Adding upstream version 115.8.0esr.upstream/115.8.0esr

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

21 files changed, 9303 insertions, 0 deletions

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));
+      });
+    });
+  });
+});