chore(release): 4.0.0

Diff: https://github.com/socketio/socket.io/compare/3.1.2...4.0.0
chore: include Engine.IO v5
2026-01-11 16:08:24 -05:00 · 2021-03-10 12:43:53 +01:00 · 2021-03-10 11:14:33 +01:00 · 2021-03-10 00:18:13 +01:00 · 2021-03-02 11:17:21 +01:00 · 2021-03-01 23:20:46 +01:00
19 changed files with 3018 additions and 286 deletions
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,19 @@
+# [4.0.0](https://github.com/socketio/socket.io/compare/3.1.2...4.0.0) (2021-03-10)
+
+
+### Bug Fixes
+
+* make io.to(...) immutable ([ac9e8ca](https://github.com/socketio/socket.io/commit/ac9e8ca6c71e00d4af45ee03f590fe56f3951186))
+
+
+### Features
+
+* add some utility methods ([b25495c](https://github.com/socketio/socket.io/commit/b25495c069031674da08e19aed68922c7c7a0e28))
+* add support for typed events ([#3822](https://github.com/socketio/socket.io/issues/3822)) ([0107510](https://github.com/socketio/socket.io/commit/0107510ba8a0f148c78029d8be8919b350feb633))
+* allow to exclude specific rooms when broadcasting ([#3789](https://github.com/socketio/socket.io/issues/3789)) ([7de2e87](https://github.com/socketio/socket.io/commit/7de2e87e888d849eb2dfc5e362af4c9e86044701))
+* allow to pass an array to io.to(...) ([085d1de](https://github.com/socketio/socket.io/commit/085d1de9df909651de8b313cc6f9f253374b702e))
+
+
 ## [3.1.2](https://github.com/socketio/socket.io/compare/3.1.1...3.1.2) (2021-02-26)


--- a/client-dist/socket.io.js
+++ b/client-dist/socket.io.js
@@ -1,5 +1,5 @@
 /*!
- * Socket.IO v3.1.2
+ * Socket.IO v4.0.0
 * (c) 2014-2021 Guillermo Rauch
 * Released under the MIT License.
 */
@@ -12,7 +12,7 @@
 		exports["io"] = factory();
 	else
 		root["io"] = factory();
-})(this, function() {
+})(self, function() {
 return /******/ (function(modules) { // webpackBootstrap
 /******/ 	// The module cache
 /******/ 	var installedModules = {};
@@ -236,10 +236,6 @@ function _defineProperties(target, props) { for (var i = 0; i < props.length; i+

 function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); return Constructor; }

-function _get(target, property, receiver) { if (typeof Reflect !== "undefined" && Reflect.get) { _get = Reflect.get; } else { _get = function _get(target, property, receiver) { var base = _superPropBase(target, property); if (!base) return; var desc = Object.getOwnPropertyDescriptor(base, property); if (desc.get) { return desc.get.call(receiver); } return desc.value; }; } return _get(target, property, receiver || target); }
-
-function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
-
 function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }

 function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
@@ -263,18 +259,18 @@ var eio = __webpack_require__(/*! engine.io-client */ "./node_modules/engine.io-

 var socket_1 = __webpack_require__(/*! ./socket */ "./build/socket.js");

-var Emitter = __webpack_require__(/*! component-emitter */ "./node_modules/component-emitter/index.js");
-
 var parser = __webpack_require__(/*! socket.io-parser */ "./node_modules/socket.io-parser/dist/index.js");

 var on_1 = __webpack_require__(/*! ./on */ "./build/on.js");

 var Backoff = __webpack_require__(/*! backo2 */ "./node_modules/backo2/index.js");

+var typed_events_1 = __webpack_require__(/*! ./typed-events */ "./build/typed-events.js");
+
 var debug = __webpack_require__(/*! debug */ "./node_modules/debug/src/browser.js")("socket.io-client:manager");

-var Manager = /*#__PURE__*/function (_Emitter) {
-  _inherits(Manager, _Emitter);
+var Manager = /*#__PURE__*/function (_typed_events_1$Stric) {
+  _inherits(Manager, _typed_events_1$Stric);

  var _super = _createSuper(Manager);

@@ -425,7 +421,7 @@ var Manager = /*#__PURE__*/function (_Emitter) {
        self.cleanup();
        self._readyState = "closed";

-        _get(_getPrototypeOf(Manager.prototype), "emit", _this2).call(_this2, "error", err);
+        _this2.emitReserved("error", err);

        if (fn) {
          fn(err);
@@ -450,6 +446,11 @@ var Manager = /*#__PURE__*/function (_Emitter) {
          socket.close();
          socket.emit("error", new Error("timeout"));
        }, timeout);
+
+        if (this.opts.autoUnref) {
+          timer.unref();
+        }
+
        this.subs.push(function subDestroy() {
          clearTimeout(timer);
        });
@@ -485,9 +486,7 @@ var Manager = /*#__PURE__*/function (_Emitter) {
      this.cleanup(); // mark as open

      this._readyState = "open";
-
-      _get(_getPrototypeOf(Manager.prototype), "emit", this).call(this, "open"); // add new subs
-
+      this.emitReserved("open"); // add new subs

      var socket = this.engine;
      this.subs.push(on_1.on(socket, "ping", this.onping.bind(this)), on_1.on(socket, "data", this.ondata.bind(this)), on_1.on(socket, "error", this.onerror.bind(this)), on_1.on(socket, "close", this.onclose.bind(this)), on_1.on(this.decoder, "decoded", this.ondecoded.bind(this)));
@@ -501,7 +500,7 @@ var Manager = /*#__PURE__*/function (_Emitter) {
  }, {
    key: "onping",
    value: function onping() {
-      _get(_getPrototypeOf(Manager.prototype), "emit", this).call(this, "ping");
+      this.emitReserved("ping");
    }
    /**
     * Called with data.
@@ -523,7 +522,7 @@ var Manager = /*#__PURE__*/function (_Emitter) {
  }, {
    key: "ondecoded",
    value: function ondecoded(packet) {
-      _get(_getPrototypeOf(Manager.prototype), "emit", this).call(this, "packet", packet);
+      this.emitReserved("packet", packet);
    }
    /**
     * Called upon socket error.
@@ -535,8 +534,7 @@ var Manager = /*#__PURE__*/function (_Emitter) {
    key: "onerror",
    value: function onerror(err) {
      debug("error", err);
-
-      _get(_getPrototypeOf(Manager.prototype), "emit", this).call(this, "error", err);
+      this.emitReserved("error", err);
    }
    /**
     * Creates a new socket for the given `nsp`.
@@ -661,8 +659,7 @@ var Manager = /*#__PURE__*/function (_Emitter) {
      this.cleanup();
      this.backoff.reset();
      this._readyState = "closed";
-
-      _get(_getPrototypeOf(Manager.prototype), "emit", this).call(this, "close", reason);
+      this.emitReserved("close", reason);

      if (this._reconnection && !this.skipReconnect) {
        this.reconnect();
@@ -685,9 +682,7 @@ var Manager = /*#__PURE__*/function (_Emitter) {
      if (this.backoff.attempts >= this._reconnectionAttempts) {
        debug("reconnect failed");
        this.backoff.reset();
-
-        _get(_getPrototypeOf(Manager.prototype), "emit", this).call(this, "reconnect_failed");
-
+        this.emitReserved("reconnect_failed");
        this._reconnecting = false;
      } else {
        var delay = this.backoff.duration();
@@ -697,7 +692,7 @@ var Manager = /*#__PURE__*/function (_Emitter) {
          if (self.skipReconnect) return;
          debug("attempting reconnect");

-          _get(_getPrototypeOf(Manager.prototype), "emit", _this3).call(_this3, "reconnect_attempt", self.backoff.attempts); // check again for the case socket closed in above events
+          _this3.emitReserved("reconnect_attempt", self.backoff.attempts); // check again for the case socket closed in above events


          if (self.skipReconnect) return;
@@ -707,13 +702,18 @@ var Manager = /*#__PURE__*/function (_Emitter) {
              self._reconnecting = false;
              self.reconnect();

-              _get(_getPrototypeOf(Manager.prototype), "emit", _this3).call(_this3, "reconnect_error", err);
+              _this3.emitReserved("reconnect_error", err);
            } else {
              debug("reconnect success");
              self.onreconnect();
            }
          });
        }, delay);
+
+        if (this.opts.autoUnref) {
+          timer.unref();
+        }
+
        this.subs.push(function subDestroy() {
          clearTimeout(timer);
        });
@@ -731,13 +731,12 @@ var Manager = /*#__PURE__*/function (_Emitter) {
      var attempt = this.backoff.attempts;
      this._reconnecting = false;
      this.backoff.reset();
-
-      _get(_getPrototypeOf(Manager.prototype), "emit", this).call(this, "reconnect", attempt);
+      this.emitReserved("reconnect", attempt);
    }
  }]);

  return Manager;
-}(Emitter);
+}(typed_events_1.StrictEventEmitter);

 exports.Manager = Manager;

@@ -818,10 +817,10 @@ exports.Socket = void 0;

 var socket_io_parser_1 = __webpack_require__(/*! socket.io-parser */ "./node_modules/socket.io-parser/dist/index.js");

-var Emitter = __webpack_require__(/*! component-emitter */ "./node_modules/component-emitter/index.js");
-
 var on_1 = __webpack_require__(/*! ./on */ "./build/on.js");

+var typed_events_1 = __webpack_require__(/*! ./typed-events */ "./build/typed-events.js");
+
 var debug = __webpack_require__(/*! debug */ "./node_modules/debug/src/browser.js")("socket.io-client:socket");
 /**
 * Internal events.
@@ -839,8 +838,8 @@ var RESERVED_EVENTS = Object.freeze({
  removeListener: 1
 });

-var Socket = /*#__PURE__*/function (_Emitter) {
-  _inherits(Socket, _Emitter);
+var Socket = /*#__PURE__*/function (_typed_events_1$Stric) {
+  _inherits(Socket, _typed_events_1$Stric);

  var _super = _createSuper(Socket);

@@ -942,7 +941,6 @@ var Socket = /*#__PURE__*/function (_Emitter) {
     * Override `emit`.
     * If the event is in `events`, it's emitted normally.
     *
-     * @param ev - event name
     * @return self
     * @public
     */
@@ -1038,7 +1036,7 @@ var Socket = /*#__PURE__*/function (_Emitter) {
    key: "onerror",
    value: function onerror(err) {
      if (!this.connected) {
-        _get(_getPrototypeOf(Socket.prototype), "emit", this).call(this, "connect_error", err);
+        this.emitReserved("connect_error", err);
      }
    }
    /**
@@ -1055,8 +1053,7 @@ var Socket = /*#__PURE__*/function (_Emitter) {
      this.connected = false;
      this.disconnected = true;
      delete this.id;
-
-      _get(_getPrototypeOf(Socket.prototype), "emit", this).call(this, "disconnect", reason);
+      this.emitReserved("disconnect", reason);
    }
    /**
     * Called with socket packet.
@@ -1077,7 +1074,7 @@ var Socket = /*#__PURE__*/function (_Emitter) {
            var id = packet.data.sid;
            this.onconnect(id);
          } else {
-            _get(_getPrototypeOf(Socket.prototype), "emit", this).call(this, "connect_error", new Error("It seems you are trying to reach a Socket.IO server in v2.x with a v3.x client, but they are not compatible (more information here: https://socket.io/docs/v3/migrating-from-2-x-to-3-0/)"));
+            this.emitReserved("connect_error", new Error("It seems you are trying to reach a Socket.IO server in v2.x with a v3.x client, but they are not compatible (more information here: https://socket.io/docs/v3/migrating-from-2-x-to-3-0/)"));
          }

          break;
@@ -1106,9 +1103,7 @@ var Socket = /*#__PURE__*/function (_Emitter) {
          var err = new Error(packet.data.message); // @ts-ignore

          err.data = packet.data.data;
-
-          _get(_getPrototypeOf(Socket.prototype), "emit", this).call(this, "connect_error", err);
-
+          this.emitReserved("connect_error", err);
          break;
      }
    }
@@ -1220,9 +1215,7 @@ var Socket = /*#__PURE__*/function (_Emitter) {
      this.id = id;
      this.connected = true;
      this.disconnected = false;
-
-      _get(_getPrototypeOf(Socket.prototype), "emit", this).call(this, "connect");
-
+      this.emitReserved("connect");
      this.emitBuffered();
    }
    /**
@@ -1429,12 +1422,172 @@ var Socket = /*#__PURE__*/function (_Emitter) {
  }]);

  return Socket;
-}(Emitter);
+}(typed_events_1.StrictEventEmitter);

 exports.Socket = Socket;

 /***/ }),

+/***/ "./build/typed-events.js":
+/*!*******************************!*\
+  !*** ./build/typed-events.js ***!
+  \*******************************/
+/*! no static exports found */
+/***/ (function(module, exports, __webpack_require__) {
+
+"use strict";
+
+
+function _typeof(obj) { "@babel/helpers - typeof"; if (typeof Symbol === "function" && typeof Symbol.iterator === "symbol") { _typeof = function _typeof(obj) { return typeof obj; }; } else { _typeof = function _typeof(obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; }; } return _typeof(obj); }
+
+function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
+
+function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }
+
+function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); return Constructor; }
+
+function _get(target, property, receiver) { if (typeof Reflect !== "undefined" && Reflect.get) { _get = Reflect.get; } else { _get = function _get(target, property, receiver) { var base = _superPropBase(target, property); if (!base) return; var desc = Object.getOwnPropertyDescriptor(base, property); if (desc.get) { return desc.get.call(receiver); } return desc.value; }; } return _get(target, property, receiver || target); }
+
+function _superPropBase(object, property) { while (!Object.prototype.hasOwnProperty.call(object, property)) { object = _getPrototypeOf(object); if (object === null) break; } return object; }
+
+function _inherits(subClass, superClass) { if (typeof superClass !== "function" && superClass !== null) { throw new TypeError("Super expression must either be null or a function"); } subClass.prototype = Object.create(superClass && superClass.prototype, { constructor: { value: subClass, writable: true, configurable: true } }); if (superClass) _setPrototypeOf(subClass, superClass); }
+
+function _setPrototypeOf(o, p) { _setPrototypeOf = Object.setPrototypeOf || function _setPrototypeOf(o, p) { o.__proto__ = p; return o; }; return _setPrototypeOf(o, p); }
+
+function _createSuper(Derived) { var hasNativeReflectConstruct = _isNativeReflectConstruct(); return function _createSuperInternal() { var Super = _getPrototypeOf(Derived), result; if (hasNativeReflectConstruct) { var NewTarget = _getPrototypeOf(this).constructor; result = Reflect.construct(Super, arguments, NewTarget); } else { result = Super.apply(this, arguments); } return _possibleConstructorReturn(this, result); }; }
+
+function _possibleConstructorReturn(self, call) { if (call && (_typeof(call) === "object" || typeof call === "function")) { return call; } return _assertThisInitialized(self); }
+
+function _assertThisInitialized(self) { if (self === void 0) { throw new ReferenceError("this hasn't been initialised - super() hasn't been called"); } return self; }
+
+function _isNativeReflectConstruct() { if (typeof Reflect === "undefined" || !Reflect.construct) return false; if (Reflect.construct.sham) return false; if (typeof Proxy === "function") return true; try { Date.prototype.toString.call(Reflect.construct(Date, [], function () {})); return true; } catch (e) { return false; } }
+
+function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__ || Object.getPrototypeOf(o); }; return _getPrototypeOf(o); }
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+exports.StrictEventEmitter = void 0;
+
+var Emitter = __webpack_require__(/*! component-emitter */ "./node_modules/component-emitter/index.js");
+/**
+ * Strictly typed version of an `EventEmitter`. A `TypedEventEmitter` takes type
+ * parameters for mappings of event names to event data types, and strictly
+ * types method calls to the `EventEmitter` according to these event maps.
+ *
+ * @typeParam ListenEvents - `EventsMap` of user-defined events that can be
+ * listened to with `on` or `once`
+ * @typeParam EmitEvents - `EventsMap` of user-defined events that can be
+ * emitted with `emit`
+ * @typeParam ReservedEvents - `EventsMap` of reserved events, that can be
+ * emitted by socket.io with `emitReserved`, and can be listened to with
+ * `listen`.
+ */
+
+
+var StrictEventEmitter = /*#__PURE__*/function (_Emitter) {
+  _inherits(StrictEventEmitter, _Emitter);
+
+  var _super = _createSuper(StrictEventEmitter);
+
+  function StrictEventEmitter() {
+    _classCallCheck(this, StrictEventEmitter);
+
+    return _super.apply(this, arguments);
+  }
+
+  _createClass(StrictEventEmitter, [{
+    key: "on",
+
+    /**
+     * Adds the `listener` function as an event listener for `ev`.
+     *
+     * @param ev Name of the event
+     * @param listener Callback function
+     */
+    value: function on(ev, listener) {
+      _get(_getPrototypeOf(StrictEventEmitter.prototype), "on", this).call(this, ev, listener);
+
+      return this;
+    }
+    /**
+     * Adds a one-time `listener` function as an event listener for `ev`.
+     *
+     * @param ev Name of the event
+     * @param listener Callback function
+     */
+
+  }, {
+    key: "once",
+    value: function once(ev, listener) {
+      _get(_getPrototypeOf(StrictEventEmitter.prototype), "once", this).call(this, ev, listener);
+
+      return this;
+    }
+    /**
+     * Emits an event.
+     *
+     * @param ev Name of the event
+     * @param args Values to send to listeners of this event
+     */
+
+  }, {
+    key: "emit",
+    value: function emit(ev) {
+      var _get2;
+
+      for (var _len = arguments.length, args = new Array(_len > 1 ? _len - 1 : 0), _key = 1; _key < _len; _key++) {
+        args[_key - 1] = arguments[_key];
+      }
+
+      (_get2 = _get(_getPrototypeOf(StrictEventEmitter.prototype), "emit", this)).call.apply(_get2, [this, ev].concat(args));
+
+      return this;
+    }
+    /**
+     * Emits a reserved event.
+     *
+     * This method is `protected`, so that only a class extending
+     * `StrictEventEmitter` can emit its own reserved events.
+     *
+     * @param ev Reserved event name
+     * @param args Arguments to emit along with the event
+     */
+
+  }, {
+    key: "emitReserved",
+    value: function emitReserved(ev) {
+      var _get3;
+
+      for (var _len2 = arguments.length, args = new Array(_len2 > 1 ? _len2 - 1 : 0), _key2 = 1; _key2 < _len2; _key2++) {
+        args[_key2 - 1] = arguments[_key2];
+      }
+
+      (_get3 = _get(_getPrototypeOf(StrictEventEmitter.prototype), "emit", this)).call.apply(_get3, [this, ev].concat(args));
+
+      return this;
+    }
+    /**
+     * Returns the listeners listening to an event.
+     *
+     * @param event Event name
+     * @returns Array of listeners subscribed to `event`
+     */
+
+  }, {
+    key: "listeners",
+    value: function listeners(event) {
+      return _get(_getPrototypeOf(StrictEventEmitter.prototype), "listeners", this).call(this, event);
+    }
+  }]);
+
+  return StrictEventEmitter;
+}(Emitter);
+
+exports.StrictEventEmitter = StrictEventEmitter;
+
+/***/ }),
+
 /***/ "./build/url.js":
 /*!**********************!*\
  !*** ./build/url.js ***!
@@ -2442,6 +2595,14 @@ var Socket = /*#__PURE__*/function (_Emitter) {
          _this.transport.close();
        }
      }, false);
+
+      if (_this.hostname !== "localhost") {
+        _this.offlineEventListener = function () {
+          _this.onClose("transport close");
+        };
+
+        addEventListener("offline", _this.offlineEventListener, false);
+      }
    }

    _this.open();
@@ -2765,6 +2926,10 @@ var Socket = /*#__PURE__*/function (_Emitter) {
      this.pingTimeoutTimer = setTimeout(function () {
        _this2.onClose("ping timeout");
      }, this.pingInterval + this.pingTimeout);
+
+      if (this.opts.autoUnref) {
+        this.pingTimeoutTimer.unref();
+      }
    }
    /**
     * Called on `drain` event
@@ -2949,7 +3114,12 @@ var Socket = /*#__PURE__*/function (_Emitter) {

        this.transport.close(); // ignore further transport communication

-        this.transport.removeAllListeners(); // set ready state
+        this.transport.removeAllListeners();
+
+        if (typeof removeEventListener === "function") {
+          removeEventListener("offline", this.offlineEventListener, false);
+        } // set ready state
+

        this.readyState = "closed"; // clear session id

@@ -3198,7 +3368,7 @@ module.exports = Transport;
 /*! no static exports found */
 /***/ (function(module, exports, __webpack_require__) {

-var XMLHttpRequest = __webpack_require__(/*! xmlhttprequest-ssl */ "./node_modules/engine.io-client/lib/xmlhttprequest.js");
+var XMLHttpRequest = __webpack_require__(/*! ../../contrib/xmlhttprequest-ssl/XMLHttpRequest */ "./node_modules/engine.io-client/lib/xmlhttprequest.js");

 var XHR = __webpack_require__(/*! ./polling-xhr */ "./node_modules/engine.io-client/lib/transports/polling-xhr.js");

@@ -3531,7 +3701,7 @@ function _isNativeReflectConstruct() { if (typeof Reflect === "undefined" || !Re
 function _getPrototypeOf(o) { _getPrototypeOf = Object.setPrototypeOf ? Object.getPrototypeOf : function _getPrototypeOf(o) { return o.__proto__ || Object.getPrototypeOf(o); }; return _getPrototypeOf(o); }

 /* global attachEvent */
-var XMLHttpRequest = __webpack_require__(/*! xmlhttprequest-ssl */ "./node_modules/engine.io-client/lib/xmlhttprequest.js");
+var XMLHttpRequest = __webpack_require__(/*! ../../contrib/xmlhttprequest-ssl/XMLHttpRequest */ "./node_modules/engine.io-client/lib/xmlhttprequest.js");

 var Polling = __webpack_require__(/*! ./polling */ "./node_modules/engine.io-client/lib/transports/polling.js");

@@ -3698,7 +3868,7 @@ var Request = /*#__PURE__*/function (_Emitter) {
  _createClass(Request, [{
    key: "create",
    value: function create() {
-      var opts = pick(this.opts, "agent", "enablesXDR", "pfx", "key", "passphrase", "cert", "ca", "ciphers", "rejectUnauthorized");
+      var opts = pick(this.opts, "agent", "enablesXDR", "pfx", "key", "passphrase", "cert", "ca", "ciphers", "rejectUnauthorized", "autoUnref");
      opts.xdomain = !!this.opts.xd;
      opts.xscheme = !!this.opts.xs;
      var xhr = this.xhr = new XMLHttpRequest(opts);
@@ -4321,22 +4491,24 @@ var WS = /*#__PURE__*/function (_Transport) {
  }, {
    key: "addEventListeners",
    value: function addEventListeners() {
-      var self = this;
+      var _this2 = this;

      this.ws.onopen = function () {
-        self.onOpen();
+        if (_this2.opts.autoUnref) {
+          _this2.ws._socket.unref();
+        }
+
+        _this2.onOpen();
      };

-      this.ws.onclose = function () {
-        self.onClose();
-      };
+      this.ws.onclose = this.onClose.bind(this);

      this.ws.onmessage = function (ev) {
-        self.onData(ev.data);
+        return _this2.onData(ev.data);
      };

      this.ws.onerror = function (e) {
-        self.onError("websocket error", e);
+        return _this2.onError("websocket error", e);
      };
    }
    /**
--- a/client-dist/socket.io.js.map
+++ b/client-dist/socket.io.js.map
--- a/client-dist/socket.io.min.js
+++ b/client-dist/socket.io.min.js
--- a/client-dist/socket.io.min.js.map
+++ b/client-dist/socket.io.min.js.map
--- a/client-dist/socket.io.msgpack.min.js
+++ b/client-dist/socket.io.msgpack.min.js
--- a/client-dist/socket.io.msgpack.min.js.map
+++ b/client-dist/socket.io.msgpack.min.js.map
--- a/lib/broadcast-operator.ts
+++ b/lib/broadcast-operator.ts
@@ -0,0 +1,315 @@
+import type { BroadcastFlags, Room, SocketId } from "socket.io-adapter";
+import { Handshake, RESERVED_EVENTS, Socket } from "./socket";
+import { PacketType } from "socket.io-parser";
+import type { Adapter } from "socket.io-adapter";
+import type {
+  EventParams,
+  EventNames,
+  EventsMap,
+  TypedEventBroadcaster,
+} from "./typed-events";
+
+export class BroadcastOperator<EmitEvents extends EventsMap>
+  implements TypedEventBroadcaster<EmitEvents> {
+  constructor(
+    private readonly adapter: Adapter,
+    private readonly rooms: Set<Room> = new Set<Room>(),
+    private readonly exceptRooms: Set<Room> = new Set<Room>(),
+    private readonly flags: BroadcastFlags = {}
+  ) {}
+
+  /**
+   * Targets a room when emitting.
+   *
+   * @param room
+   * @return a new BroadcastOperator instance
+   * @public
+   */
+  public to(room: Room | Room[]): BroadcastOperator<EmitEvents> {
+    const rooms = new Set(this.rooms);
+    if (Array.isArray(room)) {
+      room.forEach((r) => rooms.add(r));
+    } else {
+      rooms.add(room);
+    }
+    return new BroadcastOperator(
+      this.adapter,
+      rooms,
+      this.exceptRooms,
+      this.flags
+    );
+  }
+
+  /**
+   * Targets a room when emitting.
+   *
+   * @param room
+   * @return a new BroadcastOperator instance
+   * @public
+   */
+  public in(room: Room | Room[]): BroadcastOperator<EmitEvents> {
+    return this.to(room);
+  }
+
+  /**
+   * Excludes a room when emitting.
+   *
+   * @param room
+   * @return a new BroadcastOperator instance
+   * @public
+   */
+  public except(room: Room | Room[]): BroadcastOperator<EmitEvents> {
+    const exceptRooms = new Set(this.exceptRooms);
+    if (Array.isArray(room)) {
+      room.forEach((r) => exceptRooms.add(r));
+    } else {
+      exceptRooms.add(room);
+    }
+    return new BroadcastOperator(
+      this.adapter,
+      this.rooms,
+      exceptRooms,
+      this.flags
+    );
+  }
+
+  /**
+   * Sets the compress flag.
+   *
+   * @param compress - if `true`, compresses the sending data
+   * @return a new BroadcastOperator instance
+   * @public
+   */
+  public compress(compress: boolean): BroadcastOperator<EmitEvents> {
+    const flags = Object.assign({}, this.flags, { compress });
+    return new BroadcastOperator(
+      this.adapter,
+      this.rooms,
+      this.exceptRooms,
+      flags
+    );
+  }
+
+  /**
+   * Sets a modifier for a subsequent event emission that the event data may be lost if the client is not ready to
+   * receive messages (because of network slowness or other issues, or because they’re connected through long polling
+   * and is in the middle of a request-response cycle).
+   *
+   * @return a new BroadcastOperator instance
+   * @public
+   */
+  public get volatile(): BroadcastOperator<EmitEvents> {
+    const flags = Object.assign({}, this.flags, { volatile: true });
+    return new BroadcastOperator(
+      this.adapter,
+      this.rooms,
+      this.exceptRooms,
+      flags
+    );
+  }
+
+  /**
+   * Sets a modifier for a subsequent event emission that the event data will only be broadcast to the current node.
+   *
+   * @return a new BroadcastOperator instance
+   * @public
+   */
+  public get local(): BroadcastOperator<EmitEvents> {
+    const flags = Object.assign({}, this.flags, { local: true });
+    return new BroadcastOperator(
+      this.adapter,
+      this.rooms,
+      this.exceptRooms,
+      flags
+    );
+  }
+
+  /**
+   * Emits to all clients.
+   *
+   * @return Always true
+   * @public
+   */
+  public emit<Ev extends EventNames<EmitEvents>>(
+    ev: Ev,
+    ...args: EventParams<EmitEvents, Ev>
+  ): true {
+    if (RESERVED_EVENTS.has(ev)) {
+      throw new Error(`"${ev}" is a reserved event name`);
+    }
+    // set up packet object
+    const data = [ev, ...args];
+    const packet = {
+      type: PacketType.EVENT,
+      data: data,
+    };
+
+    if ("function" == typeof data[data.length - 1]) {
+      throw new Error("Callbacks are not supported when broadcasting");
+    }
+
+    this.adapter.broadcast(packet, {
+      rooms: this.rooms,
+      except: this.exceptRooms,
+      flags: this.flags,
+    });
+
+    return true;
+  }
+
+  /**
+   * Gets a list of clients.
+   *
+   * @public
+   */
+  public allSockets(): Promise<Set<SocketId>> {
+    if (!this.adapter) {
+      throw new Error(
+        "No adapter for this namespace, are you trying to get the list of clients of a dynamic namespace?"
+      );
+    }
+    return this.adapter.sockets(this.rooms);
+  }
+
+  /**
+   * Returns the matching socket instances
+   *
+   * @public
+   */
+  public fetchSockets(): Promise<RemoteSocket<EmitEvents>[]> {
+    return this.adapter
+      .fetchSockets({
+        rooms: this.rooms,
+        except: this.exceptRooms,
+      })
+      .then((sockets) => {
+        return sockets.map((socket) => {
+          if (socket instanceof Socket) {
+            // FIXME the TypeScript compiler complains about missing private properties
+            return (socket as unknown) as RemoteSocket<EmitEvents>;
+          } else {
+            return new RemoteSocket(this.adapter, socket as SocketDetails);
+          }
+        });
+      });
+  }
+
+  /**
+   * Makes the matching socket instances join the specified rooms
+   *
+   * @param room
+   * @public
+   */
+  public socketsJoin(room: Room | Room[]): void {
+    this.adapter.addSockets(
+      {
+        rooms: this.rooms,
+        except: this.exceptRooms,
+      },
+      Array.isArray(room) ? room : [room]
+    );
+  }
+
+  /**
+   * Makes the matching socket instances leave the specified rooms
+   *
+   * @param room
+   * @public
+   */
+  public socketsLeave(room: Room | Room[]): void {
+    this.adapter.delSockets(
+      {
+        rooms: this.rooms,
+        except: this.exceptRooms,
+      },
+      Array.isArray(room) ? room : [room]
+    );
+  }
+
+  /**
+   * Makes the matching socket instances disconnect
+   *
+   * @param close - whether to close the underlying connection
+   * @public
+   */
+  public disconnectSockets(close: boolean = false): void {
+    this.adapter.disconnectSockets(
+      {
+        rooms: this.rooms,
+        except: this.exceptRooms,
+      },
+      close
+    );
+  }
+}
+
+/**
+ * Format of the data when the Socket instance exists on another Socket.IO server
+ */
+interface SocketDetails {
+  id: SocketId;
+  handshake: Handshake;
+  rooms: Room[];
+  data: any;
+}
+
+/**
+ * Expose of subset of the attributes and methods of the Socket class
+ */
+export class RemoteSocket<EmitEvents extends EventsMap>
+  implements TypedEventBroadcaster<EmitEvents> {
+  public readonly id: SocketId;
+  public readonly handshake: Handshake;
+  public readonly rooms: Set<Room>;
+  public readonly data: any;
+
+  private readonly operator: BroadcastOperator<EmitEvents>;
+
+  constructor(adapter: Adapter, details: SocketDetails) {
+    this.id = details.id;
+    this.handshake = details.handshake;
+    this.rooms = new Set(details.rooms);
+    this.data = details.data;
+    this.operator = new BroadcastOperator(adapter, new Set([this.id]));
+  }
+
+  public emit<Ev extends EventNames<EmitEvents>>(
+    ev: Ev,
+    ...args: EventParams<EmitEvents, Ev>
+  ): true {
+    return this.operator.emit(ev, ...args);
+  }
+
+  /**
+   * Joins a room.
+   *
+   * @param {String|Array} room - room or array of rooms
+   * @public
+   */
+  public join(room: Room | Room[]): void {
+    return this.operator.socketsJoin(room);
+  }
+
+  /**
+   * Leaves a room.
+   *
+   * @param {String} room
+   * @public
+   */
+  public leave(room: Room): void {
+    return this.operator.socketsLeave(room);
+  }
+
+  /**
+   * Disconnects this client.
+   *
+   * @param {Boolean} close - if `true`, closes the underlying connection
+   * @return {Socket} self
+   *
+   * @public
+   */
+  public disconnect(close = false): this {
+    this.operator.disconnectSockets(close);
+    return this;
+  }
+}
--- a/lib/client.ts
+++ b/lib/client.ts
@@ -3,20 +3,24 @@ import debugModule = require("debug");
 import url = require("url");
 import type { IncomingMessage } from "http";
 import type { Namespace, Server } from "./index";
+import type { EventsMap } from "./typed-events";
 import type { Socket } from "./socket";
 import type { SocketId } from "socket.io-adapter";

 const debug = debugModule("socket.io:client");

-export class Client {
+export class Client<
+  ListenEvents extends EventsMap,
+  EmitEvents extends EventsMap
+> {
  public readonly conn;

  private readonly id: string;
-  private readonly server: Server;
+  private readonly server: Server<ListenEvents, EmitEvents>;
  private readonly encoder: Encoder;
  private readonly decoder: Decoder;
-  private sockets: Map<SocketId, Socket> = new Map();
-  private nsps: Map<string, Socket> = new Map();
+  private sockets: Map<SocketId, Socket<ListenEvents, EmitEvents>> = new Map();
+  private nsps: Map<string, Socket<ListenEvents, EmitEvents>> = new Map();
  private connectTimeout?: NodeJS.Timeout;

  /**
@@ -26,7 +30,7 @@ export class Client {
   * @param conn
   * @package
   */
-  constructor(server: Server, conn: Socket) {
+  constructor(server: Server<ListenEvents, EmitEvents>, conn: any) {
    this.server = server;
    this.conn = conn;
    this.encoder = server.encoder;
@@ -87,7 +91,7 @@ export class Client {
    this.server._checkNamespace(
      name,
      auth,
-      (dynamicNspName: Namespace | false) => {
+      (dynamicNspName: Namespace<ListenEvents, EmitEvents> | false) => {
        if (dynamicNspName) {
          debug("dynamic namespace %s was created", dynamicNspName);
          this.doConnect(name, auth);
@@ -145,7 +149,7 @@ export class Client {
   *
   * @private
   */
-  _remove(socket: Socket): void {
+  _remove(socket: Socket<ListenEvents, EmitEvents>): void {
    if (this.sockets.has(socket.id)) {
      const nsp = this.sockets.get(socket.id)!.nsp.name;
      this.sockets.delete(socket.id);
--- a/lib/index.ts
+++ b/lib/index.ts
@@ -7,7 +7,11 @@ import path = require("path");
 import engine = require("engine.io");
 import { Client } from "./client";
 import { EventEmitter } from "events";
-import { ExtendedError, Namespace } from "./namespace";
+import {
+  ExtendedError,
+  Namespace,
+  NamespaceReservedEventsMap,
+} from "./namespace";
 import { ParentNamespace } from "./parent-namespace";
 import { Adapter, Room, SocketId } from "socket.io-adapter";
 import * as parser from "socket.io-parser";
@@ -16,6 +20,13 @@ import debugModule from "debug";
 import { Socket } from "./socket";
 import type { CookieSerializeOptions } from "cookie";
 import type { CorsOptions } from "cors";
+import type { BroadcastOperator, RemoteSocket } from "./broadcast-operator";
+import {
+  EventsMap,
+  DefaultEventsMap,
+  EventParams,
+  StrictEventEmitter,
+} from "./typed-events";

 const debug = debugModule("socket.io:server");

@@ -32,7 +43,7 @@ type ParentNspNameMatchFn = (
 interface EngineOptions {
  /**
   * how many ms without a pong packet to consider the connection closed
-   * @default 5000
+   * @default 20000
   */
  pingTimeout: number;
  /**
@@ -82,10 +93,12 @@ interface EngineOptions {
  httpCompression: boolean | object;
  /**
   * what WebSocket server implementation to use. Specified module must
-   * conform to the ws interface (see ws module api docs). Default value is ws.
-   * An alternative c++ addon is also available by installing uws module.
+   * conform to the ws interface (see ws module api docs).
+   * An alternative c++ addon is also available by installing eiows module.
+   *
+   * @default `require("ws").Server`
   */
-  wsEngine: string;
+  wsEngine: Function;
  /**
   * an optional packet which will be concatenated to the handshake packet emitted by Engine.IO.
   */
@@ -155,8 +168,15 @@ interface ServerOptions extends EngineAttachOptions {
  connectTimeout: number;
 }

-export class Server extends EventEmitter {
-  public readonly sockets: Namespace;
+export class Server<
+  ListenEvents extends EventsMap = DefaultEventsMap,
+  EmitEvents extends EventsMap = ListenEvents
+> extends StrictEventEmitter<
+  {},
+  EmitEvents,
+  NamespaceReservedEventsMap<ListenEvents, EmitEvents>
+> {
+  public readonly sockets: Namespace<ListenEvents, EmitEvents>;

  /** @private */
  readonly _parser: typeof parser;
@@ -166,8 +186,11 @@ export class Server extends EventEmitter {
  /**
   * @private
   */
-  _nsps: Map<string, Namespace> = new Map();
-  private parentNsps: Map<ParentNspNameMatchFn, ParentNamespace> = new Map();
+  _nsps: Map<string, Namespace<ListenEvents, EmitEvents>> = new Map();
+  private parentNsps: Map<
+    ParentNspNameMatchFn,
+    ParentNamespace<ListenEvents, EmitEvents>
+  > = new Map();
  private _adapter?: typeof Adapter;
  private _serveClient: boolean;
  private opts: Partial<EngineOptions>;
@@ -247,7 +270,7 @@ export class Server extends EventEmitter {
  _checkNamespace(
    name: string,
    auth: { [key: string]: any },
-    fn: (nsp: Namespace | false) => void
+    fn: (nsp: Namespace<ListenEvents, EmitEvents> | false) => void
  ): void {
    if (this.parentNsps.size === 0) return fn(false);

@@ -556,8 +579,8 @@ export class Server extends EventEmitter {
   */
  public of(
    name: string | RegExp | ParentNspNameMatchFn,
-    fn?: (socket: Socket) => void
-  ): Namespace {
+    fn?: (socket: Socket<ListenEvents, EmitEvents>) => void
+  ): Namespace<ListenEvents, EmitEvents> {
    if (typeof name === "function" || name instanceof RegExp) {
      const parentNsp = new ParentNamespace(this);
      debug("initializing parent namespace %s", parentNsp.name);
@@ -615,7 +638,10 @@ export class Server extends EventEmitter {
   * @public
   */
  public use(
-    fn: (socket: Socket, next: (err?: ExtendedError) => void) => void
+    fn: (
+      socket: Socket<ListenEvents, EmitEvents>,
+      next: (err?: ExtendedError) => void
+    ) => void
  ): this {
    this.sockets.use(fn);
    return this;
@@ -624,24 +650,34 @@ export class Server extends EventEmitter {
  /**
   * Targets a room when emitting.
   *
-   * @param name
+   * @param room
   * @return self
   * @public
   */
-  public to(name: Room): this {
-    this.sockets.to(name);
-    return this;
+  public to(room: Room | Room[]): BroadcastOperator<EmitEvents> {
+    return this.sockets.to(room);
  }

  /**
   * Targets a room when emitting.
   *
+   * @param room
+   * @return self
+   * @public
+   */
+  public in(room: Room | Room[]): BroadcastOperator<EmitEvents> {
+    return this.sockets.in(room);
+  }
+
+  /**
+   * Excludes a room when emitting.
+   *
   * @param name
   * @return self
   * @public
   */
-  public in(name: Room): this {
-    this.sockets.in(name);
+  public except(name: Room | Room[]): Server<ListenEvents, EmitEvents> {
+    this.sockets.except(name);
    return this;
  }

@@ -651,7 +687,7 @@ export class Server extends EventEmitter {
   * @return self
   * @public
   */
-  public send(...args: readonly any[]): this {
+  public send(...args: EventParams<EmitEvents, "message">): this {
    this.sockets.emit("message", ...args);
    return this;
  }
@@ -662,7 +698,7 @@ export class Server extends EventEmitter {
   * @return self
   * @public
   */
-  public write(...args: readonly any[]): this {
+  public write(...args: EventParams<EmitEvents, "message">): this {
    this.sockets.emit("message", ...args);
    return this;
  }
@@ -683,9 +719,8 @@ export class Server extends EventEmitter {
   * @return self
   * @public
   */
-  public compress(compress: boolean): this {
-    this.sockets.compress(compress);
-    return this;
+  public compress(compress: boolean): BroadcastOperator<EmitEvents> {
+    return this.sockets.compress(compress);
  }

  /**
@@ -696,9 +731,8 @@ export class Server extends EventEmitter {
   * @return self
   * @public
   */
-  public get volatile(): this {
-    this.sockets.volatile;
-    return this;
+  public get volatile(): BroadcastOperator<EmitEvents> {
+    return this.sockets.volatile;
  }

  /**
@@ -707,9 +741,47 @@ export class Server extends EventEmitter {
   * @return self
   * @public
   */
-  public get local(): this {
-    this.sockets.local;
-    return this;
+  public get local(): BroadcastOperator<EmitEvents> {
+    return this.sockets.local;
+  }
+
+  /**
+   * Returns the matching socket instances
+   *
+   * @public
+   */
+  public fetchSockets(): Promise<RemoteSocket<EmitEvents>[]> {
+    return this.sockets.fetchSockets();
+  }
+
+  /**
+   * Makes the matching socket instances join the specified rooms
+   *
+   * @param room
+   * @public
+   */
+  public socketsJoin(room: Room | Room[]): void {
+    return this.sockets.socketsJoin(room);
+  }
+
+  /**
+   * Makes the matching socket instances leave the specified rooms
+   *
+   * @param room
+   * @public
+   */
+  public socketsLeave(room: Room | Room[]): void {
+    return this.sockets.socketsLeave(room);
+  }
+
+  /**
+   * Makes the matching socket instances disconnect
+   *
+   * @param close - whether to close the underlying connection
+   * @public
+   */
+  public disconnectSockets(close: boolean = false): void {
+    return this.sockets.disconnectSockets(close);
  }
 }

@@ -732,4 +804,4 @@ emitterMethods.forEach(function (fn) {
 module.exports = (srv?, opts?) => new Server(srv, opts);
 module.exports.Server = Server;

-export { Socket, ServerOptions, Namespace };
+export { Socket, ServerOptions, Namespace, BroadcastOperator, RemoteSocket };
--- a/lib/namespace.ts
+++ b/lib/namespace.ts
@@ -1,10 +1,16 @@
-import { Socket, RESERVED_EVENTS } from "./socket";
+import { Socket } from "./socket";
 import type { Server } from "./index";
+import {
+  EventParams,
+  EventNames,
+  EventsMap,
+  StrictEventEmitter,
+  DefaultEventsMap,
+} from "./typed-events";
 import type { Client } from "./client";
-import { EventEmitter } from "events";
-import { PacketType } from "socket.io-parser";
 import debugModule from "debug";
 import type { Adapter, Room, SocketId } from "socket.io-adapter";
+import { BroadcastOperator, RemoteSocket } from "./broadcast-operator";

 const debug = debugModule("socket.io:namespace");

@@ -12,26 +18,41 @@ export interface ExtendedError extends Error {
  data?: any;
 }

-export class Namespace extends EventEmitter {
+export interface NamespaceReservedEventsMap<
+  ListenEvents extends EventsMap,
+  EmitEvents extends EventsMap
+> {
+  connect: (socket: Socket<ListenEvents, EmitEvents>) => void;
+  connection: (socket: Socket<ListenEvents, EmitEvents>) => void;
+}
+
+export class Namespace<
+  ListenEvents extends EventsMap = DefaultEventsMap,
+  EmitEvents extends EventsMap = ListenEvents
+> extends StrictEventEmitter<
+  {},
+  EmitEvents,
+  NamespaceReservedEventsMap<ListenEvents, EmitEvents>
+> {
  public readonly name: string;
-  public readonly sockets: Map<SocketId, Socket> = new Map();
+  public readonly sockets: Map<
+    SocketId,
+    Socket<ListenEvents, EmitEvents>
+  > = new Map();

  public adapter: Adapter;

  /** @private */
-  readonly server: Server;
+  readonly server: Server<ListenEvents, EmitEvents>;

  /** @private */
  _fns: Array<
-    (socket: Socket, next: (err?: ExtendedError) => void) => void
+    (
+      socket: Socket<ListenEvents, EmitEvents>,
+      next: (err?: ExtendedError) => void
+    ) => void
  > = [];

-  /** @private */
-  _rooms: Set<Room> = new Set();
-
-  /** @private */
-  _flags: any = {};
-
  /** @private */
  _ids: number = 0;

@@ -41,7 +62,7 @@ export class Namespace extends EventEmitter {
   * @param server instance
   * @param name
   */
-  constructor(server: Server, name: string) {
+  constructor(server: Server<ListenEvents, EmitEvents>, name: string) {
    super();
    this.server = server;
    this.name = name;
@@ -66,7 +87,10 @@ export class Namespace extends EventEmitter {
   * @public
   */
  public use(
-    fn: (socket: Socket, next: (err?: ExtendedError) => void) => void
+    fn: (
+      socket: Socket<ListenEvents, EmitEvents>,
+      next: (err?: ExtendedError) => void
+    ) => void
  ): this {
    this._fns.push(fn);
    return this;
@@ -79,7 +103,10 @@ export class Namespace extends EventEmitter {
   * @param fn - last fn call in the middleware
   * @private
   */
-  private run(socket: Socket, fn: (err: ExtendedError | null) => void) {
+  private run(
+    socket: Socket<ListenEvents, EmitEvents>,
+    fn: (err: ExtendedError | null) => void
+  ) {
    const fns = this._fns.slice(0);
    if (!fns.length) return fn(null);

@@ -102,25 +129,34 @@ export class Namespace extends EventEmitter {
  /**
   * Targets a room when emitting.
   *
-   * @param name
+   * @param room
   * @return self
   * @public
   */
-  public to(name: Room): this {
-    this._rooms.add(name);
-    return this;
+  public to(room: Room | Room[]): BroadcastOperator<EmitEvents> {
+    return new BroadcastOperator(this.adapter).to(room);
  }

  /**
   * Targets a room when emitting.
   *
-   * @param name
+   * @param room
   * @return self
   * @public
   */
-  public in(name: Room): this {
-    this._rooms.add(name);
-    return this;
+  public in(room: Room | Room[]): BroadcastOperator<EmitEvents> {
+    return new BroadcastOperator(this.adapter).in(room);
+  }
+
+  /**
+   * Excludes a room when emitting.
+   *
+   * @param room
+   * @return self
+   * @public
+   */
+  public except(room: Room | Room[]): BroadcastOperator<EmitEvents> {
+    return new BroadcastOperator(this.adapter).except(room);
  }

  /**
@@ -129,7 +165,11 @@ export class Namespace extends EventEmitter {
   * @return {Socket}
   * @private
   */
-  _add(client: Client, query, fn?: () => void): Socket {
+  _add(
+    client: Client<ListenEvents, EmitEvents>,
+    query,
+    fn?: () => void
+  ): Socket<ListenEvents, EmitEvents> {
    debug("adding socket to nsp %s", this.name);
    const socket = new Socket(this, client, query);
    this.run(socket, (err) => {
@@ -157,8 +197,8 @@ export class Namespace extends EventEmitter {
          if (fn) fn();

          // fire user-set events
-          super.emit("connect", socket);
-          super.emit("connection", socket);
+          this.emitReserved("connect", socket);
+          this.emitReserved("connection", socket);
        } else {
          debug("next called after client was closed - ignoring socket");
        }
@@ -172,7 +212,7 @@ export class Namespace extends EventEmitter {
   *
   * @private
   */
-  _remove(socket: Socket): void {
+  _remove(socket: Socket<ListenEvents, EmitEvents>): void {
    if (this.sockets.has(socket.id)) {
      this.sockets.delete(socket.id);
    } else {
@@ -186,34 +226,11 @@ export class Namespace extends EventEmitter {
   * @return Always true
   * @public
   */
-  public emit(ev: string | Symbol, ...args: any[]): true {
-    if (RESERVED_EVENTS.has(ev)) {
-      throw new Error(`"${ev}" is a reserved event name`);
-    }
-    // set up packet object
-    args.unshift(ev);
-    const packet = {
-      type: PacketType.EVENT,
-      data: args,
-    };
-
-    if ("function" == typeof args[args.length - 1]) {
-      throw new Error("Callbacks are not supported when broadcasting");
-    }
-
-    const rooms = new Set(this._rooms);
-    const flags = Object.assign({}, this._flags);
-
-    // reset flags
-    this._rooms.clear();
-    this._flags = {};
-
-    this.adapter.broadcast(packet, {
-      rooms: rooms,
-      flags: flags,
-    });
-
-    return true;
+  public emit<Ev extends EventNames<EmitEvents>>(
+    ev: Ev,
+    ...args: EventParams<EmitEvents, Ev>
+  ): true {
+    return new BroadcastOperator<EmitEvents>(this.adapter).emit(ev, ...args);
  }

  /**
@@ -222,7 +239,7 @@ export class Namespace extends EventEmitter {
   * @return self
   * @public
   */
-  public send(...args: readonly any[]): this {
+  public send(...args: EventParams<EmitEvents, "message">): this {
    this.emit("message", ...args);
    return this;
  }
@@ -233,7 +250,7 @@ export class Namespace extends EventEmitter {
   * @return self
   * @public
   */
-  public write(...args: readonly any[]): this {
+  public write(...args: EventParams<EmitEvents, "message">): this {
    this.emit("message", ...args);
    return this;
  }
@@ -245,14 +262,7 @@ export class Namespace extends EventEmitter {
   * @public
   */
  public allSockets(): Promise<Set<SocketId>> {
-    if (!this.adapter) {
-      throw new Error(
-        "No adapter for this namespace, are you trying to get the list of clients of a dynamic namespace?"
-      );
-    }
-    const rooms = new Set(this._rooms);
-    this._rooms.clear();
-    return this.adapter.sockets(rooms);
+    return new BroadcastOperator(this.adapter).allSockets();
  }

  /**
@@ -262,9 +272,8 @@ export class Namespace extends EventEmitter {
   * @return self
   * @public
   */
-  public compress(compress: boolean): this {
-    this._flags.compress = compress;
-    return this;
+  public compress(compress: boolean): BroadcastOperator<EmitEvents> {
+    return new BroadcastOperator(this.adapter).compress(compress);
  }

  /**
@@ -275,9 +284,8 @@ export class Namespace extends EventEmitter {
   * @return self
   * @public
   */
-  public get volatile(): this {
-    this._flags.volatile = true;
-    return this;
+  public get volatile(): BroadcastOperator<EmitEvents> {
+    return new BroadcastOperator(this.adapter).volatile;
  }

  /**
@@ -286,8 +294,46 @@ export class Namespace extends EventEmitter {
   * @return self
   * @public
   */
-  public get local(): this {
-    this._flags.local = true;
-    return this;
+  public get local(): BroadcastOperator<EmitEvents> {
+    return new BroadcastOperator(this.adapter).local;
+  }
+
+  /**
+   * Returns the matching socket instances
+   *
+   * @public
+   */
+  public fetchSockets(): Promise<RemoteSocket<EmitEvents>[]> {
+    return new BroadcastOperator(this.adapter).fetchSockets();
+  }
+
+  /**
+   * Makes the matching socket instances join the specified rooms
+   *
+   * @param room
+   * @public
+   */
+  public socketsJoin(room: Room | Room[]): void {
+    return new BroadcastOperator(this.adapter).socketsJoin(room);
+  }
+
+  /**
+   * Makes the matching socket instances leave the specified rooms
+   *
+   * @param room
+   * @public
+   */
+  public socketsLeave(room: Room | Room[]): void {
+    return new BroadcastOperator(this.adapter).socketsLeave(room);
+  }
+
+  /**
+   * Makes the matching socket instances disconnect
+   *
+   * @param close - whether to close the underlying connection
+   * @public
+   */
+  public disconnectSockets(close: boolean = false): void {
+    return new BroadcastOperator(this.adapter).disconnectSockets(close);
  }
 }
--- a/lib/parent-namespace.ts
+++ b/lib/parent-namespace.ts
@@ -1,11 +1,21 @@
 import { Namespace } from "./namespace";
 import type { Server } from "./index";
+import type {
+  EventParams,
+  EventNames,
+  EventsMap,
+  DefaultEventsMap,
+} from "./typed-events";
+import type { BroadcastOptions } from "socket.io-adapter";

-export class ParentNamespace extends Namespace {
+export class ParentNamespace<
+  ListenEvents extends EventsMap = DefaultEventsMap,
+  EmitEvents extends EventsMap = ListenEvents
+> extends Namespace<ListenEvents, EmitEvents> {
  private static count: number = 0;
-  private children: Set<Namespace> = new Set();
+  private children: Set<Namespace<ListenEvents, EmitEvents>> = new Set();

-  constructor(server: Server) {
+  constructor(server: Server<ListenEvents, EmitEvents>) {
    super(server, "/_" + ParentNamespace.count++);
  }

@@ -13,29 +23,34 @@ export class ParentNamespace extends Namespace {
   * @private
   */
  _initAdapter(): void {
-    /* no-op */
+    const broadcast = (packet: any, opts: BroadcastOptions) => {
+      this.children.forEach((nsp) => {
+        nsp.adapter.broadcast(packet, opts);
+      });
+    };
+    // @ts-ignore FIXME is there a way to declare an inner class in TypeScript?
+    this.adapter = { broadcast };
  }

-  public emit(ev: string | Symbol, ...args: [...any]): true {
+  public emit<Ev extends EventNames<EmitEvents>>(
+    ev: Ev,
+    ...args: EventParams<EmitEvents, Ev>
+  ): true {
    this.children.forEach((nsp) => {
-      nsp._rooms = this._rooms;
-      nsp._flags = this._flags;
      nsp.emit(ev, ...args);
    });
-    this._rooms.clear();
-    this._flags = {};

    return true;
  }

-  createChild(name: string): Namespace {
+  createChild(name: string): Namespace<ListenEvents, EmitEvents> {
    const namespace = new Namespace(this.server, name);
    namespace._fns = this._fns.slice(0);
    this.listeners("connect").forEach((listener) =>
-      namespace.on("connect", listener as (...args: any[]) => void)
+      namespace.on("connect", listener)
    );
    this.listeners("connection").forEach((listener) =>
-      namespace.on("connection", listener as (...args: any[]) => void)
+      namespace.on("connection", listener)
    );
    this.children.add(namespace);
    this.server._nsps.set(name, namespace);
--- a/lib/socket.ts
+++ b/lib/socket.ts
@@ -1,10 +1,16 @@
-import { EventEmitter } from "events";
 import { Packet, PacketType } from "socket.io-parser";
 import url = require("url");
 import debugModule from "debug";
 import type { Server } from "./index";
+import {
+  EventParams,
+  EventNames,
+  EventsMap,
+  StrictEventEmitter,
+  DefaultEventsMap,
+} from "./typed-events";
 import type { Client } from "./client";
-import type { Namespace } from "./namespace";
+import type { Namespace, NamespaceReservedEventsMap } from "./namespace";
 import type { IncomingMessage, IncomingHttpHeaders } from "http";
 import type {
  Adapter,
@@ -14,18 +20,43 @@ import type {
 } from "socket.io-adapter";
 import base64id from "base64id";
 import type { ParsedUrlQuery } from "querystring";
+import { BroadcastOperator } from "./broadcast-operator";

 const debug = debugModule("socket.io:socket");

-export const RESERVED_EVENTS = new Set(<const>[
+type ClientReservedEvents = "connect_error";
+
+export interface SocketReservedEventsMap {
+  disconnect: (reason: string) => void;
+  disconnecting: (reason: string) => void;
+  error: (err: Error) => void;
+}
+
+// EventEmitter reserved events: https://nodejs.org/api/events.html#events_event_newlistener
+export interface EventEmitterReservedEventsMap {
+  newListener: (
+    eventName: string | Symbol,
+    listener: (...args: any[]) => void
+  ) => void;
+  removeListener: (
+    eventName: string | Symbol,
+    listener: (...args: any[]) => void
+  ) => void;
+}
+
+export const RESERVED_EVENTS: ReadonlySet<string | Symbol> = new Set<
+  | ClientReservedEvents
+  | keyof NamespaceReservedEventsMap<never, never>
+  | keyof SocketReservedEventsMap
+  | keyof EventEmitterReservedEventsMap
+>(<const>[
  "connect",
  "connect_error",
  "disconnect",
  "disconnecting",
-  // EventEmitter reserved events: https://nodejs.org/api/events.html#events_event_newlistener
  "newListener",
  "removeListener",
-]) as ReadonlySet<string | Symbol>;
+]);

 /**
 * The handshake details
@@ -77,21 +108,31 @@ export interface Handshake {
  auth: { [key: string]: any };
 }

-export class Socket extends EventEmitter {
+export class Socket<
+  ListenEvents extends EventsMap = DefaultEventsMap,
+  EmitEvents extends EventsMap = ListenEvents
+> extends StrictEventEmitter<
+  ListenEvents,
+  EmitEvents,
+  SocketReservedEventsMap
+> {
  public readonly id: SocketId;
  public readonly handshake: Handshake;
+  /**
+   * Additional information that can be attached to the Socket instance and which will be used in the fetchSockets method
+   */
+  public data: any = {};

  public connected: boolean;
  public disconnected: boolean;

-  private readonly server: Server;
+  private readonly server: Server<ListenEvents, EmitEvents>;
  private readonly adapter: Adapter;
  private acks: Map<number, () => void> = new Map();
  private fns: Array<
-    (event: Array<any>, next: (err: Error) => void) => void
+    (event: Array<any>, next: (err?: Error) => void) => void
  > = [];
  private flags: BroadcastFlags = {};
-  private _rooms: Set<Room> = new Set();
  private _anyListeners?: Array<(...args: any[]) => void>;

  /**
@@ -102,7 +143,11 @@ export class Socket extends EventEmitter {
   * @param {Object} auth
   * @package
   */
-  constructor(readonly nsp: Namespace, readonly client: Client, auth: object) {
+  constructor(
+    readonly nsp: Namespace<ListenEvents, EmitEvents>,
+    readonly client: Client<ListenEvents, EmitEvents>,
+    auth: object
+  ) {
    super();
    this.server = nsp.server;
    this.adapter = this.nsp.adapter;
@@ -143,69 +188,65 @@ export class Socket extends EventEmitter {
   * @return Always returns `true`.
   * @public
   */
-  public emit(ev: string, ...args: any[]): boolean {
+  public emit<Ev extends EventNames<EmitEvents>>(
+    ev: Ev,
+    ...args: EventParams<EmitEvents, Ev>
+  ): boolean {
    if (RESERVED_EVENTS.has(ev)) {
      throw new Error(`"${ev}" is a reserved event name`);
    }
-    args.unshift(ev);
+    const data: any[] = [ev, ...args];
    const packet: any = {
      type: PacketType.EVENT,
-      data: args,
+      data: data,
    };

    // access last argument to see if it's an ACK callback
-    if (typeof args[args.length - 1] === "function") {
-      if (this._rooms.size || this.flags.broadcast) {
-        throw new Error("Callbacks are not supported when broadcasting");
-      }
-
+    if (typeof data[data.length - 1] === "function") {
      debug("emitting packet with ack id %d", this.nsp._ids);
-      this.acks.set(this.nsp._ids, args.pop());
+      this.acks.set(this.nsp._ids, data.pop());
      packet.id = this.nsp._ids++;
    }

-    const rooms = new Set(this._rooms);
    const flags = Object.assign({}, this.flags);
-
-    // reset flags
-    this._rooms.clear();
    this.flags = {};

-    if (rooms.size || flags.broadcast) {
-      this.adapter.broadcast(packet, {
-        except: new Set([this.id]),
-        rooms: rooms,
-        flags: flags,
-      });
-    } else {
-      // dispatch packet
-      this.packet(packet, flags);
-    }
+    this.packet(packet, flags);
+
    return true;
  }

  /**
   * Targets a room when broadcasting.
   *
-   * @param name
+   * @param room
   * @return self
   * @public
   */
-  public to(name: Room): this {
-    this._rooms.add(name);
-    return this;
+  public to(room: Room | Room[]): BroadcastOperator<EmitEvents> {
+    return this.newBroadcastOperator().to(room);
  }

  /**
   * Targets a room when broadcasting.
   *
-   * @param name
+   * @param room
   * @return self
   * @public
   */
-  public in(name: Room): this {
-    this._rooms.add(name);
-    return this;
+  public in(room: Room | Room[]): BroadcastOperator<EmitEvents> {
+    return this.newBroadcastOperator().in(room);
+  }
+
+  /**
+   * Excludes a room when broadcasting.
+   *
+   * @param room
+   * @return self
+   * @public
+   */
+  public except(room: Room | Room[]): BroadcastOperator<EmitEvents> {
+    return this.newBroadcastOperator().except(room);
  }

  /**
@@ -214,7 +255,7 @@ export class Socket extends EventEmitter {
   * @return self
   * @public
   */
-  public send(...args: readonly any[]): this {
+  public send(...args: EventParams<EmitEvents, "message">): this {
    this.emit("message", ...args);
    return this;
  }
@@ -225,7 +266,7 @@ export class Socket extends EventEmitter {
   * @return self
   * @public
   */
-  public write(...args: readonly any[]): this {
+  public write(...args: EventParams<EmitEvents, "message">): this {
    this.emit("message", ...args);
    return this;
  }
@@ -416,9 +457,9 @@ export class Socket extends EventEmitter {
   *
   * @private
   */
-  _onerror(err): void {
+  _onerror(err: Error): void {
    if (this.listeners("error").length) {
-      super.emit("error", err);
+      this.emitReserved("error", err);
    } else {
      console.error("Missing error handler on `socket`.");
      console.error(err.stack);
@@ -436,13 +477,13 @@ export class Socket extends EventEmitter {
  _onclose(reason: string): this | undefined {
    if (!this.connected) return this;
    debug("closing socket - reason %s", reason);
-    super.emit("disconnecting", reason);
+    this.emitReserved("disconnecting", reason);
    this.leaveAll();
    this.nsp._remove(this);
    this.client._remove(this);
    this.connected = false;
    this.disconnected = true;
-    super.emit("disconnect", reason);
+    this.emitReserved("disconnect", reason);
    return;
  }

@@ -508,9 +549,8 @@ export class Socket extends EventEmitter {
   * @return {Socket} self
   * @public
   */
-  public get broadcast(): this {
-    this.flags.broadcast = true;
-    return this;
+  public get broadcast(): BroadcastOperator<EmitEvents> {
+    return this.newBroadcastOperator();
  }

  /**
@@ -519,9 +559,8 @@ export class Socket extends EventEmitter {
   * @return {Socket} self
   * @public
   */
-  public get local(): this {
-    this.flags.local = true;
-    return this;
+  public get local(): BroadcastOperator<EmitEvents> {
+    return this.newBroadcastOperator().local;
  }

  /**
@@ -538,7 +577,7 @@ export class Socket extends EventEmitter {
          return this._onerror(err);
        }
        if (this.connected) {
-          super.emit.apply(this, event);
+          super.emitUntyped.apply(this, event);
        } else {
          debug("ignore packet received after disconnection");
        }
@@ -554,7 +593,7 @@ export class Socket extends EventEmitter {
   * @public
   */
  public use(
-    fn: (event: Array<any>, next: (err: Error) => void) => void
+    fn: (event: Array<any>, next: (err?: Error) => void) => void
  ): this {
    this.fns.push(fn);
    return this;
@@ -674,4 +713,15 @@ export class Socket extends EventEmitter {
  public listenersAny() {
    return this._anyListeners || [];
  }
+
+  private newBroadcastOperator(): BroadcastOperator<EmitEvents> {
+    const flags = Object.assign({}, this.flags);
+    this.flags = {};
+    return new BroadcastOperator(
+      this.adapter,
+      new Set<Room>(),
+      new Set<Room>([this.id]),
+      flags
+    );
+  }
 }
--- a/lib/typed-events.ts
+++ b/lib/typed-events.ts
@@ -0,0 +1,167 @@
+import { EventEmitter } from "events";
+
+/**
+ * An events map is an interface that maps event names to their value, which
+ * represents the type of the `on` listener.
+ */
+export interface EventsMap {
+  [event: string]: any;
+}
+
+/**
+ * The default events map, used if no EventsMap is given. Using this EventsMap
+ * is equivalent to accepting all event names, and any data.
+ */
+export interface DefaultEventsMap {
+  [event: string]: (...args: any[]) => void;
+}
+
+/**
+ * Returns a union type containing all the keys of an event map.
+ */
+export type EventNames<Map extends EventsMap> = keyof Map & (string | symbol);
+
+/** The tuple type representing the parameters of an event listener */
+export type EventParams<
+  Map extends EventsMap,
+  Ev extends EventNames<Map>
+> = Parameters<Map[Ev]>;
+
+/**
+ * The event names that are either in ReservedEvents or in UserEvents
+ */
+export type ReservedOrUserEventNames<
+  ReservedEventsMap extends EventsMap,
+  UserEvents extends EventsMap
+> = EventNames<ReservedEventsMap> | EventNames<UserEvents>;
+
+/**
+ * Type of a listener of a user event or a reserved event. If `Ev` is in
+ * `ReservedEvents`, the reserved event listener is returned.
+ */
+export type ReservedOrUserListener<
+  ReservedEvents extends EventsMap,
+  UserEvents extends EventsMap,
+  Ev extends ReservedOrUserEventNames<ReservedEvents, UserEvents>
+> = Ev extends EventNames<ReservedEvents>
+  ? ReservedEvents[Ev]
+  : Ev extends EventNames<UserEvents>
+  ? UserEvents[Ev]
+  : never;
+
+/**
+ * Interface for classes that aren't `EventEmitter`s, but still expose a
+ * strictly typed `emit` method.
+ */
+export interface TypedEventBroadcaster<EmitEvents extends EventsMap> {
+  emit<Ev extends EventNames<EmitEvents>>(
+    ev: Ev,
+    ...args: EventParams<EmitEvents, Ev>
+  ): boolean;
+}
+
+/**
+ * Strictly typed version of an `EventEmitter`. A `TypedEventEmitter` takes type
+ * parameters for mappings of event names to event data types, and strictly
+ * types method calls to the `EventEmitter` according to these event maps.
+ *
+ * @typeParam ListenEvents - `EventsMap` of user-defined events that can be
+ * listened to with `on` or `once`
+ * @typeParam EmitEvents - `EventsMap` of user-defined events that can be
+ * emitted with `emit`
+ * @typeParam ReservedEvents - `EventsMap` of reserved events, that can be
+ * emitted by socket.io with `emitReserved`, and can be listened to with
+ * `listen`.
+ */
+export abstract class StrictEventEmitter<
+    ListenEvents extends EventsMap,
+    EmitEvents extends EventsMap,
+    ReservedEvents extends EventsMap = {}
+  >
+  extends EventEmitter
+  implements TypedEventBroadcaster<EmitEvents> {
+  /**
+   * Adds the `listener` function as an event listener for `ev`.
+   *
+   * @param ev Name of the event
+   * @param listener Callback function
+   */
+  on<Ev extends ReservedOrUserEventNames<ReservedEvents, ListenEvents>>(
+    ev: Ev,
+    listener: ReservedOrUserListener<ReservedEvents, ListenEvents, Ev>
+  ): this {
+    return super.on(ev, listener);
+  }
+
+  /**
+   * Adds a one-time `listener` function as an event listener for `ev`.
+   *
+   * @param ev Name of the event
+   * @param listener Callback function
+   */
+  once<Ev extends ReservedOrUserEventNames<ReservedEvents, ListenEvents>>(
+    ev: Ev,
+    listener: ReservedOrUserListener<ReservedEvents, ListenEvents, Ev>
+  ): this {
+    return super.once(ev, listener);
+  }
+
+  /**
+   * Emits an event.
+   *
+   * @param ev Name of the event
+   * @param args Values to send to listeners of this event
+   */
+  emit<Ev extends EventNames<EmitEvents>>(
+    ev: Ev,
+    ...args: EventParams<EmitEvents, Ev>
+  ): boolean {
+    return super.emit(ev, ...args);
+  }
+
+  /**
+   * Emits a reserved event.
+   *
+   * This method is `protected`, so that only a class extending
+   * `StrictEventEmitter` can emit its own reserved events.
+   *
+   * @param ev Reserved event name
+   * @param args Arguments to emit along with the event
+   */
+  protected emitReserved<Ev extends EventNames<ReservedEvents>>(
+    ev: Ev,
+    ...args: EventParams<ReservedEvents, Ev>
+  ): boolean {
+    return super.emit(ev, ...args);
+  }
+
+  /**
+   * Emits an event.
+   *
+   * This method is `protected`, so that only a class extending
+   * `StrictEventEmitter` can get around the strict typing. This is useful for
+   * calling `emit.apply`, which can be called as `emitUntyped.apply`.
+   *
+   * @param ev Event name
+   * @param args Arguments to emit along with the event
+   */
+  protected emitUntyped(ev: string, ...args: any[]): boolean {
+    return super.emit(ev, ...args);
+  }
+
+  /**
+   * Returns the listeners listening to an event.
+   *
+   * @param event Event name
+   * @returns Array of listeners subscribed to `event`
+   */
+  listeners<Ev extends ReservedOrUserEventNames<ReservedEvents, ListenEvents>>(
+    event: Ev
+  ): ReservedOrUserListener<ReservedEvents, ListenEvents, Ev>[] {
+    return super.listeners(event) as ReservedOrUserListener<
+      ReservedEvents,
+      ListenEvents,
+      Ev
+    >[];
+  }
+}
--- a/package-lock.json
+++ b/package-lock.json
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
  "name": "socket.io",
-  "version": "3.1.2",
+  "version": "4.0.0",
  "description": "node.js realtime framework server",
  "keywords": [
    "realtime",
@@ -37,7 +37,9 @@
  },
  "scripts": {
    "compile": "rimraf ./dist && tsc",
-    "test": "npm run format:check && npm run compile && nyc mocha --require ts-node/register --reporter spec --slow 200 --bail --timeout 10000 test/socket.io.ts",
+    "test": "npm run format:check && npm run compile && npm run test:types && npm run test:unit",
+    "test:types": "tsd",
+    "test:unit": "nyc mocha --require ts-node/register --reporter spec --slow 200 --bail --timeout 10000 test/socket.io.ts",
    "format:check": "prettier --check \"lib/**/*.ts\" \"test/**/*.ts\"",
    "format:fix": "prettier --write \"lib/**/*.ts\" \"test/**/*.ts\"",
    "prepack": "npm run compile"
@@ -49,8 +51,8 @@
    "accepts": "~1.3.4",
    "base64id": "~2.0.0",
    "debug": "~4.3.1",
-    "engine.io": "~4.1.0",
-    "socket.io-adapter": "~2.1.0",
+    "engine.io": "~5.0.0",
+    "socket.io-adapter": "~2.2.0",
    "socket.io-parser": "~4.0.3"
  },
  "devDependencies": {
@@ -63,11 +65,12 @@
    "nyc": "^15.1.0",
    "prettier": "^2.2.0",
    "rimraf": "^3.0.2",
-    "socket.io-client": "3.1.2",
+    "socket.io-client": "4.0.0",
    "socket.io-client-v2": "npm:socket.io-client@^2.4.0",
    "superagent": "^6.1.0",
    "supertest": "^6.0.1",
    "ts-node": "^9.0.0",
+    "tsd": "^0.14.0",
    "typescript": "^4.1.2"
  },
  "contributors": [
@@ -90,5 +93,8 @@
  ],
  "engines": {
    "node": ">=10.0.0"
+  },
+  "tsd": {
+    "directory": "test"
  }
 }
--- a/test/socket.io.test-d.ts
+++ b/test/socket.io.test-d.ts
@@ -0,0 +1,200 @@
+"use strict";
+import { Server, Socket } from "..";
+import type { DefaultEventsMap } from "../lib/typed-events";
+import { createServer } from "http";
+import { expectError, expectType } from "tsd";
+
+// This file is run by tsd, not mocha.
+
+describe("server", () => {
+  describe("no event map", () => {
+    describe("on", () => {
+      it("infers correct types for listener parameters of reserved events", (done) => {
+        const srv = createServer();
+        const sio = new Server(srv);
+        srv.listen(() => {
+          sio.on("connection", (s) => {
+            expectType<Socket<DefaultEventsMap, DefaultEventsMap>>(s);
+            s.on("disconnect", (reason) => {
+              expectType<string>(reason);
+            });
+            s.on("disconnecting", (reason) => {
+              expectType<string>(reason);
+            });
+          });
+          sio.on("connect", (s) => {
+            expectType<Socket<DefaultEventsMap, DefaultEventsMap>>(s);
+          });
+          done();
+        });
+      });
+
+      it("infers 'any' for listener parameters of other events", (done) => {
+        const srv = createServer();
+        const sio = new Server(srv);
+        srv.listen(() => {
+          sio.on("connection", (s) => {
+            s.on("random", (a, b, c) => {
+              expectType<any>(a);
+              expectType<any>(b);
+              expectType<any>(c);
+              done();
+            });
+            s.emit("random", 1, "2", [3]);
+          });
+        });
+      });
+    });
+
+    describe("emit", () => {
+      it("accepts any parameters", () => {
+        const srv = createServer();
+        const sio = new Server(srv);
+        srv.listen(() => {
+          sio.on("connection", (s) => {
+            s.emit("random", 1, "2", [3]);
+            s.emit("no parameters");
+          });
+        });
+      });
+    });
+  });
+
+  describe("single event map", () => {
+    interface BidirectionalEvents {
+      random: (a: number, b: string, c: number[]) => void;
+    }
+
+    describe("on", () => {
+      it("infers correct types for listener parameters", (done) => {
+        const srv = createServer();
+        const sio = new Server<BidirectionalEvents>(srv);
+        expectType<Server<BidirectionalEvents, BidirectionalEvents>>(sio);
+        srv.listen(() => {
+          sio.on("connection", (s) => {
+            expectType<Socket<BidirectionalEvents, BidirectionalEvents>>(s);
+            s.on("random", (a, b, c) => {
+              expectType<number>(a);
+              expectType<string>(b);
+              expectType<number[]>(c);
+              done();
+            });
+          });
+        });
+      });
+
+      it("does not accept arguments of wrong types", (done) => {
+        const srv = createServer();
+        const sio = new Server<BidirectionalEvents>(srv);
+        expectError(sio.on("random", (a, b, c) => {}));
+        srv.listen(() => {
+          expectError(sio.on("wrong name", (s) => {}));
+          sio.on("connection", (s) => {
+            s.on("random", (a, b, c) => {});
+            expectError(s.on("random"));
+            expectError(s.on("random", (a, b, c, d) => {}));
+            expectError(s.on(2, 3));
+          });
+        });
+      });
+    });
+
+    describe("emit", () => {
+      it("accepts arguments of the correct types", () => {
+        const srv = createServer();
+        const sio = new Server<BidirectionalEvents>(srv);
+        srv.listen(() => {
+          sio.on("connection", (s) => {
+            s.emit("random", 1, "2", [3]);
+          });
+        });
+      });
+
+      it("does not accept arguments of the wrong types", () => {
+        const srv = createServer();
+        const sio = new Server<BidirectionalEvents>(srv);
+        srv.listen(() => {
+          sio.on("connection", (s) => {
+            expectError(s.emit("noParameter", 2));
+            expectError(s.emit("oneParameter"));
+            expectError(s.emit("random"));
+            expectError(s.emit("oneParameter", 2, 3));
+            expectError(s.emit("random", (a, b, c) => {}));
+            expectError(s.emit("wrong name", () => {}));
+            expectError(s.emit("complicated name with spaces", 2));
+          });
+        });
+      });
+    });
+  });
+
+  describe("listen and emit event maps", () => {
+    interface ClientToServerEvents {
+      helloFromClient: (message: string) => void;
+    }
+
+    interface ServerToClientEvents {
+      helloFromServer: (message: string, x: number) => void;
+    }
+
+    describe("on", () => {
+      it("infers correct types for listener parameters", (done) => {
+        const srv = createServer();
+        const sio = new Server<ClientToServerEvents, ServerToClientEvents>(srv);
+        expectType<Server<ClientToServerEvents, ServerToClientEvents>>(sio);
+        srv.listen(() => {
+          sio.on("connection", (s) => {
+            expectType<Socket<ClientToServerEvents, ServerToClientEvents>>(s);
+            s.on("helloFromClient", (message) => {
+              expectType<string>(message);
+              done();
+            });
+          });
+        });
+      });
+
+      it("does not accept emit events", (done) => {
+        const srv = createServer();
+        const sio = new Server<ClientToServerEvents, ServerToClientEvents>(srv);
+        srv.listen(() => {
+          sio.on("connection", (s) => {
+            expectError(
+              s.on("helloFromServer", (message, number) => {
+                done();
+              })
+            );
+          });
+        });
+      });
+    });
+
+    describe("emit", () => {
+      it("accepts arguments of the correct types", (done) => {
+        const srv = createServer();
+        const sio = new Server<ClientToServerEvents, ServerToClientEvents>(srv);
+        srv.listen(() => {
+          sio.on("connection", (s) => {
+            s.emit("helloFromServer", "hi", 10);
+            done();
+          });
+        });
+      });
+
+      it("does not accept arguments of wrong types", (done) => {
+        const srv = createServer();
+        const sio = new Server<ClientToServerEvents, ServerToClientEvents>(srv);
+        srv.listen(() => {
+          sio.on("connection", (s) => {
+            expectError(s.emit("helloFromClient", "hi"));
+            expectError(s.emit("helloFromServer", "hi", 10, "10"));
+            expectError(s.emit("helloFromServer", "hi", "10"));
+            expectError(s.emit("helloFromServer", 0, 0));
+            expectError(s.emit("wrong name", 10));
+            expectError(s.emit("wrong name"));
+            done();
+          });
+        });
+      });
+    });
+  });
+});
--- a/test/socket.io.ts
+++ b/test/socket.io.ts
@@ -9,13 +9,14 @@ import request from "supertest";
 import expect from "expect.js";
 import type { AddressInfo } from "net";
 import * as io_v2 from "socket.io-client-v2";
-
-const ioc = require("socket.io-client");
+import type { SocketId } from "socket.io-adapter";
+import { io as ioc, Socket as ClientSocket } from "socket.io-client";

 import "./support/util";
+import "./utility-methods";

 // Creates a socket.io client for the given server
-function client(srv, nsp?: string | object, opts?: object) {
+function client(srv, nsp?: string | object, opts?: object): ClientSocket {
  if ("object" == typeof nsp) {
    opts = nsp;
    nsp = undefined;
@@ -227,7 +228,7 @@ describe("socket.io", () => {
      });
      request
        .options("http://localhost:54013/socket.io/default/")
-        .query({ transport: "polling" })
+        .query({ transport: "polling", EIO: 4 })
        .set("Origin", "http://localhost:54023")
        .end((err, res) => {
          expect(res.status).to.be(204);
@@ -255,7 +256,7 @@ describe("socket.io", () => {
      });
      request
        .get("http://localhost:54014/socket.io/default/")
-        .query({ transport: "polling" })
+        .query({ transport: "polling", EIO: 4 })
        .set("Origin", "http://localhost:54024")
        .end((err, res) => {
          expect(res.status).to.be(200);
@@ -275,7 +276,7 @@ describe("socket.io", () => {

      request
        .get("http://localhost:54022/socket.io/default/")
-        .query({ transport: "polling" })
+        .query({ transport: "polling", EIO: 4 })
        .end((err, res) => {
          expect(res.status).to.be(200);
          done();
@@ -289,7 +290,7 @@ describe("socket.io", () => {
      request
        .get("http://localhost:54023/socket.io/default/")
        .set("origin", "http://foo.example")
-        .query({ transport: "polling" })
+        .query({ transport: "polling", EIO: 4 })
        .end((err, res) => {
          expect(res.status).to.be(403);
          done();
@@ -332,7 +333,9 @@ describe("socket.io", () => {
      const net = require("net");
      const server = net.createServer();

-      const clientSocket = ioc("ws://0.0.0.0:" + PORT, { reconnection: false });
+      const clientSocket = ioc("ws://0.0.0.0:" + PORT, {
+        reconnection: false,
+      });

      clientSocket.on("disconnect", () => {
        expect(Object.keys(sio._nsps["/"].sockets).length).to.equal(0);
@@ -388,10 +391,22 @@ describe("socket.io", () => {
      expect(sio.write).to.be.a("function");
      expect(sio.allSockets).to.be.a("function");
      expect(sio.compress).to.be.a("function");
-      expect(sio.volatile).to.be(sio);
-      expect(sio.local).to.be(sio);
-      expect(sio.sockets._flags).to.eql({ volatile: true, local: true });
-      delete sio.sockets._flags;
+    });
+
+    it("should return an immutable broadcast operator", () => {
+      const sio = new Server();
+      const operator = sio.local.to(["room1", "room2"]).except("room3");
+      operator.compress(true).emit("hello");
+      operator.volatile.emit("hello");
+      operator.to("room4").emit("hello");
+      operator.except("room5").emit("hello");
+      sio.to("room6").emit("hello");
+      // @ts-ignore
+      expect(operator.rooms).to.contain("room1", "room2");
+      // @ts-ignore
+      expect(operator.exceptRooms).to.contain("room3");
+      // @ts-ignore
+      expect(operator.flags).to.eql({ local: true });
    });

    it("should automatically connect", (done) => {
@@ -592,7 +607,7 @@ describe("socket.io", () => {
      const srv = createServer();
      const sio = new Server(srv);
      const chatSids: string[] = [];
-      let otherSid = null;
+      let otherSid: SocketId | null = null;
      srv.listen(() => {
        const c1 = client(srv, "/chat");
        const c2 = client(srv, "/chat", { forceNew: true });
@@ -619,9 +634,9 @@ describe("socket.io", () => {
    it("should find all clients in a namespace room", (done) => {
      const srv = createServer();
      const sio = new Server(srv);
-      let chatFooSid = null;
-      let chatBarSid = null;
-      let otherSid = null;
+      let chatFooSid: SocketId | null = null;
+      let chatBarSid: SocketId | null = null;
+      let otherSid: SocketId | null = null;
      srv.listen(() => {
        const c1 = client(srv, "/chat");
        const c2 = client(srv, "/chat", { forceNew: true });
@@ -658,9 +673,9 @@ describe("socket.io", () => {
    it("should find all clients across namespace rooms", (done) => {
      const srv = createServer();
      const sio = new Server(srv);
-      let chatFooSid = null;
-      let chatBarSid = null;
-      let otherSid = null;
+      let chatFooSid: SocketId | null = null;
+      let chatBarSid: SocketId | null = null;
+      let otherSid: SocketId | null = null;
      srv.listen(() => {
        const c1 = client(srv, "/chat");
        const c2 = client(srv, "/chat", { forceNew: true });
@@ -823,6 +838,57 @@ describe("socket.io", () => {
      });
    });

+    it("should exclude a specific socket when emitting", (done) => {
+      const srv = createServer();
+      const sio = new Server(srv);
+
+      const nsp = sio.of("/nsp");
+
+      srv.listen(() => {
+        const socket1 = client(srv, "/nsp");
+        const socket2 = client(srv, "/nsp");
+
+        socket2.on("a", () => {
+          done(new Error("not"));
+        });
+        socket1.on("a", () => {
+          done();
+        });
+
+        socket2.on("connect", () => {
+          nsp.except(socket2.id).emit("a");
+        });
+      });
+    });
+
+    it("should exclude a specific room when emitting", (done) => {
+      const srv = createServer();
+      const sio = new Server(srv);
+
+      const nsp = sio.of("/nsp");
+
+      srv.listen(() => {
+        const socket1 = client(srv, "/nsp");
+        const socket2 = client(srv, "/nsp");
+
+        socket1.on("a", () => {
+          done();
+        });
+        socket2.on("a", () => {
+          done(new Error("not"));
+        });
+
+        nsp.on("connection", (socket) => {
+          socket.on("broadcast", () => {
+            socket.join("room1");
+            nsp.except("room1").emit("a");
+          });
+        });
+
+        socket2.emit("broadcast");
+      });
+    });
+
    describe("dynamic namespaces", () => {
      it("should allow connections to dynamic namespaces with a regex", (done) => {
        const srv = createServer();
@@ -889,7 +955,7 @@ describe("socket.io", () => {
      srv.listen(() => {
        const clientSocket = client(srv, { reconnection: false });
        clientSocket.on("connect", function init() {
-          clientSocket.removeListener("connect", init);
+          clientSocket.off("connect", init);
          clientSocket.io.engine.close();

          clientSocket.connect();
@@ -978,7 +1044,7 @@ describe("socket.io", () => {
              done();
            });
          });
-          s.client.ondata(null);
+          (s as any).client.ondata(null);
        });
      });
    });
@@ -2166,7 +2232,7 @@ describe("socket.io", () => {
          expect(s.rooms).to.contain(s.id, "a", "b", "c");
          s.leave("b");
          expect(s.rooms).to.contain(s.id, "a", "c");
-          s.leaveAll();
+          (s as any).leaveAll();
          expect(s.rooms.size).to.eql(0);
          done();
        });
@@ -2202,7 +2268,7 @@ describe("socket.io", () => {
          expect(s.rooms).to.contain(s.id, "a", "b");
          s.leave("unknown");
          expect(s.rooms).to.contain(s.id, "a", "b");
-          s.leaveAll();
+          (s as any).leaveAll();
          expect(s.rooms.size).to.eql(0);
          done();
        });
@@ -2222,6 +2288,106 @@ describe("socket.io", () => {
        });
      });
    });
+
+    it("should exclude specific sockets when broadcasting", (done) => {
+      const srv = createServer();
+      const sio = new Server(srv);
+
+      srv.listen(() => {
+        const socket1 = client(srv, { multiplex: false });
+        const socket2 = client(srv, { multiplex: false });
+        const socket3 = client(srv, { multiplex: false });
+
+        socket2.on("a", () => {
+          done(new Error("not"));
+        });
+        socket3.on("a", () => {
+          done(new Error("not"));
+        });
+        socket1.on("a", () => {
+          done();
+        });
+
+        sio.on("connection", (socket) => {
+          socket.on("exclude", (id) => {
+            socket.broadcast.except(id).emit("a");
+          });
+        });
+
+        socket2.on("connect", () => {
+          socket3.emit("exclude", socket2.id);
+        });
+      });
+    });
+
+    it("should exclude a specific room when broadcasting", (done) => {
+      const srv = createServer();
+      const sio = new Server(srv);
+
+      srv.listen(() => {
+        const socket1 = client(srv, { multiplex: false });
+        const socket2 = client(srv, { multiplex: false });
+        const socket3 = client(srv, { multiplex: false });
+
+        socket2.on("a", () => {
+          done(new Error("not"));
+        });
+        socket3.on("a", () => {
+          done(new Error("not"));
+        });
+        socket1.on("a", () => {
+          done();
+        });
+
+        sio.on("connection", (socket) => {
+          socket.on("join", (room, cb) => {
+            socket.join(room);
+            cb();
+          });
+          socket.on("broadcast", () => {
+            socket.broadcast.except("room1").emit("a");
+          });
+        });
+
+        socket2.emit("join", "room1", () => {
+          socket3.emit("broadcast");
+        });
+      });
+    });
+
+    it("should return an immutable broadcast operator", (done) => {
+      const srv = createServer();
+      const sio = new Server(srv);
+
+      srv.listen(() => {
+        const clientSocket = client(srv, { multiplex: false });
+
+        sio.on("connection", (socket: Socket) => {
+          const operator = socket.local
+            .compress(false)
+            .to(["room1", "room2"])
+            .except("room3");
+          operator.compress(true).emit("hello");
+          operator.volatile.emit("hello");
+          operator.to("room4").emit("hello");
+          operator.except("room5").emit("hello");
+          socket.emit("hello");
+          socket.to("room6").emit("hello");
+          // @ts-ignore
+          expect(operator.rooms).to.contain("room1", "room2");
+          // @ts-ignore
+          expect(operator.rooms).to.not.contain("room4", "room5", "room6");
+          // @ts-ignore
+          expect(operator.exceptRooms).to.contain("room3");
+          // @ts-ignore
+          expect(operator.flags).to.eql({ local: true, compress: false });
+
+          clientSocket.close();
+          sio.close();
+          done();
+        });
+      });
+    });
  });

  describe("middleware", () => {
@@ -2289,6 +2455,7 @@ describe("socket.io", () => {
        socket.on("connect_error", (err) => {
          expect(err).to.be.an(Error);
          expect(err.message).to.eql("Authentication error");
+          // @ts-ignore
          expect(err.data).to.eql({ a: "b", c: 3 });
          done();
        });
@@ -2305,7 +2472,7 @@ describe("socket.io", () => {
      srv.listen(() => {
        const socket = client(srv);
        sio.on("connection", (socket) => {
-          expect(socket.name).to.be("guillermo");
+          expect((socket as any).name).to.be("guillermo");
          done();
        });
      });
--- a/test/utility-methods.ts
+++ b/test/utility-methods.ts
@@ -0,0 +1,176 @@
+import { createServer } from "http";
+import { Server, Socket } from "..";
+import { io as ioc, Socket as ClientSocket } from "socket.io-client";
+import { Adapter, BroadcastOptions } from "socket.io-adapter";
+import expect from "expect.js";
+import type { AddressInfo } from "net";
+
+import "./support/util";
+
+const SOCKETS_COUNT = 3;
+
+const createPartialDone = (
+  count: number,
+  done: () => void,
+  callback?: () => void
+) => {
+  let i = 0;
+  return () => {
+    i++;
+    if (i === count) {
+      done();
+      if (callback) {
+        callback();
+      }
+    }
+  };
+};
+
+class DummyAdapter extends Adapter {
+  fetchSockets(opts: BroadcastOptions): Promise<any[]> {
+    return Promise.resolve([
+      {
+        id: "42",
+        handshake: {
+          headers: {
+            accept: "*/*",
+          },
+          query: {
+            transport: "polling",
+            EIO: "4",
+          },
+        },
+        rooms: ["42", "room1"],
+        data: {
+          username: "john",
+        },
+      },
+    ]);
+  }
+}
+
+describe("socket.io", () => {
+  let io: Server, clientSockets: ClientSocket[], serverSockets: Socket[];
+  beforeEach((done) => {
+    const srv = createServer();
+    io = new Server(srv);
+    srv.listen(() => {
+      const port = (srv.address() as AddressInfo).port;
+
+      clientSockets = [];
+      for (let i = 0; i < SOCKETS_COUNT; i++) {
+        clientSockets.push(ioc(`http://localhost:${port}`));
+      }
+
+      serverSockets = [];
+      io.on("connection", (socket: Socket) => {
+        serverSockets.push(socket);
+        if (serverSockets.length === SOCKETS_COUNT) {
+          done();
+        }
+      });
+    });
+  });
+
+  afterEach(() => {
+    io.close();
+    clientSockets.forEach((socket) => socket.disconnect());
+  });
+
+  describe("utility methods", () => {
+    describe("fetchSockets", () => {
+      it("returns all socket instances", async () => {
+        const sockets = await io.fetchSockets();
+        expect(sockets.length).to.eql(3);
+      });
+
+      it("returns all socket instances in the given room", async () => {
+        serverSockets[0].join(["room1", "room2"]);
+        serverSockets[1].join("room1");
+        serverSockets[2].join("room2");
+        const sockets = await io.in("room1").fetchSockets();
+        expect(sockets.length).to.eql(2);
+      });
+
+      it("works with a custom adapter", async () => {
+        io.adapter(DummyAdapter);
+        const sockets = await io.fetchSockets();
+        expect(sockets.length).to.eql(1);
+        const remoteSocket = sockets[0];
+        expect(remoteSocket.id).to.eql("42");
+        expect(remoteSocket.rooms).to.contain("42", "room1");
+        expect(remoteSocket.data).to.eql({ username: "john" });
+      });
+    });
+
+    describe("socketsJoin", () => {
+      it("makes all socket instances join the given room", () => {
+        io.socketsJoin("room1");
+        serverSockets.forEach((socket) => {
+          expect(socket.rooms).to.contain("room1");
+        });
+      });
+
+      it("makes all socket instances in a room join the given room", () => {
+        serverSockets[0].join(["room1", "room2"]);
+        serverSockets[1].join("room1");
+        serverSockets[2].join("room2");
+        io.in("room1").socketsJoin("room3");
+        expect(serverSockets[0].rooms).to.contain("room3");
+        expect(serverSockets[1].rooms).to.contain("room3");
+        expect(serverSockets[2].rooms).to.not.contain("room3");
+      });
+    });
+
+    describe("socketsLeave", () => {
+      it("makes all socket instances leave the given room", () => {
+        serverSockets[0].join(["room1", "room2"]);
+        serverSockets[1].join("room1");
+        serverSockets[2].join("room2");
+        io.socketsLeave("room1");
+        expect(serverSockets[0].rooms).to.contain("room2");
+        expect(serverSockets[0].rooms).to.not.contain("room1");
+        expect(serverSockets[1].rooms).to.not.contain("room1");
+      });
+
+      it("makes all socket instances in a room leave the given room", () => {
+        serverSockets[0].join(["room1", "room2"]);
+        serverSockets[1].join("room1");
+        serverSockets[2].join("room2");
+        io.in("room2").socketsLeave("room1");
+        expect(serverSockets[0].rooms).to.contain("room2");
+        expect(serverSockets[0].rooms).to.not.contain("room1");
+        expect(serverSockets[1].rooms).to.contain("room1");
+      });
+    });
+
+    describe("disconnectSockets", () => {
+      it("makes all socket instances disconnect", (done) => {
+        io.disconnectSockets(true);
+
+        const partialDone = createPartialDone(3, done);
+
+        clientSockets[0].on("disconnect", partialDone);
+        clientSockets[1].on("disconnect", partialDone);
+        clientSockets[2].on("disconnect", partialDone);
+      });
+
+      it("makes all socket instances in a room disconnect", (done) => {
+        serverSockets[0].join(["room1", "room2"]);
+        serverSockets[1].join("room1");
+        serverSockets[2].join("room2");
+        io.in("room2").disconnectSockets(true);
+
+        const partialDone = createPartialDone(2, done, () => {
+          clientSockets[1].off("disconnect");
+        });
+
+        clientSockets[0].on("disconnect", partialDone);
+        clientSockets[1].on("disconnect", () => {
+          done(new Error("should not happen"));
+        });
+        clientSockets[2].on("disconnect", partialDone);
+      });
+    });
+  });
+});
Author	SHA1	Message	Date
Damien Arrachequesne	5eaeffc8e2	chore(release): 4.0.0 Diff: https://github.com/socketio/socket.io/compare/3.1.2...4.0.0	2021-03-10 12:43:53 +01:00
Damien Arrachequesne	1b6d6de4ed	chore: include Engine.IO v5 Release notes: https://github.com/socketio/engine.io/releases/tag/5.0.0	2021-03-10 11:14:33 +01:00
Maxime Kjaer	0107510ba8	feat: add support for typed events (#3822 ) Syntax: ```ts interface ClientToServerEvents { "my-event": (a: number, b: string, c: number[]) => void; } interface ServerToClientEvents { hello: (message: string) => void; } const io = new Server<ClientToServerEvents, ServerToClientEvents>(httpServer); io.emit("hello", "world"); io.on("connection", (socket) => { socket.on("my-event", (a, b, c) => { // ... }); socket.emit("hello", "again"); }); ``` The events are not typed by default (inferred as any), so this change is backward compatible. Note: we could also have reused the method here ([1]) to add types to the EventEmitter, instead of creating a StrictEventEmitter class. Related: https://github.com/socketio/socket.io/issues/3742 [1]: https://github.com/binier/tiny-typed-emitter	2021-03-10 00:18:13 +01:00
Damien Arrachequesne	b25495c069	feat: add some utility methods This commit adds the following methods: - fetchSockets: returns the matching socket instances Syntax: ```js // return all Socket instances const sockets = await io.fetchSockets(); // return all Socket instances of the "admin" namespace in the "room1" room const sockets = await io.of("/admin").in("room1").fetchSockets(); ``` - socketsJoin: makes the matching socket instances join the specified rooms Syntax: ```js // make all Socket instances join the "room1" room io.socketsJoin("room1"); // make all Socket instances of the "admin" namespace in the "room1" room join the "room2" room io.of("/admin").in("room1").socketsJoin("room2"); ``` - socketsLeave: makes the matching socket instances leave the specified rooms Syntax: ```js // make all Socket instances leave the "room1" room io.socketsLeave("room1"); // make all Socket instances of the "admin" namespace in the "room1" room leave the "room2" room io.of("/admin").in("room1").socketsLeave("room2"); ``` - disconnectSockets: makes the matching socket instances disconnect Syntax: ```js // make all Socket instances disconnect io.disconnectSockets(); // make all Socket instances of the "admin" namespace in the "room1" room disconnect io.of("/admin").in("room1").disconnectSockets(); ``` Those methods share the same semantics as broadcasting. They will also work with multiple Socket.IO servers when using the Redis adapter. In that case, the fetchSockets() method will return a list of RemoteSocket instances, which expose a subset of the methods and attributes of the Socket class (the "request" attribute cannot be mocked, for example). Related: - https://github.com/socketio/socket.io/issues/3042 - https://github.com/socketio/socket.io/issues/3418 - https://github.com/socketio/socket.io/issues/3570 - https://github.com/socketio/socket.io-redis/issues/283	2021-03-02 11:17:21 +01:00
Damien Arrachequesne	085d1de9df	feat: allow to pass an array to io.to(...) In some cases it is necessary to pass an array of rooms instead of a single room. New syntax: ``` io.to(["room1", "room2"]).except(["room3"]).emit(...); socket.to(["room1", "room2"]).except(["room3"]).emit(...); ``` Related: https://github.com/socketio/socket.io/issues/3048	2021-03-01 23:20:46 +01:00
Damien Arrachequesne	ac9e8ca6c7	fix: make io.to(...) immutable Previously, broadcasting to a given room (by calling `io.to()`) would mutate the io instance, which could lead to surprising behaviors, like: ```js io.to("room1"); io.to("room2").emit(...); // also sent to room1 // or with async/await io.to("room3").emit("details", await fetchDetails()); // random behavior: maybe in room3, maybe to all clients ``` Calling `io.to()` (or any other broadcast modifier) will now return an immutable instance. Related: - https://github.com/socketio/socket.io/issues/3431 - https://github.com/socketio/socket.io/issues/3444	2021-03-01 23:17:08 +01:00
Sebastiaan Marynissen	7de2e87e88	feat: allow to exclude specific rooms when broadcasting (#3789 ) New syntax: ``` io.except("room1").emit(...); io.to("room1").except("room2").emit(...); socket.broadcast.except("room1").emit(...); socket.to("room1").except("room2").emit(...); ``` Related: - https://github.com/socketio/socket.io/issues/3629 - https://github.com/socketio/socket.io/issues/3657	2021-03-01 09:30:58 +01:00