Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

57 files changed, 15703 insertions, 0 deletions

diff --git a/testing/xpcshell/node-ws/.eslintrc.yaml b/testing/xpcshell/node-ws/.eslintrc.yaml
new file mode 100644
index 0000000000..f3d983b9c8
--- /dev/null
+++ b/testing/xpcshell/node-ws/.eslintrc.yaml
@@ -0,0 +1,19 @@
+env:
+  browser: true
+  es6: true
+  mocha: true
+  node: true
+extends:
+  - eslint:recommended
+  - plugin:prettier/recommended
+parserOptions:
+  ecmaVersion: latest
+  sourceType: module
+rules:
+  no-console: off
+  no-var: error
+  prefer-const: error
+  quotes:
+    - error
+    - single
+    - avoidEscape: true
diff --git a/testing/xpcshell/node-ws/.gitignore b/testing/xpcshell/node-ws/.gitignore
new file mode 100644
index 0000000000..e37ab1e942
--- /dev/null
+++ b/testing/xpcshell/node-ws/.gitignore
@@ -0,0 +1,4 @@
+node_modules/
+.nyc_output/
+coverage/
+.vscode/
diff --git a/testing/xpcshell/node-ws/.npmrc b/testing/xpcshell/node-ws/.npmrc
new file mode 100644
index 0000000000..43c97e719a
--- /dev/null
+++ b/testing/xpcshell/node-ws/.npmrc
@@ -0,0 +1 @@
+package-lock=false
diff --git a/testing/xpcshell/node-ws/.prettierrc.yaml b/testing/xpcshell/node-ws/.prettierrc.yaml
new file mode 100644
index 0000000000..fe2f506e34
--- /dev/null
+++ b/testing/xpcshell/node-ws/.prettierrc.yaml
@@ -0,0 +1,5 @@
+arrowParens: always
+endOfLine: lf
+proseWrap: always
+singleQuote: true
+trailingComma: none
diff --git a/testing/xpcshell/node-ws/LICENSE b/testing/xpcshell/node-ws/LICENSE
new file mode 100644
index 0000000000..65ff176bf6
--- /dev/null
+++ b/testing/xpcshell/node-ws/LICENSE
@@ -0,0 +1,19 @@
+Copyright (c) 2011 Einar Otto Stangvik <einaros@gmail.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/testing/xpcshell/node-ws/README.md b/testing/xpcshell/node-ws/README.md
new file mode 100644
index 0000000000..4ae71f6d06
--- /dev/null
+++ b/testing/xpcshell/node-ws/README.md
@@ -0,0 +1,495 @@
+# ws: a Node.js WebSocket library
+
+[![Version npm](https://img.shields.io/npm/v/ws.svg?logo=npm)](https://www.npmjs.com/package/ws)
+[![CI](https://img.shields.io/github/workflow/status/websockets/ws/CI/master?label=CI&logo=github)](https://github.com/websockets/ws/actions?query=workflow%3ACI+branch%3Amaster)
+[![Coverage Status](https://img.shields.io/coveralls/websockets/ws/master.svg?logo=coveralls)](https://coveralls.io/github/websockets/ws)
+
+ws is a simple to use, blazing fast, and thoroughly tested WebSocket client and
+server implementation.
+
+Passes the quite extensive Autobahn test suite: [server][server-report],
+[client][client-report].
+
+**Note**: This module does not work in the browser. The client in the docs is a
+reference to a back end with the role of a client in the WebSocket
+communication. Browser clients must use the native
+[`WebSocket`](https://developer.mozilla.org/en-US/docs/Web/API/WebSocket)
+object. To make the same code work seamlessly on Node.js and the browser, you
+can use one of the many wrappers available on npm, like
+[isomorphic-ws](https://github.com/heineiuo/isomorphic-ws).
+
+## Table of Contents
+
+- [Protocol support](#protocol-support)
+- [Installing](#installing)
+  - [Opt-in for performance](#opt-in-for-performance)
+- [API docs](#api-docs)
+- [WebSocket compression](#websocket-compression)
+- [Usage examples](#usage-examples)
+  - [Sending and receiving text data](#sending-and-receiving-text-data)
+  - [Sending binary data](#sending-binary-data)
+  - [Simple server](#simple-server)
+  - [External HTTP/S server](#external-https-server)
+  - [Multiple servers sharing a single HTTP/S server](#multiple-servers-sharing-a-single-https-server)
+  - [Client authentication](#client-authentication)
+  - [Server broadcast](#server-broadcast)
+  - [Round-trip time](#round-trip-time)
+  - [Use the Node.js streams API](#use-the-nodejs-streams-api)
+  - [Other examples](#other-examples)
+- [FAQ](#faq)
+  - [How to get the IP address of the client?](#how-to-get-the-ip-address-of-the-client)
+  - [How to detect and close broken connections?](#how-to-detect-and-close-broken-connections)
+  - [How to connect via a proxy?](#how-to-connect-via-a-proxy)
+- [Changelog](#changelog)
+- [License](#license)
+
+## Protocol support
+
+- **HyBi drafts 07-12** (Use the option `protocolVersion: 8`)
+- **HyBi drafts 13-17** (Current default, alternatively option
+  `protocolVersion: 13`)
+
+## Installing
+
+```
+npm install ws
+```
+
+### Opt-in for performance
+
+There are 2 optional modules that can be installed along side with the ws
+module. These modules are binary addons which improve certain operations.
+Prebuilt binaries are available for the most popular platforms so you don't
+necessarily need to have a C++ compiler installed on your machine.
+
+- `npm install --save-optional bufferutil`: Allows to efficiently perform
+  operations such as masking and unmasking the data payload of the WebSocket
+  frames.
+- `npm install --save-optional utf-8-validate`: Allows to efficiently check if a
+  message contains valid UTF-8.
+
+To not even try to require and use these modules, use the
+[`WS_NO_BUFFER_UTIL`](./doc/ws.md#ws_no_buffer_util) and
+[`WS_NO_UTF_8_VALIDATE`](./doc/ws.md#ws_no_utf_8_validate) environment
+variables. These might be useful to enhance security in systems where a user can
+put a package in the package search path of an application of another user, due
+to how the Node.js resolver algorithm works.
+
+## API docs
+
+See [`/doc/ws.md`](./doc/ws.md) for Node.js-like documentation of ws classes and
+utility functions.
+
+## WebSocket compression
+
+ws supports the [permessage-deflate extension][permessage-deflate] which enables
+the client and server to negotiate a compression algorithm and its parameters,
+and then selectively apply it to the data payloads of each WebSocket message.
+
+The extension is disabled by default on the server and enabled by default on the
+client. It adds a significant overhead in terms of performance and memory
+consumption so we suggest to enable it only if it is really needed.
+
+Note that Node.js has a variety of issues with high-performance compression,
+where increased concurrency, especially on Linux, can lead to [catastrophic
+memory fragmentation][node-zlib-bug] and slow performance. If you intend to use
+permessage-deflate in production, it is worthwhile to set up a test
+representative of your workload and ensure Node.js/zlib will handle it with
+acceptable performance and memory usage.
+
+Tuning of permessage-deflate can be done via the options defined below. You can
+also use `zlibDeflateOptions` and `zlibInflateOptions`, which is passed directly
+into the creation of [raw deflate/inflate streams][node-zlib-deflaterawdocs].
+
+See [the docs][ws-server-options] for more options.
+
+```js
+import WebSocket, { WebSocketServer } from 'ws';
+
+const wss = new WebSocketServer({
+  port: 8080,
+  perMessageDeflate: {
+    zlibDeflateOptions: {
+      // See zlib defaults.
+      chunkSize: 1024,
+      memLevel: 7,
+      level: 3
+    },
+    zlibInflateOptions: {
+      chunkSize: 10 * 1024
+    },
+    // Other options settable:
+    clientNoContextTakeover: true, // Defaults to negotiated value.
+    serverNoContextTakeover: true, // Defaults to negotiated value.
+    serverMaxWindowBits: 10, // Defaults to negotiated value.
+    // Below options specified as default values.
+    concurrencyLimit: 10, // Limits zlib concurrency for perf.
+    threshold: 1024 // Size (in bytes) below which messages
+    // should not be compressed if context takeover is disabled.
+  }
+});
+```
+
+The client will only use the extension if it is supported and enabled on the
+server. To always disable the extension on the client set the
+`perMessageDeflate` option to `false`.
+
+```js
+import WebSocket from 'ws';
+
+const ws = new WebSocket('ws://www.host.com/path', {
+  perMessageDeflate: false
+});
+```
+
+## Usage examples
+
+### Sending and receiving text data
+
+```js
+import WebSocket from 'ws';
+
+const ws = new WebSocket('ws://www.host.com/path');
+
+ws.on('open', function open() {
+  ws.send('something');
+});
+
+ws.on('message', function message(data) {
+  console.log('received: %s', data);
+});
+```
+
+### Sending binary data
+
+```js
+import WebSocket from 'ws';
+
+const ws = new WebSocket('ws://www.host.com/path');
+
+ws.on('open', function open() {
+  const array = new Float32Array(5);
+
+  for (var i = 0; i < array.length; ++i) {
+    array[i] = i / 2;
+  }
+
+  ws.send(array);
+});
+```
+
+### Simple server
+
+```js
+import { WebSocketServer } from 'ws';
+
+const wss = new WebSocketServer({ port: 8080 });
+
+wss.on('connection', function connection(ws) {
+  ws.on('message', function message(data) {
+    console.log('received: %s', data);
+  });
+
+  ws.send('something');
+});
+```
+
+### External HTTP/S server
+
+```js
+import { createServer } from 'https';
+import { readFileSync } from 'fs';
+import { WebSocketServer } from 'ws';
+
+const server = createServer({
+  cert: readFileSync('/path/to/cert.pem'),
+  key: readFileSync('/path/to/key.pem')
+});
+const wss = new WebSocketServer({ server });
+
+wss.on('connection', function connection(ws) {
+  ws.on('message', function message(data) {
+    console.log('received: %s', data);
+  });
+
+  ws.send('something');
+});
+
+server.listen(8080);
+```
+
+### Multiple servers sharing a single HTTP/S server
+
+```js
+import { createServer } from 'http';
+import { parse } from 'url';
+import { WebSocketServer } from 'ws';
+
+const server = createServer();
+const wss1 = new WebSocketServer({ noServer: true });
+const wss2 = new WebSocketServer({ noServer: true });
+
+wss1.on('connection', function connection(ws) {
+  // ...
+});
+
+wss2.on('connection', function connection(ws) {
+  // ...
+});
+
+server.on('upgrade', function upgrade(request, socket, head) {
+  const { pathname } = parse(request.url);
+
+  if (pathname === '/foo') {
+    wss1.handleUpgrade(request, socket, head, function done(ws) {
+      wss1.emit('connection', ws, request);
+    });
+  } else if (pathname === '/bar') {
+    wss2.handleUpgrade(request, socket, head, function done(ws) {
+      wss2.emit('connection', ws, request);
+    });
+  } else {
+    socket.destroy();
+  }
+});
+
+server.listen(8080);
+```
+
+### Client authentication
+
+```js
+import { createServer } from 'http';
+import { WebSocketServer } from 'ws';
+
+const server = createServer();
+const wss = new WebSocketServer({ noServer: true });
+
+wss.on('connection', function connection(ws, request, client) {
+  ws.on('message', function message(data) {
+    console.log(`Received message ${data} from user ${client}`);
+  });
+});
+
+server.on('upgrade', function upgrade(request, socket, head) {
+  // This function is not defined on purpose. Implement it with your own logic.
+  authenticate(request, function next(err, client) {
+    if (err || !client) {
+      socket.write('HTTP/1.1 401 Unauthorized\r\n\r\n');
+      socket.destroy();
+      return;
+    }
+
+    wss.handleUpgrade(request, socket, head, function done(ws) {
+      wss.emit('connection', ws, request, client);
+    });
+  });
+});
+
+server.listen(8080);
+```
+
+Also see the provided [example][session-parse-example] using `express-session`.
+
+### Server broadcast
+
+A client WebSocket broadcasting to all connected WebSocket clients, including
+itself.
+
+```js
+import WebSocket, { WebSocketServer } from 'ws';
+
+const wss = new WebSocketServer({ port: 8080 });
+
+wss.on('connection', function connection(ws) {
+  ws.on('message', function message(data, isBinary) {
+    wss.clients.forEach(function each(client) {
+      if (client.readyState === WebSocket.OPEN) {
+        client.send(data, { binary: isBinary });
+      }
+    });
+  });
+});
+```
+
+A client WebSocket broadcasting to every other connected WebSocket clients,
+excluding itself.
+
+```js
+import WebSocket, { WebSocketServer } from 'ws';
+
+const wss = new WebSocketServer({ port: 8080 });
+
+wss.on('connection', function connection(ws) {
+  ws.on('message', function message(data, isBinary) {
+    wss.clients.forEach(function each(client) {
+      if (client !== ws && client.readyState === WebSocket.OPEN) {
+        client.send(data, { binary: isBinary });
+      }
+    });
+  });
+});
+```
+
+### Round-trip time
+
+```js
+import WebSocket from 'ws';
+
+const ws = new WebSocket('wss://websocket-echo.com/');
+
+ws.on('open', function open() {
+  console.log('connected');
+  ws.send(Date.now());
+});
+
+ws.on('close', function close() {
+  console.log('disconnected');
+});
+
+ws.on('message', function message(data) {
+  console.log(`Round-trip time: ${Date.now() - data} ms`);
+
+  setTimeout(function timeout() {
+    ws.send(Date.now());
+  }, 500);
+});
+```
+
+### Use the Node.js streams API
+
+```js
+import WebSocket, { createWebSocketStream } from 'ws';
+
+const ws = new WebSocket('wss://websocket-echo.com/');
+
+const duplex = createWebSocketStream(ws, { encoding: 'utf8' });
+
+duplex.pipe(process.stdout);
+process.stdin.pipe(duplex);
+```
+
+### Other examples
+
+For a full example with a browser client communicating with a ws server, see the
+examples folder.
+
+Otherwise, see the test cases.
+
+## FAQ
+
+### How to get the IP address of the client?
+
+The remote IP address can be obtained from the raw socket.
+
+```js
+import { WebSocketServer } from 'ws';
+
+const wss = new WebSocketServer({ port: 8080 });
+
+wss.on('connection', function connection(ws, req) {
+  const ip = req.socket.remoteAddress;
+});
+```
+
+When the server runs behind a proxy like NGINX, the de-facto standard is to use
+the `X-Forwarded-For` header.
+
+```js
+wss.on('connection', function connection(ws, req) {
+  const ip = req.headers['x-forwarded-for'].split(',')[0].trim();
+});
+```
+
+### How to detect and close broken connections?
+
+Sometimes the link between the server and the client can be interrupted in a way
+that keeps both the server and the client unaware of the broken state of the
+connection (e.g. when pulling the cord).
+
+In these cases ping messages can be used as a means to verify that the remote
+endpoint is still responsive.
+
+```js
+import { WebSocketServer } from 'ws';
+
+function heartbeat() {
+  this.isAlive = true;
+}
+
+const wss = new WebSocketServer({ port: 8080 });
+
+wss.on('connection', function connection(ws) {
+  ws.isAlive = true;
+  ws.on('pong', heartbeat);
+});
+
+const interval = setInterval(function ping() {
+  wss.clients.forEach(function each(ws) {
+    if (ws.isAlive === false) return ws.terminate();
+
+    ws.isAlive = false;
+    ws.ping();
+  });
+}, 30000);
+
+wss.on('close', function close() {
+  clearInterval(interval);
+});
+```
+
+Pong messages are automatically sent in response to ping messages as required by
+the spec.
+
+Just like the server example above your clients might as well lose connection
+without knowing it. You might want to add a ping listener on your clients to
+prevent that. A simple implementation would be:
+
+```js
+import WebSocket from 'ws';
+
+function heartbeat() {
+  clearTimeout(this.pingTimeout);
+
+  // Use `WebSocket#terminate()`, which immediately destroys the connection,
+  // instead of `WebSocket#close()`, which waits for the close timer.
+  // Delay should be equal to the interval at which your server
+  // sends out pings plus a conservative assumption of the latency.
+  this.pingTimeout = setTimeout(() => {
+    this.terminate();
+  }, 30000 + 1000);
+}
+
+const client = new WebSocket('wss://websocket-echo.com/');
+
+client.on('open', heartbeat);
+client.on('ping', heartbeat);
+client.on('close', function clear() {
+  clearTimeout(this.pingTimeout);
+});
+```
+
+### How to connect via a proxy?
+
+Use a custom `http.Agent` implementation like [https-proxy-agent][] or
+[socks-proxy-agent][].
+
+## Changelog
+
+We're using the GitHub [releases][changelog] for changelog entries.
+
+## License
+
+[MIT](LICENSE)
+
+[changelog]: https://github.com/websockets/ws/releases
+[client-report]: http://websockets.github.io/ws/autobahn/clients/
+[https-proxy-agent]: https://github.com/TooTallNate/node-https-proxy-agent
+[node-zlib-bug]: https://github.com/nodejs/node/issues/8871
+[node-zlib-deflaterawdocs]:
+  https://nodejs.org/api/zlib.html#zlib_zlib_createdeflateraw_options
+[permessage-deflate]: https://tools.ietf.org/html/rfc7692
+[server-report]: http://websockets.github.io/ws/autobahn/servers/
+[session-parse-example]: ./examples/express-session-parse
+[socks-proxy-agent]: https://github.com/TooTallNate/node-socks-proxy-agent
+[ws-server-options]: ./doc/ws.md#new-websocketserveroptions-callback
diff --git a/testing/xpcshell/node-ws/SECURITY.md b/testing/xpcshell/node-ws/SECURITY.md
new file mode 100644
index 0000000000..0baf19a63b
--- /dev/null
+++ b/testing/xpcshell/node-ws/SECURITY.md
@@ -0,0 +1,39 @@
+# Security Guidelines
+
+Please contact us directly at **security@3rd-Eden.com** for any bug that might
+impact the security of this project. Please prefix the subject of your email
+with `[security]` in lowercase and square brackets. Our email filters will
+automatically prevent these messages from being moved to our spam box.
+
+You will receive an acknowledgement of your report within **24 hours**.
+
+All emails that do not include security vulnerabilities will be removed and
+blocked instantly.
+
+## Exceptions
+
+If you do not receive an acknowledgement within the said time frame please give
+us the benefit of the doubt as it's possible that we haven't seen it yet. In
+this case please send us a message **without details** using one of the
+following methods:
+
+- Contact the lead developers of this project on their personal e-mails. You can
+  find the e-mails in the git logs, for example using the following command:
+  `git --no-pager show -s --format='%an <%ae>' <gitsha>` where `<gitsha>` is the
+  SHA1 of their latest commit in the project.
+- Create a GitHub issue stating contact details and the severity of the issue.
+
+Once we have acknowledged receipt of your report and confirmed the bug ourselves
+we will work with you to fix the vulnerability and publicly acknowledge your
+responsible disclosure, if you wish. In addition to that we will create and
+publish a security advisory to
+[GitHub Security Advisories](https://github.com/websockets/ws/security/advisories?state=published).
+
+## History
+
+- 04 Jan 2016:
+  [Buffer vulnerability](https://github.com/websockets/ws/releases/tag/1.0.1)
+- 08 Nov 2017:
+  [DoS vulnerability](https://github.com/websockets/ws/releases/tag/3.3.1)
+- 25 May 2021:
+  [ReDoS in `Sec-Websocket-Protocol` header](https://github.com/websockets/ws/releases/tag/7.4.6)
diff --git a/testing/xpcshell/node-ws/bench/parser.benchmark.js b/testing/xpcshell/node-ws/bench/parser.benchmark.js
new file mode 100644
index 0000000000..a6e359d05d
--- /dev/null
+++ b/testing/xpcshell/node-ws/bench/parser.benchmark.js
@@ -0,0 +1,95 @@
+'use strict';
+
+const benchmark = require('benchmark');
+const crypto = require('crypto');
+
+const WebSocket = require('..');
+
+const Receiver = WebSocket.Receiver;
+const Sender = WebSocket.Sender;
+
+const options = {
+  fin: true,
+  rsv1: false,
+  mask: true,
+  readOnly: false
+};
+
+function createBinaryFrame(length) {
+  const list = Sender.frame(crypto.randomBytes(length), {
+    opcode: 0x02,
+    ...options
+  });
+
+  return Buffer.concat(list);
+}
+
+const pingFrame1 = Buffer.concat(
+  Sender.frame(crypto.randomBytes(5), { opcode: 0x09, ...options })
+);
+
+const textFrame = Buffer.from('819461616161' + '61'.repeat(20), 'hex');
+const pingFrame2 = Buffer.from('8980146e915a', 'hex');
+const binaryFrame1 = createBinaryFrame(125);
+const binaryFrame2 = createBinaryFrame(65535);
+const binaryFrame3 = createBinaryFrame(200 * 1024);
+const binaryFrame4 = createBinaryFrame(1024 * 1024);
+
+const suite = new benchmark.Suite();
+const receiver = new Receiver({
+  binaryType: 'nodebuffer',
+  extensions: {},
+  isServer: true,
+  skipUTF8Validation: false
+});
+
+suite.add('ping frame (5 bytes payload)', {
+  defer: true,
+  fn: (deferred) => {
+    receiver.write(pingFrame1, deferred.resolve.bind(deferred));
+  }
+});
+suite.add('ping frame (no payload)', {
+  defer: true,
+  fn: (deferred) => {
+    receiver.write(pingFrame2, deferred.resolve.bind(deferred));
+  }
+});
+suite.add('text frame (20 bytes payload)', {
+  defer: true,
+  fn: (deferred) => {
+    receiver.write(textFrame, deferred.resolve.bind(deferred));
+  }
+});
+suite.add('binary frame (125 bytes payload)', {
+  defer: true,
+  fn: (deferred) => {
+    receiver.write(binaryFrame1, deferred.resolve.bind(deferred));
+  }
+});
+suite.add('binary frame (65535 bytes payload)', {
+  defer: true,
+  fn: (deferred) => {
+    receiver.write(binaryFrame2, deferred.resolve.bind(deferred));
+  }
+});
+suite.add('binary frame (200 KiB payload)', {
+  defer: true,
+  fn: (deferred) => {
+    receiver.write(binaryFrame3, deferred.resolve.bind(deferred));
+  }
+});
+suite.add('binary frame (1 MiB payload)', {
+  defer: true,
+  fn: (deferred) => {
+    receiver.write(binaryFrame4, deferred.resolve.bind(deferred));
+  }
+});
+
+suite.on('cycle', (e) => console.log(e.target.toString()));
+
+if (require.main === module) {
+  suite.run({ async: true });
+} else {
+  module.exports = suite;
+}
diff --git a/testing/xpcshell/node-ws/bench/sender.benchmark.js b/testing/xpcshell/node-ws/bench/sender.benchmark.js
new file mode 100644
index 0000000000..89d3be24b0
--- /dev/null
+++ b/testing/xpcshell/node-ws/bench/sender.benchmark.js
@@ -0,0 +1,48 @@
+'use strict';
+
+const benchmark = require('benchmark');
+const crypto = require('crypto');
+
+const Sender = require('../').Sender;
+
+const data1 = crypto.randomBytes(64);
+const data2 = crypto.randomBytes(16 * 1024);
+const data3 = crypto.randomBytes(64 * 1024);
+const data4 = crypto.randomBytes(200 * 1024);
+const data5 = crypto.randomBytes(1024 * 1024);
+
+const opts1 = {
+  readOnly: false,
+  mask: false,
+  rsv1: false,
+  opcode: 2,
+  fin: true
+};
+const opts2 = {
+  readOnly: true,
+  rsv1: false,
+  mask: true,
+  opcode: 2,
+  fin: true
+};
+
+const suite = new benchmark.Suite();
+
+suite.add('frame, unmasked (64 B)', () => Sender.frame(data1, opts1));
+suite.add('frame, masked (64 B)', () => Sender.frame(data1, opts2));
+suite.add('frame, unmasked (16 KiB)', () => Sender.frame(data2, opts1));
+suite.add('frame, masked (16 KiB)', () => Sender.frame(data2, opts2));
+suite.add('frame, unmasked (64 KiB)', () => Sender.frame(data3, opts1));
+suite.add('frame, masked (64 KiB)', () => Sender.frame(data3, opts2));
+suite.add('frame, unmasked (200 KiB)', () => Sender.frame(data4, opts1));
+suite.add('frame, masked (200 KiB)', () => Sender.frame(data4, opts2));
+suite.add('frame, unmasked (1 MiB)', () => Sender.frame(data5, opts1));
+suite.add('frame, masked (1 MiB)', () => Sender.frame(data5, opts2));
+
+suite.on('cycle', (e) => console.log(e.target.toString()));
+
+if (require.main === module) {
+  suite.run({ async: true });
+} else {
+  module.exports = suite;
+}
diff --git a/testing/xpcshell/node-ws/bench/speed.js b/testing/xpcshell/node-ws/bench/speed.js
new file mode 100644
index 0000000000..bef6a30679
--- /dev/null
+++ b/testing/xpcshell/node-ws/bench/speed.js
@@ -0,0 +1,115 @@
+'use strict';
+
+const cluster = require('cluster');
+const http = require('http');
+
+const WebSocket = require('..');
+
+const port = 8181;
+const path = '';
+// const path = '/tmp/wss.sock';
+
+if (cluster.isMaster) {
+  const server = http.createServer();
+  const wss = new WebSocket.Server({
+    maxPayload: 600 * 1024 * 1024,
+    perMessageDeflate: false,
+    clientTracking: false,
+    server
+  });
+
+  wss.on('connection', (ws) => {
+    ws.on('message', (data, isBinary) => {
+      ws.send(data, { binary: isBinary });
+    });
+  });
+
+  server.listen(path ? { path } : { port }, () => cluster.fork());
+
+  cluster.on('exit', () => {
+    wss.close();
+    server.close();
+  });
+} else {
+  const configs = [
+    [true, 10000, 64],
+    [true, 5000, 16 * 1024],
+    [true, 1000, 128 * 1024],
+    [true, 100, 1024 * 1024],
+    [true, 1, 500 * 1024 * 1024],
+    [false, 10000, 64],
+    [false, 5000, 16 * 1024],
+    [false, 1000, 128 * 1024],
+    [false, 100, 1024 * 1024]
+  ];
+
+  const roundPrec = (num, prec) => {
+    const mul = Math.pow(10, prec);
+    return Math.round(num * mul) / mul;
+  };
+
+  const humanSize = (bytes) => {
+    if (bytes >= 1073741824) return roundPrec(bytes / 1073741824, 2) + ' GiB';
+    if (bytes >= 1048576) return roundPrec(bytes / 1048576, 2) + ' MiB';
+    if (bytes >= 1024) return roundPrec(bytes / 1024, 2) + ' KiB';
+    return roundPrec(bytes, 2) + ' B';
+  };
+
+  const largest = configs.reduce(
+    (prev, curr) => (curr[2] > prev ? curr[2] : prev),
+    0
+  );
+  console.log('Generating %s of test data...', humanSize(largest));
+  const randomBytes = Buffer.allocUnsafe(largest);
+
+  for (let i = 0; i < largest; ++i) {
+    randomBytes[i] = ~~(Math.random() * 127);
+  }
+
+  console.log(`Testing ws on ${path || '[::]:' + port}`);
+
+  const runConfig = (useBinary, roundtrips, size, cb) => {
+    const data = randomBytes.slice(0, size);
+    const url = path ? `ws+unix://${path}` : `ws://localhost:${port}`;
+    const ws = new WebSocket(url, {
+      maxPayload: 600 * 1024 * 1024
+    });
+    let roundtrip = 0;
+    let time;
+
+    ws.on('error', (err) => {
+      console.error(err.stack);
+      cluster.worker.disconnect();
+    });
+    ws.on('open', () => {
+      time = process.hrtime();
+      ws.send(data, { binary: useBinary });
+    });
+    ws.on('message', () => {
+      if (++roundtrip !== roundtrips)
+        return ws.send(data, { binary: useBinary });
+
+      let elapsed = process.hrtime(time);
+      elapsed = elapsed[0] * 1e9 + elapsed[1];
+
+      console.log(
+        '%d roundtrips of %s %s data:\t%ss\t%s',
+        roundtrips,
+        humanSize(size),
+        useBinary ? 'binary' : 'text',
+        roundPrec(elapsed / 1e9, 1),
+        humanSize(((size * 2 * roundtrips) / elapsed) * 1e9) + '/s'
+      );
+
+      ws.close();
+      cb();
+    });
+  };
+
+  (function run() {
+    if (configs.length === 0) return cluster.worker.disconnect();
+    const config = configs.shift();
+    config.push(run);
+    runConfig.apply(null, config);
+  })();
+}
diff --git a/testing/xpcshell/node-ws/browser.js b/testing/xpcshell/node-ws/browser.js
new file mode 100644
index 0000000000..ca4f628ac1
--- /dev/null
+++ b/testing/xpcshell/node-ws/browser.js
@@ -0,0 +1,8 @@
+'use strict';
+
+module.exports = function () {
+  throw new Error(
+    'ws does not work in the browser. Browser clients must use the native ' +
+      'WebSocket object'
+  );
+};
diff --git a/testing/xpcshell/node-ws/doc/ws.md b/testing/xpcshell/node-ws/doc/ws.md
new file mode 100644
index 0000000000..4888ee4c6f
--- /dev/null
+++ b/testing/xpcshell/node-ws/doc/ws.md
@@ -0,0 +1,669 @@
+# ws
+
+## Table of Contents
+
+- [Class: WebSocketServer](#class-websocketserver)
+  - [new WebSocketServer(options[, callback])](#new-websocketserveroptions-callback)
+  - [Event: 'close'](#event-close)
+  - [Event: 'connection'](#event-connection)
+  - [Event: 'error'](#event-error)
+  - [Event: 'headers'](#event-headers)
+  - [Event: 'listening'](#event-listening)
+  - [Event: 'wsClientError'](#event-wsclienterror)
+  - [server.address()](#serveraddress)
+  - [server.clients](#serverclients)
+  - [server.close([callback])](#serverclosecallback)
+  - [server.handleUpgrade(request, socket, head, callback)](#serverhandleupgraderequest-socket-head-callback)
+  - [server.shouldHandle(request)](#servershouldhandlerequest)
+- [Class: WebSocket](#class-websocket)
+  - [Ready state constants](#ready-state-constants)
+  - [new WebSocket(address[, protocols][, options])](#new-websocketaddress-protocols-options)
+    - [UNIX Domain Sockets](#unix-domain-sockets)
+  - [Event: 'close'](#event-close-1)
+  - [Event: 'error'](#event-error-1)
+  - [Event: 'message'](#event-message)
+  - [Event: 'open'](#event-open)
+  - [Event: 'ping'](#event-ping)
+  - [Event: 'pong'](#event-pong)
+  - [Event: 'redirect'](#event-redirect)
+  - [Event: 'unexpected-response'](#event-unexpected-response)
+  - [Event: 'upgrade'](#event-upgrade)
+  - [websocket.addEventListener(type, listener[, options])](#websocketaddeventlistenertype-listener-options)
+  - [websocket.binaryType](#websocketbinarytype)
+  - [websocket.bufferedAmount](#websocketbufferedamount)
+  - [websocket.close([code[, reason]])](#websocketclosecode-reason)
+  - [websocket.extensions](#websocketextensions)
+  - [websocket.isPaused](#websocketispaused)
+  - [websocket.onclose](#websocketonclose)
+  - [websocket.onerror](#websocketonerror)
+  - [websocket.onmessage](#websocketonmessage)
+  - [websocket.onopen](#websocketonopen)
+  - [websocket.pause()](#websocketpause)
+  - [websocket.ping([data[, mask]][, callback])](#websocketpingdata-mask-callback)
+  - [websocket.pong([data[, mask]][, callback])](#websocketpongdata-mask-callback)
+  - [websocket.protocol](#websocketprotocol)
+  - [websocket.readyState](#websocketreadystate)
+  - [websocket.removeEventListener(type, listener)](#websocketremoveeventlistenertype-listener)
+  - [websocket.resume()](#websocketresume)
+  - [websocket.send(data[, options][, callback])](#websocketsenddata-options-callback)
+  - [websocket.terminate()](#websocketterminate)
+  - [websocket.url](#websocketurl)
+- [createWebSocketStream(websocket[, options])](#createwebsocketstreamwebsocket-options)
+- [Environment variables](#environment-variables)
+  - [WS_NO_BUFFER_UTIL](#ws_no_buffer_util)
+  - [WS_NO_UTF_8_VALIDATE](#ws_no_utf_8_validate)
+- [Error codes](#error-codes)
+  - [WS_ERR_EXPECTED_FIN](#ws_err_expected_fin)
+  - [WS_ERR_EXPECTED_MASK](#ws_err_expected_mask)
+  - [WS_ERR_INVALID_CLOSE_CODE](#ws_err_invalid_close_code)
+  - [WS_ERR_INVALID_CONTROL_PAYLOAD_LENGTH](#ws_err_invalid_control_payload_length)
+  - [WS_ERR_INVALID_OPCODE](#ws_err_invalid_opcode)
+  - [WS_ERR_INVALID_UTF8](#ws_err_invalid_utf8)
+  - [WS_ERR_UNEXPECTED_MASK](#ws_err_unexpected_mask)
+  - [WS_ERR_UNEXPECTED_RSV_1](#ws_err_unexpected_rsv_1)
+  - [WS_ERR_UNEXPECTED_RSV_2_3](#ws_err_unexpected_rsv_2_3)
+  - [WS_ERR_UNSUPPORTED_DATA_PAYLOAD_LENGTH](#ws_err_unsupported_data_payload_length)
+  - [WS_ERR_UNSUPPORTED_MESSAGE_LENGTH](#ws_err_unsupported_message_length)
+
+## Class: WebSocketServer
+
+This class represents a WebSocket server. It extends the `EventEmitter`.
+
+### new WebSocketServer(options[, callback])
+
+- `options` {Object}
+  - `backlog` {Number} The maximum length of the queue of pending connections.
+  - `clientTracking` {Boolean} Specifies whether or not to track clients.
+  - `handleProtocols` {Function} A function which can be used to handle the
+    WebSocket subprotocols. See description below.
+  - `host` {String} The hostname where to bind the server.
+  - `maxPayload` {Number} The maximum allowed message size in bytes. Defaults to
+    100 MiB (104857600 bytes).
+  - `noServer` {Boolean} Enable no server mode.
+  - `path` {String} Accept only connections matching this path.
+  - `perMessageDeflate` {Boolean|Object} Enable/disable permessage-deflate.
+  - `port` {Number} The port where to bind the server.
+  - `server` {http.Server|https.Server} A pre-created Node.js HTTP/S server.
+  - `skipUTF8Validation` {Boolean} Specifies whether or not to skip UTF-8
+    validation for text and close messages. Defaults to `false`. Set to `true`
+    only if clients are trusted.
+  - `verifyClient` {Function} A function which can be used to validate incoming
+    connections. See description below. (Usage is discouraged: see
+    [Issue #337](https://github.com/websockets/ws/issues/377#issuecomment-462152231))
+  - `WebSocket` {Function} Specifies the `WebSocket` class to be used. It must
+    be extended from the original `WebSocket`. Defaults to `WebSocket`.
+- `callback` {Function}
+
+Create a new server instance. One and only one of `port`, `server` or `noServer`
+must be provided or an error is thrown. An HTTP server is automatically created,
+started, and used if `port` is set. To use an external HTTP/S server instead,
+specify only `server` or `noServer`. In this case the HTTP/S server must be
+started manually. The "noServer" mode allows the WebSocket server to be
+completely detached from the HTTP/S server. This makes it possible, for example,
+to share a single HTTP/S server between multiple WebSocket servers.
+
+> **NOTE:** Use of `verifyClient` is discouraged. Rather handle client
+> authentication in the `upgrade` event of the HTTP server. See examples for
+> more details.
+
+If `verifyClient` is not set then the handshake is automatically accepted. If it
+has a single parameter then `ws` will invoke it with the following argument:
+
+- `info` {Object}
+  - `origin` {String} The value in the Origin header indicated by the client.
+  - `req` {http.IncomingMessage} The client HTTP GET request.
+  - `secure` {Boolean} `true` if `req.socket.authorized` or
+    `req.socket.encrypted` is set.
+
+The return value (`Boolean`) of the function determines whether or not to accept
+the handshake.
+
+If `verifyClient` has two parameters then `ws` will invoke it with the following
+arguments:
+
+- `info` {Object} Same as above.
+- `cb` {Function} A callback that must be called by the user upon inspection of
+  the `info` fields. Arguments in this callback are:
+  - `result` {Boolean} Whether or not to accept the handshake.
+  - `code` {Number} When `result` is `false` this field determines the HTTP
+    error status code to be sent to the client.
+  - `name` {String} When `result` is `false` this field determines the HTTP
+    reason phrase.
+  - `headers` {Object} When `result` is `false` this field determines additional
+    HTTP headers to be sent to the client. For example,
+    `{ 'Retry-After': 120 }`.
+
+`handleProtocols` takes two arguments:
+
+- `protocols` {Set} The list of WebSocket subprotocols indicated by the client
+  in the `Sec-WebSocket-Protocol` header.
+- `request` {http.IncomingMessage} The client HTTP GET request.
+
+The returned value sets the value of the `Sec-WebSocket-Protocol` header in the
+HTTP 101 response. If returned value is `false` the header is not added in the
+response.
+
+If `handleProtocols` is not set then the first of the client's requested
+subprotocols is used.
+
+`perMessageDeflate` can be used to control the behavior of [permessage-deflate
+extension][permessage-deflate]. The extension is disabled when `false` (default
+value). If an object is provided then that is extension parameters:
+
+- `serverNoContextTakeover` {Boolean} Whether to use context takeover or not.
+- `clientNoContextTakeover` {Boolean} Acknowledge disabling of client context
+  takeover.
+- `serverMaxWindowBits` {Number} The value of `windowBits`.
+- `clientMaxWindowBits` {Number} Request a custom client window size.
+- `zlibDeflateOptions` {Object} [Additional options][zlib-options] to pass to
+  zlib on deflate.
+- `zlibInflateOptions` {Object} [Additional options][zlib-options] to pass to
+  zlib on inflate.
+- `threshold` {Number} Payloads smaller than this will not be compressed if
+  context takeover is disabled. Defaults to 1024 bytes.
+- `concurrencyLimit` {Number} The number of concurrent calls to zlib. Calls
+  above this limit will be queued. Default 10. You usually won't need to touch
+  this option. See [this issue][concurrency-limit] for more details.
+
+If a property is empty then either an offered configuration or a default value
+is used. When sending a fragmented message the length of the first fragment is
+compared to the threshold. This determines if compression is used for the entire
+message.
+
+`callback` will be added as a listener for the `listening` event on the HTTP
+server when not operating in "noServer" mode.
+
+### Event: 'close'
+
+Emitted when the server closes. This event depends on the `'close'` event of
+HTTP server only when it is created internally. In all other cases, the event is
+emitted independently.
+
+### Event: 'connection'
+
+- `websocket` {WebSocket}
+- `request` {http.IncomingMessage}
+
+Emitted when the handshake is complete. `request` is the http GET request sent
+by the client. Useful for parsing authority headers, cookie headers, and other
+information.
+
+### Event: 'error'
+
+- `error` {Error}
+
+Emitted when an error occurs on the underlying server.
+
+### Event: 'headers'
+
+- `headers` {Array}
+- `request` {http.IncomingMessage}
+
+Emitted before the response headers are written to the socket as part of the
+handshake. This allows you to inspect/modify the headers before they are sent.
+
+### Event: 'listening'
+
+Emitted when the underlying server has been bound.
+
+### Event: 'wsClientError'
+
+- `error` {Error}
+- `socket` {net.Socket|tls.Socket}
+- `request` {http.IncomingMessage}
+
+Emitted when an error occurs before the WebSocket connection is established.
+`socket` and `request` are respectively the socket and the HTTP request from
+which the error originated. The listener of this event is responsible for
+closing the socket. When the `'wsClientError'` event is emitted there is no
+`http.ServerResponse` object, so any HTTP response, including the response
+headers and body, must be written directly to the `socket`. If there is no
+listener for this event, the socket is closed with a default 4xx response
+containing a descriptive error message.
+
+### server.address()
+
+Returns an object with `port`, `family`, and `address` properties specifying 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.
+
+### server.clients
+
+- {Set}
+
+A set that stores all connected clients. Please note that this property is only
+added when the `clientTracking` is truthy.
+
+### server.close([callback])
+
+Prevent the server from accepting new connections and close the HTTP server if
+created internally. If an external HTTP server is used via the `server` or
+`noServer` constructor options, it must be closed manually. Existing connections
+are not closed automatically. The server emits a `'close'` event when all
+connections are closed unless an external HTTP server is used and client
+tracking is disabled. In this case the `'close'` event is emitted in the next
+tick. The optional callback is called when the `'close'` event occurs and
+receives an `Error` if the server is already closed.
+
+### server.handleUpgrade(request, socket, head, callback)
+
+- `request` {http.IncomingMessage} The client HTTP GET request.
+- `socket` {net.Socket|tls.Socket} The network socket between the server and
+  client.
+- `head` {Buffer} The first packet of the upgraded stream.
+- `callback` {Function}.
+
+Handle a HTTP upgrade request. When the HTTP server is created internally or
+when the HTTP server is passed via the `server` option, this method is called
+automatically. When operating in "noServer" mode, this method must be called
+manually.
+
+If the upgrade is successful, the `callback` is called with two arguments:
+
+- `websocket` {WebSocket} A `WebSocket` object.
+- `request` {http.IncomingMessage} The client HTTP GET request.
+
+### server.shouldHandle(request)
+
+- `request` {http.IncomingMessage} The client HTTP GET request.
+
+See if a given request should be handled by this server. By default this method
+validates the pathname of the request, matching it against the `path` option if
+provided. The return value, `true` or `false`, determines whether or not to
+accept the handshake.
+
+This method can be overridden when a custom handling logic is required.
+
+## Class: WebSocket
+
+This class represents a WebSocket. It extends the `EventEmitter`.
+
+### Ready state constants
+
+| Constant   | Value | Description                                      |
+| ---------- | ----- | ------------------------------------------------ |
+| CONNECTING | 0     | The connection is not yet open.                  |
+| OPEN       | 1     | The connection is open and ready to communicate. |
+| CLOSING    | 2     | The connection is in the process of closing.     |
+| CLOSED     | 3     | The connection is closed.                        |
+
+### new WebSocket(address[, protocols][, options])
+
+- `address` {String|url.URL} The URL to which to connect.
+- `protocols` {String|Array} The list of subprotocols.
+- `options` {Object}
+  - `followRedirects` {Boolean} Whether or not to follow redirects. Defaults to
+    `false`.
+  - `generateMask` {Function} The function used to generate the masking key. It
+    takes a `Buffer` that must be filled synchronously and is called before a
+    message is sent, for each message. By default the buffer is filled with
+    cryptographically strong random bytes.
+  - `handshakeTimeout` {Number} Timeout in milliseconds for the handshake
+    request. This is reset after every redirection.
+  - `maxPayload` {Number} The maximum allowed message size in bytes. Defaults to
+    100 MiB (104857600 bytes).
+  - `maxRedirects` {Number} The maximum number of redirects allowed. Defaults
+    to 10.
+  - `origin` {String} Value of the `Origin` or `Sec-WebSocket-Origin` header
+    depending on the `protocolVersion`.
+  - `perMessageDeflate` {Boolean|Object} Enable/disable permessage-deflate.
+  - `protocolVersion` {Number} Value of the `Sec-WebSocket-Version` header.
+  - `skipUTF8Validation` {Boolean} Specifies whether or not to skip UTF-8
+    validation for text and close messages. Defaults to `false`. Set to `true`
+    only if the server is trusted.
+  - Any other option allowed in [`http.request()`][] or [`https.request()`][].
+    Options given do not have any effect if parsed from the URL given with the
+    `address` parameter.
+
+`perMessageDeflate` default value is `true`. When using an object, parameters
+are the same of the server. The only difference is the direction of requests.
+For example, `serverNoContextTakeover` can be used to ask the server to disable
+context takeover.
+
+Create a new WebSocket instance.
+
+#### UNIX Domain Sockets
+
+`ws` supports making requests to UNIX domain sockets. To make one, use the
+following URL scheme:
+
+```
+ws+unix:///absolute/path/to/uds_socket:/pathname?search_params
+```
+
+Note that `:` is the separator between the socket path and the URL path. If the
+URL path is omitted
+
+```
+ws+unix:///absolute/path/to/uds_socket
+```
+
+it defaults to `/`.
+
+### Event: 'close'
+
+- `code` {Number}
+- `reason` {Buffer}
+
+Emitted when the connection is closed. `code` is a numeric value indicating the
+status code explaining why the connection has been closed. `reason` is a
+`Buffer` containing a human-readable string explaining why the connection has
+been closed.
+
+### Event: 'error'
+
+- `error` {Error}
+
+Emitted when an error occurs. Errors may have a `.code` property, matching one
+of the string values defined below under [Error codes](#error-codes).
+
+### Event: 'message'
+
+- `data` {Buffer|ArrayBuffer|Buffer[]}
+- `isBinary` {Boolean}
+
+Emitted when a message is received. `data` is the message content. `isBinary`
+specifies whether the message is binary or not.
+
+### Event: 'open'
+
+Emitted when the connection is established.
+
+### Event: 'ping'
+
+- `data` {Buffer}
+
+Emitted when a ping is received from the server.
+
+### Event: 'pong'
+
+- `data` {Buffer}
+
+Emitted when a pong is received from the server.
+
+### Event: 'redirect'
+
+- `url` {String}
+- `request` {http.ClientRequest}
+
+Emitted before a redirect is followed. `url` is the redirect URL. `request` is
+the HTTP GET request with the headers queued. This event gives the ability to
+inspect confidential headers and remove them on a per-redirect basis using the
+[`request.getHeader()`][] and [`request.removeHeader()`][] API. The `request`
+object should be used only for this purpose. When there is at least one listener
+for this event, no header is removed by default, even if the redirect is to a
+different domain.
+
+### Event: 'unexpected-response'
+
+- `request` {http.ClientRequest}
+- `response` {http.IncomingMessage}
+
+Emitted when the server response is not the expected one, for example a 401
+response. This event gives the ability to read the response in order to extract
+useful information. If the server sends an invalid response and there isn't a
+listener for this event, an error is emitted.
+
+### Event: 'upgrade'
+
+- `response` {http.IncomingMessage}
+
+Emitted when response headers are received from the server as part of the
+handshake. This allows you to read headers from the server, for example
+'set-cookie' headers.
+
+### websocket.addEventListener(type, listener[, options])
+
+- `type` {String} A string representing the event type to listen for.
+- `listener` {Function} The listener to add.
+- `options` {Object}
+  - `once` {Boolean} A `Boolean` indicating that the listener should be invoked
+    at most once after being added. If `true`, the listener would be
+    automatically removed when invoked.
+
+Register an event listener emulating the `EventTarget` interface. This method
+does nothing if `type` is not one of `'close'`, `'error'`, `'message'`, or
+`'open'`.
+
+### websocket.binaryType
+
+- {String}
+
+A string indicating the type of binary data being transmitted by the connection.
+This should be one of "nodebuffer", "arraybuffer" or "fragments". Defaults to
+"nodebuffer". Type "fragments" will emit the array of fragments as received from
+the sender, without copyfull concatenation, which is useful for the performance
+of binary protocols transferring large messages with multiple fragments.
+
+### websocket.bufferedAmount
+
+- {Number}
+
+The number of bytes of data that have been queued using calls to `send()` but
+not yet transmitted to the network. This deviates from the HTML standard in the
+following ways:
+
+1. If the data is immediately sent the value is `0`.
+1. All framing bytes are included.
+
+### websocket.close([code[, reason]])
+
+- `code` {Number} A numeric value indicating the status code explaining why the
+  connection is being closed.
+- `reason` {String|Buffer} The reason why the connection is closing.
+
+Initiate a closing handshake.
+
+### websocket.isPaused
+
+- {Boolean}
+
+Indicates whether the websocket is paused.
+
+### websocket.extensions
+
+- {Object}
+
+An object containing the negotiated extensions.
+
+### websocket.onclose
+
+- {Function}
+
+An event listener to be called when connection is closed. The listener receives
+a `CloseEvent` named "close".
+
+### websocket.onerror
+
+- {Function}
+
+An event listener to be called when an error occurs. The listener receives an
+`ErrorEvent` named "error".
+
+### websocket.onmessage
+
+- {Function}
+
+An event listener to be called when a message is received from the server. The
+listener receives a `MessageEvent` named "message".
+
+### websocket.onopen
+
+- {Function}
+
+An event listener to be called when the connection is established. The listener
+receives an `OpenEvent` named "open".
+
+### websocket.pause()
+
+Pause the websocket causing it to stop emitting events. Some events can still be
+emitted after this is called, until all buffered data is consumed. This method
+is a noop if the ready state is `CONNECTING` or `CLOSED`.
+
+### websocket.ping([data[, mask]][, callback])
+
+- `data` {Array|Number|Object|String|ArrayBuffer|Buffer|DataView|TypedArray} The
+  data to send in the ping frame.
+- `mask` {Boolean} Specifies whether `data` should be masked or not. Defaults to
+  `true` when `websocket` is not a server client.
+- `callback` {Function} An optional callback which is invoked when the ping
+  frame is written out. If an error occurs, the callback is called with the
+  error as its first argument.
+
+Send a ping. This method throws an error if the ready state is `CONNECTING`.
+
+### websocket.pong([data[, mask]][, callback])
+
+- `data` {Array|Number|Object|String|ArrayBuffer|Buffer|DataView|TypedArray} The
+  data to send in the pong frame.
+- `mask` {Boolean} Specifies whether `data` should be masked or not. Defaults to
+  `true` when `websocket` is not a server client.
+- `callback` {Function} An optional callback which is invoked when the pong
+  frame is written out. If an error occurs, the callback is called with the
+  error as its first argument.
+
+Send a pong. This method throws an error if the ready state is `CONNECTING`.
+
+### websocket.protocol
+
+- {String}
+
+The subprotocol selected by the server.
+
+### websocket.resume()
+
+Make a paused socket resume emitting events. This method is a noop if the ready
+state is `CONNECTING` or `CLOSED`.
+
+### websocket.readyState
+
+- {Number}
+
+The current state of the connection. This is one of the ready state constants.
+
+### websocket.removeEventListener(type, listener)
+
+- `type` {String} A string representing the event type to remove.
+- `listener` {Function} The listener to remove.
+
+Removes an event listener emulating the `EventTarget` interface. This method
+only removes listeners added with
+[`websocket.addEventListener()`](#websocketaddeventlistenertype-listener-options).
+
+### websocket.send(data[, options][, callback])
+
+- `data` {Array|Number|Object|String|ArrayBuffer|Buffer|DataView|TypedArray} The
+  data to send.
+- `options` {Object}
+  - `binary` {Boolean} Specifies whether `data` should be sent as a binary or
+    not. Default is autodetected.
+  - `compress` {Boolean} Specifies whether `data` should be compressed or not.
+    Defaults to `true` when permessage-deflate is enabled.
+  - `fin` {Boolean} Specifies whether `data` is the last fragment of a message
+    or not. Defaults to `true`.
+  - `mask` {Boolean} Specifies whether `data` should be masked or not. Defaults
+    to `true` when `websocket` is not a server client.
+- `callback` {Function} An optional callback which is invoked when `data` is
+  written out. If an error occurs, the callback is called with the error as its
+  first argument.
+
+Send `data` through the connection. This method throws an error if the ready
+state is `CONNECTING`.
+
+### websocket.terminate()
+
+Forcibly close the connection. Internally this calls [`socket.destroy()`][].
+
+### websocket.url
+
+- {String}
+
+The URL of the WebSocket server. Server clients don't have this attribute.
+
+## createWebSocketStream(websocket[, options])
+
+- `websocket` {WebSocket} A `WebSocket` object.
+- `options` {Object} [Options][duplex-options] to pass to the `Duplex`
+  constructor.
+
+Returns a `Duplex` stream that allows to use the Node.js streams API on top of a
+given `WebSocket`.
+
+## Environment variables
+
+### WS_NO_BUFFER_UTIL
+
+When set to a non empty value, prevents the optional `bufferutil` dependency
+from being required.
+
+### WS_NO_UTF_8_VALIDATE
+
+When set to a non empty value, prevents the optional `utf-8-validate` dependency
+from being required.
+
+## Error codes
+
+Errors emitted by the websocket may have a `.code` property, describing the
+specific type of error that has occurred:
+
+### WS_ERR_EXPECTED_FIN
+
+A WebSocket frame was received with the FIN bit not set when it was expected.
+
+### WS_ERR_EXPECTED_MASK
+
+An unmasked WebSocket frame was received by a WebSocket server.
+
+### WS_ERR_INVALID_CLOSE_CODE
+
+A WebSocket close frame was received with an invalid close code.
+
+### WS_ERR_INVALID_CONTROL_PAYLOAD_LENGTH
+
+A control frame with an invalid payload length was received.
+
+### WS_ERR_INVALID_OPCODE
+
+A WebSocket frame was received with an invalid opcode.
+
+### WS_ERR_INVALID_UTF8
+
+A text or close frame was received containing invalid UTF-8 data.
+
+### WS_ERR_UNEXPECTED_MASK
+
+A masked WebSocket frame was received by a WebSocket client.
+
+### WS_ERR_UNEXPECTED_RSV_1
+
+A WebSocket frame was received with the RSV1 bit set unexpectedly.
+
+### WS_ERR_UNEXPECTED_RSV_2_3
+
+A WebSocket frame was received with the RSV2 or RSV3 bit set unexpectedly.
+
+### WS_ERR_UNSUPPORTED_DATA_PAYLOAD_LENGTH
+
+A data frame was received with a length longer than the max supported length
+(2^53 - 1, due to JavaScript language limitations).
+
+### WS_ERR_UNSUPPORTED_MESSAGE_LENGTH
+
+A message was received with a length longer than the maximum supported length,
+as configured by the `maxPayload` option.
+
+[concurrency-limit]: https://github.com/websockets/ws/issues/1202
+[duplex-options]:
+  https://nodejs.org/api/stream.html#stream_new_stream_duplex_options
+[`http.request()`]:
+  https://nodejs.org/api/http.html#http_http_request_options_callback
+[`https.request()`]:
+  https://nodejs.org/api/https.html#https_https_request_options_callback
+[permessage-deflate]:
+  https://tools.ietf.org/html/draft-ietf-hybi-permessage-compression-19
+[`request.getheader()`]: https://nodejs.org/api/http.html#requestgetheadername
+[`request.removeheader()`]:
+  https://nodejs.org/api/http.html#requestremoveheadername
+[`socket.destroy()`]: https://nodejs.org/api/net.html#net_socket_destroy_error
+[zlib-options]: https://nodejs.org/api/zlib.html#zlib_class_options
diff --git a/testing/xpcshell/node-ws/examples/express-session-parse/index.js b/testing/xpcshell/node-ws/examples/express-session-parse/index.js
new file mode 100644
index 0000000000..b62a2e4a5f
--- /dev/null
+++ b/testing/xpcshell/node-ws/examples/express-session-parse/index.js
@@ -0,0 +1,101 @@
+'use strict';
+
+const session = require('express-session');
+const express = require('express');
+const http = require('http');
+const uuid = require('uuid');
+
+const { WebSocketServer } = require('../..');
+
+const app = express();
+const map = new Map();
+
+//
+// We need the same instance of the session parser in express and
+// WebSocket server.
+//
+const sessionParser = session({
+  saveUninitialized: false,
+  secret: '$eCuRiTy',
+  resave: false
+});
+
+//
+// Serve static files from the 'public' folder.
+//
+app.use(express.static('public'));
+app.use(sessionParser);
+
+app.post('/login', function (req, res) {
+  //
+  // "Log in" user and set userId to session.
+  //
+  const id = uuid.v4();
+
+  console.log(`Updating session for user ${id}`);
+  req.session.userId = id;
+  res.send({ result: 'OK', message: 'Session updated' });
+});
+
+app.delete('/logout', function (request, response) {
+  const ws = map.get(request.session.userId);
+
+  console.log('Destroying session');
+  request.session.destroy(function () {
+    if (ws) ws.close();
+
+    response.send({ result: 'OK', message: 'Session destroyed' });
+  });
+});
+
+//
+// Create an HTTP server.
+//
+const server = http.createServer(app);
+
+//
+// Create a WebSocket server completely detached from the HTTP server.
+//
+const wss = new WebSocketServer({ clientTracking: false, noServer: true });
+
+server.on('upgrade', function (request, socket, head) {
+  console.log('Parsing session from request...');
+
+  sessionParser(request, {}, () => {
+    if (!request.session.userId) {
+      socket.write('HTTP/1.1 401 Unauthorized\r\n\r\n');
+      socket.destroy();
+      return;
+    }
+
+    console.log('Session is parsed!');
+
+    wss.handleUpgrade(request, socket, head, function (ws) {
+      wss.emit('connection', ws, request);
+    });
+  });
+});
+
+wss.on('connection', function (ws, request) {
+  const userId = request.session.userId;
+
+  map.set(userId, ws);
+
+  ws.on('message', function (message) {
+    //
+    // Here we can now use session parameters.
+    //
+    console.log(`Received message ${message} from user ${userId}`);
+  });
+
+  ws.on('close', function () {
+    map.delete(userId);
+  });
+});
+
+//
+// Start the server.
+//
+server.listen(8080, function () {
+  console.log('Listening on http://localhost:8080');
+});
diff --git a/testing/xpcshell/node-ws/examples/express-session-parse/package.json b/testing/xpcshell/node-ws/examples/express-session-parse/package.json
new file mode 100644
index 0000000000..406706ce8a
--- /dev/null
+++ b/testing/xpcshell/node-ws/examples/express-session-parse/package.json
@@ -0,0 +1,11 @@
+{
+  "author": "",
+  "name": "express-session-parse",
+  "version": "0.0.0",
+  "repository": "websockets/ws",
+  "dependencies": {
+    "express": "^4.16.4",
+    "express-session": "^1.16.1",
+    "uuid": "^8.3.2"
+  }
+}
diff --git a/testing/xpcshell/node-ws/examples/express-session-parse/public/app.js b/testing/xpcshell/node-ws/examples/express-session-parse/public/app.js
new file mode 100644
index 0000000000..f70dc21835
--- /dev/null
+++ b/testing/xpcshell/node-ws/examples/express-session-parse/public/app.js
@@ -0,0 +1,67 @@
+(function () {
+  const messages = document.querySelector('#messages');
+  const wsButton = document.querySelector('#wsButton');
+  const wsSendButton = document.querySelector('#wsSendButton');
+  const logout = document.querySelector('#logout');
+  const login = document.querySelector('#login');
+
+  function showMessage(message) {
+    messages.textContent += `\n${message}`;
+    messages.scrollTop = messages.scrollHeight;
+  }
+
+  function handleResponse(response) {
+    return response.ok
+      ? response.json().then((data) => JSON.stringify(data, null, 2))
+      : Promise.reject(new Error('Unexpected response'));
+  }
+
+  login.onclick = function () {
+    fetch('/login', { method: 'POST', credentials: 'same-origin' })
+      .then(handleResponse)
+      .then(showMessage)
+      .catch(function (err) {
+        showMessage(err.message);
+      });
+  };
+
+  logout.onclick = function () {
+    fetch('/logout', { method: 'DELETE', credentials: 'same-origin' })
+      .then(handleResponse)
+      .then(showMessage)
+      .catch(function (err) {
+        showMessage(err.message);
+      });
+  };
+
+  let ws;
+
+  wsButton.onclick = function () {
+    if (ws) {
+      ws.onerror = ws.onopen = ws.onclose = null;
+      ws.close();
+    }
+
+    ws = new WebSocket(`ws://${location.host}`);
+    ws.onerror = function () {
+      showMessage('WebSocket error');
+    };
+    ws.onopen = function () {
+      showMessage('WebSocket connection established');
+    };
+    ws.onclose = function () {
+      showMessage('WebSocket connection closed');
+      ws = null;
+    };
+  };
+
+  wsSendButton.onclick = function () {
+    if (!ws) {
+      showMessage('No WebSocket connection');
+      return;
+    }
+
+    ws.send('Hello World!');
+    showMessage('Sent "Hello World!"');
+  };
+})();
diff --git a/testing/xpcshell/node-ws/examples/express-session-parse/public/index.html b/testing/xpcshell/node-ws/examples/express-session-parse/public/index.html
new file mode 100644
index 0000000000..c07aa2e87a
--- /dev/null
+++ b/testing/xpcshell/node-ws/examples/express-session-parse/public/index.html
@@ -0,0 +1,24 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+      <meta charset="utf-8">
+      <title>Express session demo</title>
+  </head>
+  <body>
+    <h1>Choose an action.</h1>
+    <button id="login" type="button" title="Simulate login">
+      Simulate login
+    </button>
+    <button id="logout" type="button" title="Simulate logout">
+      Simulate logout
+    </button>
+    <button id="wsButton" type="button" title="Open WebSocket connection">
+      Open WebSocket connection
+    </button>
+    <button id="wsSendButton" type="button" title="Send WebSocket message">
+      Send WebSocket message
+    </button>
+    <pre id="messages" style="height: 400px; overflow: scroll"></pre>
+    <script src="app.js"></script>
+  </body>
+</html>
diff --git a/testing/xpcshell/node-ws/examples/server-stats/index.js b/testing/xpcshell/node-ws/examples/server-stats/index.js
new file mode 100644
index 0000000000..e8754b5b28
--- /dev/null
+++ b/testing/xpcshell/node-ws/examples/server-stats/index.js
@@ -0,0 +1,33 @@
+'use strict';
+
+const express = require('express');
+const path = require('path');
+const { createServer } = require('http');
+
+const { WebSocketServer } = require('../..');
+
+const app = express();
+app.use(express.static(path.join(__dirname, '/public')));
+
+const server = createServer(app);
+const wss = new WebSocketServer({ server });
+
+wss.on('connection', function (ws) {
+  const id = setInterval(function () {
+    ws.send(JSON.stringify(process.memoryUsage()), function () {
+      //
+      // Ignore errors.
+      //
+    });
+  }, 100);
+  console.log('started client interval');
+
+  ws.on('close', function () {
+    console.log('stopping client interval');
+    clearInterval(id);
+  });
+});
+
+server.listen(8080, function () {
+  console.log('Listening on http://localhost:8080');
+});
diff --git a/testing/xpcshell/node-ws/examples/server-stats/package.json b/testing/xpcshell/node-ws/examples/server-stats/package.json
new file mode 100644
index 0000000000..20e2029133
--- /dev/null
+++ b/testing/xpcshell/node-ws/examples/server-stats/package.json
@@ -0,0 +1,9 @@
+{
+  "author": "",
+  "name": "serverstats",
+  "version": "0.0.0",
+  "repository": "websockets/ws",
+  "dependencies": {
+    "express": "^4.16.4"
+  }
+}
diff --git a/testing/xpcshell/node-ws/examples/server-stats/public/index.html b/testing/xpcshell/node-ws/examples/server-stats/public/index.html
new file mode 100644
index 0000000000..a82815af6f
--- /dev/null
+++ b/testing/xpcshell/node-ws/examples/server-stats/public/index.html
@@ -0,0 +1,63 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+    <meta charset="utf-8">
+    <title>Server stats</title>
+    <style>
+      table, td {
+        border: 1px solid #333;
+      }
+
+      thead {
+        background-color: #333;
+        color: #fff;
+      }
+    </style>
+  </head>
+  <body>
+    <h1>Server stats</h1>
+    <table>
+      <thead>
+        <tr>
+          <th colspan="2">Memory usage</th>
+        </tr>
+      </thead>
+      <tbody>
+        <tr>
+          <td>RSS</td>
+          <td id="rss"></td>
+        </tr>
+        <tr>
+          <td>Heap total</td>
+          <td id="heapTotal"></td>
+        </tr>
+        <tr>
+          <td>Heap used</td>
+          <td id="heapUsed"></td>
+        </tr>
+        <tr>
+          <td>External</td>
+          <td id="external"></td>
+        </tr>
+      </tbody>
+    </table>
+    <script>
+      (function() {
+        const rss = document.getElementById('rss');
+        const heapTotal = document.getElementById('heapTotal');
+        const heapUsed = document.getElementById('heapUsed');
+        const external = document.getElementById('external');
+        const ws = new WebSocket(`ws://${location.host}`);
+
+        ws.onmessage = function(event) {
+          const data = JSON.parse(event.data);
+
+          rss.textContent = data.rss;
+          heapTotal.textContent = data.heapTotal;
+          heapUsed.textContent = data.heapUsed;
+          external.textContent = data.external;
+        };
+      })();
+    </script>
+  </body>
+</html>
diff --git a/testing/xpcshell/node-ws/examples/ssl.js b/testing/xpcshell/node-ws/examples/ssl.js
new file mode 100644
index 0000000000..a5e750b799
--- /dev/null
+++ b/testing/xpcshell/node-ws/examples/ssl.js
@@ -0,0 +1,37 @@
+'use strict';
+
+const https = require('https');
+const fs = require('fs');
+
+const { WebSocket, WebSocketServer } = require('..');
+
+const server = https.createServer({
+  cert: fs.readFileSync('../test/fixtures/certificate.pem'),
+  key: fs.readFileSync('../test/fixtures/key.pem')
+});
+
+const wss = new WebSocketServer({ server });
+
+wss.on('connection', function connection(ws) {
+  ws.on('message', function message(msg) {
+    console.log(msg.toString());
+  });
+});
+
+server.listen(function listening() {
+  //
+  // If the `rejectUnauthorized` option is not `false`, the server certificate
+  // is verified against a list of well-known CAs. An 'error' event is emitted
+  // if verification fails.
+  //
+  // The certificate used in this example is self-signed so `rejectUnauthorized`
+  // is set to `false`.
+  //
+  const ws = new WebSocket(`wss://localhost:${server.address().port}`, {
+    rejectUnauthorized: false
+  });
+
+  ws.on('open', function open() {
+    ws.send('All glory to WebSockets!');
+  });
+});
diff --git a/testing/xpcshell/node-ws/index.js b/testing/xpcshell/node-ws/index.js
new file mode 100644
index 0000000000..41edb3b81b
--- /dev/null
+++ b/testing/xpcshell/node-ws/index.js
@@ -0,0 +1,13 @@
+'use strict';
+
+const WebSocket = require('./lib/websocket');
+
+WebSocket.createWebSocketStream = require('./lib/stream');
+WebSocket.Server = require('./lib/websocket-server');
+WebSocket.Receiver = require('./lib/receiver');
+WebSocket.Sender = require('./lib/sender');
+
+WebSocket.WebSocket = WebSocket;
+WebSocket.WebSocketServer = WebSocket.Server;
+
+module.exports = WebSocket;
diff --git a/testing/xpcshell/node-ws/lib/buffer-util.js b/testing/xpcshell/node-ws/lib/buffer-util.js
new file mode 100644
index 0000000000..df75955467
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/buffer-util.js
@@ -0,0 +1,127 @@
+'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);
+  let offset = 0;
+
+  for (let i = 0; i < list.length; i++) {
+    const buf = list[i];
+    target.set(buf, offset);
+    offset += buf.length;
+  }
+
+  if (offset < totalLength) return target.slice(0, offset);
+
+  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 (let 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) {
+  for (let i = 0; i < buffer.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;
+
+  let buf;
+
+  if (data instanceof ArrayBuffer) {
+    buf = Buffer.from(data);
+  } else if (ArrayBuffer.isView(data)) {
+    buf = Buffer.from(data.buffer, data.byteOffset, data.byteLength);
+  } else {
+    buf = Buffer.from(data);
+    toBuffer.readOnly = false;
+  }
+
+  return buf;
+}
+
+module.exports = {
+  concat,
+  mask: _mask,
+  toArrayBuffer,
+  toBuffer,
+  unmask: _unmask
+};
+
+/* istanbul ignore else  */
+if (!process.env.WS_NO_BUFFER_UTIL) {
+  try {
+    const bufferUtil = require('bufferutil');
+
+    module.exports.mask = function (source, mask, output, offset, length) {
+      if (length < 48) _mask(source, mask, output, offset, length);
+      else bufferUtil.mask(source, mask, output, offset, length);
+    };
+
+    module.exports.unmask = function (buffer, mask) {
+      if (buffer.length < 32) _unmask(buffer, mask);
+      else bufferUtil.unmask(buffer, mask);
+    };
+  } catch (e) {
+    // Continue regardless of the error.
+  }
+}
diff --git a/testing/xpcshell/node-ws/lib/constants.js b/testing/xpcshell/node-ws/lib/constants.js
new file mode 100644
index 0000000000..d691b30a17
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/constants.js
@@ -0,0 +1,12 @@
+'use strict';
+
+module.exports = {
+  BINARY_TYPES: ['nodebuffer', 'arraybuffer', 'fragments'],
+  EMPTY_BUFFER: Buffer.alloc(0),
+  GUID: '258EAFA5-E914-47DA-95CA-C5AB0DC85B11',
+  kForOnEventAttribute: Symbol('kIsForOnEventAttribute'),
+  kListener: Symbol('kListener'),
+  kStatusCode: Symbol('status-code'),
+  kWebSocket: Symbol('websocket'),
+  NOOP: () => {}
+};
diff --git a/testing/xpcshell/node-ws/lib/event-target.js b/testing/xpcshell/node-ws/lib/event-target.js
new file mode 100644
index 0000000000..d5abd83a0f
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/event-target.js
@@ -0,0 +1,266 @@
+'use strict';
+
+const { kForOnEventAttribute, kListener } = require('./constants');
+
+const kCode = Symbol('kCode');
+const kData = Symbol('kData');
+const kError = Symbol('kError');
+const kMessage = Symbol('kMessage');
+const kReason = Symbol('kReason');
+const kTarget = Symbol('kTarget');
+const kType = Symbol('kType');
+const kWasClean = Symbol('kWasClean');
+
+/**
+ * Class representing an event.
+ */
+class Event {
+  /**
+   * Create a new `Event`.
+   *
+   * @param {String} type The name of the event
+   * @throws {TypeError} If the `type` argument is not specified
+   */
+  constructor(type) {
+    this[kTarget] = null;
+    this[kType] = type;
+  }
+
+  /**
+   * @type {*}
+   */
+  get target() {
+    return this[kTarget];
+  }
+
+  /**
+   * @type {String}
+   */
+  get type() {
+    return this[kType];
+  }
+}
+
+Object.defineProperty(Event.prototype, 'target', { enumerable: true });
+Object.defineProperty(Event.prototype, 'type', { enumerable: true });
+
+/**
+ * Class representing a close event.
+ *
+ * @extends Event
+ */
+class CloseEvent extends Event {
+  /**
+   * Create a new `CloseEvent`.
+   *
+   * @param {String} type The name of the event
+   * @param {Object} [options] A dictionary object that allows for setting
+   *     attributes via object members of the same name
+   * @param {Number} [options.code=0] The status code explaining why the
+   *     connection was closed
+   * @param {String} [options.reason=''] A human-readable string explaining why
+   *     the connection was closed
+   * @param {Boolean} [options.wasClean=false] Indicates whether or not the
+   *     connection was cleanly closed
+   */
+  constructor(type, options = {}) {
+    super(type);
+
+    this[kCode] = options.code === undefined ? 0 : options.code;
+    this[kReason] = options.reason === undefined ? '' : options.reason;
+    this[kWasClean] = options.wasClean === undefined ? false : options.wasClean;
+  }
+
+  /**
+   * @type {Number}
+   */
+  get code() {
+    return this[kCode];
+  }
+
+  /**
+   * @type {String}
+   */
+  get reason() {
+    return this[kReason];
+  }
+
+  /**
+   * @type {Boolean}
+   */
+  get wasClean() {
+    return this[kWasClean];
+  }
+}
+
+Object.defineProperty(CloseEvent.prototype, 'code', { enumerable: true });
+Object.defineProperty(CloseEvent.prototype, 'reason', { enumerable: true });
+Object.defineProperty(CloseEvent.prototype, 'wasClean', { enumerable: true });
+
+/**
+ * Class representing an error event.
+ *
+ * @extends Event
+ */
+class ErrorEvent extends Event {
+  /**
+   * Create a new `ErrorEvent`.
+   *
+   * @param {String} type The name of the event
+   * @param {Object} [options] A dictionary object that allows for setting
+   *     attributes via object members of the same name
+   * @param {*} [options.error=null] The error that generated this event
+   * @param {String} [options.message=''] The error message
+   */
+  constructor(type, options = {}) {
+    super(type);
+
+    this[kError] = options.error === undefined ? null : options.error;
+    this[kMessage] = options.message === undefined ? '' : options.message;
+  }
+
+  /**
+   * @type {*}
+   */
+  get error() {
+    return this[kError];
+  }
+
+  /**
+   * @type {String}
+   */
+  get message() {
+    return this[kMessage];
+  }
+}
+
+Object.defineProperty(ErrorEvent.prototype, 'error', { enumerable: true });
+Object.defineProperty(ErrorEvent.prototype, 'message', { enumerable: true });
+
+/**
+ * Class representing a message event.
+ *
+ * @extends Event
+ */
+class MessageEvent extends Event {
+  /**
+   * Create a new `MessageEvent`.
+   *
+   * @param {String} type The name of the event
+   * @param {Object} [options] A dictionary object that allows for setting
+   *     attributes via object members of the same name
+   * @param {*} [options.data=null] The message content
+   */
+  constructor(type, options = {}) {
+    super(type);
+
+    this[kData] = options.data === undefined ? null : options.data;
+  }
+
+  /**
+   * @type {*}
+   */
+  get data() {
+    return this[kData];
+  }
+}
+
+Object.defineProperty(MessageEvent.prototype, 'data', { enumerable: true });
+
+/**
+ * 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} type A string representing the event type to listen for
+   * @param {Function} listener The listener to add
+   * @param {Object} [options] An options object specifies characteristics about
+   *     the event listener
+   * @param {Boolean} [options.once=false] A `Boolean` indicating that the
+   *     listener should be invoked at most once after being added. If `true`,
+   *     the listener would be automatically removed when invoked.
+   * @public
+   */
+  addEventListener(type, listener, options = {}) {
+    let wrapper;
+
+    if (type === 'message') {
+      wrapper = function onMessage(data, isBinary) {
+        const event = new MessageEvent('message', {
+          data: isBinary ? data : data.toString()
+        });
+
+        event[kTarget] = this;
+        listener.call(this, event);
+      };
+    } else if (type === 'close') {
+      wrapper = function onClose(code, message) {
+        const event = new CloseEvent('close', {
+          code,
+          reason: message.toString(),
+          wasClean: this._closeFrameReceived && this._closeFrameSent
+        });
+
+        event[kTarget] = this;
+        listener.call(this, event);
+      };
+    } else if (type === 'error') {
+      wrapper = function onError(error) {
+        const event = new ErrorEvent('error', {
+          error,
+          message: error.message
+        });
+
+        event[kTarget] = this;
+        listener.call(this, event);
+      };
+    } else if (type === 'open') {
+      wrapper = function onOpen() {
+        const event = new Event('open');
+
+        event[kTarget] = this;
+        listener.call(this, event);
+      };
+    } else {
+      return;
+    }
+
+    wrapper[kForOnEventAttribute] = !!options[kForOnEventAttribute];
+    wrapper[kListener] = listener;
+
+    if (options.once) {
+      this.once(type, wrapper);
+    } else {
+      this.on(type, wrapper);
+    }
+  },
+
+  /**
+   * Remove an event listener.
+   *
+   * @param {String} type A string representing the event type to remove
+   * @param {Function} handler The listener to remove
+   * @public
+   */
+  removeEventListener(type, handler) {
+    for (const listener of this.listeners(type)) {
+      if (listener[kListener] === handler && !listener[kForOnEventAttribute]) {
+        this.removeListener(type, listener);
+        break;
+      }
+    }
+  }
+};
+
+module.exports = {
+  CloseEvent,
+  ErrorEvent,
+  Event,
+  EventTarget,
+  MessageEvent
+};
diff --git a/testing/xpcshell/node-ws/lib/extension.js b/testing/xpcshell/node-ws/lib/extension.js
new file mode 100644
index 0000000000..3d7895c1b0
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/extension.js
@@ -0,0 +1,203 @@
+'use strict';
+
+const { tokenChars } = require('./validation');
+
+/**
+ * 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 (dest[name] === undefined) dest[name] = [elem];
+  else dest[name].push(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 = Object.create(null);
+  let params = Object.create(null);
+  let mustUnescape = false;
+  let isEscaping = false;
+  let inQuotes = false;
+  let extensionName;
+  let paramName;
+  let start = -1;
+  let code = -1;
+  let end = -1;
+  let i = 0;
+
+  for (; i < header.length; i++) {
+    code = header.charCodeAt(i);
+
+    if (extensionName === undefined) {
+      if (end === -1 && tokenChars[code] === 1) {
+        if (start === -1) start = i;
+      } else if (
+        i !== 0 &&
+        (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 = Object.create(null);
+        } 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 = Object.create(null);
+          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;
+        let 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 = Object.create(null);
+          extensionName = undefined;
+        }
+
+        paramName = undefined;
+        start = end = -1;
+      } else {
+        throw new SyntaxError(`Unexpected character at index ${i}`);
+      }
+    }
+  }
+
+  if (start === -1 || inQuotes || code === 0x20 || code === 0x09) {
+    throw new SyntaxError('Unexpected end of input');
+  }
+
+  if (end === -1) end = i;
+  const token = header.slice(start, end);
+  if (extensionName === undefined) {
+    push(offers, token, params);
+  } else {
+    if (paramName === undefined) {
+      push(params, token, true);
+    } else if (mustUnescape) {
+      push(params, paramName, token.replace(/\\/g, ''));
+    } else {
+      push(params, paramName, token);
+    }
+    push(offers, extensionName, params);
+  }
+
+  return offers;
+}
+
+/**
+ * Builds the `Sec-WebSocket-Extensions` header field value.
+ *
+ * @param {Object} extensions The map of extensions and parameters to format
+ * @return {String} A string representing the given object
+ * @public
+ */
+function format(extensions) {
+  return Object.keys(extensions)
+    .map((extension) => {
+      let configurations = extensions[extension];
+      if (!Array.isArray(configurations)) configurations = [configurations];
+      return configurations
+        .map((params) => {
+          return [extension]
+            .concat(
+              Object.keys(params).map((k) => {
+                let values = params[k];
+                if (!Array.isArray(values)) values = [values];
+                return values
+                  .map((v) => (v === true ? k : `${k}=${v}`))
+                  .join('; ');
+              })
+            )
+            .join('; ');
+        })
+        .join(', ');
+    })
+    .join(', ');
+}
+
+module.exports = { format, parse };
diff --git a/testing/xpcshell/node-ws/lib/limiter.js b/testing/xpcshell/node-ws/lib/limiter.js
new file mode 100644
index 0000000000..3fd35784ea
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/limiter.js
@@ -0,0 +1,55 @@
+'use strict';
+
+const kDone = Symbol('kDone');
+const kRun = Symbol('kRun');
+
+/**
+ * A very simple job queue with adjustable concurrency. Adapted from
+ * https://github.com/STRML/async-limiter
+ */
+class Limiter {
+  /**
+   * Creates a new `Limiter`.
+   *
+   * @param {Number} [concurrency=Infinity] The maximum number of jobs allowed
+   *     to run concurrently
+   */
+  constructor(concurrency) {
+    this[kDone] = () => {
+      this.pending--;
+      this[kRun]();
+    };
+    this.concurrency = concurrency || Infinity;
+    this.jobs = [];
+    this.pending = 0;
+  }
+
+  /**
+   * Adds a job to the queue.
+   *
+   * @param {Function} job The job to run
+   * @public
+   */
+  add(job) {
+    this.jobs.push(job);
+    this[kRun]();
+  }
+
+  /**
+   * Removes a job from the queue and runs it if possible.
+   *
+   * @private
+   */
+  [kRun]() {
+    if (this.pending === this.concurrency) return;
+
+    if (this.jobs.length) {
+      const job = this.jobs.shift();
+
+      this.pending++;
+      job(this[kDone]);
+    }
+  }
+}
+
+module.exports = Limiter;
diff --git a/testing/xpcshell/node-ws/lib/permessage-deflate.js b/testing/xpcshell/node-ws/lib/permessage-deflate.js
new file mode 100644
index 0000000000..94603c98da
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/permessage-deflate.js
@@ -0,0 +1,511 @@
+'use strict';
+
+const zlib = require('zlib');
+
+const bufferUtil = require('./buffer-util');
+const Limiter = require('./limiter');
+const { kStatusCode } = require('./constants');
+
+const TRAILER = Buffer.from([0x00, 0x00, 0xff, 0xff]);
+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|Number)} [options.clientMaxWindowBits] Advertise support
+   *     for, or request, a custom client window size
+   * @param {Boolean} [options.clientNoContextTakeover=false] Advertise/
+   *     acknowledge disabling of client context takeover
+   * @param {Number} [options.concurrencyLimit=10] The number of concurrent
+   *     calls to zlib
+   * @param {(Boolean|Number)} [options.serverMaxWindowBits] Request/confirm the
+   *     use of a custom server window size
+   * @param {Boolean} [options.serverNoContextTakeover=false] Request/accept
+   *     disabling of server context takeover
+   * @param {Number} [options.threshold=1024] Size (in bytes) below which
+   *     messages should not be compressed if context takeover is disabled
+   * @param {Object} [options.zlibDeflateOptions] Options to pass to zlib on
+   *     deflate
+   * @param {Object} [options.zlibInflateOptions] Options to pass to zlib on
+   *     inflate
+   * @param {Boolean} [isServer=false] Create the instance in either server or
+   *     client mode
+   * @param {Number} [maxPayload=0] 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) {
+      const callback = this._deflate[kCallback];
+
+      this._deflate.close();
+      this._deflate = null;
+
+      if (callback) {
+        callback(
+          new Error(
+            'The deflate stream was closed while data was being processed'
+          )
+        );
+      }
+    }
+  }
+
+  /**
+   *  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) => {
+        let 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.
+   *
+   * @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.add((done) => {
+      this._decompress(data, fin, (err, result) => {
+        done();
+        callback(err, result);
+      });
+    });
+  }
+
+  /**
+   * Compress data. Concurrency limited.
+   *
+   * @param {(Buffer|String)} 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.add((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 = `${endpoint}_max_window_bits`;
+      const windowBits =
+        typeof this.params[key] !== 'number'
+          ? zlib.Z_DEFAULT_WINDOWBITS
+          : this.params[key];
+
+      this._inflate = zlib.createInflateRaw({
+        ...this._options.zlibInflateOptions,
+        windowBits
+      });
+      this._inflate[kPerMessageDeflate] = this;
+      this._inflate[kTotalLength] = 0;
+      this._inflate[kBuffers] = [];
+      this._inflate.on('error', inflateOnError);
+      this._inflate.on('data', inflateOnData);
+    }
+
+    this._inflate[kCallback] = callback;
+
+    this._inflate.write(data);
+    if (fin) this._inflate.write(TRAILER);
+
+    this._inflate.flush(() => {
+      const err = this._inflate[kError];
+
+      if (err) {
+        this._inflate.close();
+        this._inflate = null;
+        callback(err);
+        return;
+      }
+
+      const data = bufferUtil.concat(
+        this._inflate[kBuffers],
+        this._inflate[kTotalLength]
+      );
+
+      if (this._inflate._readableState.endEmitted) {
+        this._inflate.close();
+        this._inflate = null;
+      } else {
+        this._inflate[kTotalLength] = 0;
+        this._inflate[kBuffers] = [];
+
+        if (fin && this.params[`${endpoint}_no_context_takeover`]) {
+          this._inflate.reset();
+        }
+      }
+
+      callback(null, data);
+    });
+  }
+
+  /**
+   * Compress data.
+   *
+   * @param {(Buffer|String)} 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) {
+    const endpoint = this._isServer ? 'server' : 'client';
+
+    if (!this._deflate) {
+      const key = `${endpoint}_max_window_bits`;
+      const windowBits =
+        typeof this.params[key] !== 'number'
+          ? zlib.Z_DEFAULT_WINDOWBITS
+          : this.params[key];
+
+      this._deflate = zlib.createDeflateRaw({
+        ...this._options.zlibDeflateOptions,
+        windowBits
+      });
+
+      this._deflate[kTotalLength] = 0;
+      this._deflate[kBuffers] = [];
+
+      this._deflate.on('data', deflateOnData);
+    }
+
+    this._deflate[kCallback] = callback;
+
+    this._deflate.write(data);
+    this._deflate.flush(zlib.Z_SYNC_FLUSH, () => {
+      if (!this._deflate) {
+        //
+        // The deflate stream was closed while data was being processed.
+        //
+        return;
+      }
+
+      let data = bufferUtil.concat(
+        this._deflate[kBuffers],
+        this._deflate[kTotalLength]
+      );
+
+      if (fin) data = data.slice(0, data.length - 4);
+
+      //
+      // Ensure that the callback will not be called again in
+      // `PerMessageDeflate#cleanup()`.
+      //
+      this._deflate[kCallback] = null;
+
+      this._deflate[kTotalLength] = 0;
+      this._deflate[kBuffers] = [];
+
+      if (fin && this.params[`${endpoint}_no_context_takeover`]) {
+        this._deflate.reset();
+      }
+
+      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].code = 'WS_ERR_UNSUPPORTED_MESSAGE_LENGTH';
+  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);
+}
diff --git a/testing/xpcshell/node-ws/lib/receiver.js b/testing/xpcshell/node-ws/lib/receiver.js
new file mode 100644
index 0000000000..2d29d62bb0
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/receiver.js
@@ -0,0 +1,618 @@
+'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 Writable
+ */
+class Receiver extends Writable {
+  /**
+   * Creates a Receiver instance.
+   *
+   * @param {Object} [options] Options object
+   * @param {String} [options.binaryType=nodebuffer] The type for binary data
+   * @param {Object} [options.extensions] An object containing the negotiated
+   *     extensions
+   * @param {Boolean} [options.isServer=false] Specifies whether to operate in
+   *     client or server mode
+   * @param {Number} [options.maxPayload=0] The maximum allowed message length
+   * @param {Boolean} [options.skipUTF8Validation=false] Specifies whether or
+   *     not to skip UTF-8 validation for text and close messages
+   */
+  constructor(options = {}) {
+    super();
+
+    this._binaryType = options.binaryType || BINARY_TYPES[0];
+    this._extensions = options.extensions || {};
+    this._isServer = !!options.isServer;
+    this._maxPayload = options.maxPayload | 0;
+    this._skipUTF8Validation = !!options.skipUTF8Validation;
+    this[kWebSocket] = undefined;
+
+    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
+   * @private
+   */
+  _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];
+      const offset = dst.length - n;
+
+      if (n >= buf.length) {
+        dst.set(this._buffers.shift(), offset);
+      } else {
+        dst.set(new Uint8Array(buf.buffer, buf.byteOffset, n), offset);
+        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) {
+    let 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,
+        'WS_ERR_UNEXPECTED_RSV_2_3'
+      );
+    }
+
+    const compressed = (buf[0] & 0x40) === 0x40;
+
+    if (compressed && !this._extensions[PerMessageDeflate.extensionName]) {
+      this._loop = false;
+      return error(
+        RangeError,
+        'RSV1 must be clear',
+        true,
+        1002,
+        'WS_ERR_UNEXPECTED_RSV_1'
+      );
+    }
+
+    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,
+          'WS_ERR_UNEXPECTED_RSV_1'
+        );
+      }
+
+      if (!this._fragmented) {
+        this._loop = false;
+        return error(
+          RangeError,
+          'invalid opcode 0',
+          true,
+          1002,
+          'WS_ERR_INVALID_OPCODE'
+        );
+      }
+
+      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,
+          'WS_ERR_INVALID_OPCODE'
+        );
+      }
+
+      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,
+          'WS_ERR_EXPECTED_FIN'
+        );
+      }
+
+      if (compressed) {
+        this._loop = false;
+        return error(
+          RangeError,
+          'RSV1 must be clear',
+          true,
+          1002,
+          'WS_ERR_UNEXPECTED_RSV_1'
+        );
+      }
+
+      if (this._payloadLength > 0x7d) {
+        this._loop = false;
+        return error(
+          RangeError,
+          `invalid payload length ${this._payloadLength}`,
+          true,
+          1002,
+          'WS_ERR_INVALID_CONTROL_PAYLOAD_LENGTH'
+        );
+      }
+    } else {
+      this._loop = false;
+      return error(
+        RangeError,
+        `invalid opcode ${this._opcode}`,
+        true,
+        1002,
+        'WS_ERR_INVALID_OPCODE'
+      );
+    }
+
+    if (!this._fin && !this._fragmented) this._fragmented = this._opcode;
+    this._masked = (buf[1] & 0x80) === 0x80;
+
+    if (this._isServer) {
+      if (!this._masked) {
+        this._loop = false;
+        return error(
+          RangeError,
+          'MASK must be set',
+          true,
+          1002,
+          'WS_ERR_EXPECTED_MASK'
+        );
+      }
+    } else if (this._masked) {
+      this._loop = false;
+      return error(
+        RangeError,
+        'MASK must be clear',
+        true,
+        1002,
+        'WS_ERR_UNEXPECTED_MASK'
+      );
+    }
+
+    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,
+        'WS_ERR_UNSUPPORTED_DATA_PAYLOAD_LENGTH'
+      );
+    }
+
+    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,
+          'WS_ERR_UNSUPPORTED_MESSAGE_LENGTH'
+        );
+      }
+    }
+
+    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) {
+    let data = EMPTY_BUFFER;
+
+    if (this._payloadLength) {
+      if (this._bufferedBytes < this._payloadLength) {
+        this._loop = false;
+        return;
+      }
+
+      data = this.consume(this._payloadLength);
+
+      if (
+        this._masked &&
+        (this._mask[0] | this._mask[1] | this._mask[2] | this._mask[3]) !== 0
+      ) {
+        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 length 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,
+              'WS_ERR_UNSUPPORTED_MESSAGE_LENGTH'
+            )
+          );
+        }
+
+        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) {
+        let 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, true);
+      } else {
+        const buf = concat(fragments, messageLength);
+
+        if (!this._skipUTF8Validation && !isValidUTF8(buf)) {
+          this._loop = false;
+          return error(
+            Error,
+            'invalid UTF-8 sequence',
+            true,
+            1007,
+            'WS_ERR_INVALID_UTF8'
+          );
+        }
+
+        this.emit('message', buf, false);
+      }
+    }
+
+    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, EMPTY_BUFFER);
+        this.end();
+      } else if (data.length === 1) {
+        return error(
+          RangeError,
+          'invalid payload length 1',
+          true,
+          1002,
+          'WS_ERR_INVALID_CONTROL_PAYLOAD_LENGTH'
+        );
+      } else {
+        const code = data.readUInt16BE(0);
+
+        if (!isValidStatusCode(code)) {
+          return error(
+            RangeError,
+            `invalid status code ${code}`,
+            true,
+            1002,
+            'WS_ERR_INVALID_CLOSE_CODE'
+          );
+        }
+
+        const buf = data.slice(2);
+
+        if (!this._skipUTF8Validation && !isValidUTF8(buf)) {
+          return error(
+            Error,
+            'invalid UTF-8 sequence',
+            true,
+            1007,
+            'WS_ERR_INVALID_UTF8'
+          );
+        }
+
+        this.emit('conclude', code, buf);
+        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 {function(new: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
+ * @param {String} errorCode The exposed error code
+ * @return {(Error|RangeError)} The error
+ * @private
+ */
+function error(ErrorCtor, message, prefix, statusCode, errorCode) {
+  const err = new ErrorCtor(
+    prefix ? `Invalid WebSocket frame: ${message}` : message
+  );
+
+  Error.captureStackTrace(err, error);
+  err.code = errorCode;
+  err[kStatusCode] = statusCode;
+  return err;
+}
diff --git a/testing/xpcshell/node-ws/lib/sender.js b/testing/xpcshell/node-ws/lib/sender.js
new file mode 100644
index 0000000000..c848853629
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/sender.js
@@ -0,0 +1,478 @@
+/* eslint no-unused-vars: ["error", { "varsIgnorePattern": "^net|tls$" }] */
+
+'use strict';
+
+const net = require('net');
+const tls = require('tls');
+const { randomFillSync } = require('crypto');
+
+const PerMessageDeflate = require('./permessage-deflate');
+const { EMPTY_BUFFER } = require('./constants');
+const { isValidStatusCode } = require('./validation');
+const { mask: applyMask, toBuffer } = require('./buffer-util');
+
+const kByteLength = Symbol('kByteLength');
+const maskBuffer = Buffer.alloc(4);
+
+/**
+ * HyBi Sender implementation.
+ */
+class Sender {
+  /**
+   * Creates a Sender instance.
+   *
+   * @param {(net.Socket|tls.Socket)} socket The connection socket
+   * @param {Object} [extensions] An object containing the negotiated extensions
+   * @param {Function} [generateMask] The function used to generate the masking
+   *     key
+   */
+  constructor(socket, extensions, generateMask) {
+    this._extensions = extensions || {};
+
+    if (generateMask) {
+      this._generateMask = generateMask;
+      this._maskBuffer = Buffer.alloc(4);
+    }
+
+    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|String)} data The data to frame
+   * @param {Object} options Options object
+   * @param {Boolean} [options.fin=false] Specifies whether or not to set the
+   *     FIN bit
+   * @param {Function} [options.generateMask] The function used to generate the
+   *     masking key
+   * @param {Boolean} [options.mask=false] Specifies whether or not to mask
+   *     `data`
+   * @param {Buffer} [options.maskBuffer] The buffer used to store the masking
+   *     key
+   * @param {Number} options.opcode The opcode
+   * @param {Boolean} [options.readOnly=false] Specifies whether `data` can be
+   *     modified
+   * @param {Boolean} [options.rsv1=false] Specifies whether or not to set the
+   *     RSV1 bit
+   * @return {(Buffer|String)[]} The framed data
+   * @public
+   */
+  static frame(data, options) {
+    let mask;
+    let merge = false;
+    let offset = 2;
+    let skipMasking = false;
+
+    if (options.mask) {
+      mask = options.maskBuffer || maskBuffer;
+
+      if (options.generateMask) {
+        options.generateMask(mask);
+      } else {
+        randomFillSync(mask, 0, 4);
+      }
+
+      skipMasking = (mask[0] | mask[1] | mask[2] | mask[3]) === 0;
+      offset = 6;
+    }
+
+    let dataLength;
+
+    if (typeof data === 'string') {
+      if (
+        (!options.mask || skipMasking) &&
+        options[kByteLength] !== undefined
+      ) {
+        dataLength = options[kByteLength];
+      } else {
+        data = Buffer.from(data);
+        dataLength = data.length;
+      }
+    } else {
+      dataLength = data.length;
+      merge = options.mask && options.readOnly && !skipMasking;
+    }
+
+    let payloadLength = dataLength;
+
+    if (dataLength >= 65536) {
+      offset += 8;
+      payloadLength = 127;
+    } else if (dataLength > 125) {
+      offset += 2;
+      payloadLength = 126;
+    }
+
+    const target = Buffer.allocUnsafe(merge ? dataLength + 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(dataLength, 2);
+    } else if (payloadLength === 127) {
+      target[2] = target[3] = 0;
+      target.writeUIntBE(dataLength, 4, 6);
+    }
+
+    if (!options.mask) return [target, data];
+
+    target[1] |= 0x80;
+    target[offset - 4] = mask[0];
+    target[offset - 3] = mask[1];
+    target[offset - 2] = mask[2];
+    target[offset - 1] = mask[3];
+
+    if (skipMasking) return [target, data];
+
+    if (merge) {
+      applyMask(data, mask, target, offset, dataLength);
+      return [target];
+    }
+
+    applyMask(data, mask, data, 0, dataLength);
+    return [target, data];
+  }
+
+  /**
+   * Sends a close message to the other peer.
+   *
+   * @param {Number} [code] The status code component of the body
+   * @param {(String|Buffer)} [data] The message component of the body
+   * @param {Boolean} [mask=false] Specifies whether or not to mask the message
+   * @param {Function} [cb] Callback
+   * @public
+   */
+  close(code, data, mask, cb) {
+    let 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.length) {
+      buf = Buffer.allocUnsafe(2);
+      buf.writeUInt16BE(code, 0);
+    } else {
+      const length = Buffer.byteLength(data);
+
+      if (length > 123) {
+        throw new RangeError('The message must not be greater than 123 bytes');
+      }
+
+      buf = Buffer.allocUnsafe(2 + length);
+      buf.writeUInt16BE(code, 0);
+
+      if (typeof data === 'string') {
+        buf.write(data, 2);
+      } else {
+        buf.set(data, 2);
+      }
+    }
+
+    const options = {
+      [kByteLength]: buf.length,
+      fin: true,
+      generateMask: this._generateMask,
+      mask,
+      maskBuffer: this._maskBuffer,
+      opcode: 0x08,
+      readOnly: false,
+      rsv1: false
+    };
+
+    if (this._deflating) {
+      this.enqueue([this.dispatch, buf, false, options, cb]);
+    } else {
+      this.sendFrame(Sender.frame(buf, options), cb);
+    }
+  }
+
+  /**
+   * Sends a ping message to the other peer.
+   *
+   * @param {*} data The message to send
+   * @param {Boolean} [mask=false] Specifies whether or not to mask `data`
+   * @param {Function} [cb] Callback
+   * @public
+   */
+  ping(data, mask, cb) {
+    let byteLength;
+    let readOnly;
+
+    if (typeof data === 'string') {
+      byteLength = Buffer.byteLength(data);
+      readOnly = false;
+    } else {
+      data = toBuffer(data);
+      byteLength = data.length;
+      readOnly = toBuffer.readOnly;
+    }
+
+    if (byteLength > 125) {
+      throw new RangeError('The data size must not be greater than 125 bytes');
+    }
+
+    const options = {
+      [kByteLength]: byteLength,
+      fin: true,
+      generateMask: this._generateMask,
+      mask,
+      maskBuffer: this._maskBuffer,
+      opcode: 0x09,
+      readOnly,
+      rsv1: false
+    };
+
+    if (this._deflating) {
+      this.enqueue([this.dispatch, data, false, options, cb]);
+    } else {
+      this.sendFrame(Sender.frame(data, options), cb);
+    }
+  }
+
+  /**
+   * Sends a pong message to the other peer.
+   *
+   * @param {*} data The message to send
+   * @param {Boolean} [mask=false] Specifies whether or not to mask `data`
+   * @param {Function} [cb] Callback
+   * @public
+   */
+  pong(data, mask, cb) {
+    let byteLength;
+    let readOnly;
+
+    if (typeof data === 'string') {
+      byteLength = Buffer.byteLength(data);
+      readOnly = false;
+    } else {
+      data = toBuffer(data);
+      byteLength = data.length;
+      readOnly = toBuffer.readOnly;
+    }
+
+    if (byteLength > 125) {
+      throw new RangeError('The data size must not be greater than 125 bytes');
+    }
+
+    const options = {
+      [kByteLength]: byteLength,
+      fin: true,
+      generateMask: this._generateMask,
+      mask,
+      maskBuffer: this._maskBuffer,
+      opcode: 0x0a,
+      readOnly,
+      rsv1: false
+    };
+
+    if (this._deflating) {
+      this.enqueue([this.dispatch, data, false, options, cb]);
+    } else {
+      this.sendFrame(Sender.frame(data, options), cb);
+    }
+  }
+
+  /**
+   * Sends a data message to the other peer.
+   *
+   * @param {*} data The message to send
+   * @param {Object} options Options object
+   * @param {Boolean} [options.binary=false] Specifies whether `data` is binary
+   *     or text
+   * @param {Boolean} [options.compress=false] Specifies whether or not to
+   *     compress `data`
+   * @param {Boolean} [options.fin=false] Specifies whether the fragment is the
+   *     last one
+   * @param {Boolean} [options.mask=false] Specifies whether or not to mask
+   *     `data`
+   * @param {Function} [cb] Callback
+   * @public
+   */
+  send(data, options, cb) {
+    const perMessageDeflate = this._extensions[PerMessageDeflate.extensionName];
+    let opcode = options.binary ? 2 : 1;
+    let rsv1 = options.compress;
+
+    let byteLength;
+    let readOnly;
+
+    if (typeof data === 'string') {
+      byteLength = Buffer.byteLength(data);
+      readOnly = false;
+    } else {
+      data = toBuffer(data);
+      byteLength = data.length;
+      readOnly = toBuffer.readOnly;
+    }
+
+    if (this._firstFragment) {
+      this._firstFragment = false;
+      if (
+        rsv1 &&
+        perMessageDeflate &&
+        perMessageDeflate.params[
+          perMessageDeflate._isServer
+            ? 'server_no_context_takeover'
+            : 'client_no_context_takeover'
+        ]
+      ) {
+        rsv1 = byteLength >= perMessageDeflate._threshold;
+      }
+      this._compress = rsv1;
+    } else {
+      rsv1 = false;
+      opcode = 0;
+    }
+
+    if (options.fin) this._firstFragment = true;
+
+    if (perMessageDeflate) {
+      const opts = {
+        [kByteLength]: byteLength,
+        fin: options.fin,
+        generateMask: this._generateMask,
+        mask: options.mask,
+        maskBuffer: this._maskBuffer,
+        opcode,
+        readOnly,
+        rsv1
+      };
+
+      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, {
+          [kByteLength]: byteLength,
+          fin: options.fin,
+          generateMask: this._generateMask,
+          mask: options.mask,
+          maskBuffer: this._maskBuffer,
+          opcode,
+          readOnly,
+          rsv1: false
+        }),
+        cb
+      );
+    }
+  }
+
+  /**
+   * Dispatches a message.
+   *
+   * @param {(Buffer|String)} data The message to send
+   * @param {Boolean} [compress=false] Specifies whether or not to compress
+   *     `data`
+   * @param {Object} options Options object
+   * @param {Boolean} [options.fin=false] Specifies whether or not to set the
+   *     FIN bit
+   * @param {Function} [options.generateMask] The function used to generate the
+   *     masking key
+   * @param {Boolean} [options.mask=false] Specifies whether or not to mask
+   *     `data`
+   * @param {Buffer} [options.maskBuffer] The buffer used to store the masking
+   *     key
+   * @param {Number} options.opcode The opcode
+   * @param {Boolean} [options.readOnly=false] Specifies whether `data` can be
+   *     modified
+   * @param {Boolean} [options.rsv1=false] 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._bufferedBytes += options[kByteLength];
+    this._deflating = true;
+    perMessageDeflate.compress(data, options.fin, (_, buf) => {
+      if (this._socket.destroyed) {
+        const err = new Error(
+          'The socket was closed while data was being compressed'
+        );
+
+        if (typeof cb === 'function') cb(err);
+
+        for (let i = 0; i < this._queue.length; i++) {
+          const params = this._queue[i];
+          const callback = params[params.length - 1];
+
+          if (typeof callback === 'function') callback(err);
+        }
+
+        return;
+      }
+
+      this._bufferedBytes -= options[kByteLength];
+      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[3][kByteLength];
+      Reflect.apply(params[0], this, params.slice(1));
+    }
+  }
+
+  /**
+   * Enqueues a send operation.
+   *
+   * @param {Array} params Send operation parameters.
+   * @private
+   */
+  enqueue(params) {
+    this._bufferedBytes += params[3][kByteLength];
+    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;
diff --git a/testing/xpcshell/node-ws/lib/stream.js b/testing/xpcshell/node-ws/lib/stream.js
new file mode 100644
index 0000000000..230734b79a
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/stream.js
@@ -0,0 +1,159 @@
+'use strict';
+
+const { Duplex } = require('stream');
+
+/**
+ * Emits the `'close'` event on a stream.
+ *
+ * @param {Duplex} stream The stream.
+ * @private
+ */
+function emitClose(stream) {
+  stream.emit('close');
+}
+
+/**
+ * The listener of the `'end'` event.
+ *
+ * @private
+ */
+function duplexOnEnd() {
+  if (!this.destroyed && this._writableState.finished) {
+    this.destroy();
+  }
+}
+
+/**
+ * The listener of the `'error'` event.
+ *
+ * @param {Error} err The error
+ * @private
+ */
+function duplexOnError(err) {
+  this.removeListener('error', duplexOnError);
+  this.destroy();
+  if (this.listenerCount('error') === 0) {
+    // Do not suppress the throwing behavior.
+    this.emit('error', err);
+  }
+}
+
+/**
+ * Wraps a `WebSocket` in a duplex stream.
+ *
+ * @param {WebSocket} ws The `WebSocket` to wrap
+ * @param {Object} [options] The options for the `Duplex` constructor
+ * @return {Duplex} The duplex stream
+ * @public
+ */
+function createWebSocketStream(ws, options) {
+  let terminateOnDestroy = true;
+
+  const duplex = new Duplex({
+    ...options,
+    autoDestroy: false,
+    emitClose: false,
+    objectMode: false,
+    writableObjectMode: false
+  });
+
+  ws.on('message', function message(msg, isBinary) {
+    const data =
+      !isBinary && duplex._readableState.objectMode ? msg.toString() : msg;
+
+    if (!duplex.push(data)) ws.pause();
+  });
+
+  ws.once('error', function error(err) {
+    if (duplex.destroyed) return;
+
+    // Prevent `ws.terminate()` from being called by `duplex._destroy()`.
+    //
+    // - If the `'error'` event is emitted before the `'open'` event, then
+    //   `ws.terminate()` is a noop as no socket is assigned.
+    // - Otherwise, the error is re-emitted by the listener of the `'error'`
+    //   event of the `Receiver` object. The listener already closes the
+    //   connection by calling `ws.close()`. This allows a close frame to be
+    //   sent to the other peer. If `ws.terminate()` is called right after this,
+    //   then the close frame might not be sent.
+    terminateOnDestroy = false;
+    duplex.destroy(err);
+  });
+
+  ws.once('close', function close() {
+    if (duplex.destroyed) return;
+
+    duplex.push(null);
+  });
+
+  duplex._destroy = function (err, callback) {
+    if (ws.readyState === ws.CLOSED) {
+      callback(err);
+      process.nextTick(emitClose, duplex);
+      return;
+    }
+
+    let called = false;
+
+    ws.once('error', function error(err) {
+      called = true;
+      callback(err);
+    });
+
+    ws.once('close', function close() {
+      if (!called) callback(err);
+      process.nextTick(emitClose, duplex);
+    });
+
+    if (terminateOnDestroy) ws.terminate();
+  };
+
+  duplex._final = function (callback) {
+    if (ws.readyState === ws.CONNECTING) {
+      ws.once('open', function open() {
+        duplex._final(callback);
+      });
+      return;
+    }
+
+    // If the value of the `_socket` property is `null` it means that `ws` is a
+    // client websocket and the handshake failed. In fact, when this happens, a
+    // socket is never assigned to the websocket. Wait for the `'error'` event
+    // that will be emitted by the websocket.
+    if (ws._socket === null) return;
+
+    if (ws._socket._writableState.finished) {
+      callback();
+      if (duplex._readableState.endEmitted) duplex.destroy();
+    } else {
+      ws._socket.once('finish', function finish() {
+        // `duplex` is not destroyed here because the `'end'` event will be
+        // emitted on `duplex` after this `'finish'` event. The EOF signaling
+        // `null` chunk is, in fact, pushed when the websocket emits `'close'`.
+        callback();
+      });
+      ws.close();
+    }
+  };
+
+  duplex._read = function () {
+    if (ws.isPaused) ws.resume();
+  };
+
+  duplex._write = function (chunk, encoding, callback) {
+    if (ws.readyState === ws.CONNECTING) {
+      ws.once('open', function open() {
+        duplex._write(chunk, encoding, callback);
+      });
+      return;
+    }
+
+    ws.send(chunk, callback);
+  };
+
+  duplex.on('end', duplexOnEnd);
+  duplex.on('error', duplexOnError);
+  return duplex;
+}
+
+module.exports = createWebSocketStream;
diff --git a/testing/xpcshell/node-ws/lib/subprotocol.js b/testing/xpcshell/node-ws/lib/subprotocol.js
new file mode 100644
index 0000000000..d4381e8864
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/subprotocol.js
@@ -0,0 +1,62 @@
+'use strict';
+
+const { tokenChars } = require('./validation');
+
+/**
+ * Parses the `Sec-WebSocket-Protocol` header into a set of subprotocol names.
+ *
+ * @param {String} header The field value of the header
+ * @return {Set} The subprotocol names
+ * @public
+ */
+function parse(header) {
+  const protocols = new Set();
+  let start = -1;
+  let end = -1;
+  let i = 0;
+
+  for (i; i < header.length; i++) {
+    const code = header.charCodeAt(i);
+
+    if (end === -1 && tokenChars[code] === 1) {
+      if (start === -1) start = i;
+    } else if (
+      i !== 0 &&
+      (code === 0x20 /* ' ' */ || code === 0x09) /* '\t' */
+    ) {
+      if (end === -1 && start !== -1) end = i;
+    } else if (code === 0x2c /* ',' */) {
+      if (start === -1) {
+        throw new SyntaxError(`Unexpected character at index ${i}`);
+      }
+
+      if (end === -1) end = i;
+
+      const protocol = header.slice(start, end);
+
+      if (protocols.has(protocol)) {
+        throw new SyntaxError(`The "${protocol}" subprotocol is duplicated`);
+      }
+
+      protocols.add(protocol);
+      start = end = -1;
+    } else {
+      throw new SyntaxError(`Unexpected character at index ${i}`);
+    }
+  }
+
+  if (start === -1 || end !== -1) {
+    throw new SyntaxError('Unexpected end of input');
+  }
+
+  const protocol = header.slice(start, i);
+
+  if (protocols.has(protocol)) {
+    throw new SyntaxError(`The "${protocol}" subprotocol is duplicated`);
+  }
+
+  protocols.add(protocol);
+  return protocols;
+}
+
+module.exports = { parse };
diff --git a/testing/xpcshell/node-ws/lib/validation.js b/testing/xpcshell/node-ws/lib/validation.js
new file mode 100644
index 0000000000..44fc202906
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/validation.js
@@ -0,0 +1,125 @@
+'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
+];
+
+/**
+ * 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
+ */
+function isValidStatusCode(code) {
+  return (
+    (code >= 1000 &&
+      code <= 1014 &&
+      code !== 1004 &&
+      code !== 1005 &&
+      code !== 1006) ||
+    (code >= 3000 && code <= 4999)
+  );
+}
+
+/**
+ * Checks if a given buffer contains only correct UTF-8.
+ * Ported from https://www.cl.cam.ac.uk/%7Emgk25/ucs/utf8_check.c by
+ * Markus Kuhn.
+ *
+ * @param {Buffer} buf The buffer to check
+ * @return {Boolean} `true` if `buf` contains only correct UTF-8, else `false`
+ * @public
+ */
+function _isValidUTF8(buf) {
+  const len = buf.length;
+  let i = 0;
+
+  while (i < len) {
+    if ((buf[i] & 0x80) === 0) {
+      // 0xxxxxxx
+      i++;
+    } else if ((buf[i] & 0xe0) === 0xc0) {
+      // 110xxxxx 10xxxxxx
+      if (
+        i + 1 === len ||
+        (buf[i + 1] & 0xc0) !== 0x80 ||
+        (buf[i] & 0xfe) === 0xc0 // Overlong
+      ) {
+        return false;
+      }
+
+      i += 2;
+    } else if ((buf[i] & 0xf0) === 0xe0) {
+      // 1110xxxx 10xxxxxx 10xxxxxx
+      if (
+        i + 2 >= len ||
+        (buf[i + 1] & 0xc0) !== 0x80 ||
+        (buf[i + 2] & 0xc0) !== 0x80 ||
+        (buf[i] === 0xe0 && (buf[i + 1] & 0xe0) === 0x80) || // Overlong
+        (buf[i] === 0xed && (buf[i + 1] & 0xe0) === 0xa0) // Surrogate (U+D800 - U+DFFF)
+      ) {
+        return false;
+      }
+
+      i += 3;
+    } else if ((buf[i] & 0xf8) === 0xf0) {
+      // 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
+      if (
+        i + 3 >= len ||
+        (buf[i + 1] & 0xc0) !== 0x80 ||
+        (buf[i + 2] & 0xc0) !== 0x80 ||
+        (buf[i + 3] & 0xc0) !== 0x80 ||
+        (buf[i] === 0xf0 && (buf[i + 1] & 0xf0) === 0x80) || // Overlong
+        (buf[i] === 0xf4 && buf[i + 1] > 0x8f) ||
+        buf[i] > 0xf4 // > U+10FFFF
+      ) {
+        return false;
+      }
+
+      i += 4;
+    } else {
+      return false;
+    }
+  }
+
+  return true;
+}
+
+module.exports = {
+  isValidStatusCode,
+  isValidUTF8: _isValidUTF8,
+  tokenChars
+};
+
+/* istanbul ignore else  */
+if (!process.env.WS_NO_UTF_8_VALIDATE) {
+  try {
+    const isValidUTF8 = require('utf-8-validate');
+
+    module.exports.isValidUTF8 = function (buf) {
+      return buf.length < 150 ? _isValidUTF8(buf) : isValidUTF8(buf);
+    };
+  } catch (e) {
+    // Continue regardless of the error.
+  }
+}
diff --git a/testing/xpcshell/node-ws/lib/websocket-server.js b/testing/xpcshell/node-ws/lib/websocket-server.js
new file mode 100644
index 0000000000..bac30eb330
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/websocket-server.js
@@ -0,0 +1,535 @@
+/* eslint no-unused-vars: ["error", { "varsIgnorePattern": "^net|tls|https$" }] */
+
+'use strict';
+
+const EventEmitter = require('events');
+const http = require('http');
+const https = require('https');
+const net = require('net');
+const tls = require('tls');
+const { createHash } = require('crypto');
+
+const extension = require('./extension');
+const PerMessageDeflate = require('./permessage-deflate');
+const subprotocol = require('./subprotocol');
+const WebSocket = require('./websocket');
+const { GUID, kWebSocket } = require('./constants');
+
+const keyRegex = /^[+/0-9A-Za-z]{22}==$/;
+
+const RUNNING = 0;
+const CLOSING = 1;
+const CLOSED = 2;
+
+/**
+ * Class representing a WebSocket server.
+ *
+ * @extends EventEmitter
+ */
+class WebSocketServer extends EventEmitter {
+  /**
+   * Create a `WebSocketServer` instance.
+   *
+   * @param {Object} options Configuration options
+   * @param {Number} [options.backlog=511] The maximum length of the queue of
+   *     pending connections
+   * @param {Boolean} [options.clientTracking=true] Specifies whether or not to
+   *     track clients
+   * @param {Function} [options.handleProtocols] A hook to handle protocols
+   * @param {String} [options.host] The hostname where to bind the server
+   * @param {Number} [options.maxPayload=104857600] The maximum allowed message
+   *     size
+   * @param {Boolean} [options.noServer=false] Enable no server mode
+   * @param {String} [options.path] Accept only connections matching this path
+   * @param {(Boolean|Object)} [options.perMessageDeflate=false] Enable/disable
+   *     permessage-deflate
+   * @param {Number} [options.port] The port where to bind the server
+   * @param {(http.Server|https.Server)} [options.server] A pre-created HTTP/S
+   *     server to use
+   * @param {Boolean} [options.skipUTF8Validation=false] Specifies whether or
+   *     not to skip UTF-8 validation for text and close messages
+   * @param {Function} [options.verifyClient] A hook to reject connections
+   * @param {Function} [options.WebSocket=WebSocket] Specifies the `WebSocket`
+   *     class to use. It must be the `WebSocket` class or class that extends it
+   * @param {Function} [callback] A listener for the `listening` event
+   */
+  constructor(options, callback) {
+    super();
+
+    options = {
+      maxPayload: 100 * 1024 * 1024,
+      skipUTF8Validation: false,
+      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,
+      WebSocket,
+      ...options
+    };
+
+    if (
+      (options.port == null && !options.server && !options.noServer) ||
+      (options.port != null && (options.server || options.noServer)) ||
+      (options.server && options.noServer)
+    ) {
+      throw new TypeError(
+        'One and only 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) {
+      const emitConnection = this.emit.bind(this, 'connection');
+
+      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, emitConnection);
+        }
+      });
+    }
+
+    if (options.perMessageDeflate === true) options.perMessageDeflate = {};
+    if (options.clientTracking) {
+      this.clients = new Set();
+      this._shouldEmitClose = false;
+    }
+
+    this.options = options;
+    this._state = RUNNING;
+  }
+
+  /**
+   * 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();
+  }
+
+  /**
+   * Stop the server from accepting new connections and emit the `'close'` event
+   * when all existing connections are closed.
+   *
+   * @param {Function} [cb] A one-time listener for the `'close'` event
+   * @public
+   */
+  close(cb) {
+    if (this._state === CLOSED) {
+      if (cb) {
+        this.once('close', () => {
+          cb(new Error('The server is not running'));
+        });
+      }
+
+      process.nextTick(emitClose, this);
+      return;
+    }
+
+    if (cb) this.once('close', cb);
+
+    if (this._state === CLOSING) return;
+    this._state = CLOSING;
+
+    if (this.options.noServer || this.options.server) {
+      if (this._server) {
+        this._removeListeners();
+        this._removeListeners = this._server = null;
+      }
+
+      if (this.clients) {
+        if (!this.clients.size) {
+          process.nextTick(emitClose, this);
+        } else {
+          this._shouldEmitClose = true;
+        }
+      } else {
+        process.nextTick(emitClose, this);
+      }
+    } else {
+      const server = this._server;
+
+      this._removeListeners();
+      this._removeListeners = this._server = null;
+
+      //
+      // The HTTP/S server was created internally. Close it, and rely on its
+      // `'close'` event.
+      //
+      server.close(() => {
+        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|tls.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'];
+    const version = +req.headers['sec-websocket-version'];
+
+    if (req.method !== 'GET') {
+      const message = 'Invalid HTTP method';
+      abortHandshakeOrEmitwsClientError(this, req, socket, 405, message);
+      return;
+    }
+
+    if (req.headers.upgrade.toLowerCase() !== 'websocket') {
+      const message = 'Invalid Upgrade header';
+      abortHandshakeOrEmitwsClientError(this, req, socket, 400, message);
+      return;
+    }
+
+    if (!key || !keyRegex.test(key)) {
+      const message = 'Missing or invalid Sec-WebSocket-Key header';
+      abortHandshakeOrEmitwsClientError(this, req, socket, 400, message);
+      return;
+    }
+
+    if (version !== 8 && version !== 13) {
+      const message = 'Missing or invalid Sec-WebSocket-Version header';
+      abortHandshakeOrEmitwsClientError(this, req, socket, 400, message);
+      return;
+    }
+
+    if (!this.shouldHandle(req)) {
+      abortHandshake(socket, 400);
+      return;
+    }
+
+    const secWebSocketProtocol = req.headers['sec-websocket-protocol'];
+    let protocols = new Set();
+
+    if (secWebSocketProtocol !== undefined) {
+      try {
+        protocols = subprotocol.parse(secWebSocketProtocol);
+      } catch (err) {
+        const message = 'Invalid Sec-WebSocket-Protocol header';
+        abortHandshakeOrEmitwsClientError(this, req, socket, 400, message);
+        return;
+      }
+    }
+
+    const secWebSocketExtensions = req.headers['sec-websocket-extensions'];
+    const extensions = {};
+
+    if (
+      this.options.perMessageDeflate &&
+      secWebSocketExtensions !== undefined
+    ) {
+      const perMessageDeflate = new PerMessageDeflate(
+        this.options.perMessageDeflate,
+        true,
+        this.options.maxPayload
+      );
+
+      try {
+        const offers = extension.parse(secWebSocketExtensions);
+
+        if (offers[PerMessageDeflate.extensionName]) {
+          perMessageDeflate.accept(offers[PerMessageDeflate.extensionName]);
+          extensions[PerMessageDeflate.extensionName] = perMessageDeflate;
+        }
+      } catch (err) {
+        const message =
+          'Invalid or unacceptable Sec-WebSocket-Extensions header';
+        abortHandshakeOrEmitwsClientError(this, req, socket, 400, message);
+        return;
+      }
+    }
+
+    //
+    // Optionally call external client verification handler.
+    //
+    if (this.options.verifyClient) {
+      const info = {
+        origin:
+          req.headers[`${version === 8 ? 'sec-websocket-origin' : 'origin'}`],
+        secure: !!(req.socket.authorized || req.socket.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(
+            extensions,
+            key,
+            protocols,
+            req,
+            socket,
+            head,
+            cb
+          );
+        });
+        return;
+      }
+
+      if (!this.options.verifyClient(info)) return abortHandshake(socket, 401);
+    }
+
+    this.completeUpgrade(extensions, key, protocols, req, socket, head, cb);
+  }
+
+  /**
+   * Upgrade the connection to WebSocket.
+   *
+   * @param {Object} extensions The accepted extensions
+   * @param {String} key The value of the `Sec-WebSocket-Key` header
+   * @param {Set} protocols The subprotocols
+   * @param {http.IncomingMessage} req The request object
+   * @param {(net.Socket|tls.Socket)} socket The network socket between the
+   *     server and client
+   * @param {Buffer} head The first packet of the upgraded stream
+   * @param {Function} cb Callback
+   * @throws {Error} If called more than once with the same socket
+   * @private
+   */
+  completeUpgrade(extensions, key, protocols, req, socket, head, cb) {
+    //
+    // Destroy the socket if the client has already sent a FIN packet.
+    //
+    if (!socket.readable || !socket.writable) return socket.destroy();
+
+    if (socket[kWebSocket]) {
+      throw new Error(
+        'server.handleUpgrade() was called more than once with the same ' +
+          'socket, possibly due to a misconfiguration'
+      );
+    }
+
+    if (this._state > RUNNING) return abortHandshake(socket, 503);
+
+    const digest = 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 this.options.WebSocket(null);
+
+    if (protocols.size) {
+      //
+      // Optionally call external protocol selection handler.
+      //
+      const protocol = this.options.handleProtocols
+        ? this.options.handleProtocols(protocols, req)
+        : protocols.values().next().value;
+
+      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, {
+      maxPayload: this.options.maxPayload,
+      skipUTF8Validation: this.options.skipUTF8Validation
+    });
+
+    if (this.clients) {
+      this.clients.add(ws);
+      ws.on('close', () => {
+        this.clients.delete(ws);
+
+        if (this._shouldEmitClose && !this.clients.size) {
+          process.nextTick(emitClose, this);
+        }
+      });
+    }
+
+    cb(ws, req);
+  }
+}
+
+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._state = CLOSED;
+  server.emit('close');
+}
+
+/**
+ * Handle socket errors.
+ *
+ * @private
+ */
+function socketOnError() {
+  this.destroy();
+}
+
+/**
+ * Close the connection when preconditions are not fulfilled.
+ *
+ * @param {(net.Socket|tls.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) {
+  //
+  // The socket is writable unless the user destroyed or ended it before calling
+  // `server.handleUpgrade()` or in the `verifyClient` function, which is a user
+  // error. Handling this does not make much sense as the worst that can happen
+  // is that some of the data written by the user might be discarded due to the
+  // call to `socket.end()` below, which triggers an `'error'` event that in
+  // turn causes the socket to be destroyed.
+  //
+  message = message || http.STATUS_CODES[code];
+  headers = {
+    Connection: 'close',
+    'Content-Type': 'text/html',
+    'Content-Length': Buffer.byteLength(message),
+    ...headers
+  };
+
+  socket.once('finish', socket.destroy);
+
+  socket.end(
+    `HTTP/1.1 ${code} ${http.STATUS_CODES[code]}\r\n` +
+      Object.keys(headers)
+        .map((h) => `${h}: ${headers[h]}`)
+        .join('\r\n') +
+      '\r\n\r\n' +
+      message
+  );
+}
+
+/**
+ * Emit a `'wsClientError'` event on a `WebSocketServer` if there is at least
+ * one listener for it, otherwise call `abortHandshake()`.
+ *
+ * @param {WebSocketServer} server The WebSocket server
+ * @param {http.IncomingMessage} req The request object
+ * @param {(net.Socket|tls.Socket)} socket The socket of the upgrade request
+ * @param {Number} code The HTTP response status code
+ * @param {String} message The HTTP response body
+ * @private
+ */
+function abortHandshakeOrEmitwsClientError(server, req, socket, code, message) {
+  if (server.listenerCount('wsClientError')) {
+    const err = new Error(message);
+    Error.captureStackTrace(err, abortHandshakeOrEmitwsClientError);
+
+    server.emit('wsClientError', err, socket, req);
+  } else {
+    abortHandshake(socket, code, message);
+  }
+}
diff --git a/testing/xpcshell/node-ws/lib/websocket.js b/testing/xpcshell/node-ws/lib/websocket.js
new file mode 100644
index 0000000000..3132cc1500
--- /dev/null
+++ b/testing/xpcshell/node-ws/lib/websocket.js
@@ -0,0 +1,1305 @@
+/* eslint no-unused-vars: ["error", { "varsIgnorePattern": "^Readable$" }] */
+
+'use strict';
+
+const EventEmitter = require('events');
+const https = require('https');
+const http = require('http');
+const net = require('net');
+const tls = require('tls');
+const { randomBytes, createHash } = require('crypto');
+const { Readable } = require('stream');
+const { URL } = require('url');
+
+const PerMessageDeflate = require('./permessage-deflate');
+const Receiver = require('./receiver');
+const Sender = require('./sender');
+const {
+  BINARY_TYPES,
+  EMPTY_BUFFER,
+  GUID,
+  kForOnEventAttribute,
+  kListener,
+  kStatusCode,
+  kWebSocket,
+  NOOP
+} = require('./constants');
+const {
+  EventTarget: { addEventListener, removeEventListener }
+} = require('./event-target');
+const { format, parse } = require('./extension');
+const { toBuffer } = require('./buffer-util');
+
+const closeTimeout = 30 * 1000;
+const kAborted = Symbol('kAborted');
+const protocolVersions = [8, 13];
+const readyStates = ['CONNECTING', 'OPEN', 'CLOSING', 'CLOSED'];
+const subprotocolRegex = /^[!#$%&'*+\-.0-9A-Z^_`|a-z~]+$/;
+
+/**
+ * Class representing a WebSocket.
+ *
+ * @extends EventEmitter
+ */
+class WebSocket extends EventEmitter {
+  /**
+   * Create a new `WebSocket`.
+   *
+   * @param {(String|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._binaryType = BINARY_TYPES[0];
+    this._closeCode = 1006;
+    this._closeFrameReceived = false;
+    this._closeFrameSent = false;
+    this._closeMessage = EMPTY_BUFFER;
+    this._closeTimer = null;
+    this._extensions = {};
+    this._paused = false;
+    this._protocol = '';
+    this._readyState = WebSocket.CONNECTING;
+    this._receiver = null;
+    this._sender = null;
+    this._socket = null;
+
+    if (address !== null) {
+      this._bufferedAmount = 0;
+      this._isServer = false;
+      this._redirects = 0;
+
+      if (protocols === undefined) {
+        protocols = [];
+      } else if (!Array.isArray(protocols)) {
+        if (typeof protocols === 'object' && protocols !== null) {
+          options = protocols;
+          protocols = [];
+        } else {
+          protocols = [protocols];
+        }
+      }
+
+      initAsClient(this, address, protocols, options);
+    } else {
+      this._isServer = true;
+    }
+  }
+
+  /**
+   * 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 this._bufferedAmount;
+
+    return this._socket._writableState.length + this._sender._bufferedBytes;
+  }
+
+  /**
+   * @type {String}
+   */
+  get extensions() {
+    return Object.keys(this._extensions).join();
+  }
+
+  /**
+   * @type {Boolean}
+   */
+  get isPaused() {
+    return this._paused;
+  }
+
+  /**
+   * @type {Function}
+   */
+  /* istanbul ignore next */
+  get onclose() {
+    return null;
+  }
+
+  /**
+   * @type {Function}
+   */
+  /* istanbul ignore next */
+  get onerror() {
+    return null;
+  }
+
+  /**
+   * @type {Function}
+   */
+  /* istanbul ignore next */
+  get onopen() {
+    return null;
+  }
+
+  /**
+   * @type {Function}
+   */
+  /* istanbul ignore next */
+  get onmessage() {
+    return null;
+  }
+
+  /**
+   * @type {String}
+   */
+  get protocol() {
+    return this._protocol;
+  }
+
+  /**
+   * @type {Number}
+   */
+  get readyState() {
+    return this._readyState;
+  }
+
+  /**
+   * @type {String}
+   */
+  get url() {
+    return this._url;
+  }
+
+  /**
+   * Set up the socket and the internal resources.
+   *
+   * @param {(net.Socket|tls.Socket)} socket The network socket between the
+   *     server and client
+   * @param {Buffer} head The first packet of the upgraded stream
+   * @param {Object} options Options object
+   * @param {Function} [options.generateMask] The function used to generate the
+   *     masking key
+   * @param {Number} [options.maxPayload=0] The maximum allowed message size
+   * @param {Boolean} [options.skipUTF8Validation=false] Specifies whether or
+   *     not to skip UTF-8 validation for text and close messages
+   * @private
+   */
+  setSocket(socket, head, options) {
+    const receiver = new Receiver({
+      binaryType: this.binaryType,
+      extensions: this._extensions,
+      isServer: this._isServer,
+      maxPayload: options.maxPayload,
+      skipUTF8Validation: options.skipUTF8Validation
+    });
+
+    this._sender = new Sender(socket, this._extensions, options.generateMask);
+    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() {
+    if (!this._socket) {
+      this._readyState = WebSocket.CLOSED;
+      this.emit('close', this._closeCode, this._closeMessage);
+      return;
+    }
+
+    if (this._extensions[PerMessageDeflate.extensionName]) {
+      this._extensions[PerMessageDeflate.extensionName].cleanup();
+    }
+
+    this._receiver.removeAllListeners();
+    this._readyState = WebSocket.CLOSED;
+    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|Buffer)} [data] The reason 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._receiver._writableState.errorEmitted)
+      ) {
+        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._receiver._writableState.errorEmitted
+      ) {
+        this._socket.end();
+      }
+    });
+
+    //
+    // Specify a timeout for the closing handshake to complete.
+    //
+    this._closeTimer = setTimeout(
+      this._socket.destroy.bind(this._socket),
+      closeTimeout
+    );
+  }
+
+  /**
+   * Pause the socket.
+   *
+   * @public
+   */
+  pause() {
+    if (
+      this.readyState === WebSocket.CONNECTING ||
+      this.readyState === WebSocket.CLOSED
+    ) {
+      return;
+    }
+
+    this._paused = true;
+    this._socket.pause();
+  }
+
+  /**
+   * 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 (this.readyState === WebSocket.CONNECTING) {
+      throw new Error('WebSocket is not open: readyState 0 (CONNECTING)');
+    }
+
+    if (typeof data === 'function') {
+      cb = data;
+      data = mask = undefined;
+    } else if (typeof mask === 'function') {
+      cb = mask;
+      mask = undefined;
+    }
+
+    if (typeof data === 'number') data = data.toString();
+
+    if (this.readyState !== WebSocket.OPEN) {
+      sendAfterClose(this, data, cb);
+      return;
+    }
+
+    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 (this.readyState === WebSocket.CONNECTING) {
+      throw new Error('WebSocket is not open: readyState 0 (CONNECTING)');
+    }
+
+    if (typeof data === 'function') {
+      cb = data;
+      data = mask = undefined;
+    } else if (typeof mask === 'function') {
+      cb = mask;
+      mask = undefined;
+    }
+
+    if (typeof data === 'number') data = data.toString();
+
+    if (this.readyState !== WebSocket.OPEN) {
+      sendAfterClose(this, data, cb);
+      return;
+    }
+
+    if (mask === undefined) mask = !this._isServer;
+    this._sender.pong(data || EMPTY_BUFFER, mask, cb);
+  }
+
+  /**
+   * Resume the socket.
+   *
+   * @public
+   */
+  resume() {
+    if (
+      this.readyState === WebSocket.CONNECTING ||
+      this.readyState === WebSocket.CLOSED
+    ) {
+      return;
+    }
+
+    this._paused = false;
+    if (!this._receiver._writableState.needDrain) this._socket.resume();
+  }
+
+  /**
+   * Send a data message.
+   *
+   * @param {*} data The message to send
+   * @param {Object} [options] Options object
+   * @param {Boolean} [options.binary] Specifies whether `data` is binary or
+   *     text
+   * @param {Boolean} [options.compress] Specifies whether or not to compress
+   *     `data`
+   * @param {Boolean} [options.fin=true] 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 (this.readyState === WebSocket.CONNECTING) {
+      throw new Error('WebSocket is not open: readyState 0 (CONNECTING)');
+    }
+
+    if (typeof options === 'function') {
+      cb = options;
+      options = {};
+    }
+
+    if (typeof data === 'number') data = data.toString();
+
+    if (this.readyState !== WebSocket.OPEN) {
+      sendAfterClose(this, data, cb);
+      return;
+    }
+
+    const opts = {
+      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();
+    }
+  }
+}
+
+/**
+ * @constant {Number} CONNECTING
+ * @memberof WebSocket
+ */
+Object.defineProperty(WebSocket, 'CONNECTING', {
+  enumerable: true,
+  value: readyStates.indexOf('CONNECTING')
+});
+
+/**
+ * @constant {Number} CONNECTING
+ * @memberof WebSocket.prototype
+ */
+Object.defineProperty(WebSocket.prototype, 'CONNECTING', {
+  enumerable: true,
+  value: readyStates.indexOf('CONNECTING')
+});
+
+/**
+ * @constant {Number} OPEN
+ * @memberof WebSocket
+ */
+Object.defineProperty(WebSocket, 'OPEN', {
+  enumerable: true,
+  value: readyStates.indexOf('OPEN')
+});
+
+/**
+ * @constant {Number} OPEN
+ * @memberof WebSocket.prototype
+ */
+Object.defineProperty(WebSocket.prototype, 'OPEN', {
+  enumerable: true,
+  value: readyStates.indexOf('OPEN')
+});
+
+/**
+ * @constant {Number} CLOSING
+ * @memberof WebSocket
+ */
+Object.defineProperty(WebSocket, 'CLOSING', {
+  enumerable: true,
+  value: readyStates.indexOf('CLOSING')
+});
+
+/**
+ * @constant {Number} CLOSING
+ * @memberof WebSocket.prototype
+ */
+Object.defineProperty(WebSocket.prototype, 'CLOSING', {
+  enumerable: true,
+  value: readyStates.indexOf('CLOSING')
+});
+
+/**
+ * @constant {Number} CLOSED
+ * @memberof WebSocket
+ */
+Object.defineProperty(WebSocket, 'CLOSED', {
+  enumerable: true,
+  value: readyStates.indexOf('CLOSED')
+});
+
+/**
+ * @constant {Number} CLOSED
+ * @memberof WebSocket.prototype
+ */
+Object.defineProperty(WebSocket.prototype, 'CLOSED', {
+  enumerable: true,
+  value: readyStates.indexOf('CLOSED')
+});
+
+[
+  'binaryType',
+  'bufferedAmount',
+  'extensions',
+  'isPaused',
+  'protocol',
+  'readyState',
+  'url'
+].forEach((property) => {
+  Object.defineProperty(WebSocket.prototype, property, { enumerable: true });
+});
+
+//
+// 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}`, {
+    enumerable: true,
+    get() {
+      for (const listener of this.listeners(method)) {
+        if (listener[kForOnEventAttribute]) return listener[kListener];
+      }
+
+      return null;
+    },
+    set(handler) {
+      for (const listener of this.listeners(method)) {
+        if (listener[kForOnEventAttribute]) {
+          this.removeListener(method, listener);
+          break;
+        }
+      }
+
+      if (typeof handler !== 'function') return;
+
+      this.addEventListener(method, handler, {
+        [kForOnEventAttribute]: true
+      });
+    }
+  });
+});
+
+WebSocket.prototype.addEventListener = addEventListener;
+WebSocket.prototype.removeEventListener = removeEventListener;
+
+module.exports = WebSocket;
+
+/**
+ * Initialize a WebSocket client.
+ *
+ * @param {WebSocket} websocket The client to initialize
+ * @param {(String|URL)} address The URL to which to connect
+ * @param {Array} protocols The subprotocols
+ * @param {Object} [options] Connection options
+ * @param {Boolean} [options.followRedirects=false] Whether or not to follow
+ *     redirects
+ * @param {Function} [options.generateMask] The function used to generate the
+ *     masking key
+ * @param {Number} [options.handshakeTimeout] Timeout in milliseconds for the
+ *     handshake request
+ * @param {Number} [options.maxPayload=104857600] The maximum allowed message
+ *     size
+ * @param {Number} [options.maxRedirects=10] The maximum number of redirects
+ *     allowed
+ * @param {String} [options.origin] Value of the `Origin` or
+ *     `Sec-WebSocket-Origin` header
+ * @param {(Boolean|Object)} [options.perMessageDeflate=true] Enable/disable
+ *     permessage-deflate
+ * @param {Number} [options.protocolVersion=13] Value of the
+ *     `Sec-WebSocket-Version` header
+ * @param {Boolean} [options.skipUTF8Validation=false] Specifies whether or
+ *     not to skip UTF-8 validation for text and close messages
+ * @private
+ */
+function initAsClient(websocket, address, protocols, options) {
+  const opts = {
+    protocolVersion: protocolVersions[1],
+    maxPayload: 100 * 1024 * 1024,
+    skipUTF8Validation: false,
+    perMessageDeflate: true,
+    followRedirects: false,
+    maxRedirects: 10,
+    ...options,
+    createConnection: undefined,
+    socketPath: undefined,
+    hostname: undefined,
+    protocol: undefined,
+    timeout: undefined,
+    method: 'GET',
+    host: undefined,
+    path: undefined,
+    port: undefined
+  };
+
+  if (!protocolVersions.includes(opts.protocolVersion)) {
+    throw new RangeError(
+      `Unsupported protocol version: ${opts.protocolVersion} ` +
+        `(supported versions: ${protocolVersions.join(', ')})`
+    );
+  }
+
+  let parsedUrl;
+
+  if (address instanceof URL) {
+    parsedUrl = address;
+    websocket._url = address.href;
+  } else {
+    try {
+      parsedUrl = new URL(address);
+    } catch (e) {
+      throw new SyntaxError(`Invalid URL: ${address}`);
+    }
+
+    websocket._url = address;
+  }
+
+  const isSecure = parsedUrl.protocol === 'wss:';
+  const isUnixSocket = parsedUrl.protocol === 'ws+unix:';
+  let invalidURLMessage;
+
+  if (parsedUrl.protocol !== 'ws:' && !isSecure && !isUnixSocket) {
+    invalidURLMessage =
+      'The URL\'s protocol must be one of "ws:", "wss:", or "ws+unix:"';
+  } else if (isUnixSocket && !parsedUrl.pathname) {
+    invalidURLMessage = "The URL's pathname is empty";
+  } else if (parsedUrl.hash) {
+    invalidURLMessage = 'The URL contains a fragment identifier';
+  }
+
+  if (invalidURLMessage) {
+    const err = new SyntaxError(invalidURLMessage);
+
+    if (websocket._redirects === 0) {
+      throw err;
+    } else {
+      emitErrorAndClose(websocket, err);
+      return;
+    }
+  }
+
+  const defaultPort = isSecure ? 443 : 80;
+  const key = randomBytes(16).toString('base64');
+  const request = isSecure ? https.request : http.request;
+  const protocolSet = new Set();
+  let 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 = {
+    ...opts.headers,
+    'Sec-WebSocket-Version': opts.protocolVersion,
+    'Sec-WebSocket-Key': key,
+    Connection: 'Upgrade',
+    Upgrade: 'websocket'
+  };
+  opts.path = parsedUrl.pathname + parsedUrl.search;
+  opts.timeout = opts.handshakeTimeout;
+
+  if (opts.perMessageDeflate) {
+    perMessageDeflate = new PerMessageDeflate(
+      opts.perMessageDeflate !== true ? opts.perMessageDeflate : {},
+      false,
+      opts.maxPayload
+    );
+    opts.headers['Sec-WebSocket-Extensions'] = format({
+      [PerMessageDeflate.extensionName]: perMessageDeflate.offer()
+    });
+  }
+  if (protocols.length) {
+    for (const protocol of protocols) {
+      if (
+        typeof protocol !== 'string' ||
+        !subprotocolRegex.test(protocol) ||
+        protocolSet.has(protocol)
+      ) {
+        throw new SyntaxError(
+          'An invalid or duplicated subprotocol was specified'
+        );
+      }
+
+      protocolSet.add(protocol);
+    }
+
+    opts.headers['Sec-WebSocket-Protocol'] = protocols.join(',');
+  }
+  if (opts.origin) {
+    if (opts.protocolVersion < 13) {
+      opts.headers['Sec-WebSocket-Origin'] = opts.origin;
+    } else {
+      opts.headers.Origin = opts.origin;
+    }
+  }
+  if (parsedUrl.username || parsedUrl.password) {
+    opts.auth = `${parsedUrl.username}:${parsedUrl.password}`;
+  }
+
+  if (isUnixSocket) {
+    const parts = opts.path.split(':');
+
+    opts.socketPath = parts[0];
+    opts.path = parts[1];
+  }
+
+  let req;
+
+  if (opts.followRedirects) {
+    if (websocket._redirects === 0) {
+      websocket._originalUnixSocket = isUnixSocket;
+      websocket._originalSecure = isSecure;
+      websocket._originalHostOrSocketPath = isUnixSocket
+        ? opts.socketPath
+        : parsedUrl.host;
+
+      const headers = options && options.headers;
+
+      //
+      // Shallow copy the user provided options so that headers can be changed
+      // without mutating the original object.
+      //
+      options = { ...options, headers: {} };
+
+      if (headers) {
+        for (const [key, value] of Object.entries(headers)) {
+          options.headers[key.toLowerCase()] = value;
+        }
+      }
+    } else if (websocket.listenerCount('redirect') === 0) {
+      const isSameHost = isUnixSocket
+        ? websocket._originalUnixSocket
+          ? opts.socketPath === websocket._originalHostOrSocketPath
+          : false
+        : websocket._originalUnixSocket
+        ? false
+        : parsedUrl.host === websocket._originalHostOrSocketPath;
+
+      if (!isSameHost || (websocket._originalSecure && !isSecure)) {
+        //
+        // Match curl 7.77.0 behavior and drop the following headers. These
+        // headers are also dropped when following a redirect to a subdomain.
+        //
+        delete opts.headers.authorization;
+        delete opts.headers.cookie;
+
+        if (!isSameHost) delete opts.headers.host;
+
+        opts.auth = undefined;
+      }
+    }
+
+    //
+    // Match curl 7.77.0 behavior and make the first `Authorization` header win.
+    // If the `Authorization` header is set, then there is nothing to do as it
+    // will take precedence.
+    //
+    if (opts.auth && !options.headers.authorization) {
+      options.headers.authorization =
+        'Basic ' + Buffer.from(opts.auth).toString('base64');
+    }
+
+    req = websocket._req = request(opts);
+
+    if (websocket._redirects) {
+      //
+      // Unlike what is done for the `'upgrade'` event, no early exit is
+      // triggered here if the user calls `websocket.close()` or
+      // `websocket.terminate()` from a listener of the `'redirect'` event. This
+      // is because the user can also call `request.destroy()` with an error
+      // before calling `websocket.close()` or `websocket.terminate()` and this
+      // would result in an error being emitted on the `request` object with no
+      // `'error'` event listeners attached.
+      //
+      websocket.emit('redirect', websocket.url, req);
+    }
+  } else {
+    req = websocket._req = request(opts);
+  }
+
+  if (opts.timeout) {
+    req.on('timeout', () => {
+      abortHandshake(websocket, req, 'Opening handshake has timed out');
+    });
+  }
+
+  req.on('error', (err) => {
+    if (req === null || req[kAborted]) return;
+
+    req = websocket._req = null;
+    emitErrorAndClose(websocket, err);
+  });
+
+  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();
+
+      let addr;
+
+      try {
+        addr = new URL(location, address);
+      } catch (e) {
+        const err = new SyntaxError(`Invalid URL: ${location}`);
+        emitErrorAndClose(websocket, err);
+        return;
+      }
+
+      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;
+
+    if (res.headers.upgrade.toLowerCase() !== 'websocket') {
+      abortHandshake(websocket, socket, 'Invalid Upgrade header');
+      return;
+    }
+
+    const digest = 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'];
+    let protError;
+
+    if (serverProt !== undefined) {
+      if (!protocolSet.size) {
+        protError = 'Server sent a subprotocol but none was requested';
+      } else if (!protocolSet.has(serverProt)) {
+        protError = 'Server sent an invalid subprotocol';
+      }
+    } else if (protocolSet.size) {
+      protError = 'Server sent no subprotocol';
+    }
+
+    if (protError) {
+      abortHandshake(websocket, socket, protError);
+      return;
+    }
+
+    if (serverProt) websocket._protocol = serverProt;
+
+    const secWebSocketExtensions = res.headers['sec-websocket-extensions'];
+
+    if (secWebSocketExtensions !== undefined) {
+      if (!perMessageDeflate) {
+        const message =
+          'Server sent a Sec-WebSocket-Extensions header but no extension ' +
+          'was requested';
+        abortHandshake(websocket, socket, message);
+        return;
+      }
+
+      let extensions;
+
+      try {
+        extensions = parse(secWebSocketExtensions);
+      } catch (err) {
+        const message = 'Invalid Sec-WebSocket-Extensions header';
+        abortHandshake(websocket, socket, message);
+        return;
+      }
+
+      const extensionNames = Object.keys(extensions);
+
+      if (
+        extensionNames.length !== 1 ||
+        extensionNames[0] !== PerMessageDeflate.extensionName
+      ) {
+        const message = 'Server indicated an extension that was not requested';
+        abortHandshake(websocket, socket, message);
+        return;
+      }
+
+      try {
+        perMessageDeflate.accept(extensions[PerMessageDeflate.extensionName]);
+      } catch (err) {
+        const message = 'Invalid Sec-WebSocket-Extensions header';
+        abortHandshake(websocket, socket, message);
+        return;
+      }
+
+      websocket._extensions[PerMessageDeflate.extensionName] =
+        perMessageDeflate;
+    }
+
+    websocket.setSocket(socket, head, {
+      generateMask: opts.generateMask,
+      maxPayload: opts.maxPayload,
+      skipUTF8Validation: opts.skipUTF8Validation
+    });
+  });
+
+  req.end();
+}
+
+/**
+ * Emit the `'error'` and `'close'` events.
+ *
+ * @param {WebSocket} websocket The WebSocket instance
+ * @param {Error} The error to emit
+ * @private
+ */
+function emitErrorAndClose(websocket, err) {
+  websocket._readyState = WebSocket.CLOSING;
+  websocket.emit('error', err);
+  websocket.emitClose();
+}
+
+/**
+ * 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) {
+  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;
+
+  if (!options.servername && options.servername !== '') {
+    options.servername = net.isIP(options.host) ? '' : options.host;
+  }
+
+  return tls.connect(options);
+}
+
+/**
+ * Abort the handshake and emit an error.
+ *
+ * @param {WebSocket} websocket The WebSocket instance
+ * @param {(http.ClientRequest|net.Socket|tls.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[kAborted] = true;
+    stream.abort();
+
+    if (stream.socket && !stream.socket.destroyed) {
+      //
+      // On Node.js >= 14.3.0 `request.abort()` does not destroy the socket if
+      // called after the request completed. See
+      // https://github.com/websockets/ws/issues/1869.
+      //
+      stream.socket.destroy();
+    }
+
+    process.nextTick(emitErrorAndClose, websocket, err);
+  } else {
+    stream.destroy(err);
+    stream.once('error', websocket.emit.bind(websocket, 'error'));
+    stream.once('close', websocket.emitClose.bind(websocket));
+  }
+}
+
+/**
+ * Handle cases where the `ping()`, `pong()`, or `send()` methods are called
+ * when the `readyState` attribute is `CLOSING` or `CLOSED`.
+ *
+ * @param {WebSocket} websocket The WebSocket instance
+ * @param {*} [data] The data to send
+ * @param {Function} [cb] Callback
+ * @private
+ */
+function sendAfterClose(websocket, data, cb) {
+  if (data) {
+    const length = toBuffer(data).length;
+
+    //
+    // The `_bufferedAmount` property is used only when the peer is a client and
+    // the opening handshake fails. Under these circumstances, in fact, the
+    // `setSocket()` method is not called, so the `_socket` and `_sender`
+    // properties are set to `null`.
+    //
+    if (websocket._socket) websocket._sender._bufferedBytes += length;
+    else websocket._bufferedAmount += length;
+  }
+
+  if (cb) {
+    const err = new Error(
+      `WebSocket is not open: readyState ${websocket.readyState} ` +
+        `(${readyStates[websocket.readyState]})`
+    );
+    cb(err);
+  }
+}
+
+/**
+ * The listener of the `Receiver` `'conclude'` event.
+ *
+ * @param {Number} code The status code
+ * @param {Buffer} reason The reason for closing
+ * @private
+ */
+function receiverOnConclude(code, reason) {
+  const websocket = this[kWebSocket];
+
+  websocket._closeFrameReceived = true;
+  websocket._closeMessage = reason;
+  websocket._closeCode = code;
+
+  if (websocket._socket[kWebSocket] === undefined) return;
+
+  websocket._socket.removeListener('data', socketOnData);
+  process.nextTick(resume, websocket._socket);
+
+  if (code === 1005) websocket.close();
+  else websocket.close(code, reason);
+}
+
+/**
+ * The listener of the `Receiver` `'drain'` event.
+ *
+ * @private
+ */
+function receiverOnDrain() {
+  const websocket = this[kWebSocket];
+
+  if (!websocket.isPaused) websocket._socket.resume();
+}
+
+/**
+ * The listener of the `Receiver` `'error'` event.
+ *
+ * @param {(RangeError|Error)} err The emitted error
+ * @private
+ */
+function receiverOnError(err) {
+  const websocket = this[kWebSocket];
+
+  if (websocket._socket[kWebSocket] !== undefined) {
+    websocket._socket.removeListener('data', socketOnData);
+
+    //
+    // On Node.js < 14.0.0 the `'error'` event is emitted synchronously. See
+    // https://github.com/websockets/ws/issues/1940.
+    //
+    process.nextTick(resume, websocket._socket);
+
+    websocket.close(err[kStatusCode]);
+  }
+
+  websocket.emit('error', err);
+}
+
+/**
+ * The listener of the `Receiver` `'finish'` event.
+ *
+ * @private
+ */
+function receiverOnFinish() {
+  this[kWebSocket].emitClose();
+}
+
+/**
+ * The listener of the `Receiver` `'message'` event.
+ *
+ * @param {Buffer|ArrayBuffer|Buffer[])} data The message
+ * @param {Boolean} isBinary Specifies whether the message is binary or not
+ * @private
+ */
+function receiverOnMessage(data, isBinary) {
+  this[kWebSocket].emit('message', data, isBinary);
+}
+
+/**
+ * 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);
+}
+
+/**
+ * Resume a readable stream
+ *
+ * @param {Readable} stream The readable stream
+ * @private
+ */
+function resume(stream) {
+  stream.resume();
+}
+
+/**
+ * The listener of the `net.Socket` `'close'` event.
+ *
+ * @private
+ */
+function socketOnClose() {
+  const websocket = this[kWebSocket];
+
+  this.removeListener('close', socketOnClose);
+  this.removeListener('data', socketOnData);
+  this.removeListener('end', socketOnEnd);
+
+  websocket._readyState = WebSocket.CLOSING;
+
+  let chunk;
+
+  //
+  // 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.
+  //
+  if (
+    !this._readableState.endEmitted &&
+    !websocket._closeFrameReceived &&
+    !websocket._receiver._writableState.errorEmitted &&
+    (chunk = websocket._socket.read()) !== null
+  ) {
+    websocket._receiver.write(chunk);
+  }
+
+  websocket._receiver.end();
+
+  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);
+
+  if (websocket) {
+    websocket._readyState = WebSocket.CLOSING;
+    this.destroy();
+  }
+}
diff --git a/testing/xpcshell/node-ws/package.json b/testing/xpcshell/node-ws/package.json
new file mode 100644
index 0000000000..27b9244a46
--- /dev/null
+++ b/testing/xpcshell/node-ws/package.json
@@ -0,0 +1,61 @@
+{
+  "name": "ws",
+  "version": "8.8.1",
+  "description": "Simple to use, blazing fast and thoroughly tested websocket client and server for Node.js",
+  "keywords": [
+    "HyBi",
+    "Push",
+    "RFC-6455",
+    "WebSocket",
+    "WebSockets",
+    "real-time"
+  ],
+  "homepage": "https://github.com/websockets/ws",
+  "bugs": "https://github.com/websockets/ws/issues",
+  "repository": "websockets/ws",
+  "author": "Einar Otto Stangvik <einaros@gmail.com> (http://2x.io)",
+  "license": "MIT",
+  "main": "index.js",
+  "exports": {
+    "import": "./wrapper.mjs",
+    "require": "./index.js"
+  },
+  "browser": "browser.js",
+  "engines": {
+    "node": ">=10.0.0"
+  },
+  "files": [
+    "browser.js",
+    "index.js",
+    "lib/*.js",
+    "wrapper.mjs"
+  ],
+  "scripts": {
+    "test": "nyc --reporter=lcov --reporter=text mocha --throw-deprecation test/*.test.js",
+    "integration": "mocha --throw-deprecation test/*.integration.js",
+    "lint": "eslint --ignore-path .gitignore . && prettier --check --ignore-path .gitignore \"**/*.{json,md,yaml,yml}\""
+  },
+  "peerDependencies": {
+    "bufferutil": "^4.0.1",
+    "utf-8-validate": "^5.0.2"
+  },
+  "peerDependenciesMeta": {
+    "bufferutil": {
+      "optional": true
+    },
+    "utf-8-validate": {
+      "optional": true
+    }
+  },
+  "devDependencies": {
+    "benchmark": "^2.1.4",
+    "bufferutil": "^4.0.1",
+    "eslint": "^8.0.0",
+    "eslint-config-prettier": "^8.1.0",
+    "eslint-plugin-prettier": "^4.0.0",
+    "mocha": "^8.4.0",
+    "nyc": "^15.0.0",
+    "prettier": "^2.0.5",
+    "utf-8-validate": "^5.0.2"
+  }
+}
diff --git a/testing/xpcshell/node-ws/test/autobahn-server.js b/testing/xpcshell/node-ws/test/autobahn-server.js
new file mode 100644
index 0000000000..24ade11497
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/autobahn-server.js
@@ -0,0 +1,17 @@
+'use strict';
+
+const WebSocket = require('../');
+
+const port = process.argv.length > 2 ? parseInt(process.argv[2]) : 9001;
+const wss = new WebSocket.Server({ port }, () => {
+  console.log(
+    `Listening to port ${port}. Use extra argument to define the port`
+  );
+});
+
+wss.on('connection', (ws) => {
+  ws.on('message', (data, isBinary) => {
+    ws.send(data, { binary: isBinary });
+  });
+  ws.on('error', (e) => console.error(e));
+});
diff --git a/testing/xpcshell/node-ws/test/autobahn.js b/testing/xpcshell/node-ws/test/autobahn.js
new file mode 100644
index 0000000000..51532fc52e
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/autobahn.js
@@ -0,0 +1,39 @@
+'use strict';
+
+const WebSocket = require('../');
+
+let currentTest = 1;
+let testCount;
+
+function nextTest() {
+  let ws;
+
+  if (currentTest > testCount) {
+    ws = new WebSocket('ws://localhost:9001/updateReports?agent=ws');
+    return;
+  }
+
+  console.log(`Running test case ${currentTest}/${testCount}`);
+
+  ws = new WebSocket(
+    `ws://localhost:9001/runCase?case=${currentTest}&agent=ws`
+  );
+  ws.on('message', (data, isBinary) => {
+    ws.send(data, { binary: isBinary });
+  });
+  ws.on('close', () => {
+    currentTest++;
+    process.nextTick(nextTest);
+  });
+  ws.on('error', (e) => console.error(e));
+}
+
+const ws = new WebSocket('ws://localhost:9001/getCaseCount');
+ws.on('message', (data) => {
+  testCount = parseInt(data);
+});
+ws.on('close', () => {
+  if (testCount > 0) {
+    nextTest();
+  }
+});
diff --git a/testing/xpcshell/node-ws/test/buffer-util.test.js b/testing/xpcshell/node-ws/test/buffer-util.test.js
new file mode 100644
index 0000000000..a6b84c94b1
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/buffer-util.test.js
@@ -0,0 +1,15 @@
+'use strict';
+
+const assert = require('assert');
+
+const { concat } = require('../lib/buffer-util');
+
+describe('bufferUtil', () => {
+  describe('concat', () => {
+    it('never returns uninitialized data', () => {
+      const buf = concat([Buffer.from([1, 2]), Buffer.from([3, 4])], 6);
+
+      assert.ok(buf.equals(Buffer.from([1, 2, 3, 4])));
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/create-websocket-stream.test.js b/testing/xpcshell/node-ws/test/create-websocket-stream.test.js
new file mode 100644
index 0000000000..4d51958cd9
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/create-websocket-stream.test.js
@@ -0,0 +1,598 @@
+'use strict';
+
+const assert = require('assert');
+const EventEmitter = require('events');
+const { createServer } = require('http');
+const { Duplex } = require('stream');
+const { randomBytes } = require('crypto');
+
+const createWebSocketStream = require('../lib/stream');
+const Sender = require('../lib/sender');
+const WebSocket = require('..');
+const { EMPTY_BUFFER } = require('../lib/constants');
+
+describe('createWebSocketStream', () => {
+  it('is exposed as a property of the `WebSocket` class', () => {
+    assert.strictEqual(WebSocket.createWebSocketStream, createWebSocketStream);
+  });
+
+  it('returns a `Duplex` stream', () => {
+    const duplex = createWebSocketStream(new EventEmitter());
+
+    assert.ok(duplex instanceof Duplex);
+  });
+
+  it('passes the options object to the `Duplex` constructor', (done) => {
+    const wss = new WebSocket.Server({ port: 0 }, () => {
+      const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+      const duplex = createWebSocketStream(ws, {
+        allowHalfOpen: false,
+        encoding: 'utf8'
+      });
+
+      duplex.on('data', (chunk) => {
+        assert.strictEqual(chunk, 'hi');
+
+        duplex.on('close', () => {
+          wss.close(done);
+        });
+      });
+    });
+
+    wss.on('connection', (ws) => {
+      ws.send(Buffer.from('hi'));
+      ws.close();
+    });
+  });
+
+  describe('The returned stream', () => {
+    it('buffers writes if `readyState` is `CONNECTING`', (done) => {
+      const chunk = randomBytes(1024);
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        assert.strictEqual(ws.readyState, WebSocket.CONNECTING);
+
+        const duplex = createWebSocketStream(ws);
+
+        duplex.write(chunk);
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (message, isBinary) => {
+          ws.on('close', (code, reason) => {
+            assert.deepStrictEqual(message, chunk);
+            assert.ok(isBinary);
+            assert.strictEqual(code, 1005);
+            assert.strictEqual(reason, EMPTY_BUFFER);
+            wss.close(done);
+          });
+        });
+
+        ws.close();
+      });
+    });
+
+    it('errors if a write occurs when `readyState` is `CLOSING`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        const duplex = createWebSocketStream(ws);
+
+        duplex.on('error', (err) => {
+          assert.ok(duplex.destroyed);
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket is not open: readyState 2 (CLOSING)'
+          );
+
+          duplex.on('close', () => {
+            wss.close(done);
+          });
+        });
+
+        ws.on('open', () => {
+          ws._receiver.on('conclude', () => {
+            duplex.write('hi');
+          });
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+      });
+    });
+
+    it('errors if a write occurs when `readyState` is `CLOSED`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        const duplex = createWebSocketStream(ws);
+
+        duplex.on('error', (err) => {
+          assert.ok(duplex.destroyed);
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket is not open: readyState 3 (CLOSED)'
+          );
+
+          duplex.on('close', () => {
+            wss.close(done);
+          });
+        });
+
+        ws.on('close', () => {
+          duplex.write('hi');
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+      });
+    });
+
+    it('does not error if `_final()` is called while connecting', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        assert.strictEqual(ws.readyState, WebSocket.CONNECTING);
+
+        const duplex = createWebSocketStream(ws);
+
+        duplex.on('close', () => {
+          wss.close(done);
+        });
+
+        duplex.resume();
+        duplex.end();
+      });
+    });
+
+    it('makes `_final()` a noop if no socket is assigned', (done) => {
+      const server = createServer();
+
+      server.on('upgrade', (request, socket) => {
+        socket.on('end', socket.end);
+
+        const headers = [
+          'HTTP/1.1 101 Switching Protocols',
+          'Upgrade: websocket',
+          'Connection: Upgrade',
+          'Sec-WebSocket-Accept: foo'
+        ];
+
+        socket.write(headers.concat('\r\n').join('\r\n'));
+      });
+
+      server.listen(() => {
+        const called = [];
+        const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+        const duplex = WebSocket.createWebSocketStream(ws);
+        const final = duplex._final;
+
+        duplex._final = (callback) => {
+          called.push('final');
+          assert.strictEqual(ws.readyState, WebSocket.CLOSING);
+          assert.strictEqual(ws._socket, null);
+
+          final(callback);
+        };
+
+        duplex.on('error', (err) => {
+          called.push('error');
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'Invalid Sec-WebSocket-Accept header'
+          );
+        });
+
+        duplex.on('finish', () => {
+          called.push('finish');
+        });
+
+        duplex.on('close', () => {
+          assert.deepStrictEqual(called, ['final', 'error']);
+          server.close(done);
+        });
+
+        ws.on('upgrade', () => {
+          process.nextTick(() => {
+            duplex.end();
+          });
+        });
+      });
+    });
+
+    it('reemits errors', (done) => {
+      let duplexCloseEventEmitted = false;
+      let serverClientCloseEventEmitted = false;
+
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        const duplex = createWebSocketStream(ws);
+
+        duplex.on('error', (err) => {
+          assert.ok(err instanceof RangeError);
+          assert.strictEqual(err.code, 'WS_ERR_INVALID_OPCODE');
+          assert.strictEqual(
+            err.message,
+            'Invalid WebSocket frame: invalid opcode 5'
+          );
+
+          duplex.on('close', () => {
+            duplexCloseEventEmitted = true;
+            if (serverClientCloseEventEmitted) wss.close(done);
+          });
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws._socket.write(Buffer.from([0x85, 0x00]));
+        ws.on('close', (code, reason) => {
+          assert.strictEqual(code, 1002);
+          assert.deepStrictEqual(reason, EMPTY_BUFFER);
+
+          serverClientCloseEventEmitted = true;
+          if (duplexCloseEventEmitted) wss.close(done);
+        });
+      });
+    });
+
+    it('does not swallow errors that may occur while destroying', (done) => {
+      const frame = Buffer.concat(
+        Sender.frame(Buffer.from([0x22, 0xfa, 0xec, 0x78]), {
+          fin: true,
+          rsv1: true,
+          opcode: 0x02,
+          mask: false,
+          readOnly: false
+        })
+      );
+
+      const wss = new WebSocket.Server(
+        {
+          perMessageDeflate: true,
+          port: 0
+        },
+        () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+          const duplex = createWebSocketStream(ws);
+
+          duplex.on('error', (err) => {
+            assert.ok(err instanceof Error);
+            assert.strictEqual(err.code, 'Z_DATA_ERROR');
+            assert.strictEqual(err.errno, -3);
+
+            duplex.on('close', () => {
+              wss.close(done);
+            });
+          });
+
+          let bytesRead = 0;
+
+          ws.on('open', () => {
+            ws._socket.on('data', (chunk) => {
+              bytesRead += chunk.length;
+              if (bytesRead === frame.length) duplex.destroy();
+            });
+          });
+        }
+      );
+
+      wss.on('connection', (ws) => {
+        ws._socket.write(frame);
+      });
+    });
+
+    it("does not suppress the throwing behavior of 'error' events", (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        createWebSocketStream(ws);
+      });
+
+      wss.on('connection', (ws) => {
+        ws._socket.write(Buffer.from([0x85, 0x00]));
+      });
+
+      assert.strictEqual(process.listenerCount('uncaughtException'), 1);
+
+      const [listener] = process.listeners('uncaughtException');
+
+      process.removeAllListeners('uncaughtException');
+      process.once('uncaughtException', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          'Invalid WebSocket frame: invalid opcode 5'
+        );
+
+        process.on('uncaughtException', listener);
+        wss.close(done);
+      });
+    });
+
+    it("is destroyed after 'end' and 'finish' are emitted (1/2)", (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const events = [];
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        const duplex = createWebSocketStream(ws);
+
+        duplex.on('end', () => {
+          events.push('end');
+          assert.ok(duplex.destroyed);
+        });
+
+        duplex.on('close', () => {
+          assert.deepStrictEqual(events, ['finish', 'end']);
+          wss.close(done);
+        });
+
+        duplex.on('finish', () => {
+          events.push('finish');
+          assert.ok(!duplex.destroyed);
+          assert.ok(duplex.readable);
+
+          duplex.resume();
+        });
+
+        ws.on('close', () => {
+          duplex.end();
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.send('foo');
+        ws.close();
+      });
+    });
+
+    it("is destroyed after 'end' and 'finish' are emitted (2/2)", (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const events = [];
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        const duplex = createWebSocketStream(ws);
+
+        duplex.on('end', () => {
+          events.push('end');
+          assert.ok(!duplex.destroyed);
+          assert.ok(duplex.writable);
+
+          duplex.end();
+        });
+
+        duplex.on('close', () => {
+          assert.deepStrictEqual(events, ['end', 'finish']);
+          wss.close(done);
+        });
+
+        duplex.on('finish', () => {
+          events.push('finish');
+        });
+
+        duplex.resume();
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+      });
+    });
+
+    it('handles backpressure (1/3)', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        // eslint-disable-next-line no-unused-vars
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+      });
+
+      wss.on('connection', (ws) => {
+        const duplex = createWebSocketStream(ws);
+
+        duplex.resume();
+
+        duplex.on('drain', () => {
+          duplex.on('close', () => {
+            wss.close(done);
+          });
+
+          duplex.end();
+        });
+
+        const chunk = randomBytes(1024);
+        let ret;
+
+        do {
+          ret = duplex.write(chunk);
+        } while (ret !== false);
+      });
+    });
+
+    it('handles backpressure (2/3)', (done) => {
+      const wss = new WebSocket.Server(
+        { port: 0, perMessageDeflate: true },
+        () => {
+          const called = [];
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+          const duplex = createWebSocketStream(ws);
+          const read = duplex._read;
+
+          duplex._read = () => {
+            duplex._read = read;
+            called.push('read');
+            assert.ok(ws._receiver._writableState.needDrain);
+            read();
+            assert.ok(ws._socket.isPaused());
+          };
+
+          ws.on('open', () => {
+            ws._socket.on('pause', () => {
+              duplex.resume();
+            });
+
+            ws._receiver.on('drain', () => {
+              called.push('drain');
+              assert.ok(!ws._socket.isPaused());
+              duplex.end();
+            });
+
+            const opts = {
+              fin: true,
+              opcode: 0x02,
+              mask: false,
+              readOnly: false
+            };
+
+            const list = [
+              ...Sender.frame(randomBytes(16 * 1024), { rsv1: false, ...opts }),
+              ...Sender.frame(Buffer.alloc(1), { rsv1: true, ...opts })
+            ];
+
+            // This hack is used because there is no guarantee that more than
+            // 16 KiB will be sent as a single TCP packet.
+            ws._socket.push(Buffer.concat(list));
+          });
+
+          duplex.on('close', () => {
+            assert.deepStrictEqual(called, ['read', 'drain']);
+            wss.close(done);
+          });
+        }
+      );
+    });
+
+    it('handles backpressure (3/3)', (done) => {
+      const wss = new WebSocket.Server(
+        { port: 0, perMessageDeflate: true },
+        () => {
+          const called = [];
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+          const duplex = createWebSocketStream(ws);
+          const read = duplex._read;
+
+          duplex._read = () => {
+            called.push('read');
+            assert.ok(!ws._receiver._writableState.needDrain);
+            read();
+            assert.ok(!ws._socket.isPaused());
+            duplex.end();
+          };
+
+          ws.on('open', () => {
+            ws._receiver.on('drain', () => {
+              called.push('drain');
+              assert.ok(ws._socket.isPaused());
+              duplex.resume();
+            });
+
+            const opts = {
+              fin: true,
+              opcode: 0x02,
+              mask: false,
+              readOnly: false
+            };
+
+            const list = [
+              ...Sender.frame(randomBytes(16 * 1024), { rsv1: false, ...opts }),
+              ...Sender.frame(Buffer.alloc(1), { rsv1: true, ...opts })
+            ];
+
+            ws._socket.push(Buffer.concat(list));
+          });
+
+          duplex.on('close', () => {
+            assert.deepStrictEqual(called, ['drain', 'read']);
+            wss.close(done);
+          });
+        }
+      );
+    });
+
+    it('can be destroyed (1/2)', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const error = new Error('Oops');
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        const duplex = createWebSocketStream(ws);
+
+        duplex.on('error', (err) => {
+          assert.strictEqual(err, error);
+
+          duplex.on('close', () => {
+            wss.close(done);
+          });
+        });
+
+        ws.on('open', () => {
+          duplex.destroy(error);
+        });
+      });
+    });
+
+    it('can be destroyed (2/2)', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        const duplex = createWebSocketStream(ws);
+
+        duplex.on('close', () => {
+          wss.close(done);
+        });
+
+        ws.on('open', () => {
+          duplex.destroy();
+        });
+      });
+    });
+
+    it('converts text messages to strings in readable object mode', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const events = [];
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        const duplex = createWebSocketStream(ws, { readableObjectMode: true });
+
+        duplex.on('data', (data) => {
+          events.push('data');
+          assert.strictEqual(data, 'foo');
+        });
+
+        duplex.on('end', () => {
+          events.push('end');
+          duplex.end();
+        });
+
+        duplex.on('close', () => {
+          assert.deepStrictEqual(events, ['data', 'end']);
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.send('foo');
+        ws.close();
+      });
+    });
+
+    it('resumes the socket if `readyState` is `CLOSING`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        const duplex = createWebSocketStream(ws);
+
+        ws.on('message', () => {
+          assert.ok(ws._socket.isPaused());
+
+          duplex.on('close', () => {
+            wss.close(done);
+          });
+
+          duplex.end();
+
+          process.nextTick(() => {
+            assert.strictEqual(ws.readyState, WebSocket.CLOSING);
+            duplex.resume();
+          });
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.send(randomBytes(16 * 1024));
+      });
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/event-target.test.js b/testing/xpcshell/node-ws/test/event-target.test.js
new file mode 100644
index 0000000000..5caaa5c273
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/event-target.test.js
@@ -0,0 +1,253 @@
+'use strict';
+
+const assert = require('assert');
+
+const {
+  CloseEvent,
+  ErrorEvent,
+  Event,
+  MessageEvent
+} = require('../lib/event-target');
+
+describe('Event', () => {
+  describe('#ctor', () => {
+    it('takes a `type` argument', () => {
+      const event = new Event('foo');
+
+      assert.strictEqual(event.type, 'foo');
+    });
+  });
+
+  describe('Properties', () => {
+    describe('`target`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          Event.prototype,
+          'target'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('defaults to `null`', () => {
+        const event = new Event('foo');
+
+        assert.strictEqual(event.target, null);
+      });
+    });
+
+    describe('`type`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          Event.prototype,
+          'type'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+    });
+  });
+});
+
+describe('CloseEvent', () => {
+  it('inherits from `Event`', () => {
+    assert.ok(CloseEvent.prototype instanceof Event);
+  });
+
+  describe('#ctor', () => {
+    it('takes a `type` argument', () => {
+      const event = new CloseEvent('foo');
+
+      assert.strictEqual(event.type, 'foo');
+    });
+
+    it('takes an optional `options` argument', () => {
+      const event = new CloseEvent('close', {
+        code: 1000,
+        reason: 'foo',
+        wasClean: true
+      });
+
+      assert.strictEqual(event.type, 'close');
+      assert.strictEqual(event.code, 1000);
+      assert.strictEqual(event.reason, 'foo');
+      assert.strictEqual(event.wasClean, true);
+    });
+  });
+
+  describe('Properties', () => {
+    describe('`code`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          CloseEvent.prototype,
+          'code'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('defaults to 0', () => {
+        const event = new CloseEvent('close');
+
+        assert.strictEqual(event.code, 0);
+      });
+    });
+
+    describe('`reason`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          CloseEvent.prototype,
+          'reason'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('defaults to an empty string', () => {
+        const event = new CloseEvent('close');
+
+        assert.strictEqual(event.reason, '');
+      });
+    });
+
+    describe('`wasClean`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          CloseEvent.prototype,
+          'wasClean'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('defaults to false', () => {
+        const event = new CloseEvent('close');
+
+        assert.strictEqual(event.wasClean, false);
+      });
+    });
+  });
+});
+
+describe('ErrorEvent', () => {
+  it('inherits from `Event`', () => {
+    assert.ok(ErrorEvent.prototype instanceof Event);
+  });
+
+  describe('#ctor', () => {
+    it('takes a `type` argument', () => {
+      const event = new ErrorEvent('foo');
+
+      assert.strictEqual(event.type, 'foo');
+    });
+
+    it('takes an optional `options` argument', () => {
+      const error = new Error('Oops');
+      const event = new ErrorEvent('error', { error, message: error.message });
+
+      assert.strictEqual(event.type, 'error');
+      assert.strictEqual(event.error, error);
+      assert.strictEqual(event.message, error.message);
+    });
+  });
+
+  describe('Properties', () => {
+    describe('`error`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          ErrorEvent.prototype,
+          'error'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('defaults to `null`', () => {
+        const event = new ErrorEvent('error');
+
+        assert.strictEqual(event.error, null);
+      });
+    });
+
+    describe('`message`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          ErrorEvent.prototype,
+          'message'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('defaults to an empty string', () => {
+        const event = new ErrorEvent('error');
+
+        assert.strictEqual(event.message, '');
+      });
+    });
+  });
+});
+
+describe('MessageEvent', () => {
+  it('inherits from `Event`', () => {
+    assert.ok(MessageEvent.prototype instanceof Event);
+  });
+
+  describe('#ctor', () => {
+    it('takes a `type` argument', () => {
+      const event = new MessageEvent('foo');
+
+      assert.strictEqual(event.type, 'foo');
+    });
+
+    it('takes an optional `options` argument', () => {
+      const event = new MessageEvent('message', { data: 'bar' });
+
+      assert.strictEqual(event.type, 'message');
+      assert.strictEqual(event.data, 'bar');
+    });
+  });
+
+  describe('Properties', () => {
+    describe('`data`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          MessageEvent.prototype,
+          'data'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('defaults to `null`', () => {
+        const event = new MessageEvent('message');
+
+        assert.strictEqual(event.data, null);
+      });
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/extension.test.js b/testing/xpcshell/node-ws/test/extension.test.js
new file mode 100644
index 0000000000..a4b3e749d0
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/extension.test.js
@@ -0,0 +1,190 @@
+'use strict';
+
+const assert = require('assert');
+
+const { format, parse } = require('../lib/extension');
+
+describe('extension', () => {
+  describe('parse', () => {
+    it('parses a single extension', () => {
+      assert.deepStrictEqual(parse('foo'), {
+        foo: [{ __proto__: null }],
+        __proto__: null
+      });
+    });
+
+    it('parses params', () => {
+      assert.deepStrictEqual(parse('foo;bar;baz=1;bar=2'), {
+        foo: [{ bar: [true, '2'], baz: ['1'], __proto__: null }],
+        __proto__: null
+      });
+    });
+
+    it('parses multiple extensions', () => {
+      assert.deepStrictEqual(parse('foo,bar;baz,foo;baz'), {
+        foo: [{ __proto__: null }, { baz: [true], __proto__: null }],
+        bar: [{ baz: [true], __proto__: null }],
+        __proto__: null
+      });
+    });
+
+    it('parses quoted params', () => {
+      assert.deepStrictEqual(parse('foo;bar="hi"'), {
+        foo: [{ bar: ['hi'], __proto__: null }],
+        __proto__: null
+      });
+      assert.deepStrictEqual(parse('foo;bar="\\0"'), {
+        foo: [{ bar: ['0'], __proto__: null }],
+        __proto__: null
+      });
+      assert.deepStrictEqual(parse('foo;bar="b\\a\\z"'), {
+        foo: [{ bar: ['baz'], __proto__: null }],
+        __proto__: null
+      });
+      assert.deepStrictEqual(parse('foo;bar="b\\az";bar'), {
+        foo: [{ bar: ['baz', true], __proto__: null }],
+        __proto__: null
+      });
+      assert.throws(
+        () => parse('foo;bar="baz"qux'),
+        /^SyntaxError: Unexpected character at index 13$/
+      );
+      assert.throws(
+        () => parse('foo;bar="baz" qux'),
+        /^SyntaxError: Unexpected character at index 14$/
+      );
+    });
+
+    it('works with names that match `Object.prototype` property names', () => {
+      assert.deepStrictEqual(parse('hasOwnProperty, toString'), {
+        hasOwnProperty: [{ __proto__: null }],
+        toString: [{ __proto__: null }],
+        __proto__: null
+      });
+      assert.deepStrictEqual(parse('foo;constructor'), {
+        foo: [{ constructor: [true], __proto__: null }],
+        __proto__: null
+      });
+    });
+
+    it('ignores the optional white spaces', () => {
+      const header = 'foo; bar\t; \tbaz=1\t ;  bar="1"\t\t, \tqux\t ;norf';
+
+      assert.deepStrictEqual(parse(header), {
+        foo: [{ bar: [true, '1'], baz: ['1'], __proto__: null }],
+        qux: [{ norf: [true], __proto__: null }],
+        __proto__: null
+      });
+    });
+
+    it('throws an error if a name is empty', () => {
+      [
+        [',', 0],
+        ['foo,,', 4],
+        ['foo,  ,', 6],
+        ['foo;=', 4],
+        ['foo; =', 5],
+        ['foo;;', 4],
+        ['foo; ;', 5],
+        ['foo;bar=,', 8],
+        ['foo;bar=""', 9]
+      ].forEach((element) => {
+        assert.throws(
+          () => parse(element[0]),
+          new RegExp(
+            `^SyntaxError: Unexpected character at index ${element[1]}$`
+          )
+        );
+      });
+    });
+
+    it('throws an error if a white space is misplaced', () => {
+      [
+        [' foo', 0],
+        ['f oo', 2],
+        ['foo;ba r', 7],
+        ['foo;bar =', 8],
+        ['foo;bar= ', 8],
+        ['foo;bar=ba z', 11]
+      ].forEach((element) => {
+        assert.throws(
+          () => parse(element[0]),
+          new RegExp(
+            `^SyntaxError: Unexpected character at index ${element[1]}$`
+          )
+        );
+      });
+    });
+
+    it('throws an error if a token contains invalid characters', () => {
+      [
+        ['f@o', 1],
+        ['f\\oo', 1],
+        ['"foo"', 0],
+        ['f"oo"', 1],
+        ['foo;b@r', 5],
+        ['foo;b\\ar', 5],
+        ['foo;"bar"', 4],
+        ['foo;b"ar"', 5],
+        ['foo;bar=b@z', 9],
+        ['foo;bar=b\\az ', 9],
+        ['foo;bar="b@z"', 10],
+        ['foo;bar="baz;"', 12],
+        ['foo;bar=b"az"', 9],
+        ['foo;bar="\\\\"', 10]
+      ].forEach((element) => {
+        assert.throws(
+          () => parse(element[0]),
+          new RegExp(
+            `^SyntaxError: Unexpected character at index ${element[1]}$`
+          )
+        );
+      });
+    });
+
+    it('throws an error if the header value ends prematurely', () => {
+      [
+        '',
+        'foo ',
+        'foo\t',
+        'foo, ',
+        'foo;',
+        'foo;bar ',
+        'foo;bar,',
+        'foo;bar; ',
+        'foo;bar=',
+        'foo;bar="baz',
+        'foo;bar="1\\',
+        'foo;bar="baz" '
+      ].forEach((header) => {
+        assert.throws(
+          () => parse(header),
+          /^SyntaxError: Unexpected end of input$/
+        );
+      });
+    });
+  });
+
+  describe('format', () => {
+    it('formats a single extension', () => {
+      const extensions = format({ foo: {} });
+
+      assert.strictEqual(extensions, 'foo');
+    });
+
+    it('formats params', () => {
+      const extensions = format({ foo: { bar: [true, 2], baz: 1 } });
+
+      assert.strictEqual(extensions, 'foo; bar; bar=2; baz=1');
+    });
+
+    it('formats multiple extensions', () => {
+      const extensions = format({
+        foo: [{}, { baz: true }],
+        bar: { baz: true }
+      });
+
+      assert.strictEqual(extensions, 'foo, foo; baz, bar; baz');
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/fixtures/ca-certificate.pem b/testing/xpcshell/node-ws/test/fixtures/ca-certificate.pem
new file mode 100644
index 0000000000..0f1658821d
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/fixtures/ca-certificate.pem
@@ -0,0 +1,12 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/testing/xpcshell/node-ws/test/fixtures/ca-key.pem b/testing/xpcshell/node-ws/test/fixtures/ca-key.pem
new file mode 100644
index 0000000000..a9352fb6a2
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/fixtures/ca-key.pem
@@ -0,0 +1,5 @@
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEIAa/Onpk27cLkqzje69Bac8yG+LTBXIPWT8yGlyjEFbboAoGCCqGSM49
+AwEHoUQDQgAEhxO+UA0DelzaP+9dWEm3JGmvK+JbdIRpILQA2gRU/UJ/YHJuaJmq
+Xj2U++hX/a8IzHEvmD10uye25PkBy4oSTA==
+-----END EC PRIVATE KEY-----
diff --git a/testing/xpcshell/node-ws/test/fixtures/certificate.pem b/testing/xpcshell/node-ws/test/fixtures/certificate.pem
new file mode 100644
index 0000000000..538553ee08
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/fixtures/certificate.pem
@@ -0,0 +1,12 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/testing/xpcshell/node-ws/test/fixtures/client-certificate.pem b/testing/xpcshell/node-ws/test/fixtures/client-certificate.pem
new file mode 100644
index 0000000000..0e20560b8c
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/fixtures/client-certificate.pem
@@ -0,0 +1,12 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/testing/xpcshell/node-ws/test/fixtures/client-key.pem b/testing/xpcshell/node-ws/test/fixtures/client-key.pem
new file mode 100644
index 0000000000..e034f57fc2
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/fixtures/client-key.pem
@@ -0,0 +1,5 @@
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEIKVGskK0UR86WwMo5H0+hNAFGRBYsEevK3ye4y1YberVoAoGCCqGSM49
+AwEHoUQDQgAE8B5TUtm9d0zIQU0lgVwJ+kxD8a7Lxvd2WclJZqxDDl0jF9oSO7L+
+utGDY/nhshNgld917EMVd01KoudX1IyLvA==
+-----END EC PRIVATE KEY-----
diff --git a/testing/xpcshell/node-ws/test/fixtures/key.pem b/testing/xpcshell/node-ws/test/fixtures/key.pem
new file mode 100644
index 0000000000..05bfdb71ed
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/fixtures/key.pem
@@ -0,0 +1,5 @@
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEIIjLz7YEWIrsGem2+YV8eJhHhetsjYIrjuqJLbdG7B3zoAoGCCqGSM49
+AwEHoUQDQgAECockYXUlTnnGyVODuV5Af4hqHW5wjqpnIbOE15hNz67+UqzQ4Tgw
+76zlk18Ed/x663TXzsz3W+eGprvDzsKaIQ==
+-----END EC PRIVATE KEY-----
diff --git a/testing/xpcshell/node-ws/test/limiter.test.js b/testing/xpcshell/node-ws/test/limiter.test.js
new file mode 100644
index 0000000000..95141f0f5c
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/limiter.test.js
@@ -0,0 +1,41 @@
+'use strict';
+
+const assert = require('assert');
+
+const Limiter = require('../lib/limiter');
+
+describe('Limiter', () => {
+  describe('#ctor', () => {
+    it('takes a `concurrency` argument', () => {
+      const limiter = new Limiter(0);
+
+      assert.strictEqual(limiter.concurrency, Infinity);
+    });
+  });
+
+  describe('#kRun', () => {
+    it('limits the number of jobs allowed to run concurrently', (done) => {
+      const limiter = new Limiter(1);
+
+      limiter.add((callback) => {
+        setImmediate(() => {
+          callback();
+
+          assert.strictEqual(limiter.jobs.length, 0);
+          assert.strictEqual(limiter.pending, 1);
+        });
+      });
+
+      limiter.add((callback) => {
+        setImmediate(() => {
+          callback();
+
+          assert.strictEqual(limiter.pending, 0);
+          done();
+        });
+      });
+
+      assert.strictEqual(limiter.jobs.length, 1);
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/permessage-deflate.test.js b/testing/xpcshell/node-ws/test/permessage-deflate.test.js
new file mode 100644
index 0000000000..a9c9bf165c
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/permessage-deflate.test.js
@@ -0,0 +1,647 @@
+'use strict';
+
+const assert = require('assert');
+
+const PerMessageDeflate = require('../lib/permessage-deflate');
+const extension = require('../lib/extension');
+
+describe('PerMessageDeflate', () => {
+  describe('#offer', () => {
+    it('creates an offer', () => {
+      const perMessageDeflate = new PerMessageDeflate();
+
+      assert.deepStrictEqual(perMessageDeflate.offer(), {
+        client_max_window_bits: true
+      });
+    });
+
+    it('uses the configuration options', () => {
+      const perMessageDeflate = new PerMessageDeflate({
+        serverNoContextTakeover: true,
+        clientNoContextTakeover: true,
+        serverMaxWindowBits: 10,
+        clientMaxWindowBits: 11
+      });
+
+      assert.deepStrictEqual(perMessageDeflate.offer(), {
+        server_no_context_takeover: true,
+        client_no_context_takeover: true,
+        server_max_window_bits: 10,
+        client_max_window_bits: 11
+      });
+    });
+  });
+
+  describe('#accept', () => {
+    it('throws an error if a parameter has multiple values', () => {
+      const perMessageDeflate = new PerMessageDeflate();
+      const extensions = extension.parse(
+        'permessage-deflate; server_no_context_takeover; server_no_context_takeover'
+      );
+
+      assert.throws(
+        () => perMessageDeflate.accept(extensions['permessage-deflate']),
+        /^Error: Parameter "server_no_context_takeover" must have only a single value$/
+      );
+    });
+
+    it('throws an error if a parameter has an invalid name', () => {
+      const perMessageDeflate = new PerMessageDeflate();
+      const extensions = extension.parse('permessage-deflate;foo');
+
+      assert.throws(
+        () => perMessageDeflate.accept(extensions['permessage-deflate']),
+        /^Error: Unknown parameter "foo"$/
+      );
+    });
+
+    it('throws an error if client_no_context_takeover has a value', () => {
+      const perMessageDeflate = new PerMessageDeflate();
+      const extensions = extension.parse(
+        'permessage-deflate; client_no_context_takeover=10'
+      );
+
+      assert.throws(
+        () => perMessageDeflate.accept(extensions['permessage-deflate']),
+        /^TypeError: Invalid value for parameter "client_no_context_takeover": 10$/
+      );
+    });
+
+    it('throws an error if server_no_context_takeover has a value', () => {
+      const perMessageDeflate = new PerMessageDeflate();
+      const extensions = extension.parse(
+        'permessage-deflate; server_no_context_takeover=10'
+      );
+
+      assert.throws(
+        () => perMessageDeflate.accept(extensions['permessage-deflate']),
+        /^TypeError: Invalid value for parameter "server_no_context_takeover": 10$/
+      );
+    });
+
+    it('throws an error if server_max_window_bits has an invalid value', () => {
+      const perMessageDeflate = new PerMessageDeflate();
+
+      let extensions = extension.parse(
+        'permessage-deflate; server_max_window_bits=7'
+      );
+      assert.throws(
+        () => perMessageDeflate.accept(extensions['permessage-deflate']),
+        /^TypeError: Invalid value for parameter "server_max_window_bits": 7$/
+      );
+
+      extensions = extension.parse(
+        'permessage-deflate; server_max_window_bits'
+      );
+      assert.throws(
+        () => perMessageDeflate.accept(extensions['permessage-deflate']),
+        /^TypeError: Invalid value for parameter "server_max_window_bits": true$/
+      );
+    });
+
+    describe('As server', () => {
+      it('accepts an offer with no parameters', () => {
+        const perMessageDeflate = new PerMessageDeflate({}, true);
+
+        assert.deepStrictEqual(perMessageDeflate.accept([{}]), {});
+      });
+
+      it('accepts an offer with parameters', () => {
+        const perMessageDeflate = new PerMessageDeflate({}, true);
+        const extensions = extension.parse(
+          'permessage-deflate; server_no_context_takeover; ' +
+            'client_no_context_takeover; server_max_window_bits=10; ' +
+            'client_max_window_bits=11'
+        );
+
+        assert.deepStrictEqual(
+          perMessageDeflate.accept(extensions['permessage-deflate']),
+          {
+            server_no_context_takeover: true,
+            client_no_context_takeover: true,
+            server_max_window_bits: 10,
+            client_max_window_bits: 11,
+            __proto__: null
+          }
+        );
+      });
+
+      it('prefers the configuration options', () => {
+        const perMessageDeflate = new PerMessageDeflate(
+          {
+            serverNoContextTakeover: true,
+            clientNoContextTakeover: true,
+            serverMaxWindowBits: 12,
+            clientMaxWindowBits: 11
+          },
+          true
+        );
+        const extensions = extension.parse(
+          'permessage-deflate; server_max_window_bits=14; client_max_window_bits=13'
+        );
+
+        assert.deepStrictEqual(
+          perMessageDeflate.accept(extensions['permessage-deflate']),
+          {
+            server_no_context_takeover: true,
+            client_no_context_takeover: true,
+            server_max_window_bits: 12,
+            client_max_window_bits: 11,
+            __proto__: null
+          }
+        );
+      });
+
+      it('accepts the first supported offer', () => {
+        const perMessageDeflate = new PerMessageDeflate(
+          { serverMaxWindowBits: 11 },
+          true
+        );
+        const extensions = extension.parse(
+          'permessage-deflate; server_max_window_bits=10, permessage-deflate'
+        );
+
+        assert.deepStrictEqual(
+          perMessageDeflate.accept(extensions['permessage-deflate']),
+          {
+            server_max_window_bits: 11,
+            __proto__: null
+          }
+        );
+      });
+
+      it('throws an error if server_no_context_takeover is unsupported', () => {
+        const perMessageDeflate = new PerMessageDeflate(
+          { serverNoContextTakeover: false },
+          true
+        );
+        const extensions = extension.parse(
+          'permessage-deflate; server_no_context_takeover'
+        );
+
+        assert.throws(
+          () => perMessageDeflate.accept(extensions['permessage-deflate']),
+          /^Error: None of the extension offers can be accepted$/
+        );
+      });
+
+      it('throws an error if server_max_window_bits is unsupported', () => {
+        const perMessageDeflate = new PerMessageDeflate(
+          { serverMaxWindowBits: false },
+          true
+        );
+        const extensions = extension.parse(
+          'permessage-deflate; server_max_window_bits=10'
+        );
+
+        assert.throws(
+          () => perMessageDeflate.accept(extensions['permessage-deflate']),
+          /^Error: None of the extension offers can be accepted$/
+        );
+      });
+
+      it('throws an error if server_max_window_bits is less than configuration', () => {
+        const perMessageDeflate = new PerMessageDeflate(
+          { serverMaxWindowBits: 11 },
+          true
+        );
+        const extensions = extension.parse(
+          'permessage-deflate; server_max_window_bits=10'
+        );
+
+        assert.throws(
+          () => perMessageDeflate.accept(extensions['permessage-deflate']),
+          /^Error: None of the extension offers can be accepted$/
+        );
+      });
+
+      it('throws an error if client_max_window_bits is unsupported on client', () => {
+        const perMessageDeflate = new PerMessageDeflate(
+          { clientMaxWindowBits: 10 },
+          true
+        );
+        const extensions = extension.parse('permessage-deflate');
+
+        assert.throws(
+          () => perMessageDeflate.accept(extensions['permessage-deflate']),
+          /^Error: None of the extension offers can be accepted$/
+        );
+      });
+
+      it('throws an error if client_max_window_bits has an invalid value', () => {
+        const perMessageDeflate = new PerMessageDeflate({}, true);
+
+        const extensions = extension.parse(
+          'permessage-deflate; client_max_window_bits=16'
+        );
+        assert.throws(
+          () => perMessageDeflate.accept(extensions['permessage-deflate']),
+          /^TypeError: Invalid value for parameter "client_max_window_bits": 16$/
+        );
+      });
+    });
+
+    describe('As client', () => {
+      it('accepts a response with no parameters', () => {
+        const perMessageDeflate = new PerMessageDeflate({});
+
+        assert.deepStrictEqual(perMessageDeflate.accept([{}]), {});
+      });
+
+      it('accepts a response with parameters', () => {
+        const perMessageDeflate = new PerMessageDeflate({});
+        const extensions = extension.parse(
+          'permessage-deflate; server_no_context_takeover; ' +
+            'client_no_context_takeover; server_max_window_bits=10; ' +
+            'client_max_window_bits=11'
+        );
+
+        assert.deepStrictEqual(
+          perMessageDeflate.accept(extensions['permessage-deflate']),
+          {
+            server_no_context_takeover: true,
+            client_no_context_takeover: true,
+            server_max_window_bits: 10,
+            client_max_window_bits: 11,
+            __proto__: null
+          }
+        );
+      });
+
+      it('throws an error if client_no_context_takeover is unsupported', () => {
+        const perMessageDeflate = new PerMessageDeflate({
+          clientNoContextTakeover: false
+        });
+        const extensions = extension.parse(
+          'permessage-deflate; client_no_context_takeover'
+        );
+
+        assert.throws(
+          () => perMessageDeflate.accept(extensions['permessage-deflate']),
+          /^Error: Unexpected parameter "client_no_context_takeover"$/
+        );
+      });
+
+      it('throws an error if client_max_window_bits is unsupported', () => {
+        const perMessageDeflate = new PerMessageDeflate({
+          clientMaxWindowBits: false
+        });
+        const extensions = extension.parse(
+          'permessage-deflate; client_max_window_bits=10'
+        );
+
+        assert.throws(
+          () => perMessageDeflate.accept(extensions['permessage-deflate']),
+          /^Error: Unexpected or invalid parameter "client_max_window_bits"$/
+        );
+      });
+
+      it('throws an error if client_max_window_bits is greater than configuration', () => {
+        const perMessageDeflate = new PerMessageDeflate({
+          clientMaxWindowBits: 10
+        });
+        const extensions = extension.parse(
+          'permessage-deflate; client_max_window_bits=11'
+        );
+
+        assert.throws(
+          () => perMessageDeflate.accept(extensions['permessage-deflate']),
+          /^Error: Unexpected or invalid parameter "client_max_window_bits"$/
+        );
+      });
+
+      it('throws an error if client_max_window_bits has an invalid value', () => {
+        const perMessageDeflate = new PerMessageDeflate();
+
+        let extensions = extension.parse(
+          'permessage-deflate; client_max_window_bits=16'
+        );
+        assert.throws(
+          () => perMessageDeflate.accept(extensions['permessage-deflate']),
+          /^TypeError: Invalid value for parameter "client_max_window_bits": 16$/
+        );
+
+        extensions = extension.parse(
+          'permessage-deflate; client_max_window_bits'
+        );
+        assert.throws(
+          () => perMessageDeflate.accept(extensions['permessage-deflate']),
+          /^TypeError: Invalid value for parameter "client_max_window_bits": true$/
+        );
+      });
+
+      it('uses the config value if client_max_window_bits is not specified', () => {
+        const perMessageDeflate = new PerMessageDeflate({
+          clientMaxWindowBits: 10
+        });
+
+        assert.deepStrictEqual(perMessageDeflate.accept([{}]), {
+          client_max_window_bits: 10
+        });
+      });
+    });
+  });
+
+  describe('#compress and #decompress', () => {
+    it('works with unfragmented messages', (done) => {
+      const perMessageDeflate = new PerMessageDeflate();
+      const buf = Buffer.from([1, 2, 3]);
+
+      perMessageDeflate.accept([{}]);
+      perMessageDeflate.compress(buf, true, (err, data) => {
+        if (err) return done(err);
+
+        perMessageDeflate.decompress(data, true, (err, data) => {
+          if (err) return done(err);
+
+          assert.ok(data.equals(buf));
+          done();
+        });
+      });
+    });
+
+    it('works with fragmented messages', (done) => {
+      const perMessageDeflate = new PerMessageDeflate();
+      const buf = Buffer.from([1, 2, 3, 4]);
+
+      perMessageDeflate.accept([{}]);
+
+      perMessageDeflate.compress(buf.slice(0, 2), false, (err, compressed1) => {
+        if (err) return done(err);
+
+        perMessageDeflate.compress(buf.slice(2), true, (err, compressed2) => {
+          if (err) return done(err);
+
+          perMessageDeflate.decompress(compressed1, false, (err, data1) => {
+            if (err) return done(err);
+
+            perMessageDeflate.decompress(compressed2, true, (err, data2) => {
+              if (err) return done(err);
+
+              assert.ok(Buffer.concat([data1, data2]).equals(buf));
+              done();
+            });
+          });
+        });
+      });
+    });
+
+    it('works with the negotiated parameters', (done) => {
+      const perMessageDeflate = new PerMessageDeflate({
+        memLevel: 5,
+        level: 9
+      });
+      const extensions = extension.parse(
+        'permessage-deflate; server_no_context_takeover; ' +
+          'client_no_context_takeover; server_max_window_bits=10; ' +
+          'client_max_window_bits=11'
+      );
+      const buf = Buffer.from("Some compressible data, it's compressible.");
+
+      perMessageDeflate.accept(extensions['permessage-deflate']);
+
+      perMessageDeflate.compress(buf, true, (err, data) => {
+        if (err) return done(err);
+
+        perMessageDeflate.decompress(data, true, (err, data) => {
+          if (err) return done(err);
+
+          assert.ok(data.equals(buf));
+          done();
+        });
+      });
+    });
+
+    it('honors the `level` option', (done) => {
+      const lev0 = new PerMessageDeflate({
+        zlibDeflateOptions: { level: 0 }
+      });
+      const lev9 = new PerMessageDeflate({
+        zlibDeflateOptions: { level: 9 }
+      });
+      const extensionStr =
+        'permessage-deflate; server_no_context_takeover; ' +
+        'client_no_context_takeover; server_max_window_bits=10; ' +
+        'client_max_window_bits=11';
+      const buf = Buffer.from("Some compressible data, it's compressible.");
+
+      lev0.accept(extension.parse(extensionStr)['permessage-deflate']);
+      lev9.accept(extension.parse(extensionStr)['permessage-deflate']);
+
+      lev0.compress(buf, true, (err, compressed1) => {
+        if (err) return done(err);
+
+        lev0.decompress(compressed1, true, (err, decompressed1) => {
+          if (err) return done(err);
+
+          lev9.compress(buf, true, (err, compressed2) => {
+            if (err) return done(err);
+
+            lev9.decompress(compressed2, true, (err, decompressed2) => {
+              if (err) return done(err);
+
+              // Level 0 compression actually adds a few bytes due to headers.
+              assert.ok(compressed1.length > buf.length);
+              // Level 9 should not, of course.
+              assert.ok(compressed2.length < buf.length);
+              // Ensure they both decompress back properly.
+              assert.ok(decompressed1.equals(buf));
+              assert.ok(decompressed2.equals(buf));
+              done();
+            });
+          });
+        });
+      });
+    });
+
+    it('honors the `zlib{Deflate,Inflate}Options` option', (done) => {
+      const lev0 = new PerMessageDeflate({
+        zlibDeflateOptions: {
+          level: 0,
+          chunkSize: 256
+        },
+        zlibInflateOptions: {
+          chunkSize: 2048
+        }
+      });
+      const lev9 = new PerMessageDeflate({
+        zlibDeflateOptions: {
+          level: 9,
+          chunkSize: 128
+        },
+        zlibInflateOptions: {
+          chunkSize: 1024
+        }
+      });
+
+      // Note no context takeover so we can get a hold of the raw streams after
+      // we do the dance.
+      const extensionStr =
+        'permessage-deflate; server_max_window_bits=10; ' +
+        'client_max_window_bits=11';
+      const buf = Buffer.from("Some compressible data, it's compressible.");
+
+      lev0.accept(extension.parse(extensionStr)['permessage-deflate']);
+      lev9.accept(extension.parse(extensionStr)['permessage-deflate']);
+
+      lev0.compress(buf, true, (err, compressed1) => {
+        if (err) return done(err);
+
+        lev0.decompress(compressed1, true, (err, decompressed1) => {
+          if (err) return done(err);
+
+          lev9.compress(buf, true, (err, compressed2) => {
+            if (err) return done(err);
+
+            lev9.decompress(compressed2, true, (err, decompressed2) => {
+              if (err) return done(err);
+              // Level 0 compression actually adds a few bytes due to headers.
+              assert.ok(compressed1.length > buf.length);
+              // Level 9 should not, of course.
+              assert.ok(compressed2.length < buf.length);
+              // Ensure they both decompress back properly.
+              assert.ok(decompressed1.equals(buf));
+              assert.ok(decompressed2.equals(buf));
+
+              // Assert options were set.
+              assert.ok(lev0._deflate._level === 0);
+              assert.ok(lev9._deflate._level === 9);
+              assert.ok(lev0._deflate._chunkSize === 256);
+              assert.ok(lev9._deflate._chunkSize === 128);
+              assert.ok(lev0._inflate._chunkSize === 2048);
+              assert.ok(lev9._inflate._chunkSize === 1024);
+              done();
+            });
+          });
+        });
+      });
+    });
+
+    it("doesn't use contex takeover if not allowed", (done) => {
+      const perMessageDeflate = new PerMessageDeflate({}, true);
+      const extensions = extension.parse(
+        'permessage-deflate;server_no_context_takeover'
+      );
+      const buf = Buffer.from('foofoo');
+
+      perMessageDeflate.accept(extensions['permessage-deflate']);
+
+      perMessageDeflate.compress(buf, true, (err, compressed1) => {
+        if (err) return done(err);
+
+        perMessageDeflate.decompress(compressed1, true, (err, data) => {
+          if (err) return done(err);
+
+          assert.ok(data.equals(buf));
+          perMessageDeflate.compress(data, true, (err, compressed2) => {
+            if (err) return done(err);
+
+            assert.strictEqual(compressed2.length, compressed1.length);
+            perMessageDeflate.decompress(compressed2, true, (err, data) => {
+              if (err) return done(err);
+
+              assert.ok(data.equals(buf));
+              done();
+            });
+          });
+        });
+      });
+    });
+
+    it('uses contex takeover if allowed', (done) => {
+      const perMessageDeflate = new PerMessageDeflate({}, true);
+      const extensions = extension.parse('permessage-deflate');
+      const buf = Buffer.from('foofoo');
+
+      perMessageDeflate.accept(extensions['permessage-deflate']);
+
+      perMessageDeflate.compress(buf, true, (err, compressed1) => {
+        if (err) return done(err);
+
+        perMessageDeflate.decompress(compressed1, true, (err, data) => {
+          if (err) return done(err);
+
+          assert.ok(data.equals(buf));
+          perMessageDeflate.compress(data, true, (err, compressed2) => {
+            if (err) return done(err);
+
+            assert.ok(compressed2.length < compressed1.length);
+            perMessageDeflate.decompress(compressed2, true, (err, data) => {
+              if (err) return done(err);
+
+              assert.ok(data.equals(buf));
+              done();
+            });
+          });
+        });
+      });
+    });
+
+    it('calls the callback when an error occurs (inflate)', (done) => {
+      const perMessageDeflate = new PerMessageDeflate();
+      const data = Buffer.from('something invalid');
+
+      perMessageDeflate.accept([{}]);
+      perMessageDeflate.decompress(data, true, (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.code, 'Z_DATA_ERROR');
+        assert.strictEqual(err.errno, -3);
+        done();
+      });
+    });
+
+    it("doesn't call the callback twice when `maxPayload` is exceeded", (done) => {
+      const perMessageDeflate = new PerMessageDeflate({}, false, 25);
+      const buf = Buffer.from('A'.repeat(50));
+
+      perMessageDeflate.accept([{}]);
+      perMessageDeflate.compress(buf, true, (err, data) => {
+        if (err) return done(err);
+
+        perMessageDeflate.decompress(data, true, (err) => {
+          assert.ok(err instanceof RangeError);
+          assert.strictEqual(err.message, 'Max payload size exceeded');
+          done();
+        });
+      });
+    });
+
+    it('calls the callback if the deflate stream is closed prematurely', (done) => {
+      const perMessageDeflate = new PerMessageDeflate();
+      const buf = Buffer.from('A'.repeat(50));
+
+      perMessageDeflate.accept([{}]);
+      perMessageDeflate.compress(buf, true, (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          'The deflate stream was closed while data was being processed'
+        );
+        done();
+      });
+
+      process.nextTick(() => perMessageDeflate.cleanup());
+    });
+
+    it('recreates the inflate stream if it ends', (done) => {
+      const perMessageDeflate = new PerMessageDeflate();
+      const extensions = extension.parse(
+        'permessage-deflate; client_no_context_takeover; ' +
+          'server_no_context_takeover'
+      );
+      const buf = Buffer.from('33343236313533b7000000', 'hex');
+      const expected = Buffer.from('12345678');
+
+      perMessageDeflate.accept(extensions['permessage-deflate']);
+
+      perMessageDeflate.decompress(buf, true, (err, data) => {
+        assert.ok(data.equals(expected));
+
+        perMessageDeflate.decompress(buf, true, (err, data) => {
+          assert.ok(data.equals(expected));
+          done();
+        });
+      });
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/receiver.test.js b/testing/xpcshell/node-ws/test/receiver.test.js
new file mode 100644
index 0000000000..7ee35f7402
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/receiver.test.js
@@ -0,0 +1,1086 @@
+'use strict';
+
+const assert = require('assert');
+const crypto = require('crypto');
+
+const PerMessageDeflate = require('../lib/permessage-deflate');
+const Receiver = require('../lib/receiver');
+const Sender = require('../lib/sender');
+const { EMPTY_BUFFER, kStatusCode } = require('../lib/constants');
+
+describe('Receiver', () => {
+  it('parses an unmasked text message', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, Buffer.from('Hello'));
+      assert.ok(!isBinary);
+      done();
+    });
+
+    receiver.write(Buffer.from('810548656c6c6f', 'hex'));
+  });
+
+  it('parses a close message', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('conclude', (code, data) => {
+      assert.strictEqual(code, 1005);
+      assert.strictEqual(data, EMPTY_BUFFER);
+      done();
+    });
+
+    receiver.write(Buffer.from('8800', 'hex'));
+  });
+
+  it('parses a close message spanning multiple writes', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('conclude', (code, data) => {
+      assert.strictEqual(code, 1000);
+      assert.deepStrictEqual(data, Buffer.from('DONE'));
+      done();
+    });
+
+    receiver.write(Buffer.from('8806', 'hex'));
+    receiver.write(Buffer.from('03e8444F4E45', 'hex'));
+  });
+
+  it('parses a masked text message', (done) => {
+    const receiver = new Receiver({ isServer: true });
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, Buffer.from('5:::{"name":"echo"}'));
+      assert.ok(!isBinary);
+      done();
+    });
+
+    receiver.write(
+      Buffer.from('81933483a86801b992524fa1c60959e68a5216e6cb005ba1d5', 'hex')
+    );
+  });
+
+  it('parses a masked text message longer than 125 B', (done) => {
+    const receiver = new Receiver({ isServer: true });
+    const msg = Buffer.from('A'.repeat(200));
+
+    const list = Sender.frame(msg, {
+      fin: true,
+      rsv1: false,
+      opcode: 0x01,
+      mask: true,
+      readOnly: true
+    });
+
+    const frame = Buffer.concat(list);
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, msg);
+      assert.ok(!isBinary);
+      done();
+    });
+
+    receiver.write(frame.slice(0, 2));
+    setImmediate(() => receiver.write(frame.slice(2)));
+  });
+
+  it('parses a really long masked text message', (done) => {
+    const receiver = new Receiver({ isServer: true });
+    const msg = Buffer.from('A'.repeat(64 * 1024));
+
+    const list = Sender.frame(msg, {
+      fin: true,
+      rsv1: false,
+      opcode: 0x01,
+      mask: true,
+      readOnly: true
+    });
+
+    const frame = Buffer.concat(list);
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, msg);
+      assert.ok(!isBinary);
+      done();
+    });
+
+    receiver.write(frame);
+  });
+
+  it('parses a 300 B fragmented masked text message', (done) => {
+    const receiver = new Receiver({ isServer: true });
+    const msg = Buffer.from('A'.repeat(300));
+
+    const fragment1 = msg.slice(0, 150);
+    const fragment2 = msg.slice(150);
+
+    const options = { rsv1: false, mask: true, readOnly: true };
+
+    const frame1 = Buffer.concat(
+      Sender.frame(fragment1, {
+        fin: false,
+        opcode: 0x01,
+        ...options
+      })
+    );
+    const frame2 = Buffer.concat(
+      Sender.frame(fragment2, {
+        fin: true,
+        opcode: 0x00,
+        ...options
+      })
+    );
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, msg);
+      assert.ok(!isBinary);
+      done();
+    });
+
+    receiver.write(frame1);
+    receiver.write(frame2);
+  });
+
+  it('parses a ping message', (done) => {
+    const receiver = new Receiver({ isServer: true });
+    const msg = Buffer.from('Hello');
+
+    const list = Sender.frame(msg, {
+      fin: true,
+      rsv1: false,
+      opcode: 0x09,
+      mask: true,
+      readOnly: true
+    });
+
+    const frame = Buffer.concat(list);
+
+    receiver.on('ping', (data) => {
+      assert.deepStrictEqual(data, msg);
+      done();
+    });
+
+    receiver.write(frame);
+  });
+
+  it('parses a ping message with no data', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('ping', (data) => {
+      assert.strictEqual(data, EMPTY_BUFFER);
+      done();
+    });
+
+    receiver.write(Buffer.from('8900', 'hex'));
+  });
+
+  it('parses a 300 B fragmented masked text message with a ping in the middle (1/2)', (done) => {
+    const receiver = new Receiver({ isServer: true });
+    const msg = Buffer.from('A'.repeat(300));
+    const pingMessage = Buffer.from('Hello');
+
+    const fragment1 = msg.slice(0, 150);
+    const fragment2 = msg.slice(150);
+
+    const options = { rsv1: false, mask: true, readOnly: true };
+
+    const frame1 = Buffer.concat(
+      Sender.frame(fragment1, {
+        fin: false,
+        opcode: 0x01,
+        ...options
+      })
+    );
+    const frame2 = Buffer.concat(
+      Sender.frame(pingMessage, {
+        fin: true,
+        opcode: 0x09,
+        ...options
+      })
+    );
+    const frame3 = Buffer.concat(
+      Sender.frame(fragment2, {
+        fin: true,
+        opcode: 0x00,
+        ...options
+      })
+    );
+
+    let gotPing = false;
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, msg);
+      assert.ok(!isBinary);
+      assert.ok(gotPing);
+      done();
+    });
+    receiver.on('ping', (data) => {
+      gotPing = true;
+      assert.ok(data.equals(pingMessage));
+    });
+
+    receiver.write(frame1);
+    receiver.write(frame2);
+    receiver.write(frame3);
+  });
+
+  it('parses a 300 B fragmented masked text message with a ping in the middle (2/2)', (done) => {
+    const receiver = new Receiver({ isServer: true });
+    const msg = Buffer.from('A'.repeat(300));
+    const pingMessage = Buffer.from('Hello');
+
+    const fragment1 = msg.slice(0, 150);
+    const fragment2 = msg.slice(150);
+
+    const options = { rsv1: false, mask: true, readOnly: false };
+
+    const frame1 = Buffer.concat(
+      Sender.frame(Buffer.from(fragment1), {
+        fin: false,
+        opcode: 0x01,
+        ...options
+      })
+    );
+    const frame2 = Buffer.concat(
+      Sender.frame(Buffer.from(pingMessage), {
+        fin: true,
+        opcode: 0x09,
+        ...options
+      })
+    );
+    const frame3 = Buffer.concat(
+      Sender.frame(Buffer.from(fragment2), {
+        fin: true,
+        opcode: 0x00,
+        ...options
+      })
+    );
+
+    let chunks = [];
+    const splitBuffer = (buf) => {
+      const i = Math.floor(buf.length / 2);
+      return [buf.slice(0, i), buf.slice(i)];
+    };
+
+    chunks = chunks.concat(splitBuffer(frame1));
+    chunks = chunks.concat(splitBuffer(frame2));
+    chunks = chunks.concat(splitBuffer(frame3));
+
+    let gotPing = false;
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, msg);
+      assert.ok(!isBinary);
+      assert.ok(gotPing);
+      done();
+    });
+    receiver.on('ping', (data) => {
+      gotPing = true;
+      assert.ok(data.equals(pingMessage));
+    });
+
+    for (let i = 0; i < chunks.length; ++i) {
+      receiver.write(chunks[i]);
+    }
+  });
+
+  it('parses a 100 B masked binary message', (done) => {
+    const receiver = new Receiver({ isServer: true });
+    const msg = crypto.randomBytes(100);
+
+    const list = Sender.frame(msg, {
+      fin: true,
+      rsv1: false,
+      opcode: 0x02,
+      mask: true,
+      readOnly: true
+    });
+
+    const frame = Buffer.concat(list);
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, msg);
+      assert.ok(isBinary);
+      done();
+    });
+
+    receiver.write(frame);
+  });
+
+  it('parses a 256 B masked binary message', (done) => {
+    const receiver = new Receiver({ isServer: true });
+    const msg = crypto.randomBytes(256);
+
+    const list = Sender.frame(msg, {
+      fin: true,
+      rsv1: false,
+      opcode: 0x02,
+      mask: true,
+      readOnly: true
+    });
+
+    const frame = Buffer.concat(list);
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, msg);
+      assert.ok(isBinary);
+      done();
+    });
+
+    receiver.write(frame);
+  });
+
+  it('parses a 200 KiB masked binary message', (done) => {
+    const receiver = new Receiver({ isServer: true });
+    const msg = crypto.randomBytes(200 * 1024);
+
+    const list = Sender.frame(msg, {
+      fin: true,
+      rsv1: false,
+      opcode: 0x02,
+      mask: true,
+      readOnly: true
+    });
+
+    const frame = Buffer.concat(list);
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, msg);
+      assert.ok(isBinary);
+      done();
+    });
+
+    receiver.write(frame);
+  });
+
+  it('parses a 200 KiB unmasked binary message', (done) => {
+    const receiver = new Receiver();
+    const msg = crypto.randomBytes(200 * 1024);
+
+    const list = Sender.frame(msg, {
+      fin: true,
+      rsv1: false,
+      opcode: 0x02,
+      mask: false,
+      readOnly: true
+    });
+
+    const frame = Buffer.concat(list);
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, msg);
+      assert.ok(isBinary);
+      done();
+    });
+
+    receiver.write(frame);
+  });
+
+  it('parses a compressed message', (done) => {
+    const perMessageDeflate = new PerMessageDeflate();
+    perMessageDeflate.accept([{}]);
+
+    const receiver = new Receiver({
+      extensions: {
+        'permessage-deflate': perMessageDeflate
+      }
+    });
+    const buf = Buffer.from('Hello');
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, buf);
+      assert.ok(!isBinary);
+      done();
+    });
+
+    perMessageDeflate.compress(buf, true, (err, data) => {
+      if (err) return done(err);
+
+      receiver.write(Buffer.from([0xc1, data.length]));
+      receiver.write(data);
+    });
+  });
+
+  it('parses a compressed and fragmented message', (done) => {
+    const perMessageDeflate = new PerMessageDeflate();
+    perMessageDeflate.accept([{}]);
+
+    const receiver = new Receiver({
+      extensions: {
+        'permessage-deflate': perMessageDeflate
+      }
+    });
+    const buf1 = Buffer.from('foo');
+    const buf2 = Buffer.from('bar');
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, Buffer.concat([buf1, buf2]));
+      assert.ok(!isBinary);
+      done();
+    });
+
+    perMessageDeflate.compress(buf1, false, (err, fragment1) => {
+      if (err) return done(err);
+
+      receiver.write(Buffer.from([0x41, fragment1.length]));
+      receiver.write(fragment1);
+
+      perMessageDeflate.compress(buf2, true, (err, fragment2) => {
+        if (err) return done(err);
+
+        receiver.write(Buffer.from([0x80, fragment2.length]));
+        receiver.write(fragment2);
+      });
+    });
+  });
+
+  it('parses a buffer with thousands of frames', (done) => {
+    const buf = Buffer.allocUnsafe(40000);
+
+    for (let i = 0; i < buf.length; i += 2) {
+      buf[i] = 0x81;
+      buf[i + 1] = 0x00;
+    }
+
+    const receiver = new Receiver();
+    let counter = 0;
+
+    receiver.on('message', (data, isBinary) => {
+      assert.strictEqual(data, EMPTY_BUFFER);
+      assert.ok(!isBinary);
+      if (++counter === 20000) done();
+    });
+
+    receiver.write(buf);
+  });
+
+  it('resets `totalPayloadLength` only on final frame (unfragmented)', (done) => {
+    const receiver = new Receiver({ maxPayload: 10 });
+
+    receiver.on('message', (data, isBinary) => {
+      assert.strictEqual(receiver._totalPayloadLength, 0);
+      assert.deepStrictEqual(data, Buffer.from('Hello'));
+      assert.ok(!isBinary);
+      done();
+    });
+
+    assert.strictEqual(receiver._totalPayloadLength, 0);
+    receiver.write(Buffer.from('810548656c6c6f', 'hex'));
+  });
+
+  it('resets `totalPayloadLength` only on final frame (fragmented)', (done) => {
+    const receiver = new Receiver({ maxPayload: 10 });
+
+    receiver.on('message', (data, isBinary) => {
+      assert.strictEqual(receiver._totalPayloadLength, 0);
+      assert.deepStrictEqual(data, Buffer.from('Hello'));
+      assert.ok(!isBinary);
+      done();
+    });
+
+    assert.strictEqual(receiver._totalPayloadLength, 0);
+    receiver.write(Buffer.from('01024865', 'hex'));
+    assert.strictEqual(receiver._totalPayloadLength, 2);
+    receiver.write(Buffer.from('80036c6c6f', 'hex'));
+  });
+
+  it('resets `totalPayloadLength` only on final frame (fragmented + ping)', (done) => {
+    const receiver = new Receiver({ maxPayload: 10 });
+    let data;
+
+    receiver.on('ping', (buf) => {
+      assert.strictEqual(receiver._totalPayloadLength, 2);
+      data = buf;
+    });
+    receiver.on('message', (buf, isBinary) => {
+      assert.strictEqual(receiver._totalPayloadLength, 0);
+      assert.deepStrictEqual(data, EMPTY_BUFFER);
+      assert.deepStrictEqual(buf, Buffer.from('Hello'));
+      assert.ok(isBinary);
+      done();
+    });
+
+    assert.strictEqual(receiver._totalPayloadLength, 0);
+    receiver.write(Buffer.from('02024865', 'hex'));
+    receiver.write(Buffer.from('8900', 'hex'));
+    receiver.write(Buffer.from('80036c6c6f', 'hex'));
+  });
+
+  it('ignores any data after a close frame', (done) => {
+    const perMessageDeflate = new PerMessageDeflate();
+    perMessageDeflate.accept([{}]);
+
+    const receiver = new Receiver({
+      extensions: {
+        'permessage-deflate': perMessageDeflate
+      }
+    });
+    const results = [];
+    const push = results.push.bind(results);
+
+    receiver.on('conclude', push).on('message', push);
+    receiver.on('finish', () => {
+      assert.deepStrictEqual(results, [
+        EMPTY_BUFFER,
+        false,
+        1005,
+        EMPTY_BUFFER
+      ]);
+      done();
+    });
+
+    receiver.write(Buffer.from([0xc1, 0x01, 0x00]));
+    receiver.write(Buffer.from([0x88, 0x00]));
+    receiver.write(Buffer.from([0x81, 0x00]));
+  });
+
+  it('emits an error if RSV1 is on and permessage-deflate is disabled', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_UNEXPECTED_RSV_1');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: RSV1 must be clear'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0xc2, 0x80, 0x00, 0x00, 0x00, 0x00]));
+  });
+
+  it('emits an error if RSV1 is on and opcode is 0', (done) => {
+    const perMessageDeflate = new PerMessageDeflate();
+    perMessageDeflate.accept([{}]);
+
+    const receiver = new Receiver({
+      extensions: {
+        'permessage-deflate': perMessageDeflate
+      }
+    });
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_UNEXPECTED_RSV_1');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: RSV1 must be clear'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x40, 0x00]));
+  });
+
+  it('emits an error if RSV2 is on', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_UNEXPECTED_RSV_2_3');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: RSV2 and RSV3 must be clear'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0xa2, 0x00]));
+  });
+
+  it('emits an error if RSV3 is on', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_UNEXPECTED_RSV_2_3');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: RSV2 and RSV3 must be clear'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x92, 0x00]));
+  });
+
+  it('emits an error if the first frame in a fragmented message has opcode 0', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_INVALID_OPCODE');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: invalid opcode 0'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x00, 0x00]));
+  });
+
+  it('emits an error if a frame has opcode 1 in the middle of a fragmented message', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_INVALID_OPCODE');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: invalid opcode 1'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x01, 0x00]));
+    receiver.write(Buffer.from([0x01, 0x00]));
+  });
+
+  it('emits an error if a frame has opcode 2 in the middle of a fragmented message', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_INVALID_OPCODE');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: invalid opcode 2'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x01, 0x00]));
+    receiver.write(Buffer.from([0x02, 0x00]));
+  });
+
+  it('emits an error if a control frame has the FIN bit off', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_EXPECTED_FIN');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: FIN must be set'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x09, 0x00]));
+  });
+
+  it('emits an error if a control frame has the RSV1 bit on', (done) => {
+    const perMessageDeflate = new PerMessageDeflate();
+    perMessageDeflate.accept([{}]);
+
+    const receiver = new Receiver({
+      extensions: {
+        'permessage-deflate': perMessageDeflate
+      }
+    });
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_UNEXPECTED_RSV_1');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: RSV1 must be clear'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0xc9, 0x00]));
+  });
+
+  it('emits an error if a control frame has the FIN bit off', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_EXPECTED_FIN');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: FIN must be set'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x09, 0x00]));
+  });
+
+  it('emits an error if a frame has the MASK bit off (server mode)', (done) => {
+    const receiver = new Receiver({ isServer: true });
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_EXPECTED_MASK');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: MASK must be set'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x81, 0x02, 0x68, 0x69]));
+  });
+
+  it('emits an error if a frame has the MASK bit on (client mode)', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_UNEXPECTED_MASK');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: MASK must be clear'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(
+      Buffer.from([0x81, 0x82, 0x56, 0x3a, 0xac, 0x80, 0x3e, 0x53])
+    );
+  });
+
+  it('emits an error if a control frame has a payload bigger than 125 B', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_INVALID_CONTROL_PAYLOAD_LENGTH');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: invalid payload length 126'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x89, 0x7e]));
+  });
+
+  it('emits an error if a data frame has a payload bigger than 2^53 - 1 B', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_UNSUPPORTED_DATA_PAYLOAD_LENGTH');
+      assert.strictEqual(
+        err.message,
+        'Unsupported WebSocket frame: payload length > 2^53 - 1'
+      );
+      assert.strictEqual(err[kStatusCode], 1009);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x82, 0x7f]));
+    setImmediate(() =>
+      receiver.write(
+        Buffer.from([0x00, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00])
+      )
+    );
+  });
+
+  it('emits an error if a text frame contains invalid UTF-8 data (1/2)', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof Error);
+      assert.strictEqual(err.code, 'WS_ERR_INVALID_UTF8');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: invalid UTF-8 sequence'
+      );
+      assert.strictEqual(err[kStatusCode], 1007);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x81, 0x04, 0xce, 0xba, 0xe1, 0xbd]));
+  });
+
+  it('emits an error if a text frame contains invalid UTF-8 data (2/2)', (done) => {
+    const perMessageDeflate = new PerMessageDeflate();
+    perMessageDeflate.accept([{}]);
+
+    const receiver = new Receiver({
+      extensions: {
+        'permessage-deflate': perMessageDeflate
+      }
+    });
+    const buf = Buffer.from([0xce, 0xba, 0xe1, 0xbd]);
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof Error);
+      assert.strictEqual(err.code, 'WS_ERR_INVALID_UTF8');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: invalid UTF-8 sequence'
+      );
+      assert.strictEqual(err[kStatusCode], 1007);
+      done();
+    });
+
+    perMessageDeflate.compress(buf, true, (err, data) => {
+      if (err) return done(err);
+
+      receiver.write(Buffer.from([0xc1, data.length]));
+      receiver.write(data);
+    });
+  });
+
+  it('emits an error if a close frame has a payload of 1 B', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_INVALID_CONTROL_PAYLOAD_LENGTH');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: invalid payload length 1'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x88, 0x01, 0x00]));
+  });
+
+  it('emits an error if a close frame contains an invalid close code', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_INVALID_CLOSE_CODE');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: invalid status code 0'
+      );
+      assert.strictEqual(err[kStatusCode], 1002);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x88, 0x02, 0x00, 0x00]));
+  });
+
+  it('emits an error if a close frame contains invalid UTF-8 data', (done) => {
+    const receiver = new Receiver();
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof Error);
+      assert.strictEqual(err.code, 'WS_ERR_INVALID_UTF8');
+      assert.strictEqual(
+        err.message,
+        'Invalid WebSocket frame: invalid UTF-8 sequence'
+      );
+      assert.strictEqual(err[kStatusCode], 1007);
+      done();
+    });
+
+    receiver.write(
+      Buffer.from([0x88, 0x06, 0x03, 0xef, 0xce, 0xba, 0xe1, 0xbd])
+    );
+  });
+
+  it('emits an error if a frame payload length is bigger than `maxPayload`', (done) => {
+    const receiver = new Receiver({ isServer: true, maxPayload: 20 * 1024 });
+    const msg = crypto.randomBytes(200 * 1024);
+
+    const list = Sender.frame(msg, {
+      fin: true,
+      rsv1: false,
+      opcode: 0x02,
+      mask: true,
+      readOnly: true
+    });
+
+    const frame = Buffer.concat(list);
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_UNSUPPORTED_MESSAGE_LENGTH');
+      assert.strictEqual(err.message, 'Max payload size exceeded');
+      assert.strictEqual(err[kStatusCode], 1009);
+      done();
+    });
+
+    receiver.write(frame);
+  });
+
+  it('emits an error if the message length exceeds `maxPayload`', (done) => {
+    const perMessageDeflate = new PerMessageDeflate({}, false, 25);
+    perMessageDeflate.accept([{}]);
+
+    const receiver = new Receiver({
+      extensions: { 'permessage-deflate': perMessageDeflate },
+      isServer: false,
+      maxPayload: 25
+    });
+    const buf = Buffer.from('A'.repeat(50));
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_UNSUPPORTED_MESSAGE_LENGTH');
+      assert.strictEqual(err.message, 'Max payload size exceeded');
+      assert.strictEqual(err[kStatusCode], 1009);
+      done();
+    });
+
+    perMessageDeflate.compress(buf, true, (err, data) => {
+      if (err) return done(err);
+
+      receiver.write(Buffer.from([0xc1, data.length]));
+      receiver.write(data);
+    });
+  });
+
+  it('emits an error if the sum of fragment lengths exceeds `maxPayload`', (done) => {
+    const perMessageDeflate = new PerMessageDeflate({}, false, 25);
+    perMessageDeflate.accept([{}]);
+
+    const receiver = new Receiver({
+      extensions: { 'permessage-deflate': perMessageDeflate },
+      isServer: false,
+      maxPayload: 25
+    });
+    const buf = Buffer.from('A'.repeat(15));
+
+    receiver.on('error', (err) => {
+      assert.ok(err instanceof RangeError);
+      assert.strictEqual(err.code, 'WS_ERR_UNSUPPORTED_MESSAGE_LENGTH');
+      assert.strictEqual(err.message, 'Max payload size exceeded');
+      assert.strictEqual(err[kStatusCode], 1009);
+      done();
+    });
+
+    perMessageDeflate.compress(buf, false, (err, fragment1) => {
+      if (err) return done(err);
+
+      receiver.write(Buffer.from([0x41, fragment1.length]));
+      receiver.write(fragment1);
+
+      perMessageDeflate.compress(buf, true, (err, fragment2) => {
+        if (err) return done(err);
+
+        receiver.write(Buffer.from([0x80, fragment2.length]));
+        receiver.write(fragment2);
+      });
+    });
+  });
+
+  it("honors the 'nodebuffer' binary type", (done) => {
+    const receiver = new Receiver();
+    const frags = [
+      crypto.randomBytes(7321),
+      crypto.randomBytes(137),
+      crypto.randomBytes(285787),
+      crypto.randomBytes(3)
+    ];
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, Buffer.concat(frags));
+      assert.ok(isBinary);
+      done();
+    });
+
+    frags.forEach((frag, i) => {
+      Sender.frame(frag, {
+        fin: i === frags.length - 1,
+        opcode: i === 0 ? 2 : 0,
+        readOnly: true,
+        mask: false,
+        rsv1: false
+      }).forEach((buf) => receiver.write(buf));
+    });
+  });
+
+  it("honors the 'arraybuffer' binary type", (done) => {
+    const receiver = new Receiver({ binaryType: 'arraybuffer' });
+    const frags = [
+      crypto.randomBytes(19221),
+      crypto.randomBytes(954),
+      crypto.randomBytes(623987)
+    ];
+
+    receiver.on('message', (data, isBinary) => {
+      assert.ok(data instanceof ArrayBuffer);
+      assert.deepStrictEqual(Buffer.from(data), Buffer.concat(frags));
+      assert.ok(isBinary);
+      done();
+    });
+
+    frags.forEach((frag, i) => {
+      Sender.frame(frag, {
+        fin: i === frags.length - 1,
+        opcode: i === 0 ? 2 : 0,
+        readOnly: true,
+        mask: false,
+        rsv1: false
+      }).forEach((buf) => receiver.write(buf));
+    });
+  });
+
+  it("honors the 'fragments' binary type", (done) => {
+    const receiver = new Receiver({ binaryType: 'fragments' });
+    const frags = [
+      crypto.randomBytes(17),
+      crypto.randomBytes(419872),
+      crypto.randomBytes(83),
+      crypto.randomBytes(9928),
+      crypto.randomBytes(1)
+    ];
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, frags);
+      assert.ok(isBinary);
+      done();
+    });
+
+    frags.forEach((frag, i) => {
+      Sender.frame(frag, {
+        fin: i === frags.length - 1,
+        opcode: i === 0 ? 2 : 0,
+        readOnly: true,
+        mask: false,
+        rsv1: false
+      }).forEach((buf) => receiver.write(buf));
+    });
+  });
+
+  it('honors the `skipUTF8Validation` option (1/2)', (done) => {
+    const receiver = new Receiver({ skipUTF8Validation: true });
+
+    receiver.on('message', (data, isBinary) => {
+      assert.deepStrictEqual(data, Buffer.from([0xf8]));
+      assert.ok(!isBinary);
+      done();
+    });
+
+    receiver.write(Buffer.from([0x81, 0x01, 0xf8]));
+  });
+
+  it('honors the `skipUTF8Validation` option (2/2)', (done) => {
+    const receiver = new Receiver({ skipUTF8Validation: true });
+
+    receiver.on('conclude', (code, data) => {
+      assert.strictEqual(code, 1000);
+      assert.deepStrictEqual(data, Buffer.from([0xf8]));
+      done();
+    });
+
+    receiver.write(Buffer.from([0x88, 0x03, 0x03, 0xe8, 0xf8]));
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/sender.test.js b/testing/xpcshell/node-ws/test/sender.test.js
new file mode 100644
index 0000000000..532239fa1a
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/sender.test.js
@@ -0,0 +1,370 @@
+'use strict';
+
+const assert = require('assert');
+
+const extension = require('../lib/extension');
+const PerMessageDeflate = require('../lib/permessage-deflate');
+const Sender = require('../lib/sender');
+const { EMPTY_BUFFER } = require('../lib/constants');
+
+class MockSocket {
+  constructor({ write } = {}) {
+    this.readable = true;
+    this.writable = true;
+
+    if (write) this.write = write;
+  }
+
+  cork() {}
+  write() {}
+  uncork() {}
+}
+
+describe('Sender', () => {
+  describe('.frame', () => {
+    it('does not mutate the input buffer if data is `readOnly`', () => {
+      const buf = Buffer.from([1, 2, 3, 4, 5]);
+
+      Sender.frame(buf, {
+        readOnly: true,
+        rsv1: false,
+        mask: true,
+        opcode: 2,
+        fin: true
+      });
+
+      assert.ok(buf.equals(Buffer.from([1, 2, 3, 4, 5])));
+    });
+
+    it('honors the `rsv1` option', () => {
+      const list = Sender.frame(EMPTY_BUFFER, {
+        readOnly: false,
+        mask: false,
+        rsv1: true,
+        opcode: 1,
+        fin: true
+      });
+
+      assert.strictEqual(list[0][0] & 0x40, 0x40);
+    });
+
+    it('accepts a string as first argument', () => {
+      const list = Sender.frame('€', {
+        readOnly: false,
+        rsv1: false,
+        mask: false,
+        opcode: 1,
+        fin: true
+      });
+
+      assert.deepStrictEqual(list[0], Buffer.from('8103', 'hex'));
+      assert.deepStrictEqual(list[1], Buffer.from('e282ac', 'hex'));
+    });
+  });
+
+  describe('#send', () => {
+    it('compresses data if compress option is enabled', (done) => {
+      const chunks = [];
+      const perMessageDeflate = new PerMessageDeflate();
+      const mockSocket = new MockSocket({
+        write: (chunk) => {
+          chunks.push(chunk);
+          if (chunks.length !== 6) return;
+
+          assert.strictEqual(chunks[0].length, 2);
+          assert.strictEqual(chunks[0][0] & 0x40, 0x40);
+
+          assert.strictEqual(chunks[2].length, 2);
+          assert.strictEqual(chunks[2][0] & 0x40, 0x40);
+
+          assert.strictEqual(chunks[4].length, 2);
+          assert.strictEqual(chunks[4][0] & 0x40, 0x40);
+          done();
+        }
+      });
+      const sender = new Sender(mockSocket, {
+        'permessage-deflate': perMessageDeflate
+      });
+
+      perMessageDeflate.accept([{}]);
+
+      const options = { compress: true, fin: true };
+      const array = new Uint8Array([0x68, 0x69]);
+
+      sender.send(array.buffer, options);
+      sender.send(array, options);
+      sender.send('hi', options);
+    });
+
+    describe('when context takeover is disabled', () => {
+      it('honors the compression threshold', (done) => {
+        const chunks = [];
+        const perMessageDeflate = new PerMessageDeflate();
+        const mockSocket = new MockSocket({
+          write: (chunk) => {
+            chunks.push(chunk);
+            if (chunks.length !== 2) return;
+
+            assert.strictEqual(chunks[0].length, 2);
+            assert.notStrictEqual(chunk[0][0] & 0x40, 0x40);
+            assert.strictEqual(chunks[1], 'hi');
+            done();
+          }
+        });
+        const sender = new Sender(mockSocket, {
+          'permessage-deflate': perMessageDeflate
+        });
+        const extensions = extension.parse(
+          'permessage-deflate; client_no_context_takeover'
+        );
+
+        perMessageDeflate.accept(extensions['permessage-deflate']);
+
+        sender.send('hi', { compress: true, fin: true });
+      });
+
+      it('compresses all fragments of a fragmented message', (done) => {
+        const chunks = [];
+        const perMessageDeflate = new PerMessageDeflate({ threshold: 3 });
+        const mockSocket = new MockSocket({
+          write: (chunk) => {
+            chunks.push(chunk);
+            if (chunks.length !== 4) return;
+
+            assert.strictEqual(chunks[0].length, 2);
+            assert.strictEqual(chunks[0][0] & 0x40, 0x40);
+            assert.strictEqual(chunks[1].length, 9);
+
+            assert.strictEqual(chunks[2].length, 2);
+            assert.strictEqual(chunks[2][0] & 0x40, 0x00);
+            assert.strictEqual(chunks[3].length, 4);
+            done();
+          }
+        });
+        const sender = new Sender(mockSocket, {
+          'permessage-deflate': perMessageDeflate
+        });
+        const extensions = extension.parse(
+          'permessage-deflate; client_no_context_takeover'
+        );
+
+        perMessageDeflate.accept(extensions['permessage-deflate']);
+
+        sender.send('123', { compress: true, fin: false });
+        sender.send('12', { compress: true, fin: true });
+      });
+
+      it('does not compress any fragments of a fragmented message', (done) => {
+        const chunks = [];
+        const perMessageDeflate = new PerMessageDeflate({ threshold: 3 });
+        const mockSocket = new MockSocket({
+          write: (chunk) => {
+            chunks.push(chunk);
+            if (chunks.length !== 4) return;
+
+            assert.strictEqual(chunks[0].length, 2);
+            assert.strictEqual(chunks[0][0] & 0x40, 0x00);
+            assert.strictEqual(chunks[1].length, 2);
+
+            assert.strictEqual(chunks[2].length, 2);
+            assert.strictEqual(chunks[2][0] & 0x40, 0x00);
+            assert.strictEqual(chunks[3].length, 3);
+            done();
+          }
+        });
+        const sender = new Sender(mockSocket, {
+          'permessage-deflate': perMessageDeflate
+        });
+        const extensions = extension.parse(
+          'permessage-deflate; client_no_context_takeover'
+        );
+
+        perMessageDeflate.accept(extensions['permessage-deflate']);
+
+        sender.send('12', { compress: true, fin: false });
+        sender.send('123', { compress: true, fin: true });
+      });
+
+      it('compresses empty buffer as first fragment', (done) => {
+        const chunks = [];
+        const perMessageDeflate = new PerMessageDeflate({ threshold: 0 });
+        const mockSocket = new MockSocket({
+          write: (chunk) => {
+            chunks.push(chunk);
+            if (chunks.length !== 4) return;
+
+            assert.strictEqual(chunks[0].length, 2);
+            assert.strictEqual(chunks[0][0] & 0x40, 0x40);
+            assert.strictEqual(chunks[1].length, 5);
+
+            assert.strictEqual(chunks[2].length, 2);
+            assert.strictEqual(chunks[2][0] & 0x40, 0x00);
+            assert.strictEqual(chunks[3].length, 6);
+            done();
+          }
+        });
+        const sender = new Sender(mockSocket, {
+          'permessage-deflate': perMessageDeflate
+        });
+        const extensions = extension.parse(
+          'permessage-deflate; client_no_context_takeover'
+        );
+
+        perMessageDeflate.accept(extensions['permessage-deflate']);
+
+        sender.send(Buffer.alloc(0), { compress: true, fin: false });
+        sender.send('data', { compress: true, fin: true });
+      });
+
+      it('compresses empty buffer as last fragment', (done) => {
+        const chunks = [];
+        const perMessageDeflate = new PerMessageDeflate({ threshold: 0 });
+        const mockSocket = new MockSocket({
+          write: (chunk) => {
+            chunks.push(chunk);
+            if (chunks.length !== 4) return;
+
+            assert.strictEqual(chunks[0].length, 2);
+            assert.strictEqual(chunks[0][0] & 0x40, 0x40);
+            assert.strictEqual(chunks[1].length, 10);
+
+            assert.strictEqual(chunks[2].length, 2);
+            assert.strictEqual(chunks[2][0] & 0x40, 0x00);
+            assert.strictEqual(chunks[3].length, 1);
+            done();
+          }
+        });
+        const sender = new Sender(mockSocket, {
+          'permessage-deflate': perMessageDeflate
+        });
+        const extensions = extension.parse(
+          'permessage-deflate; client_no_context_takeover'
+        );
+
+        perMessageDeflate.accept(extensions['permessage-deflate']);
+
+        sender.send('data', { compress: true, fin: false });
+        sender.send(Buffer.alloc(0), { compress: true, fin: true });
+      });
+    });
+  });
+
+  describe('#ping', () => {
+    it('works with multiple types of data', (done) => {
+      const perMessageDeflate = new PerMessageDeflate();
+      let count = 0;
+      const mockSocket = new MockSocket({
+        write: (data) => {
+          if (++count < 3) return;
+
+          if (count % 2) {
+            assert.ok(data.equals(Buffer.from([0x89, 0x02])));
+          } else if (count < 8) {
+            assert.ok(data.equals(Buffer.from([0x68, 0x69])));
+          } else {
+            assert.strictEqual(data, 'hi');
+            done();
+          }
+        }
+      });
+      const sender = new Sender(mockSocket, {
+        'permessage-deflate': perMessageDeflate
+      });
+
+      perMessageDeflate.accept([{}]);
+
+      const array = new Uint8Array([0x68, 0x69]);
+
+      sender.send('foo', { compress: true, fin: true });
+      sender.ping(array.buffer, false);
+      sender.ping(array, false);
+      sender.ping('hi', false);
+    });
+  });
+
+  describe('#pong', () => {
+    it('works with multiple types of data', (done) => {
+      const perMessageDeflate = new PerMessageDeflate();
+      let count = 0;
+      const mockSocket = new MockSocket({
+        write: (data) => {
+          if (++count < 3) return;
+
+          if (count % 2) {
+            assert.ok(data.equals(Buffer.from([0x8a, 0x02])));
+          } else if (count < 8) {
+            assert.ok(data.equals(Buffer.from([0x68, 0x69])));
+          } else {
+            assert.strictEqual(data, 'hi');
+            done();
+          }
+        }
+      });
+      const sender = new Sender(mockSocket, {
+        'permessage-deflate': perMessageDeflate
+      });
+
+      perMessageDeflate.accept([{}]);
+
+      const array = new Uint8Array([0x68, 0x69]);
+
+      sender.send('foo', { compress: true, fin: true });
+      sender.pong(array.buffer, false);
+      sender.pong(array, false);
+      sender.pong('hi', false);
+    });
+  });
+
+  describe('#close', () => {
+    it('throws an error if the first argument is invalid', () => {
+      const mockSocket = new MockSocket();
+      const sender = new Sender(mockSocket);
+
+      assert.throws(
+        () => sender.close('error'),
+        /^TypeError: First argument must be a valid error code number$/
+      );
+
+      assert.throws(
+        () => sender.close(1004),
+        /^TypeError: First argument must be a valid error code number$/
+      );
+    });
+
+    it('throws an error if the message is greater than 123 bytes', () => {
+      const mockSocket = new MockSocket();
+      const sender = new Sender(mockSocket);
+
+      assert.throws(
+        () => sender.close(1000, 'a'.repeat(124)),
+        /^RangeError: The message must not be greater than 123 bytes$/
+      );
+    });
+
+    it('should consume all data before closing', (done) => {
+      const perMessageDeflate = new PerMessageDeflate();
+
+      let count = 0;
+      const mockSocket = new MockSocket({
+        write: (data, cb) => {
+          count++;
+          if (cb) cb();
+        }
+      });
+      const sender = new Sender(mockSocket, {
+        'permessage-deflate': perMessageDeflate
+      });
+
+      perMessageDeflate.accept([{}]);
+
+      sender.send('foo', { compress: true, fin: true });
+      sender.send('bar', { compress: true, fin: true });
+      sender.send('baz', { compress: true, fin: true });
+
+      sender.close(1000, undefined, false, () => {
+        assert.strictEqual(count, 8);
+        done();
+      });
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/subprotocol.test.js b/testing/xpcshell/node-ws/test/subprotocol.test.js
new file mode 100644
index 0000000000..91dd5d69d8
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/subprotocol.test.js
@@ -0,0 +1,91 @@
+'use strict';
+
+const assert = require('assert');
+
+const { parse } = require('../lib/subprotocol');
+
+describe('subprotocol', () => {
+  describe('parse', () => {
+    it('parses a single subprotocol', () => {
+      assert.deepStrictEqual(parse('foo'), new Set(['foo']));
+    });
+
+    it('parses multiple subprotocols', () => {
+      assert.deepStrictEqual(
+        parse('foo,bar,baz'),
+        new Set(['foo', 'bar', 'baz'])
+      );
+    });
+
+    it('ignores the optional white spaces', () => {
+      const header = 'foo , bar\t, \tbaz\t ,  qux\t\t,norf';
+
+      assert.deepStrictEqual(
+        parse(header),
+        new Set(['foo', 'bar', 'baz', 'qux', 'norf'])
+      );
+    });
+
+    it('throws an error if a subprotocol is empty', () => {
+      [
+        [',', 0],
+        ['foo,,', 4],
+        ['foo,  ,', 6]
+      ].forEach((element) => {
+        assert.throws(
+          () => parse(element[0]),
+          new RegExp(
+            `^SyntaxError: Unexpected character at index ${element[1]}$`
+          )
+        );
+      });
+    });
+
+    it('throws an error if a subprotocol is duplicated', () => {
+      ['foo,foo,bar', 'foo,bar,foo'].forEach((header) => {
+        assert.throws(
+          () => parse(header),
+          /^SyntaxError: The "foo" subprotocol is duplicated$/
+        );
+      });
+    });
+
+    it('throws an error if a white space is misplaced', () => {
+      [
+        ['f oo', 2],
+        [' foo', 0]
+      ].forEach((element) => {
+        assert.throws(
+          () => parse(element[0]),
+          new RegExp(
+            `^SyntaxError: Unexpected character at index ${element[1]}$`
+          )
+        );
+      });
+    });
+
+    it('throws an error if a subprotocol contains invalid characters', () => {
+      [
+        ['f@o', 1],
+        ['f\\oo', 1],
+        ['foo,b@r', 5]
+      ].forEach((element) => {
+        assert.throws(
+          () => parse(element[0]),
+          new RegExp(
+            `^SyntaxError: Unexpected character at index ${element[1]}$`
+          )
+        );
+      });
+    });
+
+    it('throws an error if the header value ends prematurely', () => {
+      ['foo ', 'foo, ', 'foo,bar ', 'foo,bar,'].forEach((header) => {
+        assert.throws(
+          () => parse(header),
+          /^SyntaxError: Unexpected end of input$/
+        );
+      });
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/validation.test.js b/testing/xpcshell/node-ws/test/validation.test.js
new file mode 100644
index 0000000000..5718b12f02
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/validation.test.js
@@ -0,0 +1,52 @@
+'use strict';
+
+const assert = require('assert');
+
+const { isValidUTF8 } = require('../lib/validation');
+
+describe('extension', () => {
+  describe('isValidUTF8', () => {
+    it('returns false if it finds invalid bytes', () => {
+      assert.strictEqual(isValidUTF8(Buffer.from([0xf8])), false);
+    });
+
+    it('returns false for overlong encodings', () => {
+      assert.strictEqual(isValidUTF8(Buffer.from([0xc0, 0xa0])), false);
+      assert.strictEqual(isValidUTF8(Buffer.from([0xe0, 0x80, 0xa0])), false);
+      assert.strictEqual(
+        isValidUTF8(Buffer.from([0xf0, 0x80, 0x80, 0xa0])),
+        false
+      );
+    });
+
+    it('returns false for code points in the range U+D800 - U+DFFF', () => {
+      for (let i = 0xa0; i < 0xc0; i++) {
+        for (let j = 0x80; j < 0xc0; j++) {
+          assert.strictEqual(isValidUTF8(Buffer.from([0xed, i, j])), false);
+        }
+      }
+    });
+
+    it('returns false for code points greater than U+10FFFF', () => {
+      assert.strictEqual(
+        isValidUTF8(Buffer.from([0xf4, 0x90, 0x80, 0x80])),
+        false
+      );
+      assert.strictEqual(
+        isValidUTF8(Buffer.from([0xf5, 0x80, 0x80, 0x80])),
+        false
+      );
+    });
+
+    it('returns true for a well-formed UTF-8 byte sequence', () => {
+      // prettier-ignore
+      const buf = Buffer.from([
+        0xe2, 0x82, 0xAC, // €
+        0xf0, 0x90, 0x8c, 0x88, // 𐍈
+        0x24 // $
+      ]);
+
+      assert.strictEqual(isValidUTF8(buf), true);
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/websocket-server.test.js b/testing/xpcshell/node-ws/test/websocket-server.test.js
new file mode 100644
index 0000000000..12928ff495
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/websocket-server.test.js
@@ -0,0 +1,1284 @@
+/* eslint no-unused-vars: ["error", { "varsIgnorePattern": "^ws$" }] */
+
+'use strict';
+
+const assert = require('assert');
+const crypto = require('crypto');
+const https = require('https');
+const http = require('http');
+const path = require('path');
+const net = require('net');
+const fs = require('fs');
+const os = require('os');
+
+const Sender = require('../lib/sender');
+const WebSocket = require('..');
+const { NOOP } = require('../lib/constants');
+
+describe('WebSocketServer', () => {
+  describe('#ctor', () => {
+    it('throws an error if no option object is passed', () => {
+      assert.throws(
+        () => new WebSocket.Server(),
+        new RegExp(
+          '^TypeError: One and only one of the "port", "server", or ' +
+            '"noServer" options must be specified$'
+        )
+      );
+    });
+
+    describe('options', () => {
+      it('throws an error if required options are not specified', () => {
+        assert.throws(
+          () => new WebSocket.Server({}),
+          new RegExp(
+            '^TypeError: One and only one of the "port", "server", or ' +
+              '"noServer" options must be specified$'
+          )
+        );
+      });
+
+      it('throws an error if mutually exclusive options are specified', () => {
+        const server = http.createServer();
+        const variants = [
+          { port: 0, noServer: true, server },
+          { port: 0, noServer: true },
+          { port: 0, server },
+          { noServer: true, server }
+        ];
+
+        for (const options of variants) {
+          assert.throws(
+            () => new WebSocket.Server(options),
+            new RegExp(
+              '^TypeError: One and only one of the "port", "server", or ' +
+                '"noServer" options must be specified$'
+            )
+          );
+        }
+      });
+
+      it('exposes options passed to constructor', (done) => {
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          assert.strictEqual(wss.options.port, 0);
+          wss.close(done);
+        });
+      });
+
+      it('accepts the `maxPayload` option', (done) => {
+        const maxPayload = 20480;
+        const wss = new WebSocket.Server(
+          {
+            perMessageDeflate: true,
+            maxPayload,
+            port: 0
+          },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+            ws.on('open', ws.close);
+          }
+        );
+
+        wss.on('connection', (ws) => {
+          assert.strictEqual(ws._receiver._maxPayload, maxPayload);
+          assert.strictEqual(
+            ws._receiver._extensions['permessage-deflate']._maxPayload,
+            maxPayload
+          );
+          wss.close(done);
+        });
+      });
+
+      it('honors the `WebSocket` option', (done) => {
+        class CustomWebSocket extends WebSocket.WebSocket {
+          get foo() {
+            return 'foo';
+          }
+        }
+
+        const wss = new WebSocket.Server(
+          {
+            port: 0,
+            WebSocket: CustomWebSocket
+          },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+            ws.on('open', ws.close);
+          }
+        );
+
+        wss.on('connection', (ws) => {
+          assert.ok(ws instanceof CustomWebSocket);
+          assert.strictEqual(ws.foo, 'foo');
+          wss.close(done);
+        });
+      });
+    });
+
+    it('emits an error if http server bind fails', (done) => {
+      const wss1 = new WebSocket.Server({ port: 0 }, () => {
+        const wss2 = new WebSocket.Server({
+          port: wss1.address().port
+        });
+
+        wss2.on('error', () => wss1.close(done));
+      });
+    });
+
+    it('starts a server on a given port', (done) => {
+      const port = 1337;
+      const wss = new WebSocket.Server({ port }, () => {
+        const ws = new WebSocket(`ws://localhost:${port}`);
+
+        ws.on('open', ws.close);
+      });
+
+      wss.on('connection', () => wss.close(done));
+    });
+
+    it('binds the server on any IPv6 address when available', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        assert.strictEqual(wss._server.address().address, '::');
+        wss.close(done);
+      });
+    });
+
+    it('uses a precreated http server', (done) => {
+      const server = http.createServer();
+
+      server.listen(0, () => {
+        const wss = new WebSocket.Server({ server });
+
+        wss.on('connection', () => {
+          server.close(done);
+        });
+
+        const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+        ws.on('open', ws.close);
+      });
+    });
+
+    it('426s for non-Upgrade requests', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        http.get(`http://localhost:${wss.address().port}`, (res) => {
+          let body = '';
+
+          assert.strictEqual(res.statusCode, 426);
+          res.on('data', (chunk) => {
+            body += chunk;
+          });
+          res.on('end', () => {
+            assert.strictEqual(body, http.STATUS_CODES[426]);
+            wss.close(done);
+          });
+        });
+      });
+    });
+
+    it('uses a precreated http server listening on unix socket', function (done) {
+      //
+      // Skip this test on Windows. The URL parser:
+      //
+      // - Throws an error if the named pipe uses backward slashes.
+      // - Incorrectly parses the path if the named pipe uses forward slashes.
+      //
+      if (process.platform === 'win32') return this.skip();
+
+      const server = http.createServer();
+      const sockPath = path.join(
+        os.tmpdir(),
+        `ws.${crypto.randomBytes(16).toString('hex')}.sock`
+      );
+
+      server.listen(sockPath, () => {
+        const wss = new WebSocket.Server({ server });
+
+        wss.on('connection', (ws, req) => {
+          if (wss.clients.size === 1) {
+            assert.strictEqual(req.url, '/foo?bar=bar');
+          } else {
+            assert.strictEqual(req.url, '/');
+
+            for (const client of wss.clients) {
+              client.close();
+            }
+
+            server.close(done);
+          }
+        });
+
+        const ws = new WebSocket(`ws+unix://${sockPath}:/foo?bar=bar`);
+        ws.on('open', () => new WebSocket(`ws+unix://${sockPath}`));
+      });
+    });
+  });
+
+  describe('#address', () => {
+    it('returns the address of the server', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const addr = wss.address();
+
+        assert.deepStrictEqual(addr, wss._server.address());
+        wss.close(done);
+      });
+    });
+
+    it('throws an error when operating in "noServer" mode', () => {
+      const wss = new WebSocket.Server({ noServer: true });
+
+      assert.throws(() => {
+        wss.address();
+      }, /^Error: The server is operating in "noServer" mode$/);
+    });
+
+    it('returns `null` if called after close', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        wss.close(() => {
+          assert.strictEqual(wss.address(), null);
+          done();
+        });
+      });
+    });
+  });
+
+  describe('#close', () => {
+    it('does not throw if called multiple times', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        wss.on('close', done);
+
+        wss.close();
+        wss.close();
+        wss.close();
+      });
+    });
+
+    it("doesn't close a precreated server", (done) => {
+      const server = http.createServer();
+      const realClose = server.close;
+
+      server.close = () => {
+        done(new Error('Must not close pre-created server'));
+      };
+
+      const wss = new WebSocket.Server({ server });
+
+      wss.on('connection', () => {
+        wss.close();
+        server.close = realClose;
+        server.close(done);
+      });
+
+      server.listen(0, () => {
+        const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+        ws.on('open', ws.close);
+      });
+    });
+
+    it('invokes the callback in noServer mode', (done) => {
+      const wss = new WebSocket.Server({ noServer: true });
+
+      wss.close(done);
+    });
+
+    it('cleans event handlers on precreated server', (done) => {
+      const server = http.createServer();
+      const wss = new WebSocket.Server({ server });
+
+      server.listen(0, () => {
+        wss.close(() => {
+          assert.strictEqual(server.listenerCount('listening'), 0);
+          assert.strictEqual(server.listenerCount('upgrade'), 0);
+          assert.strictEqual(server.listenerCount('error'), 0);
+
+          server.close(done);
+        });
+      });
+    });
+
+    it("emits the 'close' event after the server closes", (done) => {
+      let serverCloseEventEmitted = false;
+
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        net.createConnection({ port: wss.address().port });
+      });
+
+      wss._server.on('connection', (socket) => {
+        wss.close();
+
+        //
+        // The server is closing. Ensure this does not emit a `'close'`
+        // event before the server is actually closed.
+        //
+        wss.close();
+
+        process.nextTick(() => {
+          socket.end();
+        });
+      });
+
+      wss._server.on('close', () => {
+        serverCloseEventEmitted = true;
+      });
+
+      wss.on('close', () => {
+        assert.ok(serverCloseEventEmitted);
+        done();
+      });
+    });
+
+    it("emits the 'close' event if client tracking is disabled", (done) => {
+      const wss = new WebSocket.Server({
+        noServer: true,
+        clientTracking: false
+      });
+
+      wss.on('close', done);
+      wss.close();
+    });
+
+    it('calls the callback if the server is already closed', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        wss.close(() => {
+          assert.strictEqual(wss._state, 2);
+
+          wss.close((err) => {
+            assert.ok(err instanceof Error);
+            assert.strictEqual(err.message, 'The server is not running');
+            done();
+          });
+        });
+      });
+    });
+
+    it("emits the 'close' event if the server is already closed", (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        wss.close(() => {
+          assert.strictEqual(wss._state, 2);
+
+          wss.on('close', done);
+          wss.close();
+        });
+      });
+    });
+  });
+
+  describe('#clients', () => {
+    it('returns a list of connected clients', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        assert.strictEqual(wss.clients.size, 0);
+
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', ws.close);
+      });
+
+      wss.on('connection', () => {
+        assert.strictEqual(wss.clients.size, 1);
+        wss.close(done);
+      });
+    });
+
+    it('can be disabled', (done) => {
+      const wss = new WebSocket.Server(
+        { port: 0, clientTracking: false },
+        () => {
+          assert.strictEqual(wss.clients, undefined);
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          ws.on('open', () => ws.close());
+        }
+      );
+
+      wss.on('connection', (ws) => {
+        assert.strictEqual(wss.clients, undefined);
+        ws.on('close', () => wss.close(done));
+      });
+    });
+
+    it('is updated when client terminates the connection', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => ws.terminate());
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('close', () => {
+          assert.strictEqual(wss.clients.size, 0);
+          wss.close(done);
+        });
+      });
+    });
+
+    it('is updated when client closes the connection', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => ws.close());
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('close', () => {
+          assert.strictEqual(wss.clients.size, 0);
+          wss.close(done);
+        });
+      });
+    });
+  });
+
+  describe('#shouldHandle', () => {
+    it('returns true when the path matches', () => {
+      const wss = new WebSocket.Server({ noServer: true, path: '/foo' });
+
+      assert.strictEqual(wss.shouldHandle({ url: '/foo' }), true);
+      assert.strictEqual(wss.shouldHandle({ url: '/foo?bar=baz' }), true);
+    });
+
+    it("returns false when the path doesn't match", () => {
+      const wss = new WebSocket.Server({ noServer: true, path: '/foo' });
+
+      assert.strictEqual(wss.shouldHandle({ url: '/bar' }), false);
+    });
+  });
+
+  describe('#handleUpgrade', () => {
+    it('can be used for a pre-existing server', (done) => {
+      const server = http.createServer();
+
+      server.listen(0, () => {
+        const wss = new WebSocket.Server({ noServer: true });
+
+        server.on('upgrade', (req, socket, head) => {
+          wss.handleUpgrade(req, socket, head, (ws) => {
+            ws.send('hello');
+            ws.close();
+          });
+        });
+
+        const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+        ws.on('message', (message, isBinary) => {
+          assert.deepStrictEqual(message, Buffer.from('hello'));
+          assert.ok(!isBinary);
+          server.close(done);
+        });
+      });
+    });
+
+    it("closes the connection when path doesn't match", (done) => {
+      const wss = new WebSocket.Server({ port: 0, path: '/ws' }, () => {
+        const req = http.get({
+          port: wss.address().port,
+          headers: {
+            Connection: 'Upgrade',
+            Upgrade: 'websocket',
+            'Sec-WebSocket-Key': 'dGhlIHNhbXBsZSBub25jZQ==',
+            'Sec-WebSocket-Version': 13
+          }
+        });
+
+        req.on('response', (res) => {
+          assert.strictEqual(res.statusCode, 400);
+          wss.close(done);
+        });
+      });
+    });
+
+    it('closes the connection when protocol version is Hixie-76', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const req = http.get({
+          port: wss.address().port,
+          headers: {
+            Connection: 'Upgrade',
+            Upgrade: 'WebSocket',
+            'Sec-WebSocket-Key1': '4 @1  46546xW%0l 1 5',
+            'Sec-WebSocket-Key2': '12998 5 Y3 1  .P00',
+            'Sec-WebSocket-Protocol': 'sample'
+          }
+        });
+
+        req.on('response', (res) => {
+          assert.strictEqual(res.statusCode, 400);
+
+          const chunks = [];
+
+          res.on('data', (chunk) => {
+            chunks.push(chunk);
+          });
+
+          res.on('end', () => {
+            assert.strictEqual(
+              Buffer.concat(chunks).toString(),
+              'Missing or invalid Sec-WebSocket-Key header'
+            );
+            wss.close(done);
+          });
+        });
+      });
+    });
+  });
+
+  describe('#completeUpgrade', () => {
+    it('throws an error if called twice with the same socket', (done) => {
+      const server = http.createServer();
+
+      server.listen(0, () => {
+        const wss = new WebSocket.Server({ noServer: true });
+
+        server.on('upgrade', (req, socket, head) => {
+          wss.handleUpgrade(req, socket, head, (ws) => {
+            ws.close();
+          });
+          assert.throws(
+            () => wss.handleUpgrade(req, socket, head, NOOP),
+            (err) => {
+              assert.ok(err instanceof Error);
+              assert.strictEqual(
+                err.message,
+                'server.handleUpgrade() was called more than once with the ' +
+                  'same socket, possibly due to a misconfiguration'
+              );
+              return true;
+            }
+          );
+        });
+
+        const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+        ws.on('open', () => {
+          ws.on('close', () => {
+            server.close(done);
+          });
+        });
+      });
+    });
+  });
+
+  describe('Connection establishing', () => {
+    it('fails if the HTTP method is not GET', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const req = http.request({
+          method: 'POST',
+          port: wss.address().port,
+          headers: {
+            Connection: 'Upgrade',
+            Upgrade: 'websocket'
+          }
+        });
+
+        req.on('response', (res) => {
+          assert.strictEqual(res.statusCode, 405);
+
+          const chunks = [];
+
+          res.on('data', (chunk) => {
+            chunks.push(chunk);
+          });
+
+          res.on('end', () => {
+            assert.strictEqual(
+              Buffer.concat(chunks).toString(),
+              'Invalid HTTP method'
+            );
+            wss.close(done);
+          });
+        });
+
+        req.end();
+      });
+
+      wss.on('connection', () => {
+        done(new Error("Unexpected 'connection' event"));
+      });
+    });
+
+    it('fails if the Upgrade header field value is not "websocket"', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const req = http.get({
+          port: wss.address().port,
+          headers: {
+            Connection: 'Upgrade',
+            Upgrade: 'foo'
+          }
+        });
+
+        req.on('response', (res) => {
+          assert.strictEqual(res.statusCode, 400);
+
+          const chunks = [];
+
+          res.on('data', (chunk) => {
+            chunks.push(chunk);
+          });
+
+          res.on('end', () => {
+            assert.strictEqual(
+              Buffer.concat(chunks).toString(),
+              'Invalid Upgrade header'
+            );
+            wss.close(done);
+          });
+        });
+      });
+
+      wss.on('connection', () => {
+        done(new Error("Unexpected 'connection' event"));
+      });
+    });
+
+    it('fails if the Sec-WebSocket-Key header is invalid (1/2)', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const req = http.get({
+          port: wss.address().port,
+          headers: {
+            Connection: 'Upgrade',
+            Upgrade: 'websocket'
+          }
+        });
+
+        req.on('response', (res) => {
+          assert.strictEqual(res.statusCode, 400);
+
+          const chunks = [];
+
+          res.on('data', (chunk) => {
+            chunks.push(chunk);
+          });
+
+          res.on('end', () => {
+            assert.strictEqual(
+              Buffer.concat(chunks).toString(),
+              'Missing or invalid Sec-WebSocket-Key header'
+            );
+            wss.close(done);
+          });
+        });
+      });
+
+      wss.on('connection', () => {
+        done(new Error("Unexpected 'connection' event"));
+      });
+    });
+
+    it('fails if the Sec-WebSocket-Key header is invalid (2/2)', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const req = http.get({
+          port: wss.address().port,
+          headers: {
+            Connection: 'Upgrade',
+            Upgrade: 'websocket',
+            'Sec-WebSocket-Key': 'P5l8BJcZwRc='
+          }
+        });
+
+        req.on('response', (res) => {
+          assert.strictEqual(res.statusCode, 400);
+
+          const chunks = [];
+
+          res.on('data', (chunk) => {
+            chunks.push(chunk);
+          });
+
+          res.on('end', () => {
+            assert.strictEqual(
+              Buffer.concat(chunks).toString(),
+              'Missing or invalid Sec-WebSocket-Key header'
+            );
+            wss.close(done);
+          });
+        });
+      });
+
+      wss.on('connection', () => {
+        done(new Error("Unexpected 'connection' event"));
+      });
+    });
+
+    it('fails if the Sec-WebSocket-Version header is invalid (1/2)', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const req = http.get({
+          port: wss.address().port,
+          headers: {
+            Connection: 'Upgrade',
+            Upgrade: 'websocket',
+            'Sec-WebSocket-Key': 'dGhlIHNhbXBsZSBub25jZQ=='
+          }
+        });
+
+        req.on('response', (res) => {
+          assert.strictEqual(res.statusCode, 400);
+
+          const chunks = [];
+
+          res.on('data', (chunk) => {
+            chunks.push(chunk);
+          });
+
+          res.on('end', () => {
+            assert.strictEqual(
+              Buffer.concat(chunks).toString(),
+              'Missing or invalid Sec-WebSocket-Version header'
+            );
+            wss.close(done);
+          });
+        });
+      });
+
+      wss.on('connection', () => {
+        done(new Error("Unexpected 'connection' event"));
+      });
+    });
+
+    it('fails if the Sec-WebSocket-Version header is invalid (2/2)', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const req = http.get({
+          port: wss.address().port,
+          headers: {
+            Connection: 'Upgrade',
+            Upgrade: 'websocket',
+            'Sec-WebSocket-Key': 'dGhlIHNhbXBsZSBub25jZQ==',
+            'Sec-WebSocket-Version': 12
+          }
+        });
+
+        req.on('response', (res) => {
+          assert.strictEqual(res.statusCode, 400);
+
+          const chunks = [];
+
+          res.on('data', (chunk) => {
+            chunks.push(chunk);
+          });
+
+          res.on('end', () => {
+            assert.strictEqual(
+              Buffer.concat(chunks).toString(),
+              'Missing or invalid Sec-WebSocket-Version header'
+            );
+            wss.close(done);
+          });
+        });
+      });
+
+      wss.on('connection', () => {
+        done(new Error("Unexpected 'connection' event"));
+      });
+    });
+
+    it('fails is the Sec-WebSocket-Protocol header is invalid', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const req = http.get({
+          port: wss.address().port,
+          headers: {
+            Connection: 'Upgrade',
+            Upgrade: 'websocket',
+            'Sec-WebSocket-Key': 'dGhlIHNhbXBsZSBub25jZQ==',
+            'Sec-WebSocket-Version': 13,
+            'Sec-WebSocket-Protocol': 'foo;bar'
+          }
+        });
+
+        req.on('response', (res) => {
+          assert.strictEqual(res.statusCode, 400);
+
+          const chunks = [];
+
+          res.on('data', (chunk) => {
+            chunks.push(chunk);
+          });
+
+          res.on('end', () => {
+            assert.strictEqual(
+              Buffer.concat(chunks).toString(),
+              'Invalid Sec-WebSocket-Protocol header'
+            );
+            wss.close(done);
+          });
+        });
+      });
+
+      wss.on('connection', () => {
+        done(new Error("Unexpected 'connection' event"));
+      });
+    });
+
+    it('fails if the Sec-WebSocket-Extensions header is invalid', (done) => {
+      const wss = new WebSocket.Server(
+        {
+          perMessageDeflate: true,
+          port: 0
+        },
+        () => {
+          const req = http.get({
+            port: wss.address().port,
+            headers: {
+              Connection: 'Upgrade',
+              Upgrade: 'websocket',
+              'Sec-WebSocket-Key': 'dGhlIHNhbXBsZSBub25jZQ==',
+              'Sec-WebSocket-Version': 13,
+              'Sec-WebSocket-Extensions':
+                'permessage-deflate; server_max_window_bits=foo'
+            }
+          });
+
+          req.on('response', (res) => {
+            assert.strictEqual(res.statusCode, 400);
+
+            const chunks = [];
+
+            res.on('data', (chunk) => {
+              chunks.push(chunk);
+            });
+
+            res.on('end', () => {
+              assert.strictEqual(
+                Buffer.concat(chunks).toString(),
+                'Invalid or unacceptable Sec-WebSocket-Extensions header'
+              );
+              wss.close(done);
+            });
+          });
+        }
+      );
+
+      wss.on('connection', () => {
+        done(new Error("Unexpected 'connection' event"));
+      });
+    });
+
+    it("emits the 'wsClientError' event", (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const req = http.request({
+          method: 'POST',
+          port: wss.address().port,
+          headers: {
+            Connection: 'Upgrade',
+            Upgrade: 'websocket'
+          }
+        });
+
+        req.on('response', (res) => {
+          assert.strictEqual(res.statusCode, 400);
+          wss.close(done);
+        });
+
+        req.end();
+      });
+
+      wss.on('wsClientError', (err, socket, request) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.message, 'Invalid HTTP method');
+
+        assert.ok(request instanceof http.IncomingMessage);
+        assert.strictEqual(request.method, 'POST');
+
+        socket.end('HTTP/1.1 400 Bad Request\r\n\r\n');
+      });
+
+      wss.on('connection', () => {
+        done(new Error("Unexpected 'connection' event"));
+      });
+    });
+
+    it('fails if the WebSocket server is closing or closed', (done) => {
+      const server = http.createServer();
+      const wss = new WebSocket.Server({ noServer: true });
+
+      server.on('upgrade', (req, socket, head) => {
+        wss.close();
+        wss.handleUpgrade(req, socket, head, () => {
+          done(new Error('Unexpected callback invocation'));
+        });
+      });
+
+      server.listen(0, () => {
+        const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+        ws.on('unexpected-response', (req, res) => {
+          assert.strictEqual(res.statusCode, 503);
+          res.resume();
+          server.close(done);
+        });
+      });
+    });
+
+    it('handles unsupported extensions', (done) => {
+      const wss = new WebSocket.Server(
+        {
+          perMessageDeflate: true,
+          port: 0
+        },
+        () => {
+          const req = http.get({
+            port: wss.address().port,
+            headers: {
+              Connection: 'Upgrade',
+              Upgrade: 'websocket',
+              'Sec-WebSocket-Key': 'dGhlIHNhbXBsZSBub25jZQ==',
+              'Sec-WebSocket-Version': 13,
+              'Sec-WebSocket-Extensions': 'foo; bar'
+            }
+          });
+
+          req.on('upgrade', (res, socket, head) => {
+            if (head.length) socket.unshift(head);
+
+            socket.once('data', (chunk) => {
+              assert.strictEqual(chunk[0], 0x88);
+              socket.destroy();
+              wss.close(done);
+            });
+          });
+        }
+      );
+
+      wss.on('connection', (ws) => {
+        assert.strictEqual(ws.extensions, '');
+        ws.close();
+      });
+    });
+
+    describe('`verifyClient`', () => {
+      it('can reject client synchronously', (done) => {
+        const wss = new WebSocket.Server(
+          {
+            verifyClient: () => false,
+            port: 0
+          },
+          () => {
+            const req = http.get({
+              port: wss.address().port,
+              headers: {
+                Connection: 'Upgrade',
+                Upgrade: 'websocket',
+                'Sec-WebSocket-Key': 'dGhlIHNhbXBsZSBub25jZQ==',
+                'Sec-WebSocket-Version': 8
+              }
+            });
+
+            req.on('response', (res) => {
+              assert.strictEqual(res.statusCode, 401);
+              wss.close(done);
+            });
+          }
+        );
+
+        wss.on('connection', () => {
+          done(new Error("Unexpected 'connection' event"));
+        });
+      });
+
+      it('can accept client synchronously', (done) => {
+        const server = https.createServer({
+          cert: fs.readFileSync('test/fixtures/certificate.pem'),
+          key: fs.readFileSync('test/fixtures/key.pem')
+        });
+
+        const wss = new WebSocket.Server({
+          verifyClient: (info) => {
+            assert.strictEqual(info.origin, 'https://example.com');
+            assert.strictEqual(info.req.headers.foo, 'bar');
+            assert.ok(info.secure, true);
+            return true;
+          },
+          server
+        });
+
+        wss.on('connection', () => {
+          server.close(done);
+        });
+
+        server.listen(0, () => {
+          const ws = new WebSocket(`wss://localhost:${server.address().port}`, {
+            headers: { Origin: 'https://example.com', foo: 'bar' },
+            rejectUnauthorized: false
+          });
+
+          ws.on('open', ws.close);
+        });
+      });
+
+      it('can accept client asynchronously', (done) => {
+        const wss = new WebSocket.Server(
+          {
+            verifyClient: (o, cb) => process.nextTick(cb, true),
+            port: 0
+          },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+            ws.on('open', ws.close);
+          }
+        );
+
+        wss.on('connection', () => wss.close(done));
+      });
+
+      it('can reject client asynchronously', (done) => {
+        const wss = new WebSocket.Server(
+          {
+            verifyClient: (info, cb) => process.nextTick(cb, false),
+            port: 0
+          },
+          () => {
+            const req = http.get({
+              port: wss.address().port,
+              headers: {
+                Connection: 'Upgrade',
+                Upgrade: 'websocket',
+                'Sec-WebSocket-Key': 'dGhlIHNhbXBsZSBub25jZQ==',
+                'Sec-WebSocket-Version': 8
+              }
+            });
+
+            req.on('response', (res) => {
+              assert.strictEqual(res.statusCode, 401);
+              wss.close(done);
+            });
+          }
+        );
+
+        wss.on('connection', () => {
+          done(new Error("Unexpected 'connection' event"));
+        });
+      });
+
+      it('can reject client asynchronously w/ status code', (done) => {
+        const wss = new WebSocket.Server(
+          {
+            verifyClient: (info, cb) => process.nextTick(cb, false, 404),
+            port: 0
+          },
+          () => {
+            const req = http.get({
+              port: wss.address().port,
+              headers: {
+                Connection: 'Upgrade',
+                Upgrade: 'websocket',
+                'Sec-WebSocket-Key': 'dGhlIHNhbXBsZSBub25jZQ==',
+                'Sec-WebSocket-Version': 8
+              }
+            });
+
+            req.on('response', (res) => {
+              assert.strictEqual(res.statusCode, 404);
+              wss.close(done);
+            });
+          }
+        );
+
+        wss.on('connection', () => {
+          done(new Error("Unexpected 'connection' event"));
+        });
+      });
+
+      it('can reject client asynchronously w/ custom headers', (done) => {
+        const wss = new WebSocket.Server(
+          {
+            verifyClient: (info, cb) => {
+              process.nextTick(cb, false, 503, '', { 'Retry-After': 120 });
+            },
+            port: 0
+          },
+          () => {
+            const req = http.get({
+              port: wss.address().port,
+              headers: {
+                Connection: 'Upgrade',
+                Upgrade: 'websocket',
+                'Sec-WebSocket-Key': 'dGhlIHNhbXBsZSBub25jZQ==',
+                'Sec-WebSocket-Version': 8
+              }
+            });
+
+            req.on('response', (res) => {
+              assert.strictEqual(res.statusCode, 503);
+              assert.strictEqual(res.headers['retry-after'], '120');
+              wss.close(done);
+            });
+          }
+        );
+
+        wss.on('connection', () => {
+          done(new Error("Unexpected 'connection' event"));
+        });
+      });
+    });
+
+    it("doesn't emit the 'connection' event if socket is closed prematurely", (done) => {
+      const server = http.createServer();
+
+      server.listen(0, () => {
+        const wss = new WebSocket.Server({
+          verifyClient: ({ req: { socket } }, cb) => {
+            assert.strictEqual(socket.readable, true);
+            assert.strictEqual(socket.writable, true);
+
+            socket.on('end', () => {
+              assert.strictEqual(socket.readable, false);
+              assert.strictEqual(socket.writable, true);
+              cb(true);
+            });
+          },
+          server
+        });
+
+        wss.on('connection', () => {
+          done(new Error("Unexpected 'connection' event"));
+        });
+
+        const socket = net.connect(
+          {
+            port: server.address().port,
+            allowHalfOpen: true
+          },
+          () => {
+            socket.end(
+              [
+                'GET / HTTP/1.1',
+                'Host: localhost',
+                'Upgrade: websocket',
+                'Connection: Upgrade',
+                'Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==',
+                'Sec-WebSocket-Version: 13',
+                '\r\n'
+              ].join('\r\n')
+            );
+          }
+        );
+
+        socket.on('end', () => {
+          wss.close();
+          server.close(done);
+        });
+      });
+    });
+
+    it('handles data passed along with the upgrade request', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const req = http.request({
+          port: wss.address().port,
+          headers: {
+            Connection: 'Upgrade',
+            Upgrade: 'websocket',
+            'Sec-WebSocket-Key': 'dGhlIHNhbXBsZSBub25jZQ==',
+            'Sec-WebSocket-Version': 13
+          }
+        });
+
+        const list = Sender.frame(Buffer.from('Hello'), {
+          fin: true,
+          rsv1: false,
+          opcode: 0x01,
+          mask: true,
+          readOnly: false
+        });
+
+        req.write(Buffer.concat(list));
+        req.end();
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (data, isBinary) => {
+          assert.deepStrictEqual(data, Buffer.from('Hello'));
+          assert.ok(!isBinary);
+          wss.close(done);
+        });
+      });
+    });
+
+    describe('`handleProtocols`', () => {
+      it('allows to select a subprotocol', (done) => {
+        const handleProtocols = (protocols, request) => {
+          assert.ok(request instanceof http.IncomingMessage);
+          assert.strictEqual(request.url, '/');
+          return Array.from(protocols).pop();
+        };
+        const wss = new WebSocket.Server({ handleProtocols, port: 0 }, () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`, [
+            'foo',
+            'bar'
+          ]);
+
+          ws.on('open', () => {
+            assert.strictEqual(ws.protocol, 'bar');
+            wss.close(done);
+          });
+        });
+
+        wss.on('connection', (ws) => {
+          ws.close();
+        });
+      });
+    });
+
+    it("emits the 'headers' event", (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', ws.close);
+      });
+
+      wss.on('headers', (headers, request) => {
+        assert.deepStrictEqual(headers.slice(0, 3), [
+          'HTTP/1.1 101 Switching Protocols',
+          'Upgrade: websocket',
+          'Connection: Upgrade'
+        ]);
+        assert.ok(request instanceof http.IncomingMessage);
+        assert.strictEqual(request.url, '/');
+
+        wss.on('connection', () => wss.close(done));
+      });
+    });
+  });
+
+  describe('permessage-deflate', () => {
+    it('is disabled by default', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', ws.close);
+      });
+
+      wss.on('connection', (ws, req) => {
+        assert.strictEqual(
+          req.headers['sec-websocket-extensions'],
+          'permessage-deflate; client_max_window_bits'
+        );
+        assert.strictEqual(ws.extensions, '');
+        wss.close(done);
+      });
+    });
+
+    it('uses configuration options', (done) => {
+      const wss = new WebSocket.Server(
+        {
+          perMessageDeflate: { clientMaxWindowBits: 8 },
+          port: 0
+        },
+        () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          ws.on('upgrade', (res) => {
+            assert.strictEqual(
+              res.headers['sec-websocket-extensions'],
+              'permessage-deflate; client_max_window_bits=8'
+            );
+
+            wss.close(done);
+          });
+        }
+      );
+
+      wss.on('connection', (ws) => {
+        ws.close();
+      });
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/websocket.integration.js b/testing/xpcshell/node-ws/test/websocket.integration.js
new file mode 100644
index 0000000000..abd96c61e4
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/websocket.integration.js
@@ -0,0 +1,55 @@
+'use strict';
+
+const assert = require('assert');
+
+const WebSocket = require('..');
+
+describe('WebSocket', () => {
+  it('communicates successfully with echo service (ws)', (done) => {
+    const ws = new WebSocket('ws://websocket-echo.com/', {
+      protocolVersion: 13
+    });
+
+    let dataReceived = false;
+
+    ws.on('open', () => {
+      ws.send('hello');
+    });
+
+    ws.on('close', () => {
+      assert.ok(dataReceived);
+      done();
+    });
+
+    ws.on('message', (message, isBinary) => {
+      dataReceived = true;
+      assert.ok(!isBinary);
+      assert.strictEqual(message.toString(), 'hello');
+      ws.close();
+    });
+  });
+
+  it('communicates successfully with echo service (wss)', (done) => {
+    const ws = new WebSocket('wss://websocket-echo.com/', {
+      protocolVersion: 13
+    });
+
+    let dataReceived = false;
+
+    ws.on('open', () => {
+      ws.send('hello');
+    });
+
+    ws.on('close', () => {
+      assert.ok(dataReceived);
+      done();
+    });
+
+    ws.on('message', (message, isBinary) => {
+      dataReceived = true;
+      assert.ok(!isBinary);
+      assert.strictEqual(message.toString(), 'hello');
+      ws.close();
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/test/websocket.test.js b/testing/xpcshell/node-ws/test/websocket.test.js
new file mode 100644
index 0000000000..f5fbf16505
--- /dev/null
+++ b/testing/xpcshell/node-ws/test/websocket.test.js
@@ -0,0 +1,4514 @@
+/* eslint no-unused-vars: ["error", { "varsIgnorePattern": "^ws$" }] */
+
+'use strict';
+
+const assert = require('assert');
+const crypto = require('crypto');
+const https = require('https');
+const http = require('http');
+const path = require('path');
+const net = require('net');
+const tls = require('tls');
+const os = require('os');
+const fs = require('fs');
+const { URL } = require('url');
+
+const Sender = require('../lib/sender');
+const WebSocket = require('..');
+const {
+  CloseEvent,
+  ErrorEvent,
+  Event,
+  MessageEvent
+} = require('../lib/event-target');
+const { EMPTY_BUFFER, GUID, kListener, NOOP } = require('../lib/constants');
+
+class CustomAgent extends http.Agent {
+  addRequest() {}
+}
+
+describe('WebSocket', () => {
+  describe('#ctor', () => {
+    it('throws an error when using an invalid url', () => {
+      assert.throws(
+        () => new WebSocket('foo'),
+        /^SyntaxError: Invalid URL: foo$/
+      );
+
+      assert.throws(
+        () => new WebSocket('https://websocket-echo.com'),
+        /^SyntaxError: The URL's protocol must be one of "ws:", "wss:", or "ws\+unix:"$/
+      );
+
+      assert.throws(
+        () => new WebSocket('ws+unix:'),
+        /^SyntaxError: The URL's pathname is empty$/
+      );
+
+      assert.throws(
+        () => new WebSocket('wss://websocket-echo.com#foo'),
+        /^SyntaxError: The URL contains a fragment identifier$/
+      );
+    });
+
+    it('throws an error if a subprotocol is invalid or duplicated', () => {
+      for (const subprotocol of [null, '', 'a,b', ['a', 'a']]) {
+        assert.throws(
+          () => new WebSocket('ws://localhost', subprotocol),
+          /^SyntaxError: An invalid or duplicated subprotocol was specified$/
+        );
+      }
+    });
+
+    it('accepts `url.URL` objects as url', (done) => {
+      const agent = new CustomAgent();
+
+      agent.addRequest = (req, opts) => {
+        assert.strictEqual(opts.host, '::1');
+        assert.strictEqual(req.path, '/');
+        done();
+      };
+
+      const ws = new WebSocket(new URL('ws://[::1]'), { agent });
+    });
+
+    describe('options', () => {
+      it('accepts the `options` object as 3rd argument', () => {
+        const agent = new CustomAgent();
+        let count = 0;
+        let ws;
+
+        agent.addRequest = (req) => {
+          assert.strictEqual(
+            req.getHeader('sec-websocket-protocol'),
+            undefined
+          );
+          count++;
+        };
+
+        ws = new WebSocket('ws://localhost', undefined, { agent });
+        ws = new WebSocket('ws://localhost', [], { agent });
+
+        assert.strictEqual(count, 2);
+      });
+
+      it('accepts the `maxPayload` option', (done) => {
+        const maxPayload = 20480;
+        const wss = new WebSocket.Server(
+          {
+            perMessageDeflate: true,
+            port: 0
+          },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`, {
+              perMessageDeflate: true,
+              maxPayload
+            });
+
+            ws.on('open', () => {
+              assert.strictEqual(ws._receiver._maxPayload, maxPayload);
+              assert.strictEqual(
+                ws._receiver._extensions['permessage-deflate']._maxPayload,
+                maxPayload
+              );
+              wss.close(done);
+            });
+          }
+        );
+
+        wss.on('connection', (ws) => {
+          ws.close();
+        });
+      });
+
+      it('throws an error when using an invalid `protocolVersion`', () => {
+        const options = { agent: new CustomAgent(), protocolVersion: 1000 };
+
+        assert.throws(
+          () => new WebSocket('ws://localhost', options),
+          /^RangeError: Unsupported protocol version: 1000 \(supported versions: 8, 13\)$/
+        );
+      });
+
+      it('honors the `generateMask` option', (done) => {
+        const data = Buffer.from('foo');
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`, {
+            generateMask() {}
+          });
+
+          ws.on('open', () => {
+            ws.send(data);
+          });
+
+          ws.on('close', (code, reason) => {
+            assert.strictEqual(code, 1005);
+            assert.deepStrictEqual(reason, EMPTY_BUFFER);
+
+            wss.close(done);
+          });
+        });
+
+        wss.on('connection', (ws) => {
+          const chunks = [];
+
+          ws._socket.prependListener('data', (chunk) => {
+            chunks.push(chunk);
+          });
+
+          ws.on('message', (message) => {
+            assert.deepStrictEqual(message, data);
+            assert.deepStrictEqual(
+              Buffer.concat(chunks).slice(2, 6),
+              Buffer.alloc(4)
+            );
+
+            ws.close();
+          });
+        });
+      });
+    });
+  });
+
+  describe('Constants', () => {
+    const readyStates = {
+      CONNECTING: 0,
+      OPEN: 1,
+      CLOSING: 2,
+      CLOSED: 3
+    };
+
+    Object.keys(readyStates).forEach((state) => {
+      describe(`\`${state}\``, () => {
+        it('is enumerable property of class', () => {
+          const descriptor = Object.getOwnPropertyDescriptor(WebSocket, state);
+
+          assert.deepStrictEqual(descriptor, {
+            configurable: false,
+            enumerable: true,
+            value: readyStates[state],
+            writable: false
+          });
+        });
+
+        it('is enumerable property of prototype', () => {
+          const descriptor = Object.getOwnPropertyDescriptor(
+            WebSocket.prototype,
+            state
+          );
+
+          assert.deepStrictEqual(descriptor, {
+            configurable: false,
+            enumerable: true,
+            value: readyStates[state],
+            writable: false
+          });
+        });
+      });
+    });
+  });
+
+  describe('Attributes', () => {
+    describe('`binaryType`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          WebSocket.prototype,
+          'binaryType'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set !== undefined);
+      });
+
+      it("defaults to 'nodebuffer'", () => {
+        const ws = new WebSocket('ws://localhost', {
+          agent: new CustomAgent()
+        });
+
+        assert.strictEqual(ws.binaryType, 'nodebuffer');
+      });
+
+      it("can be changed to 'arraybuffer' or 'fragments'", () => {
+        const ws = new WebSocket('ws://localhost', {
+          agent: new CustomAgent()
+        });
+
+        ws.binaryType = 'arraybuffer';
+        assert.strictEqual(ws.binaryType, 'arraybuffer');
+
+        ws.binaryType = 'foo';
+        assert.strictEqual(ws.binaryType, 'arraybuffer');
+
+        ws.binaryType = 'fragments';
+        assert.strictEqual(ws.binaryType, 'fragments');
+
+        ws.binaryType = '';
+        assert.strictEqual(ws.binaryType, 'fragments');
+
+        ws.binaryType = 'nodebuffer';
+        assert.strictEqual(ws.binaryType, 'nodebuffer');
+      });
+    });
+
+    describe('`bufferedAmount`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          WebSocket.prototype,
+          'bufferedAmount'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('defaults to zero', () => {
+        const ws = new WebSocket('ws://localhost', {
+          agent: new CustomAgent()
+        });
+
+        assert.strictEqual(ws.bufferedAmount, 0);
+      });
+
+      it('defaults to zero upon "open"', (done) => {
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          ws.onopen = () => {
+            assert.strictEqual(ws.bufferedAmount, 0);
+            wss.close(done);
+          };
+        });
+
+        wss.on('connection', (ws) => {
+          ws.close();
+        });
+      });
+
+      it('takes into account the data in the sender queue', (done) => {
+        const wss = new WebSocket.Server(
+          {
+            perMessageDeflate: true,
+            port: 0
+          },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`, {
+              perMessageDeflate: { threshold: 0 }
+            });
+
+            ws.on('open', () => {
+              ws.send('foo');
+
+              assert.strictEqual(ws.bufferedAmount, 3);
+
+              ws.send('bar', (err) => {
+                assert.ifError(err);
+                assert.strictEqual(ws.bufferedAmount, 0);
+                wss.close(done);
+              });
+
+              assert.strictEqual(ws.bufferedAmount, 6);
+            });
+          }
+        );
+
+        wss.on('connection', (ws) => {
+          ws.close();
+        });
+      });
+
+      it('takes into account the data in the socket queue', (done) => {
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        });
+
+        wss.on('connection', (ws) => {
+          const data = Buffer.alloc(1024, 61);
+
+          while (ws.bufferedAmount === 0) {
+            ws.send(data);
+          }
+
+          assert.ok(ws.bufferedAmount > 0);
+          assert.strictEqual(
+            ws.bufferedAmount,
+            ws._socket._writableState.length
+          );
+
+          ws.on('close', () => wss.close(done));
+          ws.close();
+        });
+      });
+    });
+
+    describe('`extensions`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          WebSocket.prototype,
+          'bufferedAmount'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('exposes the negotiated extensions names (1/2)', (done) => {
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          assert.strictEqual(ws.extensions, '');
+
+          ws.on('open', () => {
+            assert.strictEqual(ws.extensions, '');
+            ws.on('close', () => wss.close(done));
+          });
+        });
+
+        wss.on('connection', (ws) => {
+          assert.strictEqual(ws.extensions, '');
+          ws.close();
+        });
+      });
+
+      it('exposes the negotiated extensions names (2/2)', (done) => {
+        const wss = new WebSocket.Server(
+          {
+            perMessageDeflate: true,
+            port: 0
+          },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+            assert.strictEqual(ws.extensions, '');
+
+            ws.on('open', () => {
+              assert.strictEqual(ws.extensions, 'permessage-deflate');
+              ws.on('close', () => wss.close(done));
+            });
+          }
+        );
+
+        wss.on('connection', (ws) => {
+          assert.strictEqual(ws.extensions, 'permessage-deflate');
+          ws.close();
+        });
+      });
+    });
+
+    describe('`isPaused`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          WebSocket.prototype,
+          'isPaused'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('indicates whether the websocket is paused', (done) => {
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          ws.on('open', () => {
+            ws.pause();
+            assert.ok(ws.isPaused);
+
+            ws.resume();
+            assert.ok(!ws.isPaused);
+
+            ws.close();
+            wss.close(done);
+          });
+
+          assert.ok(!ws.isPaused);
+        });
+      });
+    });
+
+    describe('`protocol`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          WebSocket.prototype,
+          'protocol'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('exposes the subprotocol selected by the server', (done) => {
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          const port = wss.address().port;
+          const ws = new WebSocket(`ws://localhost:${port}`, 'foo');
+
+          assert.strictEqual(ws.extensions, '');
+
+          ws.on('open', () => {
+            assert.strictEqual(ws.protocol, 'foo');
+            ws.on('close', () => wss.close(done));
+          });
+        });
+
+        wss.on('connection', (ws) => {
+          assert.strictEqual(ws.protocol, 'foo');
+          ws.close();
+        });
+      });
+    });
+
+    describe('`readyState`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          WebSocket.prototype,
+          'readyState'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('defaults to `CONNECTING`', () => {
+        const ws = new WebSocket('ws://localhost', {
+          agent: new CustomAgent()
+        });
+
+        assert.strictEqual(ws.readyState, WebSocket.CONNECTING);
+      });
+
+      it('is set to `OPEN` once connection is established', (done) => {
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          ws.on('open', () => {
+            assert.strictEqual(ws.readyState, WebSocket.OPEN);
+            ws.close();
+          });
+
+          ws.on('close', () => wss.close(done));
+        });
+      });
+
+      it('is set to `CLOSED` once connection is closed', (done) => {
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          ws.on('close', () => {
+            assert.strictEqual(ws.readyState, WebSocket.CLOSED);
+            wss.close(done);
+          });
+
+          ws.on('open', () => ws.close(1001));
+        });
+      });
+
+      it('is set to `CLOSED` once connection is terminated', (done) => {
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          ws.on('close', () => {
+            assert.strictEqual(ws.readyState, WebSocket.CLOSED);
+            wss.close(done);
+          });
+
+          ws.on('open', () => ws.terminate());
+        });
+      });
+    });
+
+    describe('`url`', () => {
+      it('is enumerable and configurable', () => {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          WebSocket.prototype,
+          'url'
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set === undefined);
+      });
+
+      it('exposes the server url', () => {
+        const url = 'ws://localhost';
+        const ws = new WebSocket(url, { agent: new CustomAgent() });
+
+        assert.strictEqual(ws.url, url);
+      });
+    });
+  });
+
+  describe('Events', () => {
+    it("emits an 'error' event if an error occurs", (done) => {
+      let clientCloseEventEmitted = false;
+      let serverClientCloseEventEmitted = false;
+
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('error', (err) => {
+          assert.ok(err instanceof RangeError);
+          assert.strictEqual(err.code, 'WS_ERR_INVALID_OPCODE');
+          assert.strictEqual(
+            err.message,
+            'Invalid WebSocket frame: invalid opcode 5'
+          );
+
+          ws.on('close', (code, reason) => {
+            assert.strictEqual(code, 1006);
+            assert.strictEqual(reason, EMPTY_BUFFER);
+
+            clientCloseEventEmitted = true;
+            if (serverClientCloseEventEmitted) wss.close(done);
+          });
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('close', (code, reason) => {
+          assert.strictEqual(code, 1002);
+          assert.deepStrictEqual(reason, EMPTY_BUFFER);
+
+          serverClientCloseEventEmitted = true;
+          if (clientCloseEventEmitted) wss.close(done);
+        });
+
+        ws._socket.write(Buffer.from([0x85, 0x00]));
+      });
+    });
+
+    it('does not re-emit `net.Socket` errors', (done) => {
+      const codes = ['EPIPE', 'ECONNABORTED', 'ECANCELED', 'ECONNRESET'];
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws._socket.on('error', (err) => {
+            assert.ok(err instanceof Error);
+            assert.ok(codes.includes(err.code), `Unexpected code: ${err.code}`);
+            ws.on('close', (code, message) => {
+              assert.strictEqual(code, 1006);
+              assert.strictEqual(message, EMPTY_BUFFER);
+              wss.close(done);
+            });
+          });
+
+          for (const client of wss.clients) client.terminate();
+          ws.send('foo');
+          ws.send('bar');
+        });
+      });
+    });
+
+    it("emits an 'upgrade' event", (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        ws.on('upgrade', (res) => {
+          assert.ok(res instanceof http.IncomingMessage);
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+      });
+    });
+
+    it("emits a 'ping' event", (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        ws.on('ping', () => wss.close(done));
+      });
+
+      wss.on('connection', (ws) => {
+        ws.ping();
+        ws.close();
+      });
+    });
+
+    it("emits a 'pong' event", (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+        ws.on('pong', () => wss.close(done));
+      });
+
+      wss.on('connection', (ws) => {
+        ws.pong();
+        ws.close();
+      });
+    });
+
+    it("emits a 'redirect' event", (done) => {
+      const server = http.createServer();
+      const wss = new WebSocket.Server({ noServer: true, path: '/foo' });
+
+      server.once('upgrade', (req, socket) => {
+        socket.end('HTTP/1.1 302 Found\r\nLocation: /foo\r\n\r\n');
+        server.once('upgrade', (req, socket, head) => {
+          wss.handleUpgrade(req, socket, head, (ws) => {
+            ws.close();
+          });
+        });
+      });
+
+      server.listen(() => {
+        const port = server.address().port;
+        const ws = new WebSocket(`ws://localhost:${port}`, {
+          followRedirects: true
+        });
+
+        ws.on('redirect', (url, req) => {
+          assert.strictEqual(ws._redirects, 1);
+          assert.strictEqual(url, `ws://localhost:${port}/foo`);
+          assert.ok(req instanceof http.ClientRequest);
+
+          ws.on('close', (code) => {
+            assert.strictEqual(code, 1005);
+            server.close(done);
+          });
+        });
+      });
+    });
+  });
+
+  describe('Connection establishing', () => {
+    const server = http.createServer();
+
+    beforeEach((done) => server.listen(0, done));
+    afterEach((done) => server.close(done));
+
+    it('fails if the Upgrade header field value is not "websocket"', (done) => {
+      server.once('upgrade', (req, socket) => {
+        socket.on('end', socket.end);
+        socket.write(
+          'HTTP/1.1 101 Switching Protocols\r\n' +
+            'Connection: Upgrade\r\n' +
+            'Upgrade: foo\r\n' +
+            '\r\n'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.message, 'Invalid Upgrade header');
+        done();
+      });
+    });
+
+    it('fails if the Sec-WebSocket-Accept header is invalid', (done) => {
+      server.once('upgrade', (req, socket) => {
+        socket.on('end', socket.end);
+        socket.write(
+          'HTTP/1.1 101 Switching Protocols\r\n' +
+            'Upgrade: websocket\r\n' +
+            'Connection: Upgrade\r\n' +
+            'Sec-WebSocket-Accept: CxYS6+NgJSBG74mdgLvGscRvpns=\r\n' +
+            '\r\n'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.message, 'Invalid Sec-WebSocket-Accept header');
+        done();
+      });
+    });
+
+    it('close event is raised when server closes connection', (done) => {
+      server.once('upgrade', (req, socket) => {
+        const key = crypto
+          .createHash('sha1')
+          .update(req.headers['sec-websocket-key'] + GUID)
+          .digest('base64');
+
+        socket.end(
+          'HTTP/1.1 101 Switching Protocols\r\n' +
+            'Upgrade: websocket\r\n' +
+            'Connection: Upgrade\r\n' +
+            `Sec-WebSocket-Accept: ${key}\r\n` +
+            '\r\n'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('close', (code, reason) => {
+        assert.strictEqual(code, 1006);
+        assert.strictEqual(reason, EMPTY_BUFFER);
+        done();
+      });
+    });
+
+    it('error is emitted if server aborts connection', (done) => {
+      server.once('upgrade', (req, socket) => {
+        socket.end(
+          `HTTP/1.1 401 ${http.STATUS_CODES[401]}\r\n` +
+            'Connection: close\r\n' +
+            'Content-type: text/html\r\n' +
+            `Content-Length: ${http.STATUS_CODES[401].length}\r\n` +
+            '\r\n'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.message, 'Unexpected server response: 401');
+        done();
+      });
+    });
+
+    it('unexpected response can be read when sent by server', (done) => {
+      server.once('upgrade', (req, socket) => {
+        socket.end(
+          `HTTP/1.1 401 ${http.STATUS_CODES[401]}\r\n` +
+            'Connection: close\r\n' +
+            'Content-type: text/html\r\n' +
+            'Content-Length: 3\r\n' +
+            '\r\n' +
+            'foo'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', () => done(new Error("Unexpected 'error' event")));
+      ws.on('unexpected-response', (req, res) => {
+        assert.strictEqual(res.statusCode, 401);
+
+        let data = '';
+
+        res.on('data', (v) => {
+          data += v;
+        });
+
+        res.on('end', () => {
+          assert.strictEqual(data, 'foo');
+          done();
+        });
+      });
+    });
+
+    it('request can be aborted when unexpected response is sent by server', (done) => {
+      server.once('upgrade', (req, socket) => {
+        socket.end(
+          `HTTP/1.1 401 ${http.STATUS_CODES[401]}\r\n` +
+            'Connection: close\r\n' +
+            'Content-type: text/html\r\n' +
+            'Content-Length: 3\r\n' +
+            '\r\n' +
+            'foo'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', () => done(new Error("Unexpected 'error' event")));
+      ws.on('unexpected-response', (req, res) => {
+        assert.strictEqual(res.statusCode, 401);
+
+        res.on('end', done);
+        req.abort();
+      });
+    });
+
+    it('fails if the opening handshake timeout expires', (done) => {
+      server.once('upgrade', (req, socket) => socket.on('end', socket.end));
+
+      const port = server.address().port;
+      const ws = new WebSocket(`ws://localhost:${port}`, {
+        handshakeTimeout: 100
+      });
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.message, 'Opening handshake has timed out');
+        done();
+      });
+    });
+
+    it('fails if an unexpected Sec-WebSocket-Extensions header is received', (done) => {
+      server.once('upgrade', (req, socket) => {
+        const key = crypto
+          .createHash('sha1')
+          .update(req.headers['sec-websocket-key'] + GUID)
+          .digest('base64');
+
+        socket.end(
+          'HTTP/1.1 101 Switching Protocols\r\n' +
+            'Upgrade: websocket\r\n' +
+            'Connection: Upgrade\r\n' +
+            `Sec-WebSocket-Accept: ${key}\r\n` +
+            'Sec-WebSocket-Extensions: foo\r\n' +
+            '\r\n'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`, {
+        perMessageDeflate: false
+      });
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          'Server sent a Sec-WebSocket-Extensions header but no extension ' +
+            'was requested'
+        );
+        ws.on('close', () => done());
+      });
+    });
+
+    it('fails if the Sec-WebSocket-Extensions header is invalid (1/2)', (done) => {
+      server.once('upgrade', (req, socket) => {
+        const key = crypto
+          .createHash('sha1')
+          .update(req.headers['sec-websocket-key'] + GUID)
+          .digest('base64');
+
+        socket.end(
+          'HTTP/1.1 101 Switching Protocols\r\n' +
+            'Upgrade: websocket\r\n' +
+            'Connection: Upgrade\r\n' +
+            `Sec-WebSocket-Accept: ${key}\r\n` +
+            'Sec-WebSocket-Extensions: foo;=\r\n' +
+            '\r\n'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          'Invalid Sec-WebSocket-Extensions header'
+        );
+        ws.on('close', () => done());
+      });
+    });
+
+    it('fails if the Sec-WebSocket-Extensions header is invalid (2/2)', (done) => {
+      server.once('upgrade', (req, socket) => {
+        const key = crypto
+          .createHash('sha1')
+          .update(req.headers['sec-websocket-key'] + GUID)
+          .digest('base64');
+
+        socket.end(
+          'HTTP/1.1 101 Switching Protocols\r\n' +
+            'Upgrade: websocket\r\n' +
+            'Connection: Upgrade\r\n' +
+            `Sec-WebSocket-Accept: ${key}\r\n` +
+            'Sec-WebSocket-Extensions: ' +
+            'permessage-deflate; client_max_window_bits=7\r\n' +
+            '\r\n'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          'Invalid Sec-WebSocket-Extensions header'
+        );
+        ws.on('close', () => done());
+      });
+    });
+
+    it('fails if an unexpected extension is received (1/2)', (done) => {
+      server.once('upgrade', (req, socket) => {
+        const key = crypto
+          .createHash('sha1')
+          .update(req.headers['sec-websocket-key'] + GUID)
+          .digest('base64');
+
+        socket.end(
+          'HTTP/1.1 101 Switching Protocols\r\n' +
+            'Upgrade: websocket\r\n' +
+            'Connection: Upgrade\r\n' +
+            `Sec-WebSocket-Accept: ${key}\r\n` +
+            'Sec-WebSocket-Extensions: foo\r\n' +
+            '\r\n'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          'Server indicated an extension that was not requested'
+        );
+        ws.on('close', () => done());
+      });
+    });
+
+    it('fails if an unexpected extension is received (2/2)', (done) => {
+      server.once('upgrade', (req, socket) => {
+        const key = crypto
+          .createHash('sha1')
+          .update(req.headers['sec-websocket-key'] + GUID)
+          .digest('base64');
+
+        socket.end(
+          'HTTP/1.1 101 Switching Protocols\r\n' +
+            'Upgrade: websocket\r\n' +
+            'Connection: Upgrade\r\n' +
+            `Sec-WebSocket-Accept: ${key}\r\n` +
+            'Sec-WebSocket-Extensions: permessage-deflate,foo\r\n' +
+            '\r\n'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          'Server indicated an extension that was not requested'
+        );
+        ws.on('close', () => done());
+      });
+    });
+
+    it('fails if server sends a subprotocol when none was requested', (done) => {
+      const wss = new WebSocket.Server({ server });
+
+      wss.on('headers', (headers) => {
+        headers.push('Sec-WebSocket-Protocol: foo');
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          'Server sent a subprotocol but none was requested'
+        );
+        ws.on('close', () => wss.close(done));
+      });
+    });
+
+    it('fails if server sends an invalid subprotocol (1/2)', (done) => {
+      const wss = new WebSocket.Server({
+        handleProtocols: () => 'baz',
+        server
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`, [
+        'foo',
+        'bar'
+      ]);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.message, 'Server sent an invalid subprotocol');
+        ws.on('close', () => wss.close(done));
+      });
+    });
+
+    it('fails if server sends an invalid subprotocol (2/2)', (done) => {
+      server.once('upgrade', (req, socket) => {
+        const key = crypto
+          .createHash('sha1')
+          .update(req.headers['sec-websocket-key'] + GUID)
+          .digest('base64');
+
+        socket.end(
+          'HTTP/1.1 101 Switching Protocols\r\n' +
+            'Upgrade: websocket\r\n' +
+            'Connection: Upgrade\r\n' +
+            `Sec-WebSocket-Accept: ${key}\r\n` +
+            'Sec-WebSocket-Protocol:\r\n' +
+            '\r\n'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`, [
+        'foo',
+        'bar'
+      ]);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.message, 'Server sent an invalid subprotocol');
+        ws.on('close', () => done());
+      });
+    });
+
+    it('fails if server sends no subprotocol', (done) => {
+      const wss = new WebSocket.Server({
+        handleProtocols() {},
+        server
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`, [
+        'foo',
+        'bar'
+      ]);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.message, 'Server sent no subprotocol');
+        ws.on('close', () => wss.close(done));
+      });
+    });
+
+    it('does not follow redirects by default', (done) => {
+      server.once('upgrade', (req, socket) => {
+        socket.end(
+          'HTTP/1.1 301 Moved Permanently\r\n' +
+            'Location: ws://localhost:8080\r\n' +
+            '\r\n'
+        );
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.message, 'Unexpected server response: 301');
+        assert.strictEqual(ws._redirects, 0);
+        ws.on('close', () => done());
+      });
+    });
+
+    it('honors the `followRedirects` option', (done) => {
+      const wss = new WebSocket.Server({ noServer: true, path: '/foo' });
+
+      server.once('upgrade', (req, socket) => {
+        socket.end('HTTP/1.1 302 Found\r\nLocation: /foo\r\n\r\n');
+        server.once('upgrade', (req, socket, head) => {
+          wss.handleUpgrade(req, socket, head, NOOP);
+        });
+      });
+
+      const port = server.address().port;
+      const ws = new WebSocket(`ws://localhost:${port}`, {
+        followRedirects: true
+      });
+
+      ws.on('open', () => {
+        assert.strictEqual(ws.url, `ws://localhost:${port}/foo`);
+        assert.strictEqual(ws._redirects, 1);
+        ws.on('close', () => done());
+        ws.close();
+      });
+    });
+
+    it('honors the `maxRedirects` option', (done) => {
+      const onUpgrade = (req, socket) => {
+        socket.end('HTTP/1.1 302 Found\r\nLocation: /\r\n\r\n');
+      };
+
+      server.on('upgrade', onUpgrade);
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`, {
+        followRedirects: true,
+        maxRedirects: 1
+      });
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.message, 'Maximum redirects exceeded');
+        assert.strictEqual(ws._redirects, 2);
+
+        server.removeListener('upgrade', onUpgrade);
+        ws.on('close', () => done());
+      });
+    });
+
+    it('emits an error if the redirect URL is invalid (1/2)', (done) => {
+      server.once('upgrade', (req, socket) => {
+        socket.end('HTTP/1.1 302 Found\r\nLocation: ws://\r\n\r\n');
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`, {
+        followRedirects: true
+      });
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof SyntaxError);
+        assert.strictEqual(err.message, 'Invalid URL: ws://');
+        assert.strictEqual(ws._redirects, 1);
+
+        ws.on('close', () => done());
+      });
+    });
+
+    it('emits an error if the redirect URL is invalid (2/2)', (done) => {
+      server.once('upgrade', (req, socket) => {
+        socket.end('HTTP/1.1 302 Found\r\nLocation: http://localhost\r\n\r\n');
+      });
+
+      const ws = new WebSocket(`ws://localhost:${server.address().port}`, {
+        followRedirects: true
+      });
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof SyntaxError);
+        assert.strictEqual(
+          err.message,
+          'The URL\'s protocol must be one of "ws:", "wss:", or "ws+unix:"'
+        );
+        assert.strictEqual(ws._redirects, 1);
+
+        ws.on('close', () => done());
+      });
+    });
+
+    it('uses the first url userinfo when following redirects', (done) => {
+      const wss = new WebSocket.Server({ noServer: true, path: '/foo' });
+      const authorization = 'Basic Zm9vOmJhcg==';
+
+      server.once('upgrade', (req, socket) => {
+        socket.end(
+          'HTTP/1.1 302 Found\r\n' +
+            `Location: ws://baz:qux@localhost:${port}/foo\r\n\r\n`
+        );
+        server.once('upgrade', (req, socket, head) => {
+          wss.handleUpgrade(req, socket, head, (ws, req) => {
+            assert.strictEqual(req.headers.authorization, authorization);
+            ws.close();
+          });
+        });
+      });
+
+      const port = server.address().port;
+      const ws = new WebSocket(`ws://foo:bar@localhost:${port}`, {
+        followRedirects: true
+      });
+
+      assert.strictEqual(ws._req.getHeader('Authorization'), authorization);
+
+      ws.on('close', (code) => {
+        assert.strictEqual(code, 1005);
+        assert.strictEqual(ws.url, `ws://baz:qux@localhost:${port}/foo`);
+        assert.strictEqual(ws._redirects, 1);
+
+        wss.close(done);
+      });
+    });
+
+    describe('When moving away from a secure context', () => {
+      function proxy(httpServer, httpsServer) {
+        const server = net.createServer({ allowHalfOpen: true });
+
+        server.on('connection', (socket) => {
+          socket.on('readable', function read() {
+            socket.removeListener('readable', read);
+
+            const buf = socket.read(1);
+            const target = buf[0] === 22 ? httpsServer : httpServer;
+
+            socket.unshift(buf);
+            target.emit('connection', socket);
+          });
+        });
+
+        return server;
+      }
+
+      describe("If there is no 'redirect' event listener", () => {
+        it('drops the `auth` option', (done) => {
+          const httpServer = http.createServer();
+          const httpsServer = https.createServer({
+            cert: fs.readFileSync('test/fixtures/certificate.pem'),
+            key: fs.readFileSync('test/fixtures/key.pem')
+          });
+          const server = proxy(httpServer, httpsServer);
+
+          server.listen(() => {
+            const port = server.address().port;
+
+            httpsServer.on('upgrade', (req, socket) => {
+              socket.on('error', NOOP);
+              socket.end(
+                'HTTP/1.1 302 Found\r\n' +
+                  `Location: ws://localhost:${port}/\r\n\r\n`
+              );
+            });
+
+            const wss = new WebSocket.Server({ server: httpServer });
+
+            wss.on('connection', (ws, req) => {
+              assert.strictEqual(req.headers.authorization, undefined);
+              ws.close();
+            });
+
+            const ws = new WebSocket(`wss://localhost:${port}`, {
+              auth: 'foo:bar',
+              followRedirects: true,
+              rejectUnauthorized: false
+            });
+
+            assert.strictEqual(
+              ws._req.getHeader('Authorization'),
+              'Basic Zm9vOmJhcg=='
+            );
+
+            ws.on('close', (code) => {
+              assert.strictEqual(code, 1005);
+              assert.strictEqual(ws.url, `ws://localhost:${port}/`);
+              assert.strictEqual(ws._redirects, 1);
+
+              server.close(done);
+            });
+          });
+        });
+
+        it('drops the Authorization and Cookie headers', (done) => {
+          const httpServer = http.createServer();
+          const httpsServer = https.createServer({
+            cert: fs.readFileSync('test/fixtures/certificate.pem'),
+            key: fs.readFileSync('test/fixtures/key.pem')
+          });
+          const server = proxy(httpServer, httpsServer);
+
+          server.listen(() => {
+            const port = server.address().port;
+
+            httpsServer.on('upgrade', (req, socket) => {
+              socket.on('error', NOOP);
+              socket.end(
+                'HTTP/1.1 302 Found\r\n' +
+                  `Location: ws://localhost:${port}/\r\n\r\n`
+              );
+            });
+
+            const headers = {
+              authorization: 'Basic Zm9vOmJhcg==',
+              cookie: 'foo=bar',
+              host: 'foo'
+            };
+
+            const wss = new WebSocket.Server({ server: httpServer });
+
+            wss.on('connection', (ws, req) => {
+              assert.strictEqual(req.headers.authorization, undefined);
+              assert.strictEqual(req.headers.cookie, undefined);
+              assert.strictEqual(req.headers.host, headers.host);
+
+              ws.close();
+            });
+
+            const ws = new WebSocket(`wss://localhost:${port}`, {
+              followRedirects: true,
+              headers,
+              rejectUnauthorized: false
+            });
+
+            const firstRequest = ws._req;
+
+            assert.strictEqual(
+              firstRequest.getHeader('Authorization'),
+              headers.authorization
+            );
+            assert.strictEqual(
+              firstRequest.getHeader('Cookie'),
+              headers.cookie
+            );
+            assert.strictEqual(firstRequest.getHeader('Host'), headers.host);
+
+            ws.on('close', (code) => {
+              assert.strictEqual(code, 1005);
+              assert.strictEqual(ws.url, `ws://localhost:${port}/`);
+              assert.strictEqual(ws._redirects, 1);
+
+              server.close(done);
+            });
+          });
+        });
+      });
+
+      describe("If there is at least one 'redirect' event listener", () => {
+        it('does not drop any headers by default', (done) => {
+          const httpServer = http.createServer();
+          const httpsServer = https.createServer({
+            cert: fs.readFileSync('test/fixtures/certificate.pem'),
+            key: fs.readFileSync('test/fixtures/key.pem')
+          });
+          const server = proxy(httpServer, httpsServer);
+
+          server.listen(() => {
+            const port = server.address().port;
+
+            httpsServer.on('upgrade', (req, socket) => {
+              socket.on('error', NOOP);
+              socket.end(
+                'HTTP/1.1 302 Found\r\n' +
+                  `Location: ws://localhost:${port}/\r\n\r\n`
+              );
+            });
+
+            const headers = {
+              authorization: 'Basic Zm9vOmJhcg==',
+              cookie: 'foo=bar',
+              host: 'foo'
+            };
+
+            const wss = new WebSocket.Server({ server: httpServer });
+
+            wss.on('connection', (ws, req) => {
+              assert.strictEqual(
+                req.headers.authorization,
+                headers.authorization
+              );
+              assert.strictEqual(req.headers.cookie, headers.cookie);
+              assert.strictEqual(req.headers.host, headers.host);
+
+              ws.close();
+            });
+
+            const ws = new WebSocket(`wss://localhost:${port}`, {
+              followRedirects: true,
+              headers,
+              rejectUnauthorized: false
+            });
+
+            const firstRequest = ws._req;
+
+            assert.strictEqual(
+              firstRequest.getHeader('Authorization'),
+              headers.authorization
+            );
+            assert.strictEqual(
+              firstRequest.getHeader('Cookie'),
+              headers.cookie
+            );
+            assert.strictEqual(firstRequest.getHeader('Host'), headers.host);
+
+            ws.on('redirect', (url, req) => {
+              assert.strictEqual(ws._redirects, 1);
+              assert.strictEqual(url, `ws://localhost:${port}/`);
+              assert.notStrictEqual(firstRequest, req);
+              assert.strictEqual(
+                req.getHeader('Authorization'),
+                headers.authorization
+              );
+              assert.strictEqual(req.getHeader('Cookie'), headers.cookie);
+              assert.strictEqual(req.getHeader('Host'), headers.host);
+
+              ws.on('close', (code) => {
+                assert.strictEqual(code, 1005);
+                server.close(done);
+              });
+            });
+          });
+        });
+      });
+    });
+
+    describe('When the redirect host is different', () => {
+      describe("If there is no 'redirect' event listener", () => {
+        it('drops the `auth` option', (done) => {
+          const wss = new WebSocket.Server({ port: 0 }, () => {
+            const port = wss.address().port;
+
+            server.once('upgrade', (req, socket) => {
+              socket.end(
+                'HTTP/1.1 302 Found\r\n' +
+                  `Location: ws://localhost:${port}/\r\n\r\n`
+              );
+            });
+
+            const ws = new WebSocket(
+              `ws://localhost:${server.address().port}`,
+              {
+                auth: 'foo:bar',
+                followRedirects: true
+              }
+            );
+
+            assert.strictEqual(
+              ws._req.getHeader('Authorization'),
+              'Basic Zm9vOmJhcg=='
+            );
+
+            ws.on('close', (code) => {
+              assert.strictEqual(code, 1005);
+              assert.strictEqual(ws.url, `ws://localhost:${port}/`);
+              assert.strictEqual(ws._redirects, 1);
+
+              wss.close(done);
+            });
+          });
+
+          wss.on('connection', (ws, req) => {
+            assert.strictEqual(req.headers.authorization, undefined);
+            ws.close();
+          });
+        });
+
+        it('drops the Authorization, Cookie and Host headers (1/4)', (done) => {
+          // Test the `ws:` to `ws:` case.
+
+          const wss = new WebSocket.Server({ port: 0 }, () => {
+            const port = wss.address().port;
+
+            server.once('upgrade', (req, socket) => {
+              socket.end(
+                'HTTP/1.1 302 Found\r\n' +
+                  `Location: ws://localhost:${port}/\r\n\r\n`
+              );
+            });
+
+            const headers = {
+              authorization: 'Basic Zm9vOmJhcg==',
+              cookie: 'foo=bar',
+              host: 'foo'
+            };
+
+            const ws = new WebSocket(
+              `ws://localhost:${server.address().port}`,
+              { followRedirects: true, headers }
+            );
+
+            const firstRequest = ws._req;
+
+            assert.strictEqual(
+              firstRequest.getHeader('Authorization'),
+              headers.authorization
+            );
+            assert.strictEqual(
+              firstRequest.getHeader('Cookie'),
+              headers.cookie
+            );
+            assert.strictEqual(firstRequest.getHeader('Host'), headers.host);
+
+            ws.on('close', (code) => {
+              assert.strictEqual(code, 1005);
+              assert.strictEqual(ws.url, `ws://localhost:${port}/`);
+              assert.strictEqual(ws._redirects, 1);
+
+              wss.close(done);
+            });
+          });
+
+          wss.on('connection', (ws, req) => {
+            assert.strictEqual(req.headers.authorization, undefined);
+            assert.strictEqual(req.headers.cookie, undefined);
+            assert.strictEqual(
+              req.headers.host,
+              `localhost:${wss.address().port}`
+            );
+
+            ws.close();
+          });
+        });
+
+        it('drops the Authorization, Cookie and Host headers (2/4)', function (done) {
+          if (process.platform === 'win32') return this.skip();
+
+          // Test the `ws:` to `ws+unix:` case.
+
+          const socketPath = path.join(
+            os.tmpdir(),
+            `ws.${crypto.randomBytes(16).toString('hex')}.sock`
+          );
+
+          server.once('upgrade', (req, socket) => {
+            socket.end(
+              `HTTP/1.1 302 Found\r\nLocation: ws+unix://${socketPath}\r\n\r\n`
+            );
+          });
+
+          const redirectedServer = http.createServer();
+          const wss = new WebSocket.Server({ server: redirectedServer });
+
+          wss.on('connection', (ws, req) => {
+            assert.strictEqual(req.headers.authorization, undefined);
+            assert.strictEqual(req.headers.cookie, undefined);
+            assert.strictEqual(req.headers.host, 'localhost');
+
+            ws.close();
+          });
+
+          redirectedServer.listen(socketPath, () => {
+            const headers = {
+              authorization: 'Basic Zm9vOmJhcg==',
+              cookie: 'foo=bar',
+              host: 'foo'
+            };
+
+            const ws = new WebSocket(
+              `ws://localhost:${server.address().port}`,
+              { followRedirects: true, headers }
+            );
+
+            const firstRequest = ws._req;
+
+            assert.strictEqual(
+              firstRequest.getHeader('Authorization'),
+              headers.authorization
+            );
+            assert.strictEqual(
+              firstRequest.getHeader('Cookie'),
+              headers.cookie
+            );
+            assert.strictEqual(firstRequest.getHeader('Host'), headers.host);
+
+            ws.on('close', (code) => {
+              assert.strictEqual(code, 1005);
+              assert.strictEqual(ws.url, `ws+unix://${socketPath}`);
+              assert.strictEqual(ws._redirects, 1);
+
+              redirectedServer.close(done);
+            });
+          });
+        });
+
+        it('drops the Authorization, Cookie and Host headers (3/4)', function (done) {
+          if (process.platform === 'win32') return this.skip();
+
+          // Test the `ws+unix:` to `ws+unix:` case.
+
+          const redirectingServerSocketPath = path.join(
+            os.tmpdir(),
+            `ws.${crypto.randomBytes(16).toString('hex')}.sock`
+          );
+          const redirectedServerSocketPath = path.join(
+            os.tmpdir(),
+            `ws.${crypto.randomBytes(16).toString('hex')}.sock`
+          );
+
+          const redirectingServer = http.createServer();
+
+          redirectingServer.on('upgrade', (req, socket) => {
+            socket.end(
+              'HTTP/1.1 302 Found\r\n' +
+                `Location: ws+unix://${redirectedServerSocketPath}\r\n\r\n`
+            );
+          });
+
+          const redirectedServer = http.createServer();
+          const wss = new WebSocket.Server({ server: redirectedServer });
+
+          wss.on('connection', (ws, req) => {
+            assert.strictEqual(req.headers.authorization, undefined);
+            assert.strictEqual(req.headers.cookie, undefined);
+            assert.strictEqual(req.headers.host, 'localhost');
+
+            ws.close();
+          });
+
+          redirectingServer.listen(redirectingServerSocketPath, listening);
+          redirectedServer.listen(redirectedServerSocketPath, listening);
+
+          let callCount = 0;
+
+          function listening() {
+            if (++callCount !== 2) return;
+
+            const headers = {
+              authorization: 'Basic Zm9vOmJhcg==',
+              cookie: 'foo=bar',
+              host: 'foo'
+            };
+
+            const ws = new WebSocket(
+              `ws+unix://${redirectingServerSocketPath}`,
+              { followRedirects: true, headers }
+            );
+
+            const firstRequest = ws._req;
+
+            assert.strictEqual(
+              firstRequest.getHeader('Authorization'),
+              headers.authorization
+            );
+            assert.strictEqual(
+              firstRequest.getHeader('Cookie'),
+              headers.cookie
+            );
+            assert.strictEqual(firstRequest.getHeader('Host'), headers.host);
+
+            ws.on('close', (code) => {
+              assert.strictEqual(code, 1005);
+              assert.strictEqual(
+                ws.url,
+                `ws+unix://${redirectedServerSocketPath}`
+              );
+              assert.strictEqual(ws._redirects, 1);
+
+              redirectingServer.close();
+              redirectedServer.close(done);
+            });
+          }
+        });
+
+        it('drops the Authorization, Cookie and Host headers (4/4)', function (done) {
+          if (process.platform === 'win32') return this.skip();
+
+          // Test the `ws+unix:` to `ws:` case.
+
+          const redirectingServer = http.createServer();
+          const redirectedServer = http.createServer();
+          const wss = new WebSocket.Server({ server: redirectedServer });
+
+          wss.on('connection', (ws, req) => {
+            assert.strictEqual(req.headers.authorization, undefined);
+            assert.strictEqual(req.headers.cookie, undefined);
+            assert.strictEqual(
+              req.headers.host,
+              `localhost:${redirectedServer.address().port}`
+            );
+
+            ws.close();
+          });
+
+          const socketPath = path.join(
+            os.tmpdir(),
+            `ws.${crypto.randomBytes(16).toString('hex')}.sock`
+          );
+
+          redirectingServer.listen(socketPath, listening);
+          redirectedServer.listen(0, listening);
+
+          let callCount = 0;
+
+          function listening() {
+            if (++callCount !== 2) return;
+
+            const port = redirectedServer.address().port;
+
+            redirectingServer.on('upgrade', (req, socket) => {
+              socket.end(
+                `HTTP/1.1 302 Found\r\nLocation: ws://localhost:${port}\r\n\r\n`
+              );
+            });
+
+            const headers = {
+              authorization: 'Basic Zm9vOmJhcg==',
+              cookie: 'foo=bar',
+              host: 'foo'
+            };
+
+            const ws = new WebSocket(`ws+unix://${socketPath}`, {
+              followRedirects: true,
+              headers
+            });
+
+            const firstRequest = ws._req;
+
+            assert.strictEqual(
+              firstRequest.getHeader('Authorization'),
+              headers.authorization
+            );
+            assert.strictEqual(
+              firstRequest.getHeader('Cookie'),
+              headers.cookie
+            );
+            assert.strictEqual(firstRequest.getHeader('Host'), headers.host);
+
+            ws.on('close', (code) => {
+              assert.strictEqual(code, 1005);
+              assert.strictEqual(ws.url, `ws://localhost:${port}/`);
+              assert.strictEqual(ws._redirects, 1);
+
+              redirectingServer.close();
+              redirectedServer.close(done);
+            });
+          }
+        });
+      });
+
+      describe("If there is at least one 'redirect' event listener", () => {
+        it('does not drop any headers by default', (done) => {
+          const headers = {
+            authorization: 'Basic Zm9vOmJhcg==',
+            cookie: 'foo=bar',
+            host: 'foo'
+          };
+
+          const wss = new WebSocket.Server({ port: 0 }, () => {
+            const port = wss.address().port;
+
+            server.once('upgrade', (req, socket) => {
+              socket.end(
+                'HTTP/1.1 302 Found\r\n' +
+                  `Location: ws://localhost:${port}/\r\n\r\n`
+              );
+            });
+
+            const ws = new WebSocket(
+              `ws://localhost:${server.address().port}`,
+              { followRedirects: true, headers }
+            );
+
+            const firstRequest = ws._req;
+
+            assert.strictEqual(
+              firstRequest.getHeader('Authorization'),
+              headers.authorization
+            );
+            assert.strictEqual(
+              firstRequest.getHeader('Cookie'),
+              headers.cookie
+            );
+            assert.strictEqual(firstRequest.getHeader('Host'), headers.host);
+
+            ws.on('redirect', (url, req) => {
+              assert.strictEqual(ws._redirects, 1);
+              assert.strictEqual(url, `ws://localhost:${port}/`);
+              assert.notStrictEqual(firstRequest, req);
+              assert.strictEqual(
+                req.getHeader('Authorization'),
+                headers.authorization
+              );
+              assert.strictEqual(req.getHeader('Cookie'), headers.cookie);
+              assert.strictEqual(req.getHeader('Host'), headers.host);
+
+              ws.on('close', (code) => {
+                assert.strictEqual(code, 1005);
+                wss.close(done);
+              });
+            });
+          });
+
+          wss.on('connection', (ws, req) => {
+            assert.strictEqual(
+              req.headers.authorization,
+              headers.authorization
+            );
+            assert.strictEqual(req.headers.cookie, headers.cookie);
+            assert.strictEqual(req.headers.host, headers.host);
+            ws.close();
+          });
+        });
+      });
+    });
+
+    describe("In a listener of the 'redirect' event", () => {
+      it('allows to abort the request without swallowing errors', (done) => {
+        server.once('upgrade', (req, socket) => {
+          socket.end('HTTP/1.1 302 Found\r\nLocation: /foo\r\n\r\n');
+        });
+
+        const port = server.address().port;
+        const ws = new WebSocket(`ws://localhost:${port}`, {
+          followRedirects: true
+        });
+
+        ws.on('redirect', (url, req) => {
+          assert.strictEqual(ws._redirects, 1);
+          assert.strictEqual(url, `ws://localhost:${port}/foo`);
+
+          req.on('socket', () => {
+            req.abort();
+          });
+
+          ws.on('error', (err) => {
+            assert.ok(err instanceof Error);
+            assert.strictEqual(err.message, 'socket hang up');
+
+            ws.on('close', (code) => {
+              assert.strictEqual(code, 1006);
+              done();
+            });
+          });
+        });
+      });
+
+      it('allows to remove headers', (done) => {
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          const port = wss.address().port;
+
+          server.once('upgrade', (req, socket) => {
+            socket.end(
+              'HTTP/1.1 302 Found\r\n' +
+                `Location: ws://localhost:${port}/\r\n\r\n`
+            );
+          });
+
+          const headers = {
+            authorization: 'Basic Zm9vOmJhcg==',
+            cookie: 'foo=bar'
+          };
+
+          const ws = new WebSocket(`ws://localhost:${server.address().port}`, {
+            followRedirects: true,
+            headers
+          });
+
+          ws.on('redirect', (url, req) => {
+            assert.strictEqual(ws._redirects, 1);
+            assert.strictEqual(url, `ws://localhost:${port}/`);
+            assert.strictEqual(
+              req.getHeader('Authorization'),
+              headers.authorization
+            );
+            assert.strictEqual(req.getHeader('Cookie'), headers.cookie);
+
+            req.removeHeader('authorization');
+            req.removeHeader('cookie');
+
+            ws.on('close', (code) => {
+              assert.strictEqual(code, 1005);
+              wss.close(done);
+            });
+          });
+        });
+
+        wss.on('connection', (ws, req) => {
+          assert.strictEqual(req.headers.authorization, undefined);
+          assert.strictEqual(req.headers.cookie, undefined);
+          ws.close();
+        });
+      });
+    });
+  });
+
+  describe('Connection with query string', () => {
+    it('connects when pathname is not null', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const port = wss.address().port;
+        const ws = new WebSocket(`ws://localhost:${port}/?token=qwerty`);
+
+        ws.on('open', () => {
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+      });
+    });
+
+    it('connects when pathname is null', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const port = wss.address().port;
+        const ws = new WebSocket(`ws://localhost:${port}?token=qwerty`);
+
+        ws.on('open', () => {
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+      });
+    });
+  });
+
+  describe('#pause', () => {
+    it('does nothing if `readyState` is `CONNECTING` or `CLOSED`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        assert.strictEqual(ws.readyState, WebSocket.CONNECTING);
+        assert.ok(!ws.isPaused);
+
+        ws.pause();
+        assert.ok(!ws.isPaused);
+
+        ws.on('open', () => {
+          ws.on('close', () => {
+            assert.strictEqual(ws.readyState, WebSocket.CLOSED);
+
+            ws.pause();
+            assert.ok(!ws.isPaused);
+
+            wss.close(done);
+          });
+
+          ws.close();
+        });
+      });
+    });
+
+    it('pauses the socket', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+      });
+
+      wss.on('connection', (ws) => {
+        assert.ok(!ws.isPaused);
+        assert.ok(!ws._socket.isPaused());
+
+        ws.pause();
+        assert.ok(ws.isPaused);
+        assert.ok(ws._socket.isPaused());
+
+        ws.terminate();
+        wss.close(done);
+      });
+    });
+  });
+
+  describe('#ping', () => {
+    it('throws an error if `readyState` is `CONNECTING`', () => {
+      const ws = new WebSocket('ws://localhost', {
+        lookup() {}
+      });
+
+      assert.throws(
+        () => ws.ping(),
+        /^Error: WebSocket is not open: readyState 0 \(CONNECTING\)$/
+      );
+
+      assert.throws(
+        () => ws.ping(NOOP),
+        /^Error: WebSocket is not open: readyState 0 \(CONNECTING\)$/
+      );
+    });
+
+    it('increases `bufferedAmount` if `readyState` is 2 or 3', (done) => {
+      const ws = new WebSocket('ws://localhost', {
+        lookup() {}
+      });
+
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          'WebSocket was closed before the connection was established'
+        );
+
+        assert.strictEqual(ws.readyState, WebSocket.CLOSING);
+        assert.strictEqual(ws.bufferedAmount, 0);
+
+        ws.ping('hi');
+        assert.strictEqual(ws.bufferedAmount, 2);
+
+        ws.ping();
+        assert.strictEqual(ws.bufferedAmount, 2);
+
+        ws.on('close', () => {
+          assert.strictEqual(ws.readyState, WebSocket.CLOSED);
+
+          ws.ping('hi');
+          assert.strictEqual(ws.bufferedAmount, 4);
+
+          ws.ping();
+          assert.strictEqual(ws.bufferedAmount, 4);
+
+          done();
+        });
+      });
+
+      ws.close();
+    });
+
+    it('calls the callback w/ an error if `readyState` is 2 or 3', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+
+        assert.strictEqual(ws.bufferedAmount, 0);
+
+        ws.ping('hi', (err) => {
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket is not open: readyState 2 (CLOSING)'
+          );
+          assert.strictEqual(ws.bufferedAmount, 2);
+
+          ws.on('close', () => {
+            ws.ping((err) => {
+              assert.ok(err instanceof Error);
+              assert.strictEqual(
+                err.message,
+                'WebSocket is not open: readyState 3 (CLOSED)'
+              );
+              assert.strictEqual(ws.bufferedAmount, 2);
+
+              wss.close(done);
+            });
+          });
+        });
+      });
+    });
+
+    it('can send a ping with no data', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.ping(() => {
+            ws.ping();
+            ws.close();
+          });
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        let pings = 0;
+        ws.on('ping', (data) => {
+          assert.ok(Buffer.isBuffer(data));
+          assert.strictEqual(data.length, 0);
+          if (++pings === 2) wss.close(done);
+        });
+      });
+    });
+
+    it('can send a ping with data', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.ping('hi', () => {
+            ws.ping('hi', true);
+            ws.close();
+          });
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        let pings = 0;
+        ws.on('ping', (message) => {
+          assert.strictEqual(message.toString(), 'hi');
+          if (++pings === 2) wss.close(done);
+        });
+      });
+    });
+
+    it('can send numbers as ping payload', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.ping(0);
+          ws.close();
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('ping', (message) => {
+          assert.strictEqual(message.toString(), '0');
+          wss.close(done);
+        });
+      });
+    });
+
+    it('throws an error if the data size is greater than 125 bytes', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          assert.throws(
+            () => ws.ping(Buffer.alloc(126)),
+            /^RangeError: The data size must not be greater than 125 bytes$/
+          );
+
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+      });
+    });
+  });
+
+  describe('#pong', () => {
+    it('throws an error if `readyState` is `CONNECTING`', () => {
+      const ws = new WebSocket('ws://localhost', {
+        lookup() {}
+      });
+
+      assert.throws(
+        () => ws.pong(),
+        /^Error: WebSocket is not open: readyState 0 \(CONNECTING\)$/
+      );
+
+      assert.throws(
+        () => ws.pong(NOOP),
+        /^Error: WebSocket is not open: readyState 0 \(CONNECTING\)$/
+      );
+    });
+
+    it('increases `bufferedAmount` if `readyState` is 2 or 3', (done) => {
+      const ws = new WebSocket('ws://localhost', {
+        lookup() {}
+      });
+
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          'WebSocket was closed before the connection was established'
+        );
+
+        assert.strictEqual(ws.readyState, WebSocket.CLOSING);
+        assert.strictEqual(ws.bufferedAmount, 0);
+
+        ws.pong('hi');
+        assert.strictEqual(ws.bufferedAmount, 2);
+
+        ws.pong();
+        assert.strictEqual(ws.bufferedAmount, 2);
+
+        ws.on('close', () => {
+          assert.strictEqual(ws.readyState, WebSocket.CLOSED);
+
+          ws.pong('hi');
+          assert.strictEqual(ws.bufferedAmount, 4);
+
+          ws.pong();
+          assert.strictEqual(ws.bufferedAmount, 4);
+
+          done();
+        });
+      });
+
+      ws.close();
+    });
+
+    it('calls the callback w/ an error if `readyState` is 2 or 3', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+
+        assert.strictEqual(ws.bufferedAmount, 0);
+
+        ws.pong('hi', (err) => {
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket is not open: readyState 2 (CLOSING)'
+          );
+          assert.strictEqual(ws.bufferedAmount, 2);
+
+          ws.on('close', () => {
+            ws.pong((err) => {
+              assert.ok(err instanceof Error);
+              assert.strictEqual(
+                err.message,
+                'WebSocket is not open: readyState 3 (CLOSED)'
+              );
+              assert.strictEqual(ws.bufferedAmount, 2);
+
+              wss.close(done);
+            });
+          });
+        });
+      });
+    });
+
+    it('can send a pong with no data', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.pong(() => {
+            ws.pong();
+            ws.close();
+          });
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        let pongs = 0;
+        ws.on('pong', (data) => {
+          assert.ok(Buffer.isBuffer(data));
+          assert.strictEqual(data.length, 0);
+          if (++pongs === 2) wss.close(done);
+        });
+      });
+    });
+
+    it('can send a pong with data', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.pong('hi', () => {
+            ws.pong('hi', true);
+            ws.close();
+          });
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        let pongs = 0;
+        ws.on('pong', (message) => {
+          assert.strictEqual(message.toString(), 'hi');
+          if (++pongs === 2) wss.close(done);
+        });
+      });
+    });
+
+    it('can send numbers as pong payload', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.pong(0);
+          ws.close();
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('pong', (message) => {
+          assert.strictEqual(message.toString(), '0');
+          wss.close(done);
+        });
+      });
+    });
+
+    it('throws an error if the data size is greater than 125 bytes', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          assert.throws(
+            () => ws.pong(Buffer.alloc(126)),
+            /^RangeError: The data size must not be greater than 125 bytes$/
+          );
+
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+      });
+    });
+  });
+
+  describe('#resume', () => {
+    it('does nothing if `readyState` is `CONNECTING` or `CLOSED`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        assert.strictEqual(ws.readyState, WebSocket.CONNECTING);
+        assert.ok(!ws.isPaused);
+
+        // Verify that no exception is thrown.
+        ws.resume();
+
+        ws.on('open', () => {
+          ws.pause();
+          assert.ok(ws.isPaused);
+
+          ws.on('close', () => {
+            assert.strictEqual(ws.readyState, WebSocket.CLOSED);
+
+            ws.resume();
+            assert.ok(ws.isPaused);
+
+            wss.close(done);
+          });
+
+          ws.terminate();
+        });
+      });
+    });
+
+    it('resumes the socket', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+      });
+
+      wss.on('connection', (ws) => {
+        assert.ok(!ws.isPaused);
+        assert.ok(!ws._socket.isPaused());
+
+        ws.pause();
+        assert.ok(ws.isPaused);
+        assert.ok(ws._socket.isPaused());
+
+        ws.resume();
+        assert.ok(!ws.isPaused);
+        assert.ok(!ws._socket.isPaused());
+
+        ws.close();
+        wss.close(done);
+      });
+    });
+  });
+
+  describe('#send', () => {
+    it('throws an error if `readyState` is `CONNECTING`', () => {
+      const ws = new WebSocket('ws://localhost', {
+        lookup() {}
+      });
+
+      assert.throws(
+        () => ws.send('hi'),
+        /^Error: WebSocket is not open: readyState 0 \(CONNECTING\)$/
+      );
+
+      assert.throws(
+        () => ws.send('hi', NOOP),
+        /^Error: WebSocket is not open: readyState 0 \(CONNECTING\)$/
+      );
+    });
+
+    it('increases `bufferedAmount` if `readyState` is 2 or 3', (done) => {
+      const ws = new WebSocket('ws://localhost', {
+        lookup() {}
+      });
+
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(
+          err.message,
+          'WebSocket was closed before the connection was established'
+        );
+
+        assert.strictEqual(ws.readyState, WebSocket.CLOSING);
+        assert.strictEqual(ws.bufferedAmount, 0);
+
+        ws.send('hi');
+        assert.strictEqual(ws.bufferedAmount, 2);
+
+        ws.send();
+        assert.strictEqual(ws.bufferedAmount, 2);
+
+        ws.on('close', () => {
+          assert.strictEqual(ws.readyState, WebSocket.CLOSED);
+
+          ws.send('hi');
+          assert.strictEqual(ws.bufferedAmount, 4);
+
+          ws.send();
+          assert.strictEqual(ws.bufferedAmount, 4);
+
+          done();
+        });
+      });
+
+      ws.close();
+    });
+
+    it('calls the callback w/ an error if `readyState` is 2 or 3', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+
+        assert.strictEqual(ws.bufferedAmount, 0);
+
+        ws.send('hi', (err) => {
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket is not open: readyState 2 (CLOSING)'
+          );
+          assert.strictEqual(ws.bufferedAmount, 2);
+
+          ws.on('close', () => {
+            ws.send('hi', (err) => {
+              assert.ok(err instanceof Error);
+              assert.strictEqual(
+                err.message,
+                'WebSocket is not open: readyState 3 (CLOSED)'
+              );
+              assert.strictEqual(ws.bufferedAmount, 4);
+
+              wss.close(done);
+            });
+          });
+        });
+      });
+    });
+
+    it('can send a big binary message', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const array = new Float32Array(5 * 1024 * 1024);
+
+        for (let i = 0; i < array.length; i++) {
+          array[i] = i / 5;
+        }
+
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => ws.send(array));
+        ws.on('message', (msg, isBinary) => {
+          assert.deepStrictEqual(msg, Buffer.from(array.buffer));
+          assert.ok(isBinary);
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (msg, isBinary) => {
+          assert.ok(isBinary);
+          ws.send(msg);
+          ws.close();
+        });
+      });
+    });
+
+    it('can send text data', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => ws.send('hi'));
+        ws.on('message', (message, isBinary) => {
+          assert.deepStrictEqual(message, Buffer.from('hi'));
+          assert.ok(!isBinary);
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (msg, isBinary) => {
+          ws.send(msg, { binary: isBinary });
+          ws.close();
+        });
+      });
+    });
+
+    it('does not override the `fin` option', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.send('fragment', { fin: false });
+          ws.send('fragment', { fin: true });
+          ws.close();
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (msg, isBinary) => {
+          assert.deepStrictEqual(msg, Buffer.from('fragmentfragment'));
+          assert.ok(!isBinary);
+          wss.close(done);
+        });
+      });
+    });
+
+    it('sends numbers as strings', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.send(0);
+          ws.close();
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (msg, isBinary) => {
+          assert.deepStrictEqual(msg, Buffer.from('0'));
+          assert.ok(!isBinary);
+          wss.close(done);
+        });
+      });
+    });
+
+    it('can send a `TypedArray`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const array = new Float32Array(6);
+
+        for (let i = 0; i < array.length; ++i) {
+          array[i] = i / 2;
+        }
+
+        const partial = array.subarray(2, 5);
+        const buf = Buffer.from(
+          partial.buffer,
+          partial.byteOffset,
+          partial.byteLength
+        );
+
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.send(partial);
+          ws.close();
+        });
+
+        ws.on('message', (message, isBinary) => {
+          assert.deepStrictEqual(message, buf);
+          assert.ok(isBinary);
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (msg, isBinary) => {
+          assert.ok(isBinary);
+          ws.send(msg);
+        });
+      });
+    });
+
+    it('can send an `ArrayBuffer`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const array = new Float32Array(5);
+
+        for (let i = 0; i < array.length; ++i) {
+          array[i] = i / 2;
+        }
+
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.send(array.buffer);
+          ws.close();
+        });
+
+        ws.onmessage = (event) => {
+          assert.ok(event.data.equals(Buffer.from(array.buffer)));
+          wss.close(done);
+        };
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (msg, isBinary) => {
+          assert.ok(isBinary);
+          ws.send(msg);
+        });
+      });
+    });
+
+    it('can send a `Buffer`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const buf = Buffer.from('foobar');
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.send(buf);
+          ws.close();
+        });
+
+        ws.onmessage = (event) => {
+          assert.deepStrictEqual(event.data, buf);
+          wss.close(done);
+        };
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (msg, isBinary) => {
+          assert.ok(isBinary);
+          ws.send(msg);
+        });
+      });
+    });
+
+    it('calls the callback when data is written out', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.send('hi', (err) => {
+            assert.ifError(err);
+            wss.close(done);
+          });
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.close();
+      });
+    });
+
+    it('works when the `data` argument is falsy', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws.send();
+          ws.close();
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (message, isBinary) => {
+          assert.strictEqual(message, EMPTY_BUFFER);
+          assert.ok(isBinary);
+          wss.close(done);
+        });
+      });
+    });
+
+    it('honors the `mask` option', (done) => {
+      let clientCloseEventEmitted = false;
+      let serverClientCloseEventEmitted = false;
+
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => ws.send('hi', { mask: false }));
+        ws.on('close', (code, reason) => {
+          assert.strictEqual(code, 1002);
+          assert.deepStrictEqual(reason, EMPTY_BUFFER);
+
+          clientCloseEventEmitted = true;
+          if (serverClientCloseEventEmitted) wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        const chunks = [];
+
+        ws._socket.prependListener('data', (chunk) => {
+          chunks.push(chunk);
+        });
+
+        ws.on('error', (err) => {
+          assert.ok(err instanceof RangeError);
+          assert.strictEqual(
+            err.message,
+            'Invalid WebSocket frame: MASK must be set'
+          );
+          assert.ok(
+            Buffer.concat(chunks).slice(0, 2).equals(Buffer.from('8102', 'hex'))
+          );
+
+          ws.on('close', (code, reason) => {
+            assert.strictEqual(code, 1006);
+            assert.strictEqual(reason, EMPTY_BUFFER);
+
+            serverClientCloseEventEmitted = true;
+            if (clientCloseEventEmitted) wss.close(done);
+          });
+        });
+      });
+    });
+  });
+
+  describe('#close', () => {
+    it('closes the connection if called while connecting (1/3)', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => done(new Error("Unexpected 'open' event")));
+        ws.on('error', (err) => {
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket was closed before the connection was established'
+          );
+          ws.on('close', () => wss.close(done));
+        });
+        ws.close(1001);
+      });
+    });
+
+    it('closes the connection if called while connecting (2/3)', (done) => {
+      const wss = new WebSocket.Server(
+        {
+          verifyClient: (info, cb) => setTimeout(cb, 300, true),
+          port: 0
+        },
+        () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          ws.on('open', () => done(new Error("Unexpected 'open' event")));
+          ws.on('error', (err) => {
+            assert.ok(err instanceof Error);
+            assert.strictEqual(
+              err.message,
+              'WebSocket was closed before the connection was established'
+            );
+            ws.on('close', () => wss.close(done));
+          });
+          setTimeout(() => ws.close(1001), 150);
+        }
+      );
+    });
+
+    it('closes the connection if called while connecting (3/3)', (done) => {
+      const server = http.createServer();
+
+      server.listen(0, () => {
+        const ws = new WebSocket(`ws://localhost:${server.address().port}`);
+
+        ws.on('open', () => done(new Error("Unexpected 'open' event")));
+        ws.on('error', (err) => {
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket was closed before the connection was established'
+          );
+          ws.on('close', () => {
+            server.close(done);
+          });
+        });
+
+        ws.on('unexpected-response', (req, res) => {
+          assert.strictEqual(res.statusCode, 502);
+
+          const chunks = [];
+
+          res.on('data', (chunk) => {
+            chunks.push(chunk);
+          });
+
+          res.on('end', () => {
+            assert.strictEqual(Buffer.concat(chunks).toString(), 'foo');
+            ws.close();
+          });
+        });
+      });
+
+      server.on('upgrade', (req, socket) => {
+        socket.on('end', socket.end);
+
+        socket.write(
+          `HTTP/1.1 502 ${http.STATUS_CODES[502]}\r\n` +
+            'Connection: keep-alive\r\n' +
+            'Content-type: text/html\r\n' +
+            'Content-Length: 3\r\n' +
+            '\r\n' +
+            'foo'
+        );
+      });
+    });
+
+    it('can be called from an error listener while connecting', (done) => {
+      const ws = new WebSocket('ws://localhost:1337');
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.code, 'ECONNREFUSED');
+        ws.close();
+        ws.on('close', () => done());
+      });
+    }).timeout(4000);
+
+    it("can be called from a listener of the 'redirect' event", (done) => {
+      const server = http.createServer();
+
+      server.once('upgrade', (req, socket) => {
+        socket.end('HTTP/1.1 302 Found\r\nLocation: /foo\r\n\r\n');
+      });
+
+      server.listen(() => {
+        const port = server.address().port;
+        const ws = new WebSocket(`ws://localhost:${port}`, {
+          followRedirects: true
+        });
+
+        ws.on('open', () => {
+          done(new Error("Unexpected 'open' event"));
+        });
+
+        ws.on('error', (err) => {
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket was closed before the connection was established'
+          );
+
+          ws.on('close', (code) => {
+            assert.strictEqual(code, 1006);
+            server.close(done);
+          });
+        });
+
+        ws.on('redirect', () => {
+          ws.close();
+        });
+      });
+    });
+
+    it("can be called from a listener of the 'upgrade' event", (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => done(new Error("Unexpected 'open' event")));
+        ws.on('error', (err) => {
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket was closed before the connection was established'
+          );
+          ws.on('close', () => wss.close(done));
+        });
+        ws.on('upgrade', () => ws.close());
+      });
+    });
+
+    it('sends the close status code only when necessary', (done) => {
+      let sent;
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => {
+          ws._socket.once('data', (data) => {
+            sent = data;
+          });
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws._socket.once('data', (received) => {
+          assert.deepStrictEqual(
+            received.slice(0, 2),
+            Buffer.from([0x88, 0x80])
+          );
+          assert.deepStrictEqual(sent, Buffer.from([0x88, 0x00]));
+
+          ws.on('close', (code, reason) => {
+            assert.strictEqual(code, 1005);
+            assert.strictEqual(reason, EMPTY_BUFFER);
+            wss.close(done);
+          });
+        });
+        ws.close();
+      });
+    });
+
+    it('works when close reason is not specified', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => ws.close(1000));
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('close', (code, message) => {
+          assert.strictEqual(code, 1000);
+          assert.deepStrictEqual(message, EMPTY_BUFFER);
+          wss.close(done);
+        });
+      });
+    });
+
+    it('works when close reason is specified', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => ws.close(1000, 'some reason'));
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('close', (code, message) => {
+          assert.strictEqual(code, 1000);
+          assert.deepStrictEqual(message, Buffer.from('some reason'));
+          wss.close(done);
+        });
+      });
+    });
+
+    it('permits all buffered data to be delivered', (done) => {
+      const wss = new WebSocket.Server(
+        {
+          perMessageDeflate: { threshold: 0 },
+          port: 0
+        },
+        () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+          const messages = [];
+
+          ws.on('message', (message, isBinary) => {
+            assert.ok(!isBinary);
+            messages.push(message.toString());
+          });
+          ws.on('close', (code) => {
+            assert.strictEqual(code, 1005);
+            assert.deepStrictEqual(messages, ['foo', 'bar', 'baz']);
+            wss.close(done);
+          });
+        }
+      );
+
+      wss.on('connection', (ws) => {
+        const callback = (err) => assert.ifError(err);
+
+        ws.send('foo', callback);
+        ws.send('bar', callback);
+        ws.send('baz', callback);
+        ws.close();
+        ws.close();
+      });
+    });
+
+    it('allows close code 1013', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('close', (code) => {
+          assert.strictEqual(code, 1013);
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => ws.close(1013));
+    });
+
+    it('allows close code 1014', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('close', (code) => {
+          assert.strictEqual(code, 1014);
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => ws.close(1014));
+    });
+
+    it('does nothing if `readyState` is `CLOSED`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('close', (code) => {
+          assert.strictEqual(code, 1005);
+          assert.strictEqual(ws.readyState, WebSocket.CLOSED);
+          ws.close();
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => ws.close());
+    });
+
+    it('sets a timer for the closing handshake to complete', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('close', (code, reason) => {
+          assert.strictEqual(code, 1000);
+          assert.deepStrictEqual(reason, Buffer.from('some reason'));
+          wss.close(done);
+        });
+
+        ws.on('open', () => {
+          let callbackCalled = false;
+
+          assert.strictEqual(ws._closeTimer, null);
+
+          ws.send('foo', () => {
+            callbackCalled = true;
+          });
+
+          ws.close(1000, 'some reason');
+
+          //
+          // Check that the close timer is set even if the `Sender.close()`
+          // callback is not called.
+          //
+          assert.strictEqual(callbackCalled, false);
+          assert.strictEqual(ws._closeTimer._idleTimeout, 30000);
+        });
+      });
+    });
+  });
+
+  describe('#terminate', () => {
+    it('closes the connection if called while connecting (1/2)', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => done(new Error("Unexpected 'open' event")));
+        ws.on('error', (err) => {
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket was closed before the connection was established'
+          );
+          ws.on('close', () => wss.close(done));
+        });
+        ws.terminate();
+      });
+    });
+
+    it('closes the connection if called while connecting (2/2)', (done) => {
+      const wss = new WebSocket.Server(
+        {
+          verifyClient: (info, cb) => setTimeout(cb, 300, true),
+          port: 0
+        },
+        () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          ws.on('open', () => done(new Error("Unexpected 'open' event")));
+          ws.on('error', (err) => {
+            assert.ok(err instanceof Error);
+            assert.strictEqual(
+              err.message,
+              'WebSocket was closed before the connection was established'
+            );
+            ws.on('close', () => wss.close(done));
+          });
+          setTimeout(() => ws.terminate(), 150);
+        }
+      );
+    });
+
+    it('can be called from an error listener while connecting', (done) => {
+      const ws = new WebSocket('ws://localhost:1337');
+
+      ws.on('open', () => done(new Error("Unexpected 'open' event")));
+      ws.on('error', (err) => {
+        assert.ok(err instanceof Error);
+        assert.strictEqual(err.code, 'ECONNREFUSED');
+        ws.terminate();
+        ws.on('close', () => done());
+      });
+    }).timeout(4000);
+
+    it("can be called from a listener of the 'redirect' event", (done) => {
+      const server = http.createServer();
+
+      server.once('upgrade', (req, socket) => {
+        socket.end('HTTP/1.1 302 Found\r\nLocation: /foo\r\n\r\n');
+      });
+
+      server.listen(() => {
+        const port = server.address().port;
+        const ws = new WebSocket(`ws://localhost:${port}`, {
+          followRedirects: true
+        });
+
+        ws.on('open', () => {
+          done(new Error("Unexpected 'open' event"));
+        });
+
+        ws.on('error', (err) => {
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket was closed before the connection was established'
+          );
+
+          ws.on('close', (code) => {
+            assert.strictEqual(code, 1006);
+            server.close(done);
+          });
+        });
+
+        ws.on('redirect', () => {
+          ws.terminate();
+        });
+      });
+    });
+
+    it("can be called from a listener of the 'upgrade' event", (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('open', () => done(new Error("Unexpected 'open' event")));
+        ws.on('error', (err) => {
+          assert.ok(err instanceof Error);
+          assert.strictEqual(
+            err.message,
+            'WebSocket was closed before the connection was established'
+          );
+          ws.on('close', () => wss.close(done));
+        });
+        ws.on('upgrade', () => ws.terminate());
+      });
+    });
+
+    it('does nothing if `readyState` is `CLOSED`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('close', (code) => {
+          assert.strictEqual(code, 1006);
+          assert.strictEqual(ws.readyState, WebSocket.CLOSED);
+          ws.terminate();
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => ws.terminate());
+    });
+  });
+
+  describe('WHATWG API emulation', () => {
+    it('supports the `on{close,error,message,open}` attributes', () => {
+      for (const property of ['onclose', 'onerror', 'onmessage', 'onopen']) {
+        const descriptor = Object.getOwnPropertyDescriptor(
+          WebSocket.prototype,
+          property
+        );
+
+        assert.strictEqual(descriptor.configurable, true);
+        assert.strictEqual(descriptor.enumerable, true);
+        assert.ok(descriptor.get !== undefined);
+        assert.ok(descriptor.set !== undefined);
+      }
+
+      const ws = new WebSocket('ws://localhost', { agent: new CustomAgent() });
+
+      assert.strictEqual(ws.onmessage, null);
+      assert.strictEqual(ws.onclose, null);
+      assert.strictEqual(ws.onerror, null);
+      assert.strictEqual(ws.onopen, null);
+
+      ws.onmessage = NOOP;
+      ws.onerror = NOOP;
+      ws.onclose = NOOP;
+      ws.onopen = NOOP;
+
+      assert.strictEqual(ws.onmessage, NOOP);
+      assert.strictEqual(ws.onclose, NOOP);
+      assert.strictEqual(ws.onerror, NOOP);
+      assert.strictEqual(ws.onopen, NOOP);
+
+      ws.onmessage = 'foo';
+
+      assert.strictEqual(ws.onmessage, null);
+      assert.strictEqual(ws.listenerCount('message'), 0);
+    });
+
+    it('works like the `EventEmitter` interface', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.onmessage = (messageEvent) => {
+          assert.strictEqual(messageEvent.data, 'foo');
+          ws.onclose = (closeEvent) => {
+            assert.strictEqual(closeEvent.wasClean, true);
+            assert.strictEqual(closeEvent.code, 1005);
+            assert.strictEqual(closeEvent.reason, '');
+            wss.close(done);
+          };
+          ws.close();
+        };
+
+        ws.onopen = () => ws.send('foo');
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (msg, isBinary) => {
+          ws.send(msg, { binary: isBinary });
+        });
+      });
+    });
+
+    it("doesn't return listeners added with `on`", () => {
+      const ws = new WebSocket('ws://localhost', { agent: new CustomAgent() });
+
+      ws.on('open', NOOP);
+
+      assert.deepStrictEqual(ws.listeners('open'), [NOOP]);
+      assert.strictEqual(ws.onopen, null);
+    });
+
+    it("doesn't remove listeners added with `on`", () => {
+      const ws = new WebSocket('ws://localhost', { agent: new CustomAgent() });
+
+      ws.on('close', NOOP);
+      ws.onclose = NOOP;
+
+      let listeners = ws.listeners('close');
+
+      assert.strictEqual(listeners.length, 2);
+      assert.strictEqual(listeners[0], NOOP);
+      assert.strictEqual(listeners[1][kListener], NOOP);
+
+      ws.onclose = NOOP;
+
+      listeners = ws.listeners('close');
+
+      assert.strictEqual(listeners.length, 2);
+      assert.strictEqual(listeners[0], NOOP);
+      assert.strictEqual(listeners[1][kListener], NOOP);
+    });
+
+    it('supports the `addEventListener` method', () => {
+      const events = [];
+      const ws = new WebSocket('ws://localhost', { agent: new CustomAgent() });
+
+      ws.addEventListener('foo', () => {});
+      assert.strictEqual(ws.listenerCount('foo'), 0);
+
+      ws.addEventListener('open', () => {
+        events.push('open');
+        assert.strictEqual(ws.listenerCount('open'), 1);
+      });
+
+      assert.strictEqual(ws.listenerCount('open'), 1);
+
+      ws.addEventListener(
+        'message',
+        () => {
+          events.push('message');
+          assert.strictEqual(ws.listenerCount('message'), 0);
+        },
+        { once: true }
+      );
+
+      assert.strictEqual(ws.listenerCount('message'), 1);
+
+      ws.emit('open');
+      ws.emit('message', EMPTY_BUFFER, false);
+
+      assert.deepStrictEqual(events, ['open', 'message']);
+    });
+
+    it("doesn't return listeners added with `addEventListener`", () => {
+      const ws = new WebSocket('ws://localhost', { agent: new CustomAgent() });
+
+      ws.addEventListener('open', NOOP);
+
+      const listeners = ws.listeners('open');
+
+      assert.strictEqual(listeners.length, 1);
+      assert.strictEqual(listeners[0][kListener], NOOP);
+
+      assert.strictEqual(ws.onopen, null);
+    });
+
+    it("doesn't remove listeners added with `addEventListener`", () => {
+      const ws = new WebSocket('ws://localhost', { agent: new CustomAgent() });
+
+      ws.addEventListener('close', NOOP);
+      ws.onclose = NOOP;
+
+      let listeners = ws.listeners('close');
+
+      assert.strictEqual(listeners.length, 2);
+      assert.strictEqual(listeners[0][kListener], NOOP);
+      assert.strictEqual(listeners[1][kListener], NOOP);
+
+      ws.onclose = NOOP;
+
+      listeners = ws.listeners('close');
+
+      assert.strictEqual(listeners.length, 2);
+      assert.strictEqual(listeners[0][kListener], NOOP);
+      assert.strictEqual(listeners[1][kListener], NOOP);
+    });
+
+    it('supports the `removeEventListener` method', () => {
+      const ws = new WebSocket('ws://localhost', { agent: new CustomAgent() });
+
+      ws.addEventListener('message', NOOP);
+      ws.addEventListener('open', NOOP);
+
+      assert.strictEqual(ws.listeners('message')[0][kListener], NOOP);
+      assert.strictEqual(ws.listeners('open')[0][kListener], NOOP);
+
+      ws.removeEventListener('message', () => {});
+
+      assert.strictEqual(ws.listeners('message')[0][kListener], NOOP);
+
+      ws.removeEventListener('message', NOOP);
+      ws.removeEventListener('open', NOOP);
+
+      assert.strictEqual(ws.listenerCount('message'), 0);
+      assert.strictEqual(ws.listenerCount('open'), 0);
+
+      ws.addEventListener('message', NOOP, { once: true });
+      ws.addEventListener('open', NOOP, { once: true });
+
+      assert.strictEqual(ws.listeners('message')[0][kListener], NOOP);
+      assert.strictEqual(ws.listeners('open')[0][kListener], NOOP);
+
+      ws.removeEventListener('message', () => {});
+
+      assert.strictEqual(ws.listeners('message')[0][kListener], NOOP);
+
+      ws.removeEventListener('message', NOOP);
+      ws.removeEventListener('open', NOOP);
+
+      assert.strictEqual(ws.listenerCount('message'), 0);
+      assert.strictEqual(ws.listenerCount('open'), 0);
+
+      // Multiple listeners.
+      ws.addEventListener('message', NOOP);
+      ws.addEventListener('message', NOOP);
+
+      assert.strictEqual(ws.listeners('message')[0][kListener], NOOP);
+      assert.strictEqual(ws.listeners('message')[1][kListener], NOOP);
+
+      ws.removeEventListener('message', NOOP);
+
+      assert.strictEqual(ws.listeners('message')[0][kListener], NOOP);
+
+      ws.removeEventListener('message', NOOP);
+
+      assert.strictEqual(ws.listenerCount('message'), 0);
+
+      // Listeners not added with `websocket.addEventListener()`.
+      ws.on('message', NOOP);
+
+      assert.deepStrictEqual(ws.listeners('message'), [NOOP]);
+
+      ws.removeEventListener('message', NOOP);
+
+      assert.deepStrictEqual(ws.listeners('message'), [NOOP]);
+
+      ws.onclose = NOOP;
+
+      assert.strictEqual(ws.listeners('close')[0][kListener], NOOP);
+
+      ws.removeEventListener('close', NOOP);
+
+      assert.strictEqual(ws.listeners('close')[0][kListener], NOOP);
+    });
+
+    it('wraps text data in a `MessageEvent`', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.addEventListener('open', () => {
+          ws.send('hi');
+          ws.close();
+        });
+
+        ws.addEventListener('message', (event) => {
+          assert.ok(event instanceof MessageEvent);
+          assert.strictEqual(event.data, 'hi');
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (msg, isBinary) => {
+          ws.send(msg, { binary: isBinary });
+        });
+      });
+    });
+
+    it('receives a `CloseEvent` when server closes (1000)', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.addEventListener('close', (event) => {
+          assert.ok(event instanceof CloseEvent);
+          assert.ok(event.wasClean);
+          assert.strictEqual(event.reason, '');
+          assert.strictEqual(event.code, 1000);
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => ws.close(1000));
+    });
+
+    it('receives a `CloseEvent` when server closes (4000)', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.addEventListener('close', (event) => {
+          assert.ok(event instanceof CloseEvent);
+          assert.ok(event.wasClean);
+          assert.strictEqual(event.reason, 'some daft reason');
+          assert.strictEqual(event.code, 4000);
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (ws) => ws.close(4000, 'some daft reason'));
+    });
+
+    it('sets `target` and `type` on events', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const err = new Error('forced');
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.addEventListener('open', (event) => {
+          assert.ok(event instanceof Event);
+          assert.strictEqual(event.type, 'open');
+          assert.strictEqual(event.target, ws);
+        });
+        ws.addEventListener('message', (event) => {
+          assert.ok(event instanceof MessageEvent);
+          assert.strictEqual(event.type, 'message');
+          assert.strictEqual(event.target, ws);
+          ws.close();
+        });
+        ws.addEventListener('close', (event) => {
+          assert.ok(event instanceof CloseEvent);
+          assert.strictEqual(event.type, 'close');
+          assert.strictEqual(event.target, ws);
+          ws.emit('error', err);
+        });
+        ws.addEventListener('error', (event) => {
+          assert.ok(event instanceof ErrorEvent);
+          assert.strictEqual(event.message, 'forced');
+          assert.strictEqual(event.type, 'error');
+          assert.strictEqual(event.target, ws);
+          assert.strictEqual(event.error, err);
+
+          wss.close(done);
+        });
+      });
+
+      wss.on('connection', (client) => client.send('hi'));
+    });
+
+    it('passes binary data as a Node.js `Buffer` by default', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.onmessage = (evt) => {
+          assert.ok(Buffer.isBuffer(evt.data));
+          wss.close(done);
+        };
+      });
+
+      wss.on('connection', (ws) => {
+        ws.send(new Uint8Array(4096));
+        ws.close();
+      });
+    });
+
+    it('ignores `binaryType` for text messages', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.binaryType = 'arraybuffer';
+
+        ws.onmessage = (evt) => {
+          assert.strictEqual(evt.data, 'foo');
+          wss.close(done);
+        };
+      });
+
+      wss.on('connection', (ws) => {
+        ws.send('foo');
+        ws.close();
+      });
+    });
+
+    it('allows to update `binaryType` on the fly', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        function testType(binaryType, next) {
+          const buf = Buffer.from(binaryType);
+          ws.binaryType = binaryType;
+
+          ws.onmessage = (evt) => {
+            if (binaryType === 'nodebuffer') {
+              assert.ok(Buffer.isBuffer(evt.data));
+              assert.ok(evt.data.equals(buf));
+            } else if (binaryType === 'arraybuffer') {
+              assert.ok(evt.data instanceof ArrayBuffer);
+              assert.ok(Buffer.from(evt.data).equals(buf));
+            } else if (binaryType === 'fragments') {
+              assert.deepStrictEqual(evt.data, [buf]);
+            }
+            next();
+          };
+
+          ws.send(buf);
+        }
+
+        ws.onopen = () => {
+          testType('nodebuffer', () => {
+            testType('arraybuffer', () => {
+              testType('fragments', () => {
+                ws.close();
+                wss.close(done);
+              });
+            });
+          });
+        };
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (msg, isBinary) => {
+          assert.ok(isBinary);
+          ws.send(msg);
+        });
+      });
+    });
+  });
+
+  describe('SSL', () => {
+    it('connects to secure websocket server', (done) => {
+      const server = https.createServer({
+        cert: fs.readFileSync('test/fixtures/certificate.pem'),
+        key: fs.readFileSync('test/fixtures/key.pem')
+      });
+      const wss = new WebSocket.Server({ server });
+
+      wss.on('connection', () => {
+        server.close(done);
+      });
+
+      server.listen(0, () => {
+        const ws = new WebSocket(`wss://127.0.0.1:${server.address().port}`, {
+          rejectUnauthorized: false
+        });
+
+        ws.on('open', ws.close);
+      });
+    });
+
+    it('connects to secure websocket server with client side certificate', (done) => {
+      const server = https.createServer({
+        cert: fs.readFileSync('test/fixtures/certificate.pem'),
+        ca: [fs.readFileSync('test/fixtures/ca-certificate.pem')],
+        key: fs.readFileSync('test/fixtures/key.pem'),
+        requestCert: true
+      });
+
+      const wss = new WebSocket.Server({ noServer: true });
+
+      server.on('upgrade', (request, socket, head) => {
+        assert.ok(socket.authorized);
+
+        wss.handleUpgrade(request, socket, head, (ws) => {
+          ws.on('close', (code) => {
+            assert.strictEqual(code, 1005);
+            server.close(done);
+          });
+        });
+      });
+
+      server.listen(0, () => {
+        const ws = new WebSocket(`wss://localhost:${server.address().port}`, {
+          cert: fs.readFileSync('test/fixtures/client-certificate.pem'),
+          key: fs.readFileSync('test/fixtures/client-key.pem'),
+          rejectUnauthorized: false
+        });
+
+        ws.on('open', ws.close);
+      });
+    });
+
+    it('cannot connect to secure websocket server via ws://', (done) => {
+      const server = https.createServer({
+        cert: fs.readFileSync('test/fixtures/certificate.pem'),
+        key: fs.readFileSync('test/fixtures/key.pem')
+      });
+      const wss = new WebSocket.Server({ server });
+
+      server.listen(0, () => {
+        const ws = new WebSocket(`ws://localhost:${server.address().port}`, {
+          rejectUnauthorized: false
+        });
+
+        ws.on('error', () => {
+          server.close(done);
+          wss.close();
+        });
+      });
+    });
+
+    it('can send and receive text data', (done) => {
+      const server = https.createServer({
+        cert: fs.readFileSync('test/fixtures/certificate.pem'),
+        key: fs.readFileSync('test/fixtures/key.pem')
+      });
+      const wss = new WebSocket.Server({ server });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (message, isBinary) => {
+          assert.deepStrictEqual(message, Buffer.from('foobar'));
+          assert.ok(!isBinary);
+          server.close(done);
+        });
+      });
+
+      server.listen(0, () => {
+        const ws = new WebSocket(`wss://localhost:${server.address().port}`, {
+          rejectUnauthorized: false
+        });
+
+        ws.on('open', () => {
+          ws.send('foobar');
+          ws.close();
+        });
+      });
+    });
+
+    it('can send a big binary message', (done) => {
+      const buf = crypto.randomBytes(5 * 1024 * 1024);
+      const server = https.createServer({
+        cert: fs.readFileSync('test/fixtures/certificate.pem'),
+        key: fs.readFileSync('test/fixtures/key.pem')
+      });
+      const wss = new WebSocket.Server({ server });
+
+      wss.on('connection', (ws) => {
+        ws.on('message', (message, isBinary) => {
+          assert.ok(isBinary);
+          ws.send(message);
+          ws.close();
+        });
+      });
+
+      server.listen(0, () => {
+        const ws = new WebSocket(`wss://localhost:${server.address().port}`, {
+          rejectUnauthorized: false
+        });
+
+        ws.on('open', () => ws.send(buf));
+        ws.on('message', (message, isBinary) => {
+          assert.deepStrictEqual(message, buf);
+          assert.ok(isBinary);
+
+          server.close(done);
+        });
+      });
+    }).timeout(4000);
+
+    it('allows to disable sending the SNI extension', (done) => {
+      const original = tls.connect;
+
+      tls.connect = (options) => {
+        assert.strictEqual(options.servername, '');
+        tls.connect = original;
+        done();
+      };
+
+      const ws = new WebSocket('wss://127.0.0.1', { servername: '' });
+    });
+
+    it("works around a double 'error' event bug in Node.js", function (done) {
+      //
+      // The `minVersion` and `maxVersion` options are not supported in
+      // Node.js < 10.16.0.
+      //
+      if (process.versions.modules < 64) return this.skip();
+
+      //
+      // The `'error'` event can be emitted multiple times by the
+      // `http.ClientRequest` object in Node.js < 13. This test reproduces the
+      // issue in Node.js 12.
+      //
+      const server = https.createServer({
+        cert: fs.readFileSync('test/fixtures/certificate.pem'),
+        key: fs.readFileSync('test/fixtures/key.pem'),
+        minVersion: 'TLSv1.2'
+      });
+      const wss = new WebSocket.Server({ server });
+
+      server.listen(0, () => {
+        const ws = new WebSocket(`wss://localhost:${server.address().port}`, {
+          maxVersion: 'TLSv1.1',
+          rejectUnauthorized: false
+        });
+
+        ws.on('error', (err) => {
+          assert.ok(err instanceof Error);
+          server.close(done);
+          wss.close();
+        });
+      });
+    });
+  });
+
+  describe('Request headers', () => {
+    it('adds the authorization header if the url has userinfo', (done) => {
+      const agent = new CustomAgent();
+      const userinfo = 'test:testpass';
+
+      agent.addRequest = (req) => {
+        assert.strictEqual(
+          req.getHeader('authorization'),
+          `Basic ${Buffer.from(userinfo).toString('base64')}`
+        );
+        done();
+      };
+
+      const ws = new WebSocket(`ws://${userinfo}@localhost`, { agent });
+    });
+
+    it('honors the `auth` option', (done) => {
+      const agent = new CustomAgent();
+      const auth = 'user:pass';
+
+      agent.addRequest = (req) => {
+        assert.strictEqual(
+          req.getHeader('authorization'),
+          `Basic ${Buffer.from(auth).toString('base64')}`
+        );
+        done();
+      };
+
+      const ws = new WebSocket('ws://localhost', { agent, auth });
+    });
+
+    it('favors the url userinfo over the `auth` option', (done) => {
+      const agent = new CustomAgent();
+      const auth = 'foo:bar';
+      const userinfo = 'baz:qux';
+
+      agent.addRequest = (req) => {
+        assert.strictEqual(
+          req.getHeader('authorization'),
+          `Basic ${Buffer.from(userinfo).toString('base64')}`
+        );
+        done();
+      };
+
+      const ws = new WebSocket(`ws://${userinfo}@localhost`, { agent, auth });
+    });
+
+    it('adds custom headers', (done) => {
+      const agent = new CustomAgent();
+
+      agent.addRequest = (req) => {
+        assert.strictEqual(req.getHeader('cookie'), 'foo=bar');
+        done();
+      };
+
+      const ws = new WebSocket('ws://localhost', {
+        headers: { Cookie: 'foo=bar' },
+        agent
+      });
+    });
+
+    it('excludes default ports from host header', () => {
+      const options = { lookup() {} };
+      const variants = [
+        ['wss://localhost:8443', 'localhost:8443'],
+        ['wss://localhost:443', 'localhost'],
+        ['ws://localhost:88', 'localhost:88'],
+        ['ws://localhost:80', 'localhost']
+      ];
+
+      for (const [url, host] of variants) {
+        const ws = new WebSocket(url, options);
+        assert.strictEqual(ws._req.getHeader('host'), host);
+      }
+    });
+
+    it("doesn't add the origin header by default", (done) => {
+      const agent = new CustomAgent();
+
+      agent.addRequest = (req) => {
+        assert.strictEqual(req.getHeader('origin'), undefined);
+        done();
+      };
+
+      const ws = new WebSocket('ws://localhost', { agent });
+    });
+
+    it('honors the `origin` option (1/2)', (done) => {
+      const agent = new CustomAgent();
+
+      agent.addRequest = (req) => {
+        assert.strictEqual(req.getHeader('origin'), 'https://example.com:8000');
+        done();
+      };
+
+      const ws = new WebSocket('ws://localhost', {
+        origin: 'https://example.com:8000',
+        agent
+      });
+    });
+
+    it('honors the `origin` option (2/2)', (done) => {
+      const agent = new CustomAgent();
+
+      agent.addRequest = (req) => {
+        assert.strictEqual(
+          req.getHeader('sec-websocket-origin'),
+          'https://example.com:8000'
+        );
+        done();
+      };
+
+      const ws = new WebSocket('ws://localhost', {
+        origin: 'https://example.com:8000',
+        protocolVersion: 8,
+        agent
+      });
+    });
+  });
+
+  describe('permessage-deflate', () => {
+    it('is enabled by default', (done) => {
+      const agent = new CustomAgent();
+
+      agent.addRequest = (req) => {
+        assert.strictEqual(
+          req.getHeader('sec-websocket-extensions'),
+          'permessage-deflate; client_max_window_bits'
+        );
+        done();
+      };
+
+      const ws = new WebSocket('ws://localhost', { agent });
+    });
+
+    it('can be disabled', (done) => {
+      const agent = new CustomAgent();
+
+      agent.addRequest = (req) => {
+        assert.strictEqual(
+          req.getHeader('sec-websocket-extensions'),
+          undefined
+        );
+        done();
+      };
+
+      const ws = new WebSocket('ws://localhost', {
+        perMessageDeflate: false,
+        agent
+      });
+    });
+
+    it('can send extension parameters', (done) => {
+      const agent = new CustomAgent();
+
+      const value =
+        'permessage-deflate; server_no_context_takeover;' +
+        ' client_no_context_takeover; server_max_window_bits=10;' +
+        ' client_max_window_bits';
+
+      agent.addRequest = (req) => {
+        assert.strictEqual(req.getHeader('sec-websocket-extensions'), value);
+        done();
+      };
+
+      const ws = new WebSocket('ws://localhost', {
+        perMessageDeflate: {
+          clientNoContextTakeover: true,
+          serverNoContextTakeover: true,
+          clientMaxWindowBits: true,
+          serverMaxWindowBits: 10
+        },
+        agent
+      });
+    });
+
+    it('consumes all received data when connection is closed (1/2)', (done) => {
+      const wss = new WebSocket.Server(
+        {
+          perMessageDeflate: { threshold: 0 },
+          port: 0
+        },
+        () => {
+          const messages = [];
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          ws.on('open', () => {
+            ws._socket.on('close', () => {
+              assert.strictEqual(ws._receiver._state, 5);
+            });
+          });
+
+          ws.on('message', (message, isBinary) => {
+            assert.ok(!isBinary);
+            messages.push(message.toString());
+          });
+
+          ws.on('close', (code) => {
+            assert.strictEqual(code, 1006);
+            assert.deepStrictEqual(messages, ['foo', 'bar', 'baz', 'qux']);
+            wss.close(done);
+          });
+        }
+      );
+
+      wss.on('connection', (ws) => {
+        ws.send('foo');
+        ws.send('bar');
+        ws.send('baz');
+        ws.send('qux', () => ws._socket.end());
+      });
+    });
+
+    it('consumes all received data when connection is closed (2/2)', (done) => {
+      const wss = new WebSocket.Server(
+        {
+          perMessageDeflate: true,
+          port: 0
+        },
+        () => {
+          const messageLengths = [];
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+          ws.on('open', () => {
+            ws._socket.prependListener('close', () => {
+              assert.strictEqual(ws._receiver._state, 5);
+              assert.strictEqual(ws._socket._readableState.length, 3);
+            });
+
+            const push = ws._socket.push;
+
+            // Override `ws._socket.push()` to know exactly when data is
+            // received and call `ws.terminate()` immediately after that without
+            // relying on a timer.
+            ws._socket.push = (data) => {
+              ws._socket.push = push;
+              ws._socket.push(data);
+              ws.terminate();
+            };
+
+            const payload1 = Buffer.alloc(15 * 1024);
+            const payload2 = Buffer.alloc(1);
+
+            const opts = {
+              fin: true,
+              opcode: 0x02,
+              mask: false,
+              readOnly: false
+            };
+
+            const list = [
+              ...Sender.frame(payload1, { rsv1: false, ...opts }),
+              ...Sender.frame(payload2, { rsv1: true, ...opts })
+            ];
+
+            for (let i = 0; i < 399; i++) {
+              list.push(list[list.length - 2], list[list.length - 1]);
+            }
+
+            // This hack is used because there is no guarantee that more than
+            // 16 KiB will be sent as a single TCP packet.
+            push.call(ws._socket, Buffer.concat(list));
+
+            wss.clients
+              .values()
+              .next()
+              .value.send(payload2, { compress: false });
+          });
+
+          ws.on('message', (message, isBinary) => {
+            assert.ok(isBinary);
+            messageLengths.push(message.length);
+          });
+
+          ws.on('close', (code) => {
+            assert.strictEqual(code, 1006);
+            assert.strictEqual(messageLengths.length, 402);
+            assert.strictEqual(messageLengths[0], 15360);
+            assert.strictEqual(messageLengths[messageLengths.length - 1], 1);
+            wss.close(done);
+          });
+        }
+      );
+    });
+
+    it('handles a close frame received while compressing data', (done) => {
+      const wss = new WebSocket.Server(
+        {
+          perMessageDeflate: true,
+          port: 0
+        },
+        () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`, {
+            perMessageDeflate: { threshold: 0 }
+          });
+
+          ws.on('open', () => {
+            ws._receiver.on('conclude', () => {
+              assert.ok(ws._sender._deflating);
+            });
+
+            ws.send('foo');
+            ws.send('bar');
+            ws.send('baz');
+            ws.send('qux');
+          });
+        }
+      );
+
+      wss.on('connection', (ws) => {
+        const messages = [];
+
+        ws.on('message', (message, isBinary) => {
+          assert.ok(!isBinary);
+          messages.push(message.toString());
+        });
+
+        ws.on('close', (code, reason) => {
+          assert.deepStrictEqual(messages, ['foo', 'bar', 'baz', 'qux']);
+          assert.strictEqual(code, 1000);
+          assert.deepStrictEqual(reason, EMPTY_BUFFER);
+          wss.close(done);
+        });
+
+        ws.close(1000);
+      });
+    });
+
+    describe('#close', () => {
+      it('can be used while data is being decompressed', (done) => {
+        const wss = new WebSocket.Server(
+          {
+            perMessageDeflate: true,
+            port: 0
+          },
+          () => {
+            const messages = [];
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+            ws.on('open', () => {
+              ws._socket.on('end', () => {
+                assert.strictEqual(ws._receiver._state, 5);
+              });
+            });
+
+            ws.on('message', (message, isBinary) => {
+              assert.ok(!isBinary);
+
+              if (messages.push(message.toString()) > 1) return;
+
+              ws.close(1000);
+            });
+
+            ws.on('close', (code, reason) => {
+              assert.deepStrictEqual(messages, ['', '', '', '']);
+              assert.strictEqual(code, 1000);
+              assert.deepStrictEqual(reason, EMPTY_BUFFER);
+              wss.close(done);
+            });
+          }
+        );
+
+        wss.on('connection', (ws) => {
+          const buf = Buffer.from('c10100c10100c10100c10100', 'hex');
+          ws._socket.write(buf);
+        });
+      });
+    });
+
+    describe('#send', () => {
+      it('can send text data', (done) => {
+        const wss = new WebSocket.Server(
+          {
+            perMessageDeflate: { threshold: 0 },
+            port: 0
+          },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`, {
+              perMessageDeflate: { threshold: 0 }
+            });
+
+            ws.on('open', () => {
+              ws.send('hi', { compress: true });
+              ws.close();
+            });
+
+            ws.on('message', (message, isBinary) => {
+              assert.deepStrictEqual(message, Buffer.from('hi'));
+              assert.ok(!isBinary);
+              wss.close(done);
+            });
+          }
+        );
+
+        wss.on('connection', (ws) => {
+          ws.on('message', (message, isBinary) => {
+            ws.send(message, { binary: isBinary, compress: true });
+          });
+        });
+      });
+
+      it('can send a `TypedArray`', (done) => {
+        const array = new Float32Array(5);
+
+        for (let i = 0; i < array.length; i++) {
+          array[i] = i / 2;
+        }
+
+        const wss = new WebSocket.Server(
+          {
+            perMessageDeflate: { threshold: 0 },
+            port: 0
+          },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`, {
+              perMessageDeflate: { threshold: 0 }
+            });
+
+            ws.on('open', () => {
+              ws.send(array, { compress: true });
+              ws.close();
+            });
+
+            ws.on('message', (message, isBinary) => {
+              assert.deepStrictEqual(message, Buffer.from(array.buffer));
+              assert.ok(isBinary);
+              wss.close(done);
+            });
+          }
+        );
+
+        wss.on('connection', (ws) => {
+          ws.on('message', (message, isBinary) => {
+            assert.ok(isBinary);
+            ws.send(message, { compress: true });
+          });
+        });
+      });
+
+      it('can send an `ArrayBuffer`', (done) => {
+        const array = new Float32Array(5);
+
+        for (let i = 0; i < array.length; i++) {
+          array[i] = i / 2;
+        }
+
+        const wss = new WebSocket.Server(
+          {
+            perMessageDeflate: { threshold: 0 },
+            port: 0
+          },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`, {
+              perMessageDeflate: { threshold: 0 }
+            });
+
+            ws.on('open', () => {
+              ws.send(array.buffer, { compress: true });
+              ws.close();
+            });
+
+            ws.on('message', (message, isBinary) => {
+              assert.deepStrictEqual(message, Buffer.from(array.buffer));
+              assert.ok(isBinary);
+              wss.close(done);
+            });
+          }
+        );
+
+        wss.on('connection', (ws) => {
+          ws.on('message', (message, isBinary) => {
+            assert.ok(isBinary);
+            ws.send(message, { compress: true });
+          });
+        });
+      });
+
+      it('ignores the `compress` option if the extension is disabled', (done) => {
+        const wss = new WebSocket.Server({ port: 0 }, () => {
+          const ws = new WebSocket(`ws://localhost:${wss.address().port}`, {
+            perMessageDeflate: false
+          });
+
+          ws.on('open', () => {
+            ws.send('hi', { compress: true });
+            ws.close();
+          });
+
+          ws.on('message', (message, isBinary) => {
+            assert.deepStrictEqual(message, Buffer.from('hi'));
+            assert.ok(!isBinary);
+            wss.close(done);
+          });
+        });
+
+        wss.on('connection', (ws) => {
+          ws.on('message', (message, isBinary) => {
+            ws.send(message, { binary: isBinary, compress: true });
+          });
+        });
+      });
+
+      it('calls the callback if the socket is closed prematurely', (done) => {
+        const called = [];
+        const wss = new WebSocket.Server(
+          { perMessageDeflate: true, port: 0 },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`, {
+              perMessageDeflate: { threshold: 0 }
+            });
+
+            ws.on('open', () => {
+              ws.send('foo');
+              ws.send('bar', (err) => {
+                called.push(1);
+
+                assert.strictEqual(ws.readyState, WebSocket.CLOSING);
+                assert.ok(err instanceof Error);
+                assert.strictEqual(
+                  err.message,
+                  'The socket was closed while data was being compressed'
+                );
+              });
+              ws.send('baz');
+              ws.send('qux', (err) => {
+                called.push(2);
+
+                assert.strictEqual(ws.readyState, WebSocket.CLOSING);
+                assert.ok(err instanceof Error);
+                assert.strictEqual(
+                  err.message,
+                  'The socket was closed while data was being compressed'
+                );
+              });
+            });
+          }
+        );
+
+        wss.on('connection', (ws) => {
+          ws.on('close', () => {
+            assert.deepStrictEqual(called, [1, 2]);
+            wss.close(done);
+          });
+
+          ws._socket.end();
+        });
+      });
+    });
+
+    describe('#terminate', () => {
+      it('can be used while data is being compressed', (done) => {
+        const wss = new WebSocket.Server(
+          {
+            perMessageDeflate: { threshold: 0 },
+            port: 0
+          },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`, {
+              perMessageDeflate: { threshold: 0 }
+            });
+
+            ws.on('open', () => {
+              ws.send('hi', (err) => {
+                assert.strictEqual(ws.readyState, WebSocket.CLOSING);
+                assert.ok(err instanceof Error);
+                assert.strictEqual(
+                  err.message,
+                  'The socket was closed while data was being compressed'
+                );
+
+                ws.on('close', () => {
+                  wss.close(done);
+                });
+              });
+              ws.terminate();
+            });
+          }
+        );
+      });
+
+      it('can be used while data is being decompressed', (done) => {
+        const wss = new WebSocket.Server(
+          {
+            perMessageDeflate: true,
+            port: 0
+          },
+          () => {
+            const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+            const messages = [];
+
+            ws.on('message', (message, isBinary) => {
+              assert.ok(!isBinary);
+
+              if (messages.push(message.toString()) > 1) return;
+
+              process.nextTick(() => {
+                assert.strictEqual(ws._receiver._state, 5);
+                ws.terminate();
+              });
+            });
+
+            ws.on('close', (code, reason) => {
+              assert.deepStrictEqual(messages, ['', '', '', '']);
+              assert.strictEqual(code, 1006);
+              assert.strictEqual(reason, EMPTY_BUFFER);
+              wss.close(done);
+            });
+          }
+        );
+
+        wss.on('connection', (ws) => {
+          const buf = Buffer.from('c10100c10100c10100c10100', 'hex');
+          ws._socket.write(buf);
+        });
+      });
+    });
+  });
+
+  describe('Connection close', () => {
+    it('closes cleanly after simultaneous errors (1/2)', (done) => {
+      let clientCloseEventEmitted = false;
+      let serverClientCloseEventEmitted = false;
+
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('error', (err) => {
+          assert.ok(err instanceof RangeError);
+          assert.strictEqual(err.code, 'WS_ERR_INVALID_OPCODE');
+          assert.strictEqual(
+            err.message,
+            'Invalid WebSocket frame: invalid opcode 5'
+          );
+
+          ws.on('close', (code, reason) => {
+            assert.strictEqual(code, 1006);
+            assert.strictEqual(reason, EMPTY_BUFFER);
+
+            clientCloseEventEmitted = true;
+            if (serverClientCloseEventEmitted) wss.close(done);
+          });
+        });
+
+        ws.on('open', () => {
+          // Write an invalid frame in both directions to trigger simultaneous
+          // failure.
+          const chunk = Buffer.from([0x85, 0x00]);
+
+          wss.clients.values().next().value._socket.write(chunk);
+          ws._socket.write(chunk);
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('error', (err) => {
+          assert.ok(err instanceof RangeError);
+          assert.strictEqual(err.code, 'WS_ERR_INVALID_OPCODE');
+          assert.strictEqual(
+            err.message,
+            'Invalid WebSocket frame: invalid opcode 5'
+          );
+
+          ws.on('close', (code, reason) => {
+            assert.strictEqual(code, 1006);
+            assert.strictEqual(reason, EMPTY_BUFFER);
+
+            serverClientCloseEventEmitted = true;
+            if (clientCloseEventEmitted) wss.close(done);
+          });
+        });
+      });
+    });
+
+    it('closes cleanly after simultaneous errors (2/2)', (done) => {
+      let clientCloseEventEmitted = false;
+      let serverClientCloseEventEmitted = false;
+
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+
+        ws.on('error', (err) => {
+          assert.ok(err instanceof RangeError);
+          assert.strictEqual(err.code, 'WS_ERR_INVALID_OPCODE');
+          assert.strictEqual(
+            err.message,
+            'Invalid WebSocket frame: invalid opcode 5'
+          );
+
+          ws.on('close', (code, reason) => {
+            assert.strictEqual(code, 1006);
+            assert.strictEqual(reason, EMPTY_BUFFER);
+
+            clientCloseEventEmitted = true;
+            if (serverClientCloseEventEmitted) wss.close(done);
+          });
+        });
+
+        ws.on('open', () => {
+          // Write an invalid frame in both directions and change the
+          // `readyState` to `WebSocket.CLOSING`.
+          const chunk = Buffer.from([0x85, 0x00]);
+          const serverWs = wss.clients.values().next().value;
+
+          serverWs._socket.write(chunk);
+          serverWs.close();
+
+          ws._socket.write(chunk);
+          ws.close();
+        });
+      });
+
+      wss.on('connection', (ws) => {
+        ws.on('error', (err) => {
+          assert.ok(err instanceof RangeError);
+          assert.strictEqual(err.code, 'WS_ERR_INVALID_OPCODE');
+          assert.strictEqual(
+            err.message,
+            'Invalid WebSocket frame: invalid opcode 5'
+          );
+
+          ws.on('close', (code, reason) => {
+            assert.strictEqual(code, 1006);
+            assert.strictEqual(reason, EMPTY_BUFFER);
+
+            serverClientCloseEventEmitted = true;
+            if (clientCloseEventEmitted) wss.close(done);
+          });
+        });
+      });
+    });
+
+    it('resumes the socket when an error occurs', (done) => {
+      const maxPayload = 16 * 1024;
+      const wss = new WebSocket.Server({ maxPayload, port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+      });
+
+      wss.on('connection', (ws) => {
+        const list = [
+          ...Sender.frame(Buffer.alloc(maxPayload + 1), {
+            fin: true,
+            opcode: 0x02,
+            mask: true,
+            readOnly: false
+          })
+        ];
+
+        ws.on('error', (err) => {
+          assert.ok(err instanceof RangeError);
+          assert.strictEqual(err.code, 'WS_ERR_UNSUPPORTED_MESSAGE_LENGTH');
+          assert.strictEqual(err.message, 'Max payload size exceeded');
+
+          ws.on('close', (code, reason) => {
+            assert.strictEqual(code, 1006);
+            assert.strictEqual(reason, EMPTY_BUFFER);
+            wss.close(done);
+          });
+        });
+
+        ws._socket.push(Buffer.concat(list));
+      });
+    });
+
+    it('resumes the socket when the close frame is received', (done) => {
+      const wss = new WebSocket.Server({ port: 0 }, () => {
+        const ws = new WebSocket(`ws://localhost:${wss.address().port}`);
+      });
+
+      wss.on('connection', (ws) => {
+        const opts = { fin: true, mask: true, readOnly: false };
+        const list = [
+          ...Sender.frame(Buffer.alloc(16 * 1024), { opcode: 0x02, ...opts }),
+          ...Sender.frame(EMPTY_BUFFER, { opcode: 0x08, ...opts })
+        ];
+
+        ws.on('close', (code, reason) => {
+          assert.strictEqual(code, 1005);
+          assert.strictEqual(reason, EMPTY_BUFFER);
+          wss.close(done);
+        });
+
+        ws._socket.push(Buffer.concat(list));
+      });
+    });
+  });
+});
diff --git a/testing/xpcshell/node-ws/wrapper.mjs b/testing/xpcshell/node-ws/wrapper.mjs
new file mode 100644
index 0000000000..7245ad15d0
--- /dev/null
+++ b/testing/xpcshell/node-ws/wrapper.mjs
@@ -0,0 +1,8 @@
+import createWebSocketStream from './lib/stream.js';
+import Receiver from './lib/receiver.js';
+import Sender from './lib/sender.js';
+import WebSocket from './lib/websocket.js';
+import WebSocketServer from './lib/websocket-server.js';
+
+export { createWebSocketStream, Receiver, Sender, WebSocket, WebSocketServer };
+export default WebSocket;