Updated

node_modules/ws/lib/buffer-util.js

@@ -0,0 +1,144 @@
+'use strict';
+
+const { EMPTY_BUFFER } = require('./constants');
+
+/**
+ * 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
+ */
+function concat(list, totalLength) {
+  if (list.length === 0) return EMPTY_BUFFER;
+  if (list.length === 1) return list[0];
+
+  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;
+}
+
+/**
+ * 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
+ */
+function _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
+ */
+function _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];
+  }
+}
+
+/**
+ * Converts a buffer to an `ArrayBuffer`.
+ *
+ * @param {Buffer} buf The buffer to convert
+ * @return {ArrayBuffer} Converted buffer
+ * @public
+ */
+function toArrayBuffer(buf) {
+  if (buf.byteLength === buf.buffer.byteLength) {
+    return buf.buffer;
+  }
+
+  return buf.buffer.slice(buf.byteOffset, buf.byteOffset + buf.byteLength);
+}
+
+/**
+ * Converts `data` to a `Buffer`.
+ *
+ * @param {*} data The data to convert
+ * @return {Buffer} The buffer
+ * @throws {TypeError}
+ * @public
+ */
+function toBuffer(data) {
+  toBuffer.readOnly = true;
+
+  if (Buffer.isBuffer(data)) return data;
+
+  var buf;
+
+  if (data instanceof ArrayBuffer) {
+    buf = Buffer.from(data);
+  } else if (ArrayBuffer.isView(data)) {
+    buf = viewToBuffer(data);
+  } else {
+    buf = Buffer.from(data);
+    toBuffer.readOnly = false;
+  }
+
+  return buf;
+}
+
+/**
+ * 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;
+}
+
+try {
+  const bufferUtil = require('bufferutil');
+  const bu = bufferUtil.BufferUtil || bufferUtil;
+
+  module.exports = {
+    concat,
+    mask(source, mask, output, offset, length) {
+      if (length < 48) _mask(source, mask, output, offset, length);
+      else bu.mask(source, mask, output, offset, length);
+    },
+    toArrayBuffer,
+    toBuffer,
+    unmask(buffer, mask) {
+      if (buffer.length < 32) _unmask(buffer, mask);
+      else bu.unmask(buffer, mask);
+    }
+  };
+} catch (e) /* istanbul ignore next */ {
+  module.exports = {
+    concat,
+    mask: _mask,
+    toArrayBuffer,
+    toBuffer,
+    unmask: _unmask
+  };
+}

node_modules/ws/lib/constants.js

@@ -0,0 +1,10 @@
+'use strict';
+
+module.exports = {
+  BINARY_TYPES: ['nodebuffer', 'arraybuffer', 'fragments'],
+  GUID: '258EAFA5-E914-47DA-95CA-C5AB0DC85B11',
+  kStatusCode: Symbol('status-code'),
+  kWebSocket: Symbol('websocket'),
+  EMPTY_BUFFER: Buffer.alloc(0),
+  NOOP: () => {}
+};

node_modules/ws/lib/event-target.js

@@ -0,0 +1,170 @@
+'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 {WebSocket} target A reference to the target to which the event was dispatched
+   */
+  constructor(data, target) {
+    super('message', target);
+
+    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 = target._closeFrameReceived && target._closeFrameSent;
+    this.reason = reason;
+    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);
+  }
+}
+
+/**
+ * Class representing an error event.
+ *
+ * @extends Event
+ * @private
+ */
+class ErrorEvent extends Event {
+  /**
+   * Create a new `ErrorEvent`.
+   *
+   * @param {Object} error The error that generated this event
+   * @param {WebSocket} target A reference to the target to which the event was dispatched
+   */
+  constructor(error, target) {
+    super('error', target);
+
+    this.message = error.message;
+    this.error = error;
+  }
+}
+
+/**
+ * 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) {
+      listener.call(this, new MessageEvent(data, this));
+    }
+
+    function onClose(code, message) {
+      listener.call(this, new CloseEvent(code, message, this));
+    }
+
+    function onError(error) {
+      listener.call(this, new ErrorEvent(error, this));
+    }
+
+    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/extension.js

@@ -0,0 +1,222 @@
+'use strict';
+
+//
+// Allowed token characters:
+//
+// '!', '#', '$', '%', '&', ''', '*', '+', '-',
+// '.', 0-9, A-Z, '^', '_', '`', a-z, '|', '~'
+//
+// tokenChars[32] === 0 // ' '
+// tokenChars[33] === 1 // '!'
+// tokenChars[34] === 0 // '"'
+// ...
+//
+// prettier-ignore
+const tokenChars = [
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0 - 15
+  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 16 - 31
+  0, 1, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, // 32 - 47
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, // 48 - 63
+  0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 64 - 79
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, // 80 - 95
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 96 - 111
+  1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0 // 112 - 127
+];
+
+/**
+ * Adds an offer to the map of extension offers or a parameter to the map of
+ * parameters.
+ *
+ * @param {Object} dest The map of extension offers or parameters
+ * @param {String} name The extension or parameter name
+ * @param {(Object|Boolean|String)} elem The extension parameters or the
+ *     parameter value
+ * @private
+ */
+function push(dest, name, elem) {
+  if (Object.prototype.hasOwnProperty.call(dest, name)) dest[name].push(elem);
+  else dest[name] = [elem];
+}
+
+/**
+ * Parses the `Sec-WebSocket-Extensions` header into an object.
+ *
+ * @param {String} header The field value of the header
+ * @return {Object} The parsed object
+ * @public
+ */
+function parse(header) {
+  const offers = {};
+
+  if (header === undefined || header === '') return offers;
+
+  var params = {};
+  var mustUnescape = false;
+  var isEscaping = false;
+  var inQuotes = false;
+  var extensionName;
+  var paramName;
+  var start = -1;
+  var end = -1;
+
+  for (var i = 0; i < header.length; i++) {
+    const code = header.charCodeAt(i);
+
+    if (extensionName === undefined) {
+      if (end === -1 && tokenChars[code] === 1) {
+        if (start === -1) start = i;
+      } else if (code === 0x20 /* ' ' */ || code === 0x09 /* '\t' */) {
+        if (end === -1 && start !== -1) end = i;
+      } else if (code === 0x3b /* ';' */ || code === 0x2c /* ',' */) {
+        if (start === -1) {
+          throw new SyntaxError(`Unexpected character at index ${i}`);
+        }
+
+        if (end === -1) end = i;
+        const name = header.slice(start, end);
+        if (code === 0x2c) {
+          push(offers, name, params);
+          params = {};
+        } else {
+          extensionName = name;
+        }
+
+        start = end = -1;
+      } else {
+        throw new SyntaxError(`Unexpected character at index ${i}`);
+      }
+    } else if (paramName === undefined) {
+      if (end === -1 && tokenChars[code] === 1) {
+        if (start === -1) start = i;
+      } else if (code === 0x20 || code === 0x09) {
+        if (end === -1 && start !== -1) end = i;
+      } else if (code === 0x3b || code === 0x2c) {
+        if (start === -1) {
+          throw new SyntaxError(`Unexpected character at index ${i}`);
+        }
+
+        if (end === -1) end = i;
+        push(params, header.slice(start, end), true);
+        if (code === 0x2c) {
+          push(offers, extensionName, params);
+          params = {};
+          extensionName = undefined;
+        }
+
+        start = end = -1;
+      } else if (code === 0x3d /* '=' */ && start !== -1 && end === -1) {
+        paramName = header.slice(start, i);
+        start = end = -1;
+      } else {
+        throw new SyntaxError(`Unexpected character at index ${i}`);
+      }
+    } else {
+      //
+      // The value of a quoted-string after unescaping must conform to the
+      // token ABNF, so only token characters are valid.
+      // Ref: https://tools.ietf.org/html/rfc6455#section-9.1
+      //
+      if (isEscaping) {
+        if (tokenChars[code] !== 1) {
+          throw new SyntaxError(`Unexpected character at index ${i}`);
+        }
+        if (start === -1) start = i;
+        else if (!mustUnescape) mustUnescape = true;
+        isEscaping = false;
+      } else if (inQuotes) {
+        if (tokenChars[code] === 1) {
+          if (start === -1) start = i;
+        } else if (code === 0x22 /* '"' */ && start !== -1) {
+          inQuotes = false;
+          end = i;
+        } else if (code === 0x5c /* '\' */) {
+          isEscaping = true;
+        } else {
+          throw new SyntaxError(`Unexpected character at index ${i}`);
+        }
+      } else if (code === 0x22 && header.charCodeAt(i - 1) === 0x3d) {
+        inQuotes = true;
+      } else if (end === -1 && tokenChars[code] === 1) {
+        if (start === -1) start = i;
+      } else if (start !== -1 && (code === 0x20 || code === 0x09)) {
+        if (end === -1) end = i;
+      } else if (code === 0x3b || code === 0x2c) {
+        if (start === -1) {
+          throw new SyntaxError(`Unexpected character at index ${i}`);
+        }
+
+        if (end === -1) end = i;
+        var value = header.slice(start, end);
+        if (mustUnescape) {
+          value = value.replace(/\\/g, '');
+          mustUnescape = false;
+        }
+        push(params, paramName, value);
+        if (code === 0x2c) {
+          push(offers, extensionName, params);
+          params = {};
+          extensionName = undefined;
+        }
+
+        paramName = undefined;
+        start = end = -1;
+      } else {
+        throw new SyntaxError(`Unexpected character at index ${i}`);
+      }
+    }
+  }
+
+  if (start === -1 || inQuotes) {
+    throw new SyntaxError('Unexpected end of input');
+  }
+
+  if (end === -1) end = i;
+  const token = header.slice(start, end);
+  if (extensionName === undefined) {
+    push(offers, token, {});
+  } else {
+    if (paramName === undefined) {
+      push(params, token, true);
+    } else if (mustUnescape) {
+      push(params, paramName, token.replace(/\\/g, ''));
+    } else {
+      push(params, paramName, token);
+    }
+    push(offers, extensionName, params);
+  }
+
+  return offers;
+}
+
+/**
+ * Builds the `Sec-WebSocket-Extensions` header field value.
+ *
+ * @param {Object} extensions The map of extensions and parameters to format
+ * @return {String} A string representing the given object
+ * @public
+ */
+function format(extensions) {
+  return Object.keys(extensions)
+    .map((extension) => {
+      var configurations = extensions[extension];
+      if (!Array.isArray(configurations)) configurations = [configurations];
+      return configurations
+        .map((params) => {
+          return [extension]
+            .concat(
+              Object.keys(params).map((k) => {
+                var values = params[k];
+                if (!Array.isArray(values)) values = [values];
+                return values
+                  .map((v) => (v === true ? k : `${k}=${v}`))
+                  .join('; ');
+              })
+            )
+            .join('; ');
+        })
+        .join(', ');
+    })
+    .join(', ');
+}
+
+module.exports = { format, parse };

node_modules/ws/lib/permessage-deflate.js

@@ -0,0 +1,502 @@
+'use strict';
+
+const Limiter = require('async-limiter');
+const zlib = require('zlib');
+
+const bufferUtil = require('./buffer-util');
+const { kStatusCode, NOOP } = require('./constants');
+
+const TRAILER = Buffer.from([0x00, 0x00, 0xff, 0xff]);
+const EMPTY_BLOCK = Buffer.from([0x00]);
+
+const kPerMessageDeflate = Symbol('permessage-deflate');
+const kTotalLength = Symbol('total-length');
+const kCallback = Symbol('callback');
+const kBuffers = Symbol('buffers');
+const kError = Symbol('error');
+
+//
+// We limit zlib concurrency, which prevents severe memory fragmentation
+// as documented in https://github.com/nodejs/node/issues/8871#issuecomment-250915913
+// and https://github.com/websockets/ws/issues/1202
+//
+// Intentionally global; it's the global thread pool that's an issue.
+//
+let zlibLimiter;
+
+/**
+ * permessage-deflate implementation.
+ */
+class PerMessageDeflate {
+  /**
+   * Creates a PerMessageDeflate instance.
+   *
+   * @param {Object} options Configuration options
+   * @param {Boolean} options.serverNoContextTakeover Request/accept disabling
+   *     of server context takeover
+   * @param {Boolean} options.clientNoContextTakeover Advertise/acknowledge
+   *     disabling of client context takeover
+   * @param {(Boolean|Number)} options.serverMaxWindowBits Request/confirm the
+   *     use of a custom server window size
+   * @param {(Boolean|Number)} options.clientMaxWindowBits Advertise support
+   *     for, or request, a custom client window size
+   * @param {Object} options.zlibDeflateOptions Options to pass to zlib on deflate
+   * @param {Object} options.zlibInflateOptions Options to pass to zlib on inflate
+   * @param {Number} options.threshold Size (in bytes) below which messages
+   *     should not be compressed
+   * @param {Number} options.concurrencyLimit The number of concurrent calls to
+   *     zlib
+   * @param {Boolean} isServer Create the instance in either server or client
+   *     mode
+   * @param {Number} maxPayload The maximum allowed message length
+   */
+  constructor(options, isServer, maxPayload) {
+    this._maxPayload = maxPayload | 0;
+    this._options = options || {};
+    this._threshold =
+      this._options.threshold !== undefined ? this._options.threshold : 1024;
+    this._isServer = !!isServer;
+    this._deflate = null;
+    this._inflate = null;
+
+    this.params = null;
+
+    if (!zlibLimiter) {
+      const concurrency =
+        this._options.concurrencyLimit !== undefined
+          ? this._options.concurrencyLimit
+          : 10;
+      zlibLimiter = new Limiter({ concurrency });
+    }
+  }
+
+  /**
+   * @type {String}
+   */
+  static get extensionName() {
+    return 'permessage-deflate';
+  }
+
+  /**
+   * Create an extension negotiation 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 an extension negotiation offer/response.
+   *
+   * @param {Array} configurations The extension negotiation offers/reponse
+   * @return {Object} Accepted configuration
+   * @public
+   */
+  accept(configurations) {
+    configurations = this.normalizeParams(configurations);
+
+    this.params = this._isServer
+      ? this.acceptAsServer(configurations)
+      : this.acceptAsClient(configurations);
+
+    return this.params;
+  }
+
+  /**
+   * Releases all resources used by the extension.
+   *
+   * @public
+   */
+  cleanup() {
+    if (this._inflate) {
+      this._inflate.close();
+      this._inflate = null;
+    }
+
+    if (this._deflate) {
+      this._deflate.close();
+      this._deflate = null;
+    }
+  }
+
+  /**
+   *  Accept an extension negotiation offer.
+   *
+   * @param {Array} offers The extension negotiation offers
+   * @return {Object} Accepted configuration
+   * @private
+   */
+  acceptAsServer(offers) {
+    const opts = this._options;
+    const accepted = offers.find((params) => {
+      if (
+        (opts.serverNoContextTakeover === false &&
+          params.server_no_context_takeover) ||
+        (params.server_max_window_bits &&
+          (opts.serverMaxWindowBits === false ||
+            (typeof opts.serverMaxWindowBits === 'number' &&
+              opts.serverMaxWindowBits > params.server_max_window_bits))) ||
+        (typeof opts.clientMaxWindowBits === 'number' &&
+          !params.client_max_window_bits)
+      ) {
+        return false;
+      }
+
+      return true;
+    });
+
+    if (!accepted) {
+      throw new Error('None of the extension offers can be accepted');
+    }
+
+    if (opts.serverNoContextTakeover) {
+      accepted.server_no_context_takeover = true;
+    }
+    if (opts.clientNoContextTakeover) {
+      accepted.client_no_context_takeover = true;
+    }
+    if (typeof opts.serverMaxWindowBits === 'number') {
+      accepted.server_max_window_bits = opts.serverMaxWindowBits;
+    }
+    if (typeof opts.clientMaxWindowBits === 'number') {
+      accepted.client_max_window_bits = opts.clientMaxWindowBits;
+    } else if (
+      accepted.client_max_window_bits === true ||
+      opts.clientMaxWindowBits === false
+    ) {
+      delete accepted.client_max_window_bits;
+    }
+
+    return accepted;
+  }
+
+  /**
+   * Accept the extension negotiation response.
+   *
+   * @param {Array} response The extension negotiation response
+   * @return {Object} Accepted configuration
+   * @private
+   */
+  acceptAsClient(response) {
+    const params = response[0];
+
+    if (
+      this._options.clientNoContextTakeover === false &&
+      params.client_no_context_takeover
+    ) {
+      throw new Error('Unexpected parameter "client_no_context_takeover"');
+    }
+
+    if (!params.client_max_window_bits) {
+      if (typeof this._options.clientMaxWindowBits === 'number') {
+        params.client_max_window_bits = this._options.clientMaxWindowBits;
+      }
+    } else if (
+      this._options.clientMaxWindowBits === false ||
+      (typeof this._options.clientMaxWindowBits === 'number' &&
+        params.client_max_window_bits > this._options.clientMaxWindowBits)
+    ) {
+      throw new Error(
+        'Unexpected or invalid parameter "client_max_window_bits"'
+      );
+    }
+
+    return params;
+  }
+
+  /**
+   * Normalize parameters.
+   *
+   * @param {Array} configurations The extension negotiation offers/reponse
+   * @return {Array} The offers/response with normalized parameters
+   * @private
+   */
+  normalizeParams(configurations) {
+    configurations.forEach((params) => {
+      Object.keys(params).forEach((key) => {
+        var value = params[key];
+
+        if (value.length > 1) {
+          throw new Error(`Parameter "${key}" must have only a single value`);
+        }
+
+        value = value[0];
+
+        if (key === 'client_max_window_bits') {
+          if (value !== true) {
+            const num = +value;
+            if (!Number.isInteger(num) || num < 8 || num > 15) {
+              throw new TypeError(
+                `Invalid value for parameter "${key}": ${value}`
+              );
+            }
+            value = num;
+          } else if (!this._isServer) {
+            throw new TypeError(
+              `Invalid value for parameter "${key}": ${value}`
+            );
+          }
+        } else if (key === 'server_max_window_bits') {
+          const num = +value;
+          if (!Number.isInteger(num) || num < 8 || num > 15) {
+            throw new TypeError(
+              `Invalid value for parameter "${key}": ${value}`
+            );
+          }
+          value = num;
+        } else if (
+          key === 'client_no_context_takeover' ||
+          key === 'server_no_context_takeover'
+        ) {
+          if (value !== true) {
+            throw new TypeError(
+              `Invalid value for parameter "${key}": ${value}`
+            );
+          }
+        } else {
+          throw new Error(`Unknown parameter "${key}"`);
+        }
+
+        params[key] = value;
+      });
+    });
+
+    return configurations;
+  }
+
+  /**
+   * Decompress data. Concurrency limited by async-limiter.
+   *
+   * @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) {
+    zlibLimiter.push((done) => {
+      this._decompress(data, fin, (err, result) => {
+        done();
+        callback(err, result);
+      });
+    });
+  }
+
+  /**
+   * Compress data. Concurrency limited by async-limiter.
+   *
+   * @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) {
+    zlibLimiter.push((done) => {
+      this._compress(data, fin, (err, result) => {
+        done();
+        callback(err, result);
+      });
+    });
+  }
+
+  /**
+   * Decompress data.
+   *
+   * @param {Buffer} data Compressed data
+   * @param {Boolean} fin Specifies whether or not this is the last fragment
+   * @param {Function} callback Callback
+   * @private
+   */
+  _decompress(data, fin, callback) {
+    const endpoint = this._isServer ? 'client' : 'server';
+
+    if (!this._inflate) {
+      const key = `${endpoint}_max_window_bits`;
+      const windowBits =
+        typeof this.params[key] !== 'number'
+          ? zlib.Z_DEFAULT_WINDOWBITS
+          : this.params[key];
+
+      this._inflate = zlib.createInflateRaw(
+        Object.assign({}, this._options.zlibInflateOptions, { windowBits })
+      );
+      this._inflate[kPerMessageDeflate] = this;
+      this._inflate[kTotalLength] = 0;
+      this._inflate[kBuffers] = [];
+      this._inflate.on('error', inflateOnError);
+      this._inflate.on('data', inflateOnData);
+    }
+
+    this._inflate[kCallback] = callback;
+
+    this._inflate.write(data);
+    if (fin) this._inflate.write(TRAILER);
+
+    this._inflate.flush(() => {
+      const err = this._inflate[kError];
+
+      if (err) {
+        this._inflate.close();
+        this._inflate = null;
+        callback(err);
+        return;
+      }
+
+      const data = bufferUtil.concat(
+        this._inflate[kBuffers],
+        this._inflate[kTotalLength]
+      );
+
+      if (fin && this.params[`${endpoint}_no_context_takeover`]) {
+        this._inflate.close();
+        this._inflate = null;
+      } else {
+        this._inflate[kTotalLength] = 0;
+        this._inflate[kBuffers] = [];
+      }
+
+      callback(null, data);
+    });
+  }
+
+  /**
+   * Compress data.
+   *
+   * @param {Buffer} data Data to compress
+   * @param {Boolean} fin Specifies whether or not this is the last fragment
+   * @param {Function} callback Callback
+   * @private
+   */
+  _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 key = `${endpoint}_max_window_bits`;
+      const windowBits =
+        typeof this.params[key] !== 'number'
+          ? zlib.Z_DEFAULT_WINDOWBITS
+          : this.params[key];
+
+      this._deflate = zlib.createDeflateRaw(
+        Object.assign({}, this._options.zlibDeflateOptions, { windowBits })
+      );
+
+      this._deflate[kTotalLength] = 0;
+      this._deflate[kBuffers] = [];
+
+      //
+      // An `'error'` event is emitted, only on Node.js < 10.0.0, if the
+      // `zlib.DeflateRaw` instance is closed while data is being processed.
+      // This can happen if `PerMessageDeflate#cleanup()` is called at the wrong
+      // time due to an abnormal WebSocket closure.
+      //
+      this._deflate.on('error', NOOP);
+      this._deflate.on('data', deflateOnData);
+    }
+
+    this._deflate.write(data);
+    this._deflate.flush(zlib.Z_SYNC_FLUSH, () => {
+      if (!this._deflate) {
+        //
+        // This `if` statement is only needed for Node.js < 10.0.0 because as of
+        // commit https://github.com/nodejs/node/commit/5e3f5164, the flush
+        // callback is no longer called if the deflate stream is closed while
+        // data is being processed.
+        //
+        return;
+      }
+
+      var data = bufferUtil.concat(
+        this._deflate[kBuffers],
+        this._deflate[kTotalLength]
+      );
+
+      if (fin) data = data.slice(0, data.length - 4);
+
+      if (fin && this.params[`${endpoint}_no_context_takeover`]) {
+        this._deflate.close();
+        this._deflate = null;
+      } else {
+        this._deflate[kTotalLength] = 0;
+        this._deflate[kBuffers] = [];
+      }
+
+      callback(null, data);
+    });
+  }
+}
+
+module.exports = PerMessageDeflate;
+
+/**
+ * The listener of the `zlib.DeflateRaw` stream `'data'` event.
+ *
+ * @param {Buffer} chunk A chunk of data
+ * @private
+ */
+function deflateOnData(chunk) {
+  this[kBuffers].push(chunk);
+  this[kTotalLength] += chunk.length;
+}
+
+/**
+ * The listener of the `zlib.InflateRaw` stream `'data'` event.
+ *
+ * @param {Buffer} chunk A chunk of data
+ * @private
+ */
+function inflateOnData(chunk) {
+  this[kTotalLength] += chunk.length;
+
+  if (
+    this[kPerMessageDeflate]._maxPayload < 1 ||
+    this[kTotalLength] <= this[kPerMessageDeflate]._maxPayload
+  ) {
+    this[kBuffers].push(chunk);
+    return;
+  }
+
+  this[kError] = new RangeError('Max payload size exceeded');
+  this[kError][kStatusCode] = 1009;
+  this.removeListener('data', inflateOnData);
+  this.reset();
+}
+
+/**
+ * The listener of the `zlib.InflateRaw` stream `'error'` event.
+ *
+ * @param {Error} err The emitted error
+ * @private
+ */
+function inflateOnError(err) {
+  //
+  // There is no need to call `Zlib#close()` as the handle is automatically
+  // closed when an error is emitted.
+  //
+  this[kPerMessageDeflate]._inflate = null;
+  err[kStatusCode] = 1007;
+  this[kCallback](err);
+}

node_modules/ws/lib/receiver.js

@@ -0,0 +1,492 @@
+'use strict';
+
+const { Writable } = require('stream');
+
+const PerMessageDeflate = require('./permessage-deflate');
+const {
+  BINARY_TYPES,
+  EMPTY_BUFFER,
+  kStatusCode,
+  kWebSocket
+} = require('./constants');
+const { concat, toArrayBuffer, unmask } = require('./buffer-util');
+const { isValidStatusCode, isValidUTF8 } = require('./validation');
+
+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.
+ *
+ * @extends stream.Writable
+ */
+class Receiver extends Writable {
+  /**
+   * Creates a Receiver instance.
+   *
+   * @param {String} binaryType The type for binary data
+   * @param {Object} extensions An object containing the negotiated extensions
+   * @param {Number} maxPayload The maximum allowed message length
+   */
+  constructor(binaryType, extensions, maxPayload) {
+    super();
+
+    this._binaryType = binaryType || BINARY_TYPES[0];
+    this[kWebSocket] = undefined;
+    this._extensions = extensions || {};
+    this._maxPayload = maxPayload | 0;
+
+    this._bufferedBytes = 0;
+    this._buffers = [];
+
+    this._compressed = false;
+    this._payloadLength = 0;
+    this._mask = undefined;
+    this._fragmented = 0;
+    this._masked = false;
+    this._fin = false;
+    this._opcode = 0;
+
+    this._totalPayloadLength = 0;
+    this._messageLength = 0;
+    this._fragments = [];
+
+    this._state = GET_INFO;
+    this._loop = false;
+  }
+
+  /**
+   * Implements `Writable.prototype._write()`.
+   *
+   * @param {Buffer} chunk The chunk of data to write
+   * @param {String} encoding The character encoding of `chunk`
+   * @param {Function} cb Callback
+   */
+  _write(chunk, encoding, cb) {
+    if (this._opcode === 0x08 && this._state == GET_INFO) return cb();
+
+    this._bufferedBytes += chunk.length;
+    this._buffers.push(chunk);
+    this.startLoop(cb);
+  }
+
+  /**
+   * Consumes `n` bytes from the buffered data.
+   *
+   * @param {Number} n The number of bytes to consume
+   * @return {Buffer} The consumed bytes
+   * @private
+   */
+  consume(n) {
+    this._bufferedBytes -= n;
+
+    if (n === this._buffers[0].length) return this._buffers.shift();
+
+    if (n < this._buffers[0].length) {
+      const buf = this._buffers[0];
+      this._buffers[0] = buf.slice(n);
+      return buf.slice(0, n);
+    }
+
+    const dst = Buffer.allocUnsafe(n);
+
+    do {
+      const buf = this._buffers[0];
+
+      if (n >= buf.length) {
+        this._buffers.shift().copy(dst, dst.length - n);
+      } else {
+        buf.copy(dst, dst.length - n, 0, n);
+        this._buffers[0] = buf.slice(n);
+      }
+
+      n -= buf.length;
+    } while (n > 0);
+
+    return dst;
+  }
+
+  /**
+   * Starts the parsing loop.
+   *
+   * @param {Function} cb Callback
+   * @private
+   */
+  startLoop(cb) {
+    var err;
+    this._loop = true;
+
+    do {
+      switch (this._state) {
+        case GET_INFO:
+          err = this.getInfo();
+          break;
+        case GET_PAYLOAD_LENGTH_16:
+          err = this.getPayloadLength16();
+          break;
+        case GET_PAYLOAD_LENGTH_64:
+          err = this.getPayloadLength64();
+          break;
+        case GET_MASK:
+          this.getMask();
+          break;
+        case GET_DATA:
+          err = this.getData(cb);
+          break;
+        default:
+          // `INFLATING`
+          this._loop = false;
+          return;
+      }
+    } while (this._loop);
+
+    cb(err);
+  }
+
+  /**
+   * Reads the first two bytes of a frame.
+   *
+   * @return {(RangeError|undefined)} A possible error
+   * @private
+   */
+  getInfo() {
+    if (this._bufferedBytes < 2) {
+      this._loop = false;
+      return;
+    }
+
+    const buf = this.consume(2);
+
+    if ((buf[0] & 0x30) !== 0x00) {
+      this._loop = false;
+      return error(RangeError, 'RSV2 and RSV3 must be clear', true, 1002);
+    }
+
+    const compressed = (buf[0] & 0x40) === 0x40;
+
+    if (compressed && !this._extensions[PerMessageDeflate.extensionName]) {
+      this._loop = false;
+      return error(RangeError, 'RSV1 must be clear', true, 1002);
+    }
+
+    this._fin = (buf[0] & 0x80) === 0x80;
+    this._opcode = buf[0] & 0x0f;
+    this._payloadLength = buf[1] & 0x7f;
+
+    if (this._opcode === 0x00) {
+      if (compressed) {
+        this._loop = false;
+        return error(RangeError, 'RSV1 must be clear', true, 1002);
+      }
+
+      if (!this._fragmented) {
+        this._loop = false;
+        return error(RangeError, 'invalid opcode 0', true, 1002);
+      }
+
+      this._opcode = this._fragmented;
+    } else if (this._opcode === 0x01 || this._opcode === 0x02) {
+      if (this._fragmented) {
+        this._loop = false;
+        return error(RangeError, `invalid opcode ${this._opcode}`, true, 1002);
+      }
+
+      this._compressed = compressed;
+    } else if (this._opcode > 0x07 && this._opcode < 0x0b) {
+      if (!this._fin) {
+        this._loop = false;
+        return error(RangeError, 'FIN must be set', true, 1002);
+      }
+
+      if (compressed) {
+        this._loop = false;
+        return error(RangeError, 'RSV1 must be clear', true, 1002);
+      }
+
+      if (this._payloadLength > 0x7d) {
+        this._loop = false;
+        return error(
+          RangeError,
+          `invalid payload length ${this._payloadLength}`,
+          true,
+          1002
+        );
+      }
+    } else {
+      this._loop = false;
+      return error(RangeError, `invalid opcode ${this._opcode}`, true, 1002);
+    }
+
+    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 return this.haveLength();
+  }
+
+  /**
+   * Gets extended payload length (7+16).
+   *
+   * @return {(RangeError|undefined)} A possible error
+   * @private
+   */
+  getPayloadLength16() {
+    if (this._bufferedBytes < 2) {
+      this._loop = false;
+      return;
+    }
+
+    this._payloadLength = this.consume(2).readUInt16BE(0);
+    return this.haveLength();
+  }
+
+  /**
+   * Gets extended payload length (7+64).
+   *
+   * @return {(RangeError|undefined)} A possible error
+   * @private
+   */
+  getPayloadLength64() {
+    if (this._bufferedBytes < 8) {
+      this._loop = false;
+      return;
+    }
+
+    const buf = this.consume(8);
+    const num = buf.readUInt32BE(0);
+
+    //
+    // 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._loop = false;
+      return error(
+        RangeError,
+        'Unsupported WebSocket frame: payload length > 2^53 - 1',
+        false,
+        1009
+      );
+    }
+
+    this._payloadLength = num * Math.pow(2, 32) + buf.readUInt32BE(4);
+    return this.haveLength();
+  }
+
+  /**
+   * Payload length has been read.
+   *
+   * @return {(RangeError|undefined)} A possible error
+   * @private
+   */
+  haveLength() {
+    if (this._payloadLength && this._opcode < 0x08) {
+      this._totalPayloadLength += this._payloadLength;
+      if (this._totalPayloadLength > this._maxPayload && this._maxPayload > 0) {
+        this._loop = false;
+        return error(RangeError, 'Max payload size exceeded', false, 1009);
+      }
+    }
+
+    if (this._masked) this._state = GET_MASK;
+    else this._state = GET_DATA;
+  }
+
+  /**
+   * Reads mask bytes.
+   *
+   * @private
+   */
+  getMask() {
+    if (this._bufferedBytes < 4) {
+      this._loop = false;
+      return;
+    }
+
+    this._mask = this.consume(4);
+    this._state = GET_DATA;
+  }
+
+  /**
+   * Reads data bytes.
+   *
+   * @param {Function} cb Callback
+   * @return {(Error|RangeError|undefined)} A possible error
+   * @private
+   */
+  getData(cb) {
+    var data = EMPTY_BUFFER;
+
+    if (this._payloadLength) {
+      if (this._bufferedBytes < this._payloadLength) {
+        this._loop = false;
+        return;
+      }
+
+      data = this.consume(this._payloadLength);
+      if (this._masked) unmask(data, this._mask);
+    }
+
+    if (this._opcode > 0x07) return this.controlMessage(data);
+
+    if (this._compressed) {
+      this._state = INFLATING;
+      this.decompress(data, cb);
+      return;
+    }
+
+    if (data.length) {
+      //
+      // This message is not compressed so its lenght is the sum of the payload
+      // length of all fragments.
+      //
+      this._messageLength = this._totalPayloadLength;
+      this._fragments.push(data);
+    }
+
+    return this.dataMessage();
+  }
+
+  /**
+   * Decompresses data.
+   *
+   * @param {Buffer} data Compressed data
+   * @param {Function} cb Callback
+   * @private
+   */
+  decompress(data, cb) {
+    const perMessageDeflate = this._extensions[PerMessageDeflate.extensionName];
+
+    perMessageDeflate.decompress(data, this._fin, (err, buf) => {
+      if (err) return cb(err);
+
+      if (buf.length) {
+        this._messageLength += buf.length;
+        if (this._messageLength > this._maxPayload && this._maxPayload > 0) {
+          return cb(
+            error(RangeError, 'Max payload size exceeded', false, 1009)
+          );
+        }
+
+        this._fragments.push(buf);
+      }
+
+      const er = this.dataMessage();
+      if (er) return cb(er);
+
+      this.startLoop(cb);
+    });
+  }
+
+  /**
+   * Handles a data message.
+   *
+   * @return {(Error|undefined)} A possible error
+   * @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 = concat(fragments, messageLength);
+        } else if (this._binaryType === 'arraybuffer') {
+          data = toArrayBuffer(concat(fragments, messageLength));
+        } else {
+          data = fragments;
+        }
+
+        this.emit('message', data);
+      } else {
+        const buf = concat(fragments, messageLength);
+
+        if (!isValidUTF8(buf)) {
+          this._loop = false;
+          return error(Error, 'invalid UTF-8 sequence', true, 1007);
+        }
+
+        this.emit('message', buf.toString());
+      }
+    }
+
+    this._state = GET_INFO;
+  }
+
+  /**
+   * Handles a control message.
+   *
+   * @param {Buffer} data Data to handle
+   * @return {(Error|RangeError|undefined)} A possible error
+   * @private
+   */
+  controlMessage(data) {
+    if (this._opcode === 0x08) {
+      this._loop = false;
+
+      if (data.length === 0) {
+        this.emit('conclude', 1005, '');
+        this.end();
+      } else if (data.length === 1) {
+        return error(RangeError, 'invalid payload length 1', true, 1002);
+      } else {
+        const code = data.readUInt16BE(0);
+
+        if (!isValidStatusCode(code)) {
+          return error(RangeError, `invalid status code ${code}`, true, 1002);
+        }
+
+        const buf = data.slice(2);
+
+        if (!isValidUTF8(buf)) {
+          return error(Error, 'invalid UTF-8 sequence', true, 1007);
+        }
+
+        this.emit('conclude', code, buf.toString());
+        this.end();
+      }
+    } else if (this._opcode === 0x09) {
+      this.emit('ping', data);
+    } else {
+      this.emit('pong', data);
+    }
+
+    this._state = GET_INFO;
+  }
+}
+
+module.exports = Receiver;
+
+/**
+ * Builds an error object.
+ *
+ * @param {(Error|RangeError)} ErrorCtor The error constructor
+ * @param {String} message The error message
+ * @param {Boolean} prefix Specifies whether or not to add a default prefix to
+ *     `message`
+ * @param {Number} statusCode The status code
+ * @return {(Error|RangeError)} The error
+ * @private
+ */
+function error(ErrorCtor, message, prefix, statusCode) {
+  const err = new ErrorCtor(
+    prefix ? `Invalid WebSocket frame: ${message}` : message
+  );
+
+  Error.captureStackTrace(err, error);
+  err[kStatusCode] = statusCode;
+  return err;
+}

node_modules/ws/lib/sender.js

@@ -0,0 +1,358 @@
+'use strict';
+
+const { randomBytes } = require('crypto');
+
+const PerMessageDeflate = require('./permessage-deflate');
+const { EMPTY_BUFFER } = require('./constants');
+const { isValidStatusCode } = require('./validation');
+const { mask: applyMask, toBuffer } = require('./buffer-util');
+
+/**
+ * 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._extensions = extensions || {};
+    this._socket = socket;
+
+    this._firstFragment = true;
+    this._compress = false;
+
+    this._bufferedBytes = 0;
+    this._deflating = false;
+    this._queue = [];
+  }
+
+  /**
+   * 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 = 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;
+
+    target[1] = payloadLength;
+
+    if (payloadLength === 126) {
+      target.writeUInt16BE(data.length, 2);
+    } else if (payloadLength === 127) {
+      target.writeUInt32BE(0, 2);
+      target.writeUInt32BE(data.length, 6);
+    }
+
+    if (!options.mask) return [target, data];
+
+    const mask = randomBytes(4);
+
+    target[1] |= 0x80;
+    target[offset - 4] = mask[0];
+    target[offset - 3] = mask[1];
+    target[offset - 2] = mask[2];
+    target[offset - 1] = mask[3];
+
+    if (merge) {
+      applyMask(data, mask, target, offset, data.length);
+      return [target];
+    }
+
+    applyMask(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) {
+    var buf;
+
+    if (code === undefined) {
+      buf = EMPTY_BUFFER;
+    } else if (typeof code !== 'number' || !isValidStatusCode(code)) {
+      throw new TypeError('First argument must be a valid error code number');
+    } else if (data === undefined || data === '') {
+      buf = Buffer.allocUnsafe(2);
+      buf.writeUInt16BE(code, 0);
+    } else {
+      buf = Buffer.allocUnsafe(2 + Buffer.byteLength(data));
+      buf.writeUInt16BE(code, 0);
+      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`
+   * @param {Function} cb Callback
+   * @public
+   */
+  ping(data, mask, cb) {
+    const buf = toBuffer(data);
+
+    if (this._deflating) {
+      this.enqueue([this.doPing, buf, mask, toBuffer.readOnly, cb]);
+    } else {
+      this.doPing(buf, mask, toBuffer.readOnly, cb);
+    }
+  }
+
+  /**
+   * 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
+   * @param {Function} cb Callback
+   * @private
+   */
+  doPing(data, mask, readOnly, cb) {
+    this.sendFrame(
+      Sender.frame(data, {
+        fin: true,
+        rsv1: false,
+        opcode: 0x09,
+        mask,
+        readOnly
+      }),
+      cb
+    );
+  }
+
+  /**
+   * Sends a pong message to the other peer.
+   *
+   * @param {*} data The message to send
+   * @param {Boolean} mask Specifies whether or not to mask `data`
+   * @param {Function} cb Callback
+   * @public
+   */
+  pong(data, mask, cb) {
+    const buf = toBuffer(data);
+
+    if (this._deflating) {
+      this.enqueue([this.doPong, buf, mask, toBuffer.readOnly, cb]);
+    } else {
+      this.doPong(buf, mask, toBuffer.readOnly, cb);
+    }
+  }
+
+  /**
+   * 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
+   * @param {Function} cb Callback
+   * @private
+   */
+  doPong(data, mask, readOnly, cb) {
+    this.sendFrame(
+      Sender.frame(data, {
+        fin: true,
+        rsv1: false,
+        opcode: 0x0a,
+        mask,
+        readOnly
+      }),
+      cb
+    );
+  }
+
+  /**
+   * 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) {
+    const buf = toBuffer(data);
+    const perMessageDeflate = this._extensions[PerMessageDeflate.extensionName];
+    var opcode = options.binary ? 2 : 1;
+    var rsv1 = options.compress;
+
+    if (this._firstFragment) {
+      this._firstFragment = false;
+      if (rsv1 && perMessageDeflate) {
+        rsv1 = buf.length >= perMessageDeflate._threshold;
+      }
+      this._compress = rsv1;
+    } else {
+      rsv1 = false;
+      opcode = 0;
+    }
+
+    if (options.fin) this._firstFragment = true;
+
+    if (perMessageDeflate) {
+      const opts = {
+        fin: options.fin,
+        rsv1,
+        opcode,
+        mask: options.mask,
+        readOnly: toBuffer.readOnly
+      };
+
+      if (this._deflating) {
+        this.enqueue([this.dispatch, buf, this._compress, opts, cb]);
+      } else {
+        this.dispatch(buf, this._compress, opts, cb);
+      }
+    } else {
+      this.sendFrame(
+        Sender.frame(buf, {
+          fin: options.fin,
+          rsv1: false,
+          opcode,
+          mask: options.mask,
+          readOnly: toBuffer.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;
+    }
+
+    const perMessageDeflate = this._extensions[PerMessageDeflate.extensionName];
+
+    this._deflating = true;
+    perMessageDeflate.compress(data, options.fin, (_, buf) => {
+      this._deflating = false;
+      options.readOnly = false;
+      this.sendFrame(Sender.frame(buf, options), cb);
+      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.cork();
+      this._socket.write(list[0]);
+      this._socket.write(list[1], cb);
+      this._socket.uncork();
+    } else {
+      this._socket.write(list[0], cb);
+    }
+  }
+}
+
+module.exports = Sender;

node_modules/ws/lib/validation.js

@@ -0,0 +1,30 @@
+'use strict';
+
+try {
+  const isValidUTF8 = require('utf-8-validate');
+
+  exports.isValidUTF8 =
+    typeof isValidUTF8 === 'object'
+      ? isValidUTF8.Validation.isValidUTF8 // utf-8-validate@<3.0.0
+      : isValidUTF8;
+} catch (e) /* istanbul ignore next */ {
+  exports.isValidUTF8 = () => true;
+}
+
+/**
+ * Checks if a status code is allowed in a close frame.
+ *
+ * @param {Number} code The status code
+ * @return {Boolean} `true` if the status code is valid, else `false`
+ * @public
+ */
+exports.isValidStatusCode = (code) => {
+  return (
+    (code >= 1000 &&
+      code <= 1013 &&
+      code !== 1004 &&
+      code !== 1005 &&
+      code !== 1006) ||
+    (code >= 3000 && code <= 4999)
+  );
+};

node_modules/ws/lib/websocket-server.js

@@ -0,0 +1,401 @@
+'use strict';
+
+const EventEmitter = require('events');
+const crypto = require('crypto');
+const http = require('http');
+
+const PerMessageDeflate = require('./permessage-deflate');
+const extension = require('./extension');
+const WebSocket = require('./websocket');
+const { GUID } = require('./constants');
+
+const keyRegex = /^[+/0-9A-Za-z]{22}==$/;
+
+/**
+ * Class representing a WebSocket server.
+ *
+ * @extends EventEmitter
+ */
+class WebSocketServer extends EventEmitter {
+  /**
+   * Create a `WebSocketServer` instance.
+   *
+   * @param {Object} options Configuration options
+   * @param {Number} options.backlog The maximum length of the queue of pending
+   *     connections
+   * @param {Boolean} options.clientTracking Specifies whether or not to track
+   *     clients
+   * @param {Function} options.handleProtocols An hook to handle protocols
+   * @param {String} options.host The hostname where to bind the server
+   * @param {Number} options.maxPayload The maximum allowed message size
+   * @param {Boolean} options.noServer Enable no server mode
+   * @param {String} options.path Accept only connections matching this path
+   * @param {(Boolean|Object)} options.perMessageDeflate Enable/disable
+   *     permessage-deflate
+   * @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} callback A listener for the `listening` event
+   */
+  constructor(options, callback) {
+    super();
+
+    options = Object.assign(
+      {
+        maxPayload: 100 * 1024 * 1024,
+        perMessageDeflate: false,
+        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(
+        'One of the "port", "server", or "noServer" options must be specified'
+      );
+    }
+
+    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.listen(
+        options.port,
+        options.host,
+        options.backlog,
+        callback
+      );
+    } else if (options.server) {
+      this._server = options.server;
+    }
+
+    if (this._server) {
+      this._removeListeners = addListeners(this._server, {
+        listening: this.emit.bind(this, 'listening'),
+        error: this.emit.bind(this, 'error'),
+        upgrade: (req, socket, head) => {
+          this.handleUpgrade(req, socket, head, (ws) => {
+            this.emit('connection', ws, req);
+          });
+        }
+      });
+    }
+
+    if (options.perMessageDeflate === true) options.perMessageDeflate = {};
+    if (options.clientTracking) this.clients = new Set();
+    this.options = options;
+  }
+
+  /**
+   * Returns the bound address, the address family name, and port of the server
+   * as reported by the operating system if listening on an IP socket.
+   * If the server is listening on a pipe or UNIX domain socket, the name is
+   * returned as a string.
+   *
+   * @return {(Object|String|null)} The address of the server
+   * @public
+   */
+  address() {
+    if (this.options.noServer) {
+      throw new Error('The server is operating in "noServer" mode');
+    }
+
+    if (!this._server) return null;
+    return this._server.address();
+  }
+
+  /**
+   * Close the server.
+   *
+   * @param {Function} cb Callback
+   * @public
+   */
+  close(cb) {
+    if (cb) this.once('close', cb);
+
+    //
+    // Terminate all associated clients.
+    //
+    if (this.clients) {
+      for (const client of this.clients) client.terminate();
+    }
+
+    const server = this._server;
+
+    if (server) {
+      this._removeListeners();
+      this._removeListeners = this._server = null;
+
+      //
+      // Close the http server if it was internally created.
+      //
+      if (this.options.port != null) {
+        server.close(() => this.emit('close'));
+        return;
+      }
+    }
+
+    process.nextTick(emitClose, this);
+  }
+
+  /**
+   * 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) {
+      const index = req.url.indexOf('?');
+      const pathname = index !== -1 ? req.url.slice(0, index) : req.url;
+
+      if (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', socketOnError);
+
+    const key =
+      req.headers['sec-websocket-key'] !== undefined
+        ? req.headers['sec-websocket-key'].trim()
+        : false;
+    const version = +req.headers['sec-websocket-version'];
+    const extensions = {};
+
+    if (
+      req.method !== 'GET' ||
+      req.headers.upgrade.toLowerCase() !== 'websocket' ||
+      !key ||
+      !keyRegex.test(key) ||
+      (version !== 8 && version !== 13) ||
+      !this.shouldHandle(req)
+    ) {
+      return abortHandshake(socket, 400);
+    }
+
+    if (this.options.perMessageDeflate) {
+      const perMessageDeflate = new PerMessageDeflate(
+        this.options.perMessageDeflate,
+        true,
+        this.options.maxPayload
+      );
+
+      try {
+        const offers = extension.parse(req.headers['sec-websocket-extensions']);
+
+        if (offers[PerMessageDeflate.extensionName]) {
+          perMessageDeflate.accept(offers[PerMessageDeflate.extensionName]);
+          extensions[PerMessageDeflate.extensionName] = perMessageDeflate;
+        }
+      } catch (err) {
+        return abortHandshake(socket, 400);
+      }
+    }
+
+    //
+    // 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, headers) => {
+          if (!verified) {
+            return abortHandshake(socket, code || 401, message, headers);
+          }
+
+          this.completeUpgrade(key, extensions, req, socket, head, cb);
+        });
+        return;
+      }
+
+      if (!this.options.verifyClient(info)) return abortHandshake(socket, 401);
+    }
+
+    this.completeUpgrade(key, extensions, req, socket, head, cb);
+  }
+
+  /**
+   * Upgrade the connection to WebSocket.
+   *
+   * @param {String} key The value of the `Sec-WebSocket-Key` header
+   * @param {Object} extensions The accepted extensions
+   * @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(key, extensions, 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 digest = crypto
+      .createHash('sha1')
+      .update(key + GUID)
+      .digest('base64');
+
+    const headers = [
+      'HTTP/1.1 101 Switching Protocols',
+      'Upgrade: websocket',
+      'Connection: Upgrade',
+      `Sec-WebSocket-Accept: ${digest}`
+    ];
+
+    const ws = new WebSocket(null);
+    var protocol = req.headers['sec-websocket-protocol'];
+
+    if (protocol) {
+      protocol = protocol.trim().split(/ *, */);
+
+      //
+      // Optionally call external protocol selection handler.
+      //
+      if (this.options.handleProtocols) {
+        protocol = this.options.handleProtocols(protocol, req);
+      } else {
+        protocol = protocol[0];
+      }
+
+      if (protocol) {
+        headers.push(`Sec-WebSocket-Protocol: ${protocol}`);
+        ws.protocol = protocol;
+      }
+    }
+
+    if (extensions[PerMessageDeflate.extensionName]) {
+      const params = extensions[PerMessageDeflate.extensionName].params;
+      const value = extension.format({
+        [PerMessageDeflate.extensionName]: [params]
+      });
+      headers.push(`Sec-WebSocket-Extensions: ${value}`);
+      ws._extensions = extensions;
+    }
+
+    //
+    // Allow external modification/inspection of handshake headers.
+    //
+    this.emit('headers', headers, req);
+
+    socket.write(headers.concat('\r\n').join('\r\n'));
+    socket.removeListener('error', socketOnError);
+
+    ws.setSocket(socket, head, this.options.maxPayload);
+
+    if (this.clients) {
+      this.clients.add(ws);
+      ws.on('close', () => this.clients.delete(ws));
+    }
+
+    cb(ws);
+  }
+}
+
+module.exports = WebSocketServer;
+
+/**
+ * Add event listeners on an `EventEmitter` using a map of <event, listener>
+ * pairs.
+ *
+ * @param {EventEmitter} server The event emitter
+ * @param {Object.<String, Function>} map The listeners to add
+ * @return {Function} A function that will remove the added listeners when called
+ * @private
+ */
+function addListeners(server, map) {
+  for (const event of Object.keys(map)) server.on(event, map[event]);
+
+  return function removeListeners() {
+    for (const event of Object.keys(map)) {
+      server.removeListener(event, map[event]);
+    }
+  };
+}
+
+/**
+ * Emit a `'close'` event on an `EventEmitter`.
+ *
+ * @param {EventEmitter} server The event emitter
+ * @private
+ */
+function emitClose(server) {
+  server.emit('close');
+}
+
+/**
+ * Handle premature socket errors.
+ *
+ * @private
+ */
+function socketOnError() {
+  this.destroy();
+}
+
+/**
+ * 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
+ * @param {Object} [headers] Additional HTTP response headers
+ * @private
+ */
+function abortHandshake(socket, code, message, headers) {
+  if (socket.writable) {
+    message = message || http.STATUS_CODES[code];
+    headers = Object.assign(
+      {
+        Connection: 'close',
+        'Content-type': 'text/html',
+        'Content-Length': Buffer.byteLength(message)
+      },
+      headers
+    );
+
+    socket.write(
+      `HTTP/1.1 ${code} ${http.STATUS_CODES[code]}\r\n` +
+        Object.keys(headers)
+          .map((h) => `${h}: ${headers[h]}`)
+          .join('\r\n') +
+        '\r\n\r\n' +
+        message
+    );
+  }
+
+  socket.removeListener('error', socketOnError);
+  socket.destroy();
+}

node_modules/ws/lib/websocket.js

@@ -0,0 +1,895 @@
+'use strict';
+
+const EventEmitter = require('events');
+const crypto = require('crypto');
+const https = require('https');
+const http = require('http');
+const net = require('net');
+const tls = require('tls');
+const url = require('url');
+
+const PerMessageDeflate = require('./permessage-deflate');
+const EventTarget = require('./event-target');
+const extension = require('./extension');
+const Receiver = require('./receiver');
+const Sender = require('./sender');
+const {
+  BINARY_TYPES,
+  EMPTY_BUFFER,
+  GUID,
+  kStatusCode,
+  kWebSocket,
+  NOOP
+} = require('./constants');
+
+const readyStates = ['CONNECTING', 'OPEN', 'CLOSING', 'CLOSED'];
+const protocolVersions = [8, 13];
+const closeTimeout = 30 * 1000;
+
+/**
+ * Class representing a WebSocket.
+ *
+ * @extends EventEmitter
+ */
+class WebSocket extends EventEmitter {
+  /**
+   * Create a new `WebSocket`.
+   *
+   * @param {(String|url.Url|url.URL)} address The URL to which to connect
+   * @param {(String|String[])} protocols The subprotocols
+   * @param {Object} options Connection options
+   */
+  constructor(address, protocols, options) {
+    super();
+
+    this.readyState = WebSocket.CONNECTING;
+    this.protocol = '';
+
+    this._binaryType = BINARY_TYPES[0];
+    this._closeFrameReceived = false;
+    this._closeFrameSent = false;
+    this._closeMessage = '';
+    this._closeTimer = null;
+    this._closeCode = 1006;
+    this._extensions = {};
+    this._receiver = null;
+    this._sender = null;
+    this._socket = null;
+
+    if (address !== null) {
+      this._isServer = false;
+      this._redirects = 0;
+
+      if (Array.isArray(protocols)) {
+        protocols = protocols.join(', ');
+      } else if (typeof protocols === 'object' && protocols !== null) {
+        options = protocols;
+        protocols = undefined;
+      }
+
+      initAsClient(this, address, protocols, options);
+    } else {
+      this._isServer = true;
+    }
+  }
+
+  get CONNECTING() {
+    return WebSocket.CONNECTING;
+  }
+  get CLOSING() {
+    return WebSocket.CLOSING;
+  }
+  get CLOSED() {
+    return WebSocket.CLOSED;
+  }
+  get OPEN() {
+    return WebSocket.OPEN;
+  }
+
+  /**
+   * 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 (!BINARY_TYPES.includes(type)) return;
+
+    this._binaryType = type;
+
+    //
+    // Allow to change `binaryType` on the fly.
+    //
+    if (this._receiver) this._receiver._binaryType = type;
+  }
+
+  /**
+   * @type {Number}
+   */
+  get bufferedAmount() {
+    if (!this._socket) return 0;
+
+    //
+    // `socket.bufferSize` is `undefined` if the socket is closed.
+    //
+    return (this._socket.bufferSize || 0) + this._sender._bufferedBytes;
+  }
+
+  /**
+   * @type {String}
+   */
+  get extensions() {
+    return Object.keys(this._extensions).join();
+  }
+
+  /**
+   * 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
+   * @param {Number} maxPayload The maximum allowed message size
+   * @private
+   */
+  setSocket(socket, head, maxPayload) {
+    const receiver = new Receiver(
+      this._binaryType,
+      this._extensions,
+      maxPayload
+    );
+
+    this._sender = new Sender(socket, this._extensions);
+    this._receiver = receiver;
+    this._socket = socket;
+
+    receiver[kWebSocket] = this;
+    socket[kWebSocket] = this;
+
+    receiver.on('conclude', receiverOnConclude);
+    receiver.on('drain', receiverOnDrain);
+    receiver.on('error', receiverOnError);
+    receiver.on('message', receiverOnMessage);
+    receiver.on('ping', receiverOnPing);
+    receiver.on('pong', receiverOnPong);
+
+    socket.setTimeout(0);
+    socket.setNoDelay();
+
+    if (head.length > 0) socket.unshift(head);
+
+    socket.on('close', socketOnClose);
+    socket.on('data', socketOnData);
+    socket.on('end', socketOnEnd);
+    socket.on('error', socketOnError);
+
+    this.readyState = WebSocket.OPEN;
+    this.emit('open');
+  }
+
+  /**
+   * Emit the `'close'` event.
+   *
+   * @private
+   */
+  emitClose() {
+    this.readyState = WebSocket.CLOSED;
+
+    if (!this._socket) {
+      this.emit('close', this._closeCode, this._closeMessage);
+      return;
+    }
+
+    if (this._extensions[PerMessageDeflate.extensionName]) {
+      this._extensions[PerMessageDeflate.extensionName].cleanup();
+    }
+
+    this._receiver.removeAllListeners();
+    this.emit('close', this._closeCode, this._closeMessage);
+  }
+
+  /**
+   * Start a closing handshake.
+   *
+   *          +----------+   +-----------+   +----------+
+   *     - - -|ws.close()|-->|close frame|-->|ws.close()|- - -
+   *    |     +----------+   +-----------+   +----------+     |
+   *          +----------+   +-----------+         |
+   * CLOSING  |ws.close()|<--|close frame|<--+-----+       CLOSING
+   *          +----------+   +-----------+   |
+   *    |           |                        |   +---+        |
+   *                +------------------------+-->|fin| - - - -
+   *    |         +---+                      |   +---+
+   *     - - - - -|fin|<---------------------+
+   *              +---+
+   *
+   * @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) {
+      const msg = 'WebSocket was closed before the connection was established';
+      return abortHandshake(this, this._req, msg);
+    }
+
+    if (this.readyState === WebSocket.CLOSING) {
+      if (this._closeFrameSent && this._closeFrameReceived) this._socket.end();
+      return;
+    }
+
+    this.readyState = WebSocket.CLOSING;
+    this._sender.close(code, data, !this._isServer, (err) => {
+      //
+      // This error is handled by the `'error'` listener on the socket. We only
+      // want to know if the close frame has been sent here.
+      //
+      if (err) return;
+
+      this._closeFrameSent = true;
+      if (this._closeFrameReceived) this._socket.end();
+    });
+
+    //
+    // Specify a timeout for the closing handshake to complete.
+    //
+    this._closeTimer = setTimeout(
+      this._socket.destroy.bind(this._socket),
+      closeTimeout
+    );
+  }
+
+  /**
+   * Send a ping.
+   *
+   * @param {*} data The data to send
+   * @param {Boolean} mask Indicates whether or not to mask `data`
+   * @param {Function} cb Callback which is executed when the ping is sent
+   * @public
+   */
+  ping(data, mask, cb) {
+    if (typeof data === 'function') {
+      cb = data;
+      data = mask = undefined;
+    } else if (typeof mask === 'function') {
+      cb = mask;
+      mask = undefined;
+    }
+
+    if (this.readyState !== WebSocket.OPEN) {
+      const err = new Error(
+        `WebSocket is not open: readyState ${this.readyState} ` +
+          `(${readyStates[this.readyState]})`
+      );
+
+      if (cb) return cb(err);
+      throw err;
+    }
+
+    if (typeof data === 'number') data = data.toString();
+    if (mask === undefined) mask = !this._isServer;
+    this._sender.ping(data || EMPTY_BUFFER, mask, cb);
+  }
+
+  /**
+   * Send a pong.
+   *
+   * @param {*} data The data to send
+   * @param {Boolean} mask Indicates whether or not to mask `data`
+   * @param {Function} cb Callback which is executed when the pong is sent
+   * @public
+   */
+  pong(data, mask, cb) {
+    if (typeof data === 'function') {
+      cb = data;
+      data = mask = undefined;
+    } else if (typeof mask === 'function') {
+      cb = mask;
+      mask = undefined;
+    }
+
+    if (this.readyState !== WebSocket.OPEN) {
+      const err = new Error(
+        `WebSocket is not open: readyState ${this.readyState} ` +
+          `(${readyStates[this.readyState]})`
+      );
+
+      if (cb) return cb(err);
+      throw err;
+    }
+
+    if (typeof data === 'number') data = data.toString();
+    if (mask === undefined) mask = !this._isServer;
+    this._sender.pong(data || EMPTY_BUFFER, mask, cb);
+  }
+
+  /**
+   * 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) {
+      const err = new Error(
+        `WebSocket is not open: readyState ${this.readyState} ` +
+          `(${readyStates[this.readyState]})`
+      );
+
+      if (cb) return cb(err);
+      throw err;
+    }
+
+    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 || EMPTY_BUFFER, opts, cb);
+  }
+
+  /**
+   * Forcibly close the connection.
+   *
+   * @public
+   */
+  terminate() {
+    if (this.readyState === WebSocket.CLOSED) return;
+    if (this.readyState === WebSocket.CONNECTING) {
+      const msg = 'WebSocket was closed before the connection was established';
+      return abortHandshake(this, this._req, msg);
+    }
+
+    if (this._socket) {
+      this.readyState = WebSocket.CLOSING;
+      this._socket.destroy();
+    }
+  }
+}
+
+readyStates.forEach((readyState, i) => {
+  WebSocket[readyState] = i;
+});
+
+//
+// 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;
+      }
+
+      return undefined;
+    },
+    /**
+     * 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 client.
+ *
+ * @param {WebSocket} websocket The client to initialize
+ * @param {(String|url.Url|url.URL)} address The URL to which to connect
+ * @param {String} protocols The subprotocols
+ * @param {Object} options Connection options
+ * @param {(Boolean|Object)} options.perMessageDeflate Enable/disable
+ *     permessage-deflate
+ * @param {Number} options.handshakeTimeout Timeout in milliseconds for the
+ *     handshake request
+ * @param {Number} options.protocolVersion Value of the `Sec-WebSocket-Version`
+ *     header
+ * @param {String} options.origin Value of the `Origin` or
+ *     `Sec-WebSocket-Origin` header
+ * @param {Number} options.maxPayload The maximum allowed message size
+ * @param {Boolean} options.followRedirects Whether or not to follow redirects
+ * @param {Number} options.maxRedirects The maximum number of redirects allowed
+ * @private
+ */
+function initAsClient(websocket, address, protocols, options) {
+  const opts = Object.assign(
+    {
+      protocolVersion: protocolVersions[1],
+      maxPayload: 100 * 1024 * 1024,
+      perMessageDeflate: true,
+      followRedirects: false,
+      maxRedirects: 10
+    },
+    options,
+    {
+      createConnection: undefined,
+      socketPath: undefined,
+      hostname: undefined,
+      protocol: undefined,
+      timeout: undefined,
+      method: undefined,
+      auth: undefined,
+      host: undefined,
+      path: undefined,
+      port: undefined
+    }
+  );
+
+  if (!protocolVersions.includes(opts.protocolVersion)) {
+    throw new RangeError(
+      `Unsupported protocol version: ${opts.protocolVersion} ` +
+        `(supported versions: ${protocolVersions.join(', ')})`
+    );
+  }
+
+  var parsedUrl;
+
+  if (typeof address === 'object' && address.href !== undefined) {
+    parsedUrl = address;
+    websocket.url = address.href;
+  } else {
+    //
+    // The WHATWG URL constructor is not available on Node.js < 6.13.0
+    //
+    parsedUrl = url.URL ? new url.URL(address) : url.parse(address);
+    websocket.url = address;
+  }
+
+  const isUnixSocket = parsedUrl.protocol === 'ws+unix:';
+
+  if (!parsedUrl.host && (!isUnixSocket || !parsedUrl.pathname)) {
+    throw new Error(`Invalid URL: ${websocket.url}`);
+  }
+
+  const isSecure =
+    parsedUrl.protocol === 'wss:' || parsedUrl.protocol === 'https:';
+  const defaultPort = isSecure ? 443 : 80;
+  const key = crypto.randomBytes(16).toString('base64');
+  const get = isSecure ? https.get : http.get;
+  const path = parsedUrl.search
+    ? `${parsedUrl.pathname || '/'}${parsedUrl.search}`
+    : parsedUrl.pathname || '/';
+  var perMessageDeflate;
+
+  opts.createConnection = isSecure ? tlsConnect : netConnect;
+  opts.defaultPort = opts.defaultPort || defaultPort;
+  opts.port = parsedUrl.port || defaultPort;
+  opts.host = parsedUrl.hostname.startsWith('[')
+    ? parsedUrl.hostname.slice(1, -1)
+    : parsedUrl.hostname;
+  opts.headers = Object.assign(
+    {
+      'Sec-WebSocket-Version': opts.protocolVersion,
+      'Sec-WebSocket-Key': key,
+      Connection: 'Upgrade',
+      Upgrade: 'websocket'
+    },
+    opts.headers
+  );
+  opts.path = path;
+  opts.timeout = opts.handshakeTimeout;
+
+  if (opts.perMessageDeflate) {
+    perMessageDeflate = new PerMessageDeflate(
+      opts.perMessageDeflate !== true ? opts.perMessageDeflate : {},
+      false,
+      opts.maxPayload
+    );
+    opts.headers['Sec-WebSocket-Extensions'] = extension.format({
+      [PerMessageDeflate.extensionName]: perMessageDeflate.offer()
+    });
+  }
+  if (protocols) {
+    opts.headers['Sec-WebSocket-Protocol'] = protocols;
+  }
+  if (opts.origin) {
+    if (opts.protocolVersion < 13) {
+      opts.headers['Sec-WebSocket-Origin'] = opts.origin;
+    } else {
+      opts.headers.Origin = opts.origin;
+    }
+  }
+  if (parsedUrl.auth) {
+    opts.auth = parsedUrl.auth;
+  } else if (parsedUrl.username || parsedUrl.password) {
+    opts.auth = `${parsedUrl.username}:${parsedUrl.password}`;
+  }
+
+  if (isUnixSocket) {
+    const parts = path.split(':');
+
+    opts.socketPath = parts[0];
+    opts.path = parts[1];
+  }
+
+  var req = (websocket._req = get(opts));
+
+  if (opts.timeout) {
+    req.on('timeout', () => {
+      abortHandshake(websocket, req, 'Opening handshake has timed out');
+    });
+  }
+
+  req.on('error', (err) => {
+    if (websocket._req.aborted) return;
+
+    req = websocket._req = null;
+    websocket.readyState = WebSocket.CLOSING;
+    websocket.emit('error', err);
+    websocket.emitClose();
+  });
+
+  req.on('response', (res) => {
+    const location = res.headers.location;
+    const statusCode = res.statusCode;
+
+    if (
+      location &&
+      opts.followRedirects &&
+      statusCode >= 300 &&
+      statusCode < 400
+    ) {
+      if (++websocket._redirects > opts.maxRedirects) {
+        abortHandshake(websocket, req, 'Maximum redirects exceeded');
+        return;
+      }
+
+      req.abort();
+
+      const addr = url.URL
+        ? new url.URL(location, address)
+        : url.resolve(address, location);
+
+      initAsClient(websocket, addr, protocols, options);
+    } else if (!websocket.emit('unexpected-response', req, res)) {
+      abortHandshake(
+        websocket,
+        req,
+        `Unexpected server response: ${res.statusCode}`
+      );
+    }
+  });
+
+  req.on('upgrade', (res, socket, head) => {
+    websocket.emit('upgrade', res);
+
+    //
+    // The user may have closed the connection from a listener of the `upgrade`
+    // event.
+    //
+    if (websocket.readyState !== WebSocket.CONNECTING) return;
+
+    req = websocket._req = null;
+
+    const digest = crypto
+      .createHash('sha1')
+      .update(key + GUID)
+      .digest('base64');
+
+    if (res.headers['sec-websocket-accept'] !== digest) {
+      abortHandshake(websocket, socket, 'Invalid Sec-WebSocket-Accept header');
+      return;
+    }
+
+    const serverProt = res.headers['sec-websocket-protocol'];
+    const protList = (protocols || '').split(/, */);
+    var protError;
+
+    if (!protocols && serverProt) {
+      protError = 'Server sent a subprotocol but none was requested';
+    } else if (protocols && !serverProt) {
+      protError = 'Server sent no subprotocol';
+    } else if (serverProt && !protList.includes(serverProt)) {
+      protError = 'Server sent an invalid subprotocol';
+    }
+
+    if (protError) {
+      abortHandshake(websocket, socket, protError);
+      return;
+    }
+
+    if (serverProt) websocket.protocol = serverProt;
+
+    if (perMessageDeflate) {
+      try {
+        const extensions = extension.parse(
+          res.headers['sec-websocket-extensions']
+        );
+
+        if (extensions[PerMessageDeflate.extensionName]) {
+          perMessageDeflate.accept(extensions[PerMessageDeflate.extensionName]);
+          websocket._extensions[
+            PerMessageDeflate.extensionName
+          ] = perMessageDeflate;
+        }
+      } catch (err) {
+        abortHandshake(
+          websocket,
+          socket,
+          'Invalid Sec-WebSocket-Extensions header'
+        );
+        return;
+      }
+    }
+
+    websocket.setSocket(socket, head, opts.maxPayload);
+  });
+}
+
+/**
+ * Create a `net.Socket` and initiate a connection.
+ *
+ * @param {Object} options Connection options
+ * @return {net.Socket} The newly created socket used to start the connection
+ * @private
+ */
+function netConnect(options) {
+  //
+  // Override `options.path` only if `options` is a copy of the original options
+  // object. This is always true on Node.js >= 8 but not on Node.js 6 where
+  // `options.socketPath` might be `undefined` even if the `socketPath` option
+  // was originally set.
+  //
+  if (options.protocolVersion) options.path = options.socketPath;
+  return net.connect(options);
+}
+
+/**
+ * Create a `tls.TLSSocket` and initiate a connection.
+ *
+ * @param {Object} options Connection options
+ * @return {tls.TLSSocket} The newly created socket used to start the connection
+ * @private
+ */
+function tlsConnect(options) {
+  options.path = undefined;
+  options.servername = options.servername || options.host;
+  return tls.connect(options);
+}
+
+/**
+ * Abort the handshake and emit an error.
+ *
+ * @param {WebSocket} websocket The WebSocket instance
+ * @param {(http.ClientRequest|net.Socket)} stream The request to abort or the
+ *     socket to destroy
+ * @param {String} message The error message
+ * @private
+ */
+function abortHandshake(websocket, stream, message) {
+  websocket.readyState = WebSocket.CLOSING;
+
+  const err = new Error(message);
+  Error.captureStackTrace(err, abortHandshake);
+
+  if (stream.setHeader) {
+    stream.abort();
+    stream.once('abort', websocket.emitClose.bind(websocket));
+    websocket.emit('error', err);
+  } else {
+    stream.destroy(err);
+    stream.once('error', websocket.emit.bind(websocket, 'error'));
+    stream.once('close', websocket.emitClose.bind(websocket));
+  }
+}
+
+/**
+ * The listener of the `Receiver` `'conclude'` event.
+ *
+ * @param {Number} code The status code
+ * @param {String} reason The reason for closing
+ * @private
+ */
+function receiverOnConclude(code, reason) {
+  const websocket = this[kWebSocket];
+
+  websocket._socket.removeListener('data', socketOnData);
+  websocket._socket.resume();
+
+  websocket._closeFrameReceived = true;
+  websocket._closeMessage = reason;
+  websocket._closeCode = code;
+
+  if (code === 1005) websocket.close();
+  else websocket.close(code, reason);
+}
+
+/**
+ * The listener of the `Receiver` `'drain'` event.
+ *
+ * @private
+ */
+function receiverOnDrain() {
+  this[kWebSocket]._socket.resume();
+}
+
+/**
+ * The listener of the `Receiver` `'error'` event.
+ *
+ * @param {(RangeError|Error)} err The emitted error
+ * @private
+ */
+function receiverOnError(err) {
+  const websocket = this[kWebSocket];
+
+  websocket._socket.removeListener('data', socketOnData);
+
+  websocket.readyState = WebSocket.CLOSING;
+  websocket._closeCode = err[kStatusCode];
+  websocket.emit('error', err);
+  websocket._socket.destroy();
+}
+
+/**
+ * The listener of the `Receiver` `'finish'` event.
+ *
+ * @private
+ */
+function receiverOnFinish() {
+  this[kWebSocket].emitClose();
+}
+
+/**
+ * The listener of the `Receiver` `'message'` event.
+ *
+ * @param {(String|Buffer|ArrayBuffer|Buffer[])} data The message
+ * @private
+ */
+function receiverOnMessage(data) {
+  this[kWebSocket].emit('message', data);
+}
+
+/**
+ * The listener of the `Receiver` `'ping'` event.
+ *
+ * @param {Buffer} data The data included in the ping frame
+ * @private
+ */
+function receiverOnPing(data) {
+  const websocket = this[kWebSocket];
+
+  websocket.pong(data, !websocket._isServer, NOOP);
+  websocket.emit('ping', data);
+}
+
+/**
+ * The listener of the `Receiver` `'pong'` event.
+ *
+ * @param {Buffer} data The data included in the pong frame
+ * @private
+ */
+function receiverOnPong(data) {
+  this[kWebSocket].emit('pong', data);
+}
+
+/**
+ * The listener of the `net.Socket` `'close'` event.
+ *
+ * @private
+ */
+function socketOnClose() {
+  const websocket = this[kWebSocket];
+
+  this.removeListener('close', socketOnClose);
+  this.removeListener('end', socketOnEnd);
+
+  websocket.readyState = WebSocket.CLOSING;
+
+  //
+  // The close frame might not have been received or the `'end'` event emitted,
+  // for example, if the socket was destroyed due to an error. Ensure that the
+  // `receiver` stream is closed after writing any remaining buffered data to
+  // it. If the readable side of the socket is in flowing mode then there is no
+  // buffered data as everything has been already written and `readable.read()`
+  // will return `null`. If instead, the socket is paused, any possible buffered
+  // data will be read as a single chunk and emitted synchronously in a single
+  // `'data'` event.
+  //
+  websocket._socket.read();
+  websocket._receiver.end();
+
+  this.removeListener('data', socketOnData);
+  this[kWebSocket] = undefined;
+
+  clearTimeout(websocket._closeTimer);
+
+  if (
+    websocket._receiver._writableState.finished ||
+    websocket._receiver._writableState.errorEmitted
+  ) {
+    websocket.emitClose();
+  } else {
+    websocket._receiver.on('error', receiverOnFinish);
+    websocket._receiver.on('finish', receiverOnFinish);
+  }
+}
+
+/**
+ * The listener of the `net.Socket` `'data'` event.
+ *
+ * @param {Buffer} chunk A chunk of data
+ * @private
+ */
+function socketOnData(chunk) {
+  if (!this[kWebSocket]._receiver.write(chunk)) {
+    this.pause();
+  }
+}
+
+/**
+ * The listener of the `net.Socket` `'end'` event.
+ *
+ * @private
+ */
+function socketOnEnd() {
+  const websocket = this[kWebSocket];
+
+  websocket.readyState = WebSocket.CLOSING;
+  websocket._receiver.end();
+  this.end();
+}
+
+/**
+ * The listener of the `net.Socket` `'error'` event.
+ *
+ * @private
+ */
+function socketOnError() {
+  const websocket = this[kWebSocket];
+
+  this.removeListener('error', socketOnError);
+  this.on('error', NOOP);
+
+  websocket.readyState = WebSocket.CLOSING;
+  this.destroy();
+}