataMessage();
+    }
+  }
+
+  /**
+   * Decompresses data.
+   *
+   * @param {Buffer} data Compressed data
+   * @private
+   */
+  decompress (data) {
+    const extension = this.extensions[PerMessageDeflate.extensionName];
+
+    extension.decompress(data, this.fin, (err, buf) => {
+      if (err) {
+        this.error(err, err.closeCode === 1009 ? 1009 : 1007);
+        return;
+      }
+
+      if (this.pushFragment(buf)) this.dataMessage();
+      this.startLoop();
+    });
+  }
+
+  /**
+   * Handles a data message.
+   *
+   * @private
+   */
+  dataMessage () {
+    if (this.fin) {
+      const messageLength = this.messageLength;
+      const fragments = this.fragments;
+
+      this.totalPayloadLength = 0;
+      this.messageLength = 0;
+      this.fragmented = 0;
+      this.fragments = [];
+
+      if (this.opcode === 2) {
+        var data;
+
+        if (this.binaryType === 'nodebuffer') {
+          data = toBuffer(fragments, messageLength);
+        } else if (this.binaryType === 'arraybuffer') {
+          data = toArrayBuffer(toBuffer(fragments, messageLength));
+        } else {
+          data = fragments;
+        }
+
+        this.onmessage(data, { masked: this.masked, binary: true });
+      } else {
+        const buf = toBuffer(fragments, messageLength);
+
+        if (!isValidUTF8(buf)) {
+          this.error(new Error('invalid utf8 sequence'), 1007);
+          return;
+        }
+
+        this.onmessage(buf.toString(), { masked: this.masked });
+      }
+    }
+
+    this.state = GET_INFO;
+  }
+
+  /**
+   * Handles a control message.
+   *
+   * @param {Buffer} data Data to handle
+   * @private
+   */
+  controlMessage (data) {
+    if (this.opcode === 0x08) {
+      if (data.length === 0) {
+        this.onclose(1000, '', { masked: this.masked });
+        this.loop = false;
+        this.cleanup(this.cleanupCallback);
+      } else if (data.length === 1) {
+        this.error(new Error('invalid payload length'), 1002);
+      } else {
+        const code = data.readUInt16BE(0, true);
+
+        if (!ErrorCodes.isValidErrorCode(code)) {
+          this.error(new Error(`invalid status code: ${code}`), 1002);
+          return;
+        }
+
+        const buf = data.slice(2);
+
+        if (!isValidUTF8(buf)) {
+          this.error(new Error('invalid utf8 sequence'), 1007);
+          return;
+        }
+
+        this.onclose(code, buf.toString(), { masked: this.masked });
+        this.loop = false;
+        this.cleanup(this.cleanupCallback);
+      }
+
+      return;
+    }
+
+    const flags = { masked: this.masked, binary: true };
+
+    if (this.opcode === 0x09) this.onping(data, flags);
+    else this.onpong(data, flags);
+
+    this.state = GET_INFO;
+  }
+
+  /**
+   * Handles an error.
+   *
+   * @param {Error} err The error
+   * @param {Number} code Close code
+   * @private
+   */
+  error (err, code) {
+    this.onerror(err, code);
+    this.hadError = true;
+    this.loop = false;
+    this.cleanup(this.cleanupCallback);
+  }
+
+  /**
+   * Checks payload size, disconnects socket when it exceeds `maxPayload`.
+   *
+   * @param {Number} length Payload length
+   * @private
+   */
+  maxPayloadExceeded (length) {
+    if (length === 0 || this.maxPayload < 1) return false;
+
+    const fullLength = this.totalPayloadLength + length;
+
+    if (fullLength <= this.maxPayload) {
+      this.totalPayloadLength = fullLength;
+      return false;
+    }
+
+    this.error(new Error('max payload size exceeded'), 1009);
+    return true;
+  }
+
+  /**
+   * Appends a fragment in the fragments array after checking that the sum of
+   * fragment lengths does not exceed `maxPayload`.
+   *
+   * @param {Buffer} fragment The fragment to add
+   * @return {Boolean} `true` if `maxPayload` is not exceeded, else `false`
+   * @private
+   */
+  pushFragment (fragment) {
+    if (fragment.length === 0) return true;
+
+    const totalLength = this.messageLength + fragment.length;
+
+    if (this.maxPayload < 1 || totalLength <= this.maxPayload) {
+      this.messageLength = totalLength;
+      this.fragments.push(fragment);
+      return true;
+    }
+
+    this.error(new Error('max payload size exceeded'), 1009);
+    return false;
+  }
+
+  /**
+   * Releases resources used by the receiver.
+   *
+   * @param {Function} cb Callback
+   * @public
+   */
+  cleanup (cb) {
+    this.dead = true;
+
+    if (!this.hadError && (this.loop || this.state === INFLATING)) {
+      this.cleanupCallback = cb;
+    } else {
+      this.extensions = null;
+      this.fragments = null;
+      this.buffers = null;
+      this.mask = null;
+
+      this.cleanupCallback = null;
+      this.onmessage = null;
+      this.onclose = null;
+      this.onerror = null;
+      this.onping = null;
+      this.onpong = null;
+
+      if (cb) cb();
+    }
+  }
+}
+
+module.exports = Receiver;
+
+/**
+ * Makes a buffer from a list of fragments.
+ *
+ * @param {Buffer[]} fragments The list of fragments composing the message
+ * @param {Number} messageLength The length of the message
+ * @return {Buffer}
+ * @private
+ */
+function toBuffer (fragments, messageLength) {
+  if (fragments.length === 1) return fragments[0];
+  if (fragments.length > 1) return bufferUtil.concat(fragments, messageLength);
+  return constants.EMPTY_BUFFER;
+}
+
+/**
+ * Converts a buffer to an `ArrayBuffer`.
+ *
+ * @param {Buffer} The buffer to convert
+ * @return {ArrayBuffer} Converted buffer
+ */
+function toArrayBuffer (buf) {
+  if (buf.byteOffset === 0 && buf.byteLength === buf.buffer.byteLength) {
+    return buf.buffer;
+  }
+
+  return buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
+}

node_modules/ws/lib/Sender.js

@@ -0,0 +1,403 @@
+/*!
+ * ws: a node.js websocket client
+ * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
+ * MIT Licensed
+ */
+
+'use strict';
+
+const safeBuffer = require('safe-buffer');
+const crypto = require('crypto');
+
+const PerMessageDeflate = require('./PerMessageDeflate');
+const bufferUtil = require('./BufferUtil');
+const ErrorCodes = require('./ErrorCodes');
+
+const Buffer = safeBuffer.Buffer;
+
+/**
+ * HyBi Sender implementation.
+ */
+class Sender {
+  /**
+   * Creates a Sender instance.
+   *
+   * @param {net.Socket} socket The connection socket
+   * @param {Object} extensions An object containing the negotiated extensions
+   */
+  constructor (socket, extensions) {
+    this.perMessageDeflate = (extensions || {})[PerMessageDeflate.extensionName];
+    this._socket = socket;
+
+    this.firstFragment = true;
+    this.compress = false;
+
+    this.bufferedBytes = 0;
+    this.deflating = false;
+    this.queue = [];
+
+    this.onerror = null;
+  }
+
+  /**
+   * Frames a piece of data according to the HyBi WebSocket protocol.
+   *
+   * @param {Buffer} data The data to frame
+   * @param {Object} options Options object
+   * @param {Number} options.opcode The opcode
+   * @param {Boolean} options.readOnly Specifies whether `data` can be modified
+   * @param {Boolean} options.fin Specifies whether or not to set the FIN bit
+   * @param {Boolean} options.mask Specifies whether or not to mask `data`
+   * @param {Boolean} options.rsv1 Specifies whether or not to set the RSV1 bit
+   * @return {Buffer[]} The framed data as a list of `Buffer` instances
+   * @public
+   */
+  static frame (data, options) {
+    const merge = data.length < 1024 || (options.mask && options.readOnly);
+    var offset = options.mask ? 6 : 2;
+    var payloadLength = data.length;
+
+    if (data.length >= 65536) {
+      offset += 8;
+      payloadLength = 127;
+    } else if (data.length > 125) {
+      offset += 2;
+      payloadLength = 126;
+    }
+
+    const target = Buffer.allocUnsafe(merge ? data.length + offset : offset);
+
+    target[0] = options.fin ? options.opcode | 0x80 : options.opcode;
+    if (options.rsv1) target[0] |= 0x40;
+
+    if (payloadLength === 126) {
+      target.writeUInt16BE(data.length, 2, true);
+    } else if (payloadLength === 127) {
+      target.writeUInt32BE(0, 2, true);
+      target.writeUInt32BE(data.length, 6, true);
+    }
+
+    if (!options.mask) {
+      target[1] = payloadLength;
+      if (merge) {
+        data.copy(target, offset);
+        return [target];
+      }
+
+      return [target, data];
+    }
+
+    const mask = crypto.randomBytes(4);
+
+    target[1] = payloadLength | 0x80;
+    target[offset - 4] = mask[0];
+    target[offset - 3] = mask[1];
+    target[offset - 2] = mask[2];
+    target[offset - 1] = mask[3];
+
+    if (merge) {
+      bufferUtil.mask(data, mask, target, offset, data.length);
+      return [target];
+    }
+
+    bufferUtil.mask(data, mask, data, 0, data.length);
+    return [target, data];
+  }
+
+  /**
+   * Sends a close message to the other peer.
+   *
+   * @param {(Number|undefined)} code The status code component of the body
+   * @param {String} data The message component of the body
+   * @param {Boolean} mask Specifies whether or not to mask the message
+   * @param {Function} cb Callback
+   * @public
+   */
+  close (code, data, mask, cb) {
+    if (code !== undefined && (typeof code !== 'number' || !ErrorCodes.isValidErrorCode(code))) {
+      throw new Error('first argument must be a valid error code number');
+    }
+
+    const buf = Buffer.allocUnsafe(2 + (data ? Buffer.byteLength(data) : 0));
+
+    buf.writeUInt16BE(code || 1000, 0, true);
+    if (buf.length > 2) buf.write(data, 2);
+
+    if (this.deflating) {
+      this.enqueue([this.doClose, buf, mask, cb]);
+    } else {
+      this.doClose(buf, mask, cb);
+    }
+  }
+
+  /**
+   * Frames and sends a close message.
+   *
+   * @param {Buffer} data The message to send
+   * @param {Boolean} mask Specifies whether or not to mask `data`
+   * @param {Function} cb Callback
+   * @private
+   */
+  doClose (data, mask, cb) {
+    this.sendFrame(Sender.frame(data, {
+      fin: true,
+      rsv1: false,
+      opcode: 0x08,
+      mask,
+      readOnly: false
+    }), cb);
+  }
+
+  /**
+   * Sends a ping message to the other peer.
+   *
+   * @param {*} data The message to send
+   * @param {Boolean} mask Specifies whether or not to mask `data`
+   * @public
+   */
+  ping (data, mask) {
+    var readOnly = true;
+
+    if (!Buffer.isBuffer(data)) {
+      if (data instanceof ArrayBuffer) {
+        data = Buffer.from(data);
+      } else if (ArrayBuffer.isView(data)) {
+        data = viewToBuffer(data);
+      } else {
+        data = Buffer.from(data);
+        readOnly = false;
+      }
+    }
+
+    if (this.deflating) {
+      this.enqueue([this.doPing, data, mask, readOnly]);
+    } else {
+      this.doPing(data, mask, readOnly);
+    }
+  }
+
+  /**
+   * Frames and sends a ping message.
+   *
+   * @param {*} data The message to send
+   * @param {Boolean} mask Specifies whether or not to mask `data`
+   * @param {Boolean} readOnly Specifies whether `data` can be modified
+   * @private
+   */
+  doPing (data, mask, readOnly) {
+    this.sendFrame(Sender.frame(data, {
+      fin: true,
+      rsv1: false,
+      opcode: 0x09,
+      mask,
+      readOnly
+    }));
+  }
+
+  /**
+   * Sends a pong message to the other peer.
+   *
+   * @param {*} data The message to send
+   * @param {Boolean} mask Specifies whether or not to mask `data`
+   * @public
+   */
+  pong (data, mask) {
+    var readOnly = true;
+
+    if (!Buffer.isBuffer(data)) {
+      if (data instanceof ArrayBuffer) {
+        data = Buffer.from(data);
+      } else if (ArrayBuffer.isView(data)) {
+        data = viewToBuffer(data);
+      } else {
+        data = Buffer.from(data);
+        readOnly = false;
+      }
+    }
+
+    if (this.deflating) {
+      this.enqueue([this.doPong, data, mask, readOnly]);
+    } else {
+      this.doPong(data, mask, readOnly);
+    }
+  }
+
+  /**
+   * Frames and sends a pong message.
+   *
+   * @param {*} data The message to send
+   * @param {Boolean} mask Specifies whether or not to mask `data`
+   * @param {Boolean} readOnly Specifies whether `data` can be modified
+   * @private
+   */
+  doPong (data, mask, readOnly) {
+    this.sendFrame(Sender.frame(data, {
+      fin: true,
+      rsv1: false,
+      opcode: 0x0a,
+      mask,
+      readOnly
+    }));
+  }
+
+  /**
+   * Sends a data message to the other peer.
+   *
+   * @param {*} data The message to send
+   * @param {Object} options Options object
+   * @param {Boolean} options.compress Specifies whether or not to compress `data`
+   * @param {Boolean} options.binary Specifies whether `data` is binary or text
+   * @param {Boolean} options.fin Specifies whether the fragment is the last one
+   * @param {Boolean} options.mask Specifies whether or not to mask `data`
+   * @param {Function} cb Callback
+   * @public
+   */
+  send (data, options, cb) {
+    var opcode = options.binary ? 2 : 1;
+    var rsv1 = options.compress;
+    var readOnly = true;
+
+    if (!Buffer.isBuffer(data)) {
+      if (data instanceof ArrayBuffer) {
+        data = Buffer.from(data);
+      } else if (ArrayBuffer.isView(data)) {
+        data = viewToBuffer(data);
+      } else {
+        data = Buffer.from(data);
+        readOnly = false;
+      }
+    }
+
+    if (this.firstFragment) {
+      this.firstFragment = false;
+      if (rsv1 && this.perMessageDeflate) {
+        rsv1 = data.length >= this.perMessageDeflate.threshold;
+      }
+      this.compress = rsv1;
+    } else {
+      rsv1 = false;
+      opcode = 0;
+    }
+
+    if (options.fin) this.firstFragment = true;
+
+    if (this.perMessageDeflate) {
+      const opts = {
+        fin: options.fin,
+        rsv1,
+        opcode,
+        mask: options.mask,
+        readOnly
+      };
+
+      if (this.deflating) {
+        this.enqueue([this.dispatch, data, this.compress, opts, cb]);
+      } else {
+        this.dispatch(data, this.compress, opts, cb);
+      }
+    } else {
+      this.sendFrame(Sender.frame(data, {
+        fin: options.fin,
+        rsv1: false,
+        opcode,
+        mask: options.mask,
+        readOnly
+      }), cb);
+    }
+  }
+
+  /**
+   * Dispatches a data message.
+   *
+   * @param {Buffer} data The message to send
+   * @param {Boolean} compress Specifies whether or not to compress `data`
+   * @param {Object} options Options object
+   * @param {Number} options.opcode The opcode
+   * @param {Boolean} options.readOnly Specifies whether `data` can be modified
+   * @param {Boolean} options.fin Specifies whether or not to set the FIN bit
+   * @param {Boolean} options.mask Specifies whether or not to mask `data`
+   * @param {Boolean} options.rsv1 Specifies whether or not to set the RSV1 bit
+   * @param {Function} cb Callback
+   * @private
+   */
+  dispatch (data, compress, options, cb) {
+    if (!compress) {
+      this.sendFrame(Sender.frame(data, options), cb);
+      return;
+    }
+
+    this.deflating = true;
+    this.perMessageDeflate.compress(data, options.fin, (err, buf) => {
+      if (err) {
+        if (cb) cb(err);
+        else this.onerror(err);
+        return;
+      }
+
+      options.readOnly = false;
+      this.sendFrame(Sender.frame(buf, options), cb);
+      this.deflating = false;
+      this.dequeue();
+    });
+  }
+
+  /**
+   * Executes queued send operations.
+   *
+   * @private
+   */
+  dequeue () {
+    while (!this.deflating && this.queue.length) {
+      const params = this.queue.shift();
+
+      this.bufferedBytes -= params[1].length;
+      params[0].apply(this, params.slice(1));
+    }
+  }
+
+  /**
+   * Enqueues a send operation.
+   *
+   * @param {Array} params Send operation parameters.
+   * @private
+   */
+  enqueue (params) {
+    this.bufferedBytes += params[1].length;
+    this.queue.push(params);
+  }
+
+  /**
+   * Sends a frame.
+   *
+   * @param {Buffer[]} list The frame to send
+   * @param {Function} cb Callback
+   * @private
+   */
+  sendFrame (list, cb) {
+    if (list.length === 2) {
+      this._socket.write(list[0]);
+      this._socket.write(list[1], cb);
+    } else {
+      this._socket.write(list[0], cb);
+    }
+  }
+}
+
+module.exports = Sender;
+
+/**
+ * Converts an `ArrayBuffer` view into a buffer.
+ *
+ * @param {(DataView|TypedArray)} view The view to convert
+ * @return {Buffer} Converted view
+ * @private
+ */
+function viewToBuffer (view) {
+  const buf = Buffer.from(view.buffer);
+
+  if (view.byteLength !== view.buffer.byteLength) {
+    return buf.slice(view.byteOffset, view.byteOffset + view.byteLength);
+  }
+
+  return buf;
+}

node_modules/ws/lib/Validation.js

@@ -0,0 +1,17 @@
+/*!
+ * ws: a node.js websocket client
+ * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
+ * MIT Licensed
+ */
+
+'use strict';
+
+try {
+  const isValidUTF8 = require('utf-8-validate');
+
+  module.exports = typeof isValidUTF8 === 'object'
+    ? isValidUTF8.Validation.isValidUTF8  // utf-8-validate@<3.0.0
+    : isValidUTF8;
+} catch (e) /* istanbul ignore next */ {
+  module.exports = () => true;
+}

node_modules/ws/lib/WebSocket.js

@@ -0,0 +1,712 @@
+/*!
+ * ws: a node.js websocket client
+ * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
+ * MIT Licensed
+ */
+
+'use strict';
+
+const EventEmitter = require('events');
+const crypto = require('crypto');
+const Ultron = require('ultron');
+const https = require('https');
+const http = require('http');
+const url = require('url');
+
+const PerMessageDeflate = require('./PerMessageDeflate');
+const EventTarget = require('./EventTarget');
+const Extensions = require('./Extensions');
+const constants = require('./Constants');
+const Receiver = require('./Receiver');
+const Sender = require('./Sender');
+
+const protocolVersions = [8, 13];
+const closeTimeout = 30 * 1000; // Allow 30 seconds to terminate the connection cleanly.
+
+/**
+ * Class representing a WebSocket.
+ *
+ * @extends EventEmitter
+ */
+class WebSocket extends EventEmitter {
+  /**
+   * Create a new `WebSocket`.
+   *
+   * @param {String} address The URL to which to connect
+   * @param {(String|String[])} protocols The subprotocols
+   * @param {Object} options Connection options
+   */
+  constructor (address, protocols, options) {
+    super();
+
+    if (!protocols) {
+      protocols = [];
+    } else if (typeof protocols === 'string') {
+      protocols = [protocols];
+    } else if (!Array.isArray(protocols)) {
+      options = protocols;
+      protocols = [];
+    }
+
+    this.readyState = WebSocket.CONNECTING;
+    this.bytesReceived = 0;
+    this.extensions = {};
+    this.protocol = '';
+
+    this._binaryType = constants.BINARY_TYPES[0];
+    this._finalize = this.finalize.bind(this);
+    this._finalizeCalled = false;
+    this._closeMessage = null;
+    this._closeTimer = null;
+    this._closeCode = null;
+    this._receiver = null;
+    this._sender = null;
+    this._socket = null;
+    this._ultron = null;
+
+    if (Array.isArray(address)) {
+      initAsServerClient.call(this, address[0], address[1], address[2], options);
+    } else {
+      initAsClient.call(this, address, protocols, options);
+    }
+  }
+
+  get CONNECTING () { return WebSocket.CONNECTING; }
+  get CLOSING () { return WebSocket.CLOSING; }
+  get CLOSED () { return WebSocket.CLOSED; }
+  get OPEN () { return WebSocket.OPEN; }
+
+  /**
+   * @type {Number}
+   */
+  get bufferedAmount () {
+    var amount = 0;
+
+    if (this._socket) {
+      amount = this._socket.bufferSize + this._sender.bufferedBytes;
+    }
+    return amount;
+  }
+
+  /**
+   * This deviates from the WHATWG interface since ws doesn't support the required
+   * default "blob" type (instead we define a custom "nodebuffer" type).
+   *
+   * @type {String}
+   */
+  get binaryType () {
+    return this._binaryType;
+  }
+
+  set binaryType (type) {
+    if (constants.BINARY_TYPES.indexOf(type) < 0) return;
+
+    this._binaryType = type;
+
+    //
+    // Allow to change `binaryType` on the fly.
+    //
+    if (this._receiver) this._receiver.binaryType = type;
+  }
+
+  /**
+   * Set up the socket and the internal resources.
+   *
+   * @param {net.Socket} socket The network socket between the server and client
+   * @param {Buffer} head The first packet of the upgraded stream
+   * @private
+   */
+  setSocket (socket, head) {
+    socket.setTimeout(0);
+    socket.setNoDelay();
+
+    this._receiver = new Receiver(this.extensions, this.maxPayload, this.binaryType);
+    this._sender = new Sender(socket, this.extensions);
+    this._ultron = new Ultron(socket);
+    this._socket = socket;
+
+    // socket cleanup handlers
+    this._ultron.on('close', this._finalize);
+    this._ultron.on('error', this._finalize);
+    this._ultron.on('end', this._finalize);
+
+    // ensure that the head is added to the receiver
+    if (head && head.length > 0) {
+      socket.unshift(head);
+      head = null;
+    }
+
+    // subsequent packets are pushed to the receiver
+    this._ultron.on('data', (data) => {
+      this.bytesReceived += data.length;
+      this._receiver.add(data);
+    });
+
+    // receiver event handlers
+    this._receiver.onmessage = (data, flags) => this.emit('message', data, flags);
+    this._receiver.onping = (data, flags) => {
+      this.pong(data, !this._isServer, true);
+      this.emit('ping', data, flags);
+    };
+    this._receiver.onpong = (data, flags) => this.emit('pong', data, flags);
+    this._receiver.onclose = (code, reason) => {
+      this._closeMessage = reason;
+      this._closeCode = code;
+      this.close(code, reason);
+    };
+    this._receiver.onerror = (error, code) => {
+      // close the connection when the receiver reports a HyBi error code
+      this.close(code, '');
+      this.emit('error', error);
+    };
+
+    // sender event handlers
+    this._sender.onerror = (error) => {
+      this.close(1002, '');
+      this.emit('error', error);
+    };
+
+    this.readyState = WebSocket.OPEN;
+    this.emit('open');
+  }
+
+  /**
+   * Clean up and release internal resources.
+   *
+   * @param {(Boolean|Error)} Indicates whether or not an error occurred
+   * @private
+   */
+  finalize (error) {
+    if (this._finalizeCalled) return;
+
+    this.readyState = WebSocket.CLOSING;
+    this._finalizeCalled = true;
+
+    clearTimeout(this._closeTimer);
+    this._closeTimer = null;
+
+    //
+    // If the connection was closed abnormally (with an error), or if the close
+    // control frame was malformed or not received then the close code must be
+    // 1006.
+    //
+    if (error) this._closeCode = 1006;
+
+    if (this._socket) {
+      this._ultron.destroy();
+      this._socket.on('error', function onerror () {
+        this.destroy();
+      });
+
+      if (!error) this._socket.end();
+      else this._socket.destroy();
+
+      this._socket = null;
+      this._ultron = null;
+    }
+
+    if (this._sender) {
+      this._sender = this._sender.onerror = null;
+    }
+
+    if (this._receiver) {
+      this._receiver.cleanup(() => this.emitClose());
+      this._receiver = null;
+    } else {
+      this.emitClose();
+    }
+  }
+
+  /**
+   * Emit the `close` event.
+   *
+   * @private
+   */
+  emitClose () {
+    this.readyState = WebSocket.CLOSED;
+    this.emit('close', this._closeCode || 1006, this._closeMessage || '');
+
+    if (this.extensions[PerMessageDeflate.extensionName]) {
+      this.extensions[PerMessageDeflate.extensionName].cleanup();
+    }
+
+    this.extensions = null;
+
+    this.removeAllListeners();
+    this.on('error', constants.NOOP); // Catch all errors after this.
+  }
+
+  /**
+   * Pause the socket stream.
+   *
+   * @public
+   */
+  pause () {
+    if (this.readyState !== WebSocket.OPEN) throw new Error('not opened');
+
+    this._socket.pause();
+  }
+
+  /**
+   * Resume the socket stream
+   *
+   * @public
+   */
+  resume () {
+    if (this.readyState !== WebSocket.OPEN) throw new Error('not opened');
+
+    this._socket.resume();
+  }
+
+  /**
+   * Start a closing handshake.
+   *
+   * @param {Number} code Status code explaining why the connection is closing
+   * @param {String} data A string explaining why the connection is closing
+   * @public
+   */
+  close (code, data) {
+    if (this.readyState === WebSocket.CLOSED) return;
+    if (this.readyState === WebSocket.CONNECTING) {
+      if (this._req && !this._req.aborted) {
+        this._req.abort();
+        this.emit('error', new Error('closed before the connection is established'));
+        this.finalize(true);
+      }
+      return;
+    }
+
+    if (this.readyState === WebSocket.CLOSING) {
+      if (this._closeCode && this._socket) this._socket.end();
+      return;
+    }
+
+    this.readyState = WebSocket.CLOSING;
+    this._sender.close(code, data, !this._isServer, (err) => {
+      if (err) this.emit('error', err);
+
+      if (this._socket) {
+        if (this._closeCode) this._socket.end();
+        //
+        // Ensure that the connection is cleaned up even when the closing
+        // handshake fails.
+        //
+        clearTimeout(this._closeTimer);
+        this._closeTimer = setTimeout(this._finalize, closeTimeout, true);
+      }
+    });
+  }
+
+  /**
+   * Send a ping message.
+   *
+   * @param {*} data The message to send
+   * @param {Boolean} mask Indicates whether or not to mask `data`
+   * @param {Boolean} failSilently Indicates whether or not to throw if `readyState` isn't `OPEN`
+   * @public
+   */
+  ping (data, mask, failSilently) {
+    if (this.readyState !== WebSocket.OPEN) {
+      if (failSilently) return;
+      throw new Error('not opened');
+    }
+
+    if (typeof data === 'number') data = data.toString();
+    if (mask === undefined) mask = !this._isServer;
+    this._sender.ping(data || constants.EMPTY_BUFFER, mask);
+  }
+
+  /**
+   * Send a pong message.
+   *
+   * @param {*} data The message to send
+   * @param {Boolean} mask Indicates whether or not to mask `data`
+   * @param {Boolean} failSilently Indicates whether or not to throw if `readyState` isn't `OPEN`
+   * @public
+   */
+  pong (data, mask, failSilently) {
+    if (this.readyState !== WebSocket.OPEN) {
+      if (failSilently) return;
+      throw new Error('not opened');
+    }
+
+    if (typeof data === 'number') data = data.toString();
+    if (mask === undefined) mask = !this._isServer;
+    this._sender.pong(data || constants.EMPTY_BUFFER, mask);
+  }
+
+  /**
+   * Send a data message.
+   *
+   * @param {*} data The message to send
+   * @param {Object} options Options object
+   * @param {Boolean} options.compress Specifies whether or not to compress `data`
+   * @param {Boolean} options.binary Specifies whether `data` is binary or text
+   * @param {Boolean} options.fin Specifies whether the fragment is the last one
+   * @param {Boolean} options.mask Specifies whether or not to mask `data`
+   * @param {Function} cb Callback which is executed when data is written out
+   * @public
+   */
+  send (data, options, cb) {
+    if (typeof options === 'function') {
+      cb = options;
+      options = {};
+    }
+
+    if (this.readyState !== WebSocket.OPEN) {
+      if (cb) cb(new Error('not opened'));
+      else throw new Error('not opened');
+      return;
+    }
+
+    if (typeof data === 'number') data = data.toString();
+
+    const opts = Object.assign({
+      binary: typeof data !== 'string',
+      mask: !this._isServer,
+      compress: true,
+      fin: true
+    }, options);
+
+    if (!this.extensions[PerMessageDeflate.extensionName]) {
+      opts.compress = false;
+    }
+
+    this._sender.send(data || constants.EMPTY_BUFFER, opts, cb);
+  }
+
+  /**
+   * Forcibly close the connection.
+   *
+   * @public
+   */
+  terminate () {
+    if (this.readyState === WebSocket.CLOSED) return;
+    if (this.readyState === WebSocket.CONNECTING) {
+      if (this._req && !this._req.aborted) {
+        this._req.abort();
+        this.emit('error', new Error('closed before the connection is established'));
+        this.finalize(true);
+      }
+      return;
+    }
+
+    this.finalize(true);
+  }
+}
+
+WebSocket.CONNECTING = 0;
+WebSocket.OPEN = 1;
+WebSocket.CLOSING = 2;
+WebSocket.CLOSED = 3;
+
+//
+// Add the `onopen`, `onerror`, `onclose`, and `onmessage` attributes.
+// See https://html.spec.whatwg.org/multipage/comms.html#the-websocket-interface
+//
+['open', 'error', 'close', 'message'].forEach((method) => {
+  Object.defineProperty(WebSocket.prototype, `on${method}`, {
+    /**
+     * Return the listener of the event.
+     *
+     * @return {(Function|undefined)} The event listener or `undefined`
+     * @public
+     */
+    get () {
+      const listeners = this.listeners(method);
+      for (var i = 0; i < listeners.length; i++) {
+        if (listeners[i]._listener) return listeners[i]._listener;
+      }
+    },
+    /**
+     * Add a listener for the event.
+     *
+     * @param {Function} listener The listener to add
+     * @public
+     */
+    set (listener) {
+      const listeners = this.listeners(method);
+      for (var i = 0; i < listeners.length; i++) {
+        //
+        // Remove only the listeners added via `addEventListener`.
+        //
+        if (listeners[i]._listener) this.removeListener(method, listeners[i]);
+      }
+      this.addEventListener(method, listener);
+    }
+  });
+});
+
+WebSocket.prototype.addEventListener = EventTarget.addEventListener;
+WebSocket.prototype.removeEventListener = EventTarget.removeEventListener;
+
+module.exports = WebSocket;
+
+/**
+ * Initialize a WebSocket server client.
+ *
+ * @param {http.IncomingMessage} req The request object
+ * @param {net.Socket} socket The network socket between the server and client
+ * @param {Buffer} head The first packet of the upgraded stream
+ * @param {Object} options WebSocket attributes
+ * @param {Number} options.protocolVersion The WebSocket protocol version
+ * @param {Object} options.extensions The negotiated extensions
+ * @param {Number} options.maxPayload The maximum allowed message size
+ * @param {String} options.protocol The chosen subprotocol
+ * @private
+ */
+function initAsServerClient (req, socket, head, options) {
+  this.protocolVersion = options.protocolVersion;
+  this.extensions = options.extensions;
+  this.maxPayload = options.maxPayload;
+  this.protocol = options.protocol;
+
+  this.upgradeReq = req;
+  this._isServer = true;
+
+  this.setSocket(socket, head);
+}
+
+/**
+ * Initialize a WebSocket client.
+ *
+ * @param {String} address The URL to which to connect
+ * @param {String[]} protocols The list of subprotocols
+ * @param {Object} options Connection options
+ * @param {String} options.protocol Value of the `Sec-WebSocket-Protocol` header
+ * @param {(Boolean|Object)} options.perMessageDeflate Enable/disable permessage-deflate
+ * @param {String} options.localAddress Local interface to bind for network connections
+ * @param {Number} options.protocolVersion Value of the `Sec-WebSocket-Version` header
+ * @param {Object} options.headers An object containing request headers
+ * @param {String} options.origin Value of the `Origin` or `Sec-WebSocket-Origin` header
+ * @param {http.Agent} options.agent Use the specified Agent
+ * @param {String} options.host Value of the `Host` header
+ * @param {Number} options.family IP address family to use during hostname lookup (4 or 6).
+ * @param {Function} options.checkServerIdentity A function to validate the server hostname
+ * @param {Boolean} options.rejectUnauthorized Verify or not the server certificate
+ * @param {String} options.passphrase The passphrase for the private key or pfx
+ * @param {String} options.ciphers The ciphers to use or exclude
+ * @param {(String|String[]|Buffer|Buffer[])} options.cert The certificate key
+ * @param {(String|String[]|Buffer|Buffer[])} options.key The private key
+ * @param {(String|Buffer)} options.pfx The private key, certificate, and CA certs
+ * @param {(String|String[]|Buffer|Buffer[])} options.ca Trusted certificates
+ * @private
+ */
+function initAsClient (address, protocols, options) {
+  options = Object.assign({
+    protocolVersion: protocolVersions[1],
+    protocol: protocols.join(','),
+    perMessageDeflate: true,
+    localAddress: null,
+    headers: null,
+    family: null,
+    origin: null,
+    agent: null,
+    host: null,
+
+    //
+    // SSL options.
+    //
+    checkServerIdentity: null,
+    rejectUnauthorized: null,
+    passphrase: null,
+    ciphers: null,
+    cert: null,
+    key: null,
+    pfx: null,
+    ca: null
+  }, options);
+
+  if (protocolVersions.indexOf(options.protocolVersion) === -1) {
+    throw new Error(
+      `unsupported protocol version: ${options.protocolVersion} ` +
+      `(supported versions: ${protocolVersions.join(', ')})`
+    );
+  }
+
+  this.protocolVersion = options.protocolVersion;
+  this._isServer = false;
+  this.url = address;
+
+  const serverUrl = url.parse(address);
+  const isUnixSocket = serverUrl.protocol === 'ws+unix:';
+
+  if (!serverUrl.host && (!isUnixSocket || !serverUrl.path)) {
+    throw new Error('invalid url');
+  }
+
+  const isSecure = serverUrl.protocol === 'wss:' || serverUrl.protocol === 'https:';
+  const key = crypto.randomBytes(16).toString('base64');
+  const httpObj = isSecure ? https : http;
+
+  //
+  // Prepare extensions.
+  //
+  const extensionsOffer = {};
+  var perMessageDeflate;
+
+  if (options.perMessageDeflate) {
+    perMessageDeflate = new PerMessageDeflate(
+      options.perMessageDeflate !== true ? options.perMessageDeflate : {},
+      false
+    );
+    extensionsOffer[PerMessageDeflate.extensionName] = perMessageDeflate.offer();
+  }
+
+  const requestOptions = {
+    port: serverUrl.port || (isSecure ? 443 : 80),
+    host: serverUrl.hostname,
+    path: '/',
+    headers: {
+      'Sec-WebSocket-Version': options.protocolVersion,
+      'Sec-WebSocket-Key': key,
+      'Connection': 'Upgrade',
+      'Upgrade': 'websocket'
+    }
+  };
+
+  if (options.headers) Object.assign(requestOptions.headers, options.headers);
+  if (Object.keys(extensionsOffer).length) {
+    requestOptions.headers['Sec-WebSocket-Extensions'] = Extensions.format(extensionsOffer);
+  }
+  if (options.protocol) {
+    requestOptions.headers['Sec-WebSocket-Protocol'] = options.protocol;
+  }
+  if (options.origin) {
+    if (options.protocolVersion < 13) {
+      requestOptions.headers['Sec-WebSocket-Origin'] = options.origin;
+    } else {
+      requestOptions.headers.Origin = options.origin;
+    }
+  }
+  if (options.host) requestOptions.headers.Host = options.host;
+  if (serverUrl.auth) requestOptions.auth = serverUrl.auth;
+
+  if (options.localAddress) requestOptions.localAddress = options.localAddress;
+  if (options.family) requestOptions.family = options.family;
+
+  if (isUnixSocket) {
+    const parts = serverUrl.path.split(':');
+
+    requestOptions.socketPath = parts[0];
+    requestOptions.path = parts[1];
+  } else if (serverUrl.path) {
+    //
+    // Make sure that path starts with `/`.
+    //
+    if (serverUrl.path.charAt(0) !== '/') {
+      requestOptions.path = `/${serverUrl.path}`;
+    } else {
+      requestOptions.path = serverUrl.path;
+    }
+  }
+
+  var agent = options.agent;
+
+  //
+  // A custom agent is required for these options.
+  //
+  if (
+    options.rejectUnauthorized != null ||
+    options.checkServerIdentity ||
+    options.passphrase ||
+    options.ciphers ||
+    options.cert ||
+    options.key ||
+    options.pfx ||
+    options.ca
+  ) {
+    if (options.passphrase) requestOptions.passphrase = options.passphrase;
+    if (options.ciphers) requestOptions.ciphers = options.ciphers;
+    if (options.cert) requestOptions.cert = options.cert;
+    if (options.key) requestOptions.key = options.key;
+    if (options.pfx) requestOptions.pfx = options.pfx;
+    if (options.ca) requestOptions.ca = options.ca;
+    if (options.checkServerIdentity) {
+      requestOptions.checkServerIdentity = options.checkServerIdentity;
+    }
+    if (options.rejectUnauthorized != null) {
+      requestOptions.rejectUnauthorized = options.rejectUnauthorized;
+    }
+
+    if (!agent) agent = new httpObj.Agent(requestOptions);
+  }
+
+  if (agent) requestOptions.agent = agent;
+
+  this._req = httpObj.get(requestOptions);
+
+  this._req.on('error', (error) => {
+    if (this._req.aborted) return;
+
+    this._req = null;
+    this.emit('error', error);
+    this.finalize(true);
+  });
+
+  this._req.on('response', (res) => {
+    if (!this.emit('unexpected-response', this._req, res)) {
+      this._req.abort();
+      this.emit('error', new Error(`unexpected server response (${res.statusCode})`));
+      this.finalize(true);
+    }
+  });
+
+  this._req.on('upgrade', (res, socket, head) => {
+    this.emit('headers', res.headers, res);
+
+    //
+    // The user may have closed the connection from a listener of the `headers`
+    // event.
+    //
+    if (this.readyState !== WebSocket.CONNECTING) return;
+
+    this._req = null;
+
+    const digest = crypto.createHash('sha1')
+      .update(key + constants.GUID, 'binary')
+      .digest('base64');
+
+    if (res.headers['sec-websocket-accept'] !== digest) {
+      socket.destroy();
+      this.emit('error', new Error('invalid server key'));
+      return this.finalize(true);
+    }
+
+    const serverProt = res.headers['sec-websocket-protocol'];
+    const protList = (options.protocol || '').split(/, */);
+    var protError;
+
+    if (!options.protocol && serverProt) {
+      protError = 'server sent a subprotocol even though none requested';
+    } else if (options.protocol && !serverProt) {
+      protError = 'server sent no subprotocol even though requested';
+    } else if (serverProt && protList.indexOf(serverProt) === -1) {
+      protError = 'server responded with an invalid protocol';
+    }
+
+    if (protError) {
+      socket.destroy();
+      this.emit('error', new Error(protError));
+      return this.finalize(true);
+    }
+
+    if (serverProt) this.protocol = serverProt;
+
+    const serverExtensions = Extensions.parse(res.headers['sec-websocket-extensions']);
+
+    if (perMessageDeflate && serverExtensions[PerMessageDeflate.extensionName]) {
+      try {
+        perMessageDeflate.accept(serverExtensions[PerMessageDeflate.extensionName]);
+      } catch (err) {
+        socket.destroy();
+        this.emit('error', new Error('invalid extension parameter'));
+        return this.finalize(true);
+      }
+
+      this.extensions[PerMessageDeflate.extensionName] = perMessageDeflate;
+    }
+
+    this.setSocket(socket, head);
+  });
+}

node_modules/ws/lib/WebSocketServer.js

@@ -0,0 +1,336 @@
+/*!
+ * ws: a node.js websocket client
+ * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
+ * MIT Licensed
+ */
+
+'use strict';
+
+const safeBuffer = require('safe-buffer');
+const EventEmitter = require('events');
+const crypto = require('crypto');
+const Ultron = require('ultron');
+const http = require('http');
+const url = require('url');
+
+const PerMessageDeflate = require('./PerMessageDeflate');
+const Extensions = require('./Extensions');
+const constants = require('./Constants');
+const WebSocket = require('./WebSocket');
+
+const Buffer = safeBuffer.Buffer;
+
+/**
+ * Class representing a WebSocket server.
+ *
+ * @extends EventEmitter
+ */
+class WebSocketServer extends EventEmitter {
+  /**
+   * Create a `WebSocketServer` instance.
+   *
+   * @param {Object} options Configuration options
+   * @param {String} options.host The hostname where to bind the server
+   * @param {Number} options.port The port where to bind the server
+   * @param {http.Server} options.server A pre-created HTTP/S server to use
+   * @param {Function} options.verifyClient An hook to reject connections
+   * @param {Function} options.handleProtocols An hook to handle protocols
+   * @param {String} options.path Accept only connections matching this path
+   * @param {Boolean} options.noServer Enable no server mode
+   * @param {Boolean} options.clientTracking Specifies whether or not to track clients
+   * @param {(Boolean|Object)} options.perMessageDeflate Enable/disable permessage-deflate
+   * @param {Number} options.maxPayload The maximum allowed message size
+   * @param {Function} callback A listener for the `listening` event
+   */
+  constructor (options, callback) {
+    super();
+
+    options = Object.assign({
+      maxPayload: 100 * 1024 * 1024,
+      perMessageDeflate: true,
+      handleProtocols: null,
+      clientTracking: true,
+      verifyClient: null,
+      noServer: false,
+      backlog: null, // use default (511 as implemented in net.js)
+      server: null,
+      host: null,
+      path: null,
+      port: null
+    }, options);
+
+    if (options.port == null && !options.server && !options.noServer) {
+      throw new TypeError('missing or invalid options');
+    }
+
+    if (options.port != null) {
+      this._server = http.createServer((req, res) => {
+        const body = http.STATUS_CODES[426];
+
+        res.writeHead(426, {
+          'Content-Length': body.length,
+          'Content-Type': 'text/plain'
+        });
+        res.end(body);
+      });
+      this._server.allowHalfOpen = false;
+      this._server.listen(options.port, options.host, options.backlog, callback);
+    } else if (options.server) {
+      this._server = options.server;
+    }
+
+    if (this._server) {
+      this._ultron = new Ultron(this._server);
+      this._ultron.on('listening', () => this.emit('listening'));
+      this._ultron.on('error', (err) => this.emit('error', err));
+      this._ultron.on('upgrade', (req, socket, head) => {
+        this.handleUpgrade(req, socket, head, (client) => {
+          this.emit(`connection${req.url}`, client);
+          this.emit('connection', client);
+        });
+      });
+    }
+
+    if (options.clientTracking) this.clients = new Set();
+    this.options = options;
+    this.path = options.path;
+  }
+
+  /**
+   * Close the server.
+   *
+   * @param {Function} cb Callback
+   * @public
+   */
+  close (cb) {
+    //
+    // Terminate all associated clients.
+    //
+    if (this.clients) {
+      for (const client of this.clients) client.terminate();
+    }
+
+    const server = this._server;
+
+    if (server) {
+      this._ultron.destroy();
+      this._ultron = this._server = null;
+
+      //
+      // Close the http server if it was internally created.
+      //
+      if (this.options.port != null) return server.close(cb);
+    }
+
+    if (cb) cb();
+  }
+
+  /**
+   * See if a given request should be handled by this server instance.
+   *
+   * @param {http.IncomingMessage} req Request object to inspect
+   * @return {Boolean} `true` if the request is valid, else `false`
+   * @public
+   */
+  shouldHandle (req) {
+    if (this.options.path && url.parse(req.url).pathname !== this.options.path) {
+      return false;
+    }
+
+    return true;
+  }
+
+  /**
+   * Handle a HTTP Upgrade request.
+   *
+   * @param {http.IncomingMessage} req The request object
+   * @param {net.Socket} socket The network socket between the server and client
+   * @param {Buffer} head The first packet of the upgraded stream
+   * @param {Function} cb Callback
+   * @public
+   */
+  handleUpgrade (req, socket, head, cb) {
+    socket.on('error', socketError);
+
+    const version = +req.headers['sec-websocket-version'];
+
+    if (
+      req.method !== 'GET' || req.headers.upgrade.toLowerCase() !== 'websocket' ||
+      !req.headers['sec-websocket-key'] || (version !== 8 && version !== 13) ||
+      !this.shouldHandle(req)
+    ) {
+      return abortConnection(socket, 400);
+    }
+
+    var protocol = (req.headers['sec-websocket-protocol'] || '').split(/, */);
+
+    //
+    // Optionally call external protocol selection handler.
+    //
+    if (this.options.handleProtocols) {
+      protocol = this.options.handleProtocols(protocol, req);
+      if (protocol === false) return abortConnection(socket, 401);
+    } else {
+      protocol = protocol[0];
+    }
+
+    //
+    // Optionally call external client verification handler.
+    //
+    if (this.options.verifyClient) {
+      const info = {
+        origin: req.headers[`${version === 8 ? 'sec-websocket-origin' : 'origin'}`],
+        secure: !!(req.connection.authorized || req.connection.encrypted),
+        req
+      };
+
+      if (this.options.verifyClient.length === 2) {
+        this.options.verifyClient(info, (verified, code, message) => {
+          if (!verified) return abortConnection(socket, code || 401, message);
+
+          this.completeUpgrade(protocol, version, req, socket, head, cb);
+        });
+        return;
+      } else if (!this.options.verifyClient(info)) {
+        return abortConnection(socket, 401);
+      }
+    }
+
+    this.completeUpgrade(protocol, version, req, socket, head, cb);
+  }
+
+  /**
+   * Upgrade the connection to WebSocket.
+   *
+   * @param {String} protocol The chosen subprotocol
+   * @param {Number} version The WebSocket protocol version
+   * @param {http.IncomingMessage} req The request object
+   * @param {net.Socket} socket The network socket between the server and client
+   * @param {Buffer} head The first packet of the upgraded stream
+   * @param {Function} cb Callback
+   * @private
+   */
+  completeUpgrade (protocol, version, req, socket, head, cb) {
+    //
+    // Destroy the socket if the client has already sent a FIN packet.
+    //
+    if (!socket.readable || !socket.writable) return socket.destroy();
+
+    const key = crypto.createHash('sha1')
+      .update(req.headers['sec-websocket-key'] + constants.GUID, 'binary')
+      .digest('base64');
+
+    const headers = [
+      'HTTP/1.1 101 Switching Protocols',
+      'Upgrade: websocket',
+      'Connection: Upgrade',
+      `Sec-WebSocket-Accept: ${key}`
+    ];
+
+    if (protocol) headers.push(`Sec-WebSocket-Protocol: ${protocol}`);
+
+    const offer = Extensions.parse(req.headers['sec-websocket-extensions']);
+    var extensions;
+
+    try {
+      extensions = acceptExtensions(this.options, offer);
+    } catch (err) {
+      return abortConnection(socket, 400);
+    }
+
+    const props = Object.keys(extensions);
+
+    if (props.length) {
+      const serverExtensions = props.reduce((obj, key) => {
+        obj[key] = [extensions[key].params];
+        return obj;
+      }, {});
+
+      headers.push(`Sec-WebSocket-Extensions: ${Extensions.format(serverExtensions)}`);
+    }
+
+    //
+    // Allow external modification/inspection of handshake headers.
+    //
+    this.emit('headers', headers, req);
+
+    socket.write(headers.concat('', '').join('\r\n'));
+
+    const client = new WebSocket([req, socket, head], null, {
+      maxPayload: this.options.maxPayload,
+      protocolVersion: version,
+      extensions,
+      protocol
+    });
+
+    if (this.clients) {
+      this.clients.add(client);
+      client.on('close', () => this.clients.delete(client));
+    }
+
+    socket.removeListener('error', socketError);
+    cb(client);
+  }
+}
+
+module.exports = WebSocketServer;
+
+/**
+ * Handle premature socket errors.
+ *
+ * @private
+ */
+function socketError () {
+  this.destroy();
+}
+
+/**
+ * Accept WebSocket extensions.
+ *
+ * @param {Object} options The `WebSocketServer` configuration options
+ * @param {Object} offer The parsed value of the `sec-websocket-extensions` header
+ * @return {Object} Accepted extensions
+ * @private
+ */
+function acceptExtensions (options, offer) {
+  const pmd = options.perMessageDeflate;
+  const extensions = {};
+
+  if (pmd && offer[PerMessageDeflate.extensionName]) {
+    const perMessageDeflate = new PerMessageDeflate(
+      pmd !== true ? pmd : {},
+      true,
+      options.maxPayload
+    );
+
+    perMessageDeflate.accept(offer[PerMessageDeflate.extensionName]);
+    extensions[PerMessageDeflate.extensionName] = perMessageDeflate;
+  }
+
+  return extensions;
+}
+
+/**
+ * Close the connection when preconditions are not fulfilled.
+ *
+ * @param {net.Socket} socket The socket of the upgrade request
+ * @param {Number} code The HTTP response status code
+ * @param {String} [message] The HTTP response body
+ * @private
+ */
+function abortConnection (socket, code, message) {
+  if (socket.writable) {
+    message = message || http.STATUS_CODES[code];
+    socket.write(
+      `HTTP/1.1 ${code} ${http.STATUS_CODES[code]}\r\n` +
+      'Connection: close\r\n' +
+      'Content-type: text/html\r\n' +
+      `Content-Length: ${Buffer.byteLength(message)}\r\n` +
+      '\r\n' +
+      message
+    );
+  }
+
+  socket.removeListener('error', socketError);
+  socket.destroy();
+}