From c7998d544688ce2d3e793e7b5af4dc37b67dfe1f Mon Sep 17 00:00:00 2001
From: Damien Arrachequesne <damien.arrachequesne@gmail.com>
Date: Wed, 14 Oct 2020 22:59:58 +0200
Subject: [PATCH] refactor: add Manager and Socket typings

---
 build/index.d.ts                      |  13 -
 build/index.js                        |  81 -----
 build/manager.d.ts                    | 167 ---------
 build/manager.js                      | 459 -------------------------
 build/on.d.ts                         |   3 -
 build/on.js                           |  12 -
 build/socket.d.ts                     | 148 --------
 build/socket.js                       | 388 ---------------------
 build/url.d.ts                        |   9 -
 build/url.js                          |  68 ----
 lib/index.ts                          |  22 +-
 lib/manager.ts                        | 471 ++++++++++++++++++++------
 lib/socket.ts                         | 150 ++++----
 lib/url.ts                            |  10 +-
 package.json                          |  15 +-
 test/{connection.js => connection.ts} |  62 ++--
 test/index.js                         |   6 +-
 test/{socket.js => socket.ts}         |   4 +-
 test/{url.js => url.ts}               |   7 +-
 tsconfig.json                         |   2 +-
 zuul.config.js                        |  26 +-
 21 files changed, 532 insertions(+), 1591 deletions(-)
 delete mode 100644 build/index.d.ts
 delete mode 100644 build/index.js
 delete mode 100644 build/manager.d.ts
 delete mode 100644 build/manager.js
 delete mode 100644 build/on.d.ts
 delete mode 100644 build/on.js
 delete mode 100644 build/socket.d.ts
 delete mode 100644 build/socket.js
 delete mode 100644 build/url.d.ts
 delete mode 100644 build/url.js
 rename test/{connection.js => connection.ts} (93%)
 rename test/{socket.js => socket.ts} (98%)
 rename test/{url.js => url.ts} (96%)

diff --git a/build/index.d.ts b/build/index.d.ts
deleted file mode 100644
index 052d9b51f..000000000
--- a/build/index.d.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-/**
- * Protocol version.
- *
- * @api public
- */
-export { protocol } from "socket.io-parser";
-/**
- * Expose constructors for standalone build.
- *
- * @api public
- */
-export { Manager } from "./manager";
-export { Socket } from "./socket";
diff --git a/build/index.js b/build/index.js
deleted file mode 100644
index 594239761..000000000
--- a/build/index.js
+++ /dev/null
@@ -1,81 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.Socket = exports.Manager = exports.protocol = void 0;
-const url_1 = require("./url");
-const manager_1 = require("./manager");
-const debug = require("debug")("socket.io-client");
-/**
- * Module exports.
- */
-module.exports = exports = lookup;
-/**
- * Managers cache.
- */
-const cache = (exports.managers = {});
-/**
- * Looks up an existing `Manager` for multiplexing.
- * If the user summons:
- *
- *   `io('http://localhost/a');`
- *   `io('http://localhost/b');`
- *
- * We reuse the existing instance based on same scheme/port/host,
- * and we initialize sockets for each namespace.
- *
- * @api public
- */
-function lookup(uri, opts) {
-    if (typeof uri === "object") {
-        opts = uri;
-        uri = undefined;
-    }
-    opts = opts || {};
-    const parsed = url_1.url(uri);
-    const source = parsed.source;
-    const id = parsed.id;
-    const path = parsed.path;
-    const sameNamespace = cache[id] && path in cache[id].nsps;
-    const newConnection = opts.forceNew ||
-        opts["force new connection"] ||
-        false === opts.multiplex ||
-        sameNamespace;
-    let io;
-    if (newConnection) {
-        debug("ignoring socket cache for %s", source);
-        io = new manager_1.Manager(source, opts);
-    }
-    else {
-        if (!cache[id]) {
-            debug("new io instance for %s", source);
-            cache[id] = new manager_1.Manager(source, opts);
-        }
-        io = cache[id];
-    }
-    if (parsed.query && !opts.query) {
-        opts.query = parsed.query;
-    }
-    return io.socket(parsed.path, opts);
-}
-/**
- * Protocol version.
- *
- * @api public
- */
-var socket_io_parser_1 = require("socket.io-parser");
-Object.defineProperty(exports, "protocol", { enumerable: true, get: function () { return socket_io_parser_1.protocol; } });
-/**
- * `connect`.
- *
- * @param {String} uri
- * @api public
- */
-exports.connect = lookup;
-/**
- * Expose constructors for standalone build.
- *
- * @api public
- */
-var manager_2 = require("./manager");
-Object.defineProperty(exports, "Manager", { enumerable: true, get: function () { return manager_2.Manager; } });
-var socket_1 = require("./socket");
-Object.defineProperty(exports, "Socket", { enumerable: true, get: function () { return socket_1.Socket; } });
diff --git a/build/manager.d.ts b/build/manager.d.ts
deleted file mode 100644
index 465697691..000000000
--- a/build/manager.d.ts
+++ /dev/null
@@ -1,167 +0,0 @@
-import Emitter from "component-emitter";
-export declare class Manager extends Emitter {
-    autoConnect: boolean;
-    readyState: "opening" | "open" | "closed";
-    reconnecting: boolean;
-    private readonly uri;
-    private readonly opts;
-    private nsps;
-    private subs;
-    private backoff;
-    private _reconnection;
-    private _reconnectionAttempts;
-    private _reconnectionDelay;
-    private _randomizationFactor;
-    private _reconnectionDelayMax;
-    private _timeout;
-    private connecting;
-    private encoder;
-    private decoder;
-    private engine;
-    private skipReconnect;
-    /**
-     * `Manager` constructor.
-     *
-     * @param {String} engine instance or engine uri/opts
-     * @param {Object} options
-     * @api public
-     */
-    constructor(uri: any, opts: any);
-    /**
-     * Sets the `reconnection` config.
-     *
-     * @param {Boolean} true/false if it should automatically reconnect
-     * @return {Manager} self or value
-     * @api public
-     */
-    reconnection(v?: any): boolean | this;
-    /**
-     * Sets the reconnection attempts config.
-     *
-     * @param {Number} max reconnection attempts before giving up
-     * @return {Manager} self or value
-     * @api public
-     */
-    reconnectionAttempts(v?: any): number | this;
-    /**
-     * Sets the delay between reconnections.
-     *
-     * @param {Number} delay
-     * @return {Manager} self or value
-     * @api public
-     */
-    reconnectionDelay(v?: any): number | this;
-    randomizationFactor(v?: any): number | this;
-    /**
-     * Sets the maximum delay between reconnections.
-     *
-     * @param {Number} delay
-     * @return {Manager} self or value
-     * @api public
-     */
-    reconnectionDelayMax(v?: any): number | this;
-    /**
-     * Sets the connection timeout. `false` to disable
-     *
-     * @return {Manager} self or value
-     * @api public
-     */
-    timeout(v?: any): any;
-    /**
-     * Starts trying to reconnect if reconnection is enabled and we have not
-     * started reconnecting yet
-     *
-     * @api private
-     */
-    maybeReconnectOnOpen(): void;
-    /**
-     * Sets the current transport `socket`.
-     *
-     * @param {Function} optional, callback
-     * @return {Manager} self
-     * @api public
-     */
-    open(fn?: any, opts?: any): Manager;
-    connect(fn: any, opts: any): Manager;
-    /**
-     * Called upon transport open.
-     *
-     * @api private
-     */
-    onopen(): void;
-    /**
-     * Called upon a ping.
-     *
-     * @api private
-     */
-    onping(): void;
-    /**
-     * Called with data.
-     *
-     * @api private
-     */
-    ondata(data: any): void;
-    /**
-     * Called when parser fully decodes a packet.
-     *
-     * @api private
-     */
-    ondecoded(packet: any): void;
-    /**
-     * Called upon socket error.
-     *
-     * @api private
-     */
-    onerror(err: any): void;
-    /**
-     * Creates a new socket for the given `nsp`.
-     *
-     * @return {Socket}
-     * @api public
-     */
-    socket(nsp: any, opts: any): any;
-    /**
-     * Called upon a socket close.
-     *
-     * @param {Socket} socket
-     */
-    destroy(socket: any): void;
-    /**
-     * Writes a packet.
-     *
-     * @param {Object} packet
-     * @api private
-     */
-    packet(packet: any): void;
-    /**
-     * Clean up transport subscriptions and packet buffer.
-     *
-     * @api private
-     */
-    cleanup(): void;
-    /**
-     * Close the current socket.
-     *
-     * @api private
-     */
-    close(): void;
-    disconnect(): void;
-    /**
-     * Called upon engine close.
-     *
-     * @api private
-     */
-    onclose(reason: any): void;
-    /**
-     * Attempt a reconnection.
-     *
-     * @api private
-     */
-    reconnect(): this;
-    /**
-     * Called upon successful reconnect.
-     *
-     * @api private
-     */
-    onreconnect(): void;
-}
diff --git a/build/manager.js b/build/manager.js
deleted file mode 100644
index 8eb0aa33d..000000000
--- a/build/manager.js
+++ /dev/null
@@ -1,459 +0,0 @@
-"use strict";
-var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) {
-    if (k2 === undefined) k2 = k;
-    Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } });
-}) : (function(o, m, k, k2) {
-    if (k2 === undefined) k2 = k;
-    o[k2] = m[k];
-}));
-var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) {
-    Object.defineProperty(o, "default", { enumerable: true, value: v });
-}) : function(o, v) {
-    o["default"] = v;
-});
-var __importStar = (this && this.__importStar) || function (mod) {
-    if (mod && mod.__esModule) return mod;
-    var result = {};
-    if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k);
-    __setModuleDefault(result, mod);
-    return result;
-};
-var __importDefault = (this && this.__importDefault) || function (mod) {
-    return (mod && mod.__esModule) ? mod : { "default": mod };
-};
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.Manager = void 0;
-const engine_io_client_1 = __importDefault(require("engine.io-client"));
-const socket_1 = require("./socket");
-const component_emitter_1 = __importDefault(require("component-emitter"));
-const parser = __importStar(require("socket.io-parser"));
-const on_1 = require("./on");
-const component_bind_1 = __importDefault(require("component-bind"));
-const indexof_1 = __importDefault(require("indexof"));
-const backo2_1 = __importDefault(require("backo2"));
-const debug = require("debug")("socket.io-client:manager");
-/**
- * IE6+ hasOwnProperty
- */
-const has = Object.prototype.hasOwnProperty;
-class Manager extends component_emitter_1.default {
-    /**
-     * `Manager` constructor.
-     *
-     * @param {String} engine instance or engine uri/opts
-     * @param {Object} options
-     * @api public
-     */
-    constructor(uri, opts) {
-        super();
-        this.nsps = {};
-        this.subs = [];
-        this.connecting = [];
-        if (uri && "object" === typeof uri) {
-            opts = uri;
-            uri = undefined;
-        }
-        opts = opts || {};
-        opts.path = opts.path || "/socket.io";
-        this.opts = opts;
-        this.reconnection(opts.reconnection !== false);
-        this.reconnectionAttempts(opts.reconnectionAttempts || Infinity);
-        this.reconnectionDelay(opts.reconnectionDelay || 1000);
-        this.reconnectionDelayMax(opts.reconnectionDelayMax || 5000);
-        this.randomizationFactor(opts.randomizationFactor || 0.5);
-        this.backoff = new backo2_1.default({
-            min: this.reconnectionDelay(),
-            max: this.reconnectionDelayMax(),
-            jitter: this.randomizationFactor(),
-        });
-        this.timeout(null == opts.timeout ? 20000 : opts.timeout);
-        this.readyState = "closed";
-        this.uri = uri;
-        const _parser = opts.parser || parser;
-        this.encoder = new _parser.Encoder();
-        this.decoder = new _parser.Decoder();
-        this.autoConnect = opts.autoConnect !== false;
-        if (this.autoConnect)
-            this.open();
-    }
-    /**
-     * Sets the `reconnection` config.
-     *
-     * @param {Boolean} true/false if it should automatically reconnect
-     * @return {Manager} self or value
-     * @api public
-     */
-    reconnection(v) {
-        if (!arguments.length)
-            return this._reconnection;
-        this._reconnection = !!v;
-        return this;
-    }
-    /**
-     * Sets the reconnection attempts config.
-     *
-     * @param {Number} max reconnection attempts before giving up
-     * @return {Manager} self or value
-     * @api public
-     */
-    reconnectionAttempts(v) {
-        if (!arguments.length)
-            return this._reconnectionAttempts;
-        this._reconnectionAttempts = v;
-        return this;
-    }
-    /**
-     * Sets the delay between reconnections.
-     *
-     * @param {Number} delay
-     * @return {Manager} self or value
-     * @api public
-     */
-    reconnectionDelay(v) {
-        if (!arguments.length)
-            return this._reconnectionDelay;
-        this._reconnectionDelay = v;
-        this.backoff && this.backoff.setMin(v);
-        return this;
-    }
-    randomizationFactor(v) {
-        if (!arguments.length)
-            return this._randomizationFactor;
-        this._randomizationFactor = v;
-        this.backoff && this.backoff.setJitter(v);
-        return this;
-    }
-    /**
-     * Sets the maximum delay between reconnections.
-     *
-     * @param {Number} delay
-     * @return {Manager} self or value
-     * @api public
-     */
-    reconnectionDelayMax(v) {
-        if (!arguments.length)
-            return this._reconnectionDelayMax;
-        this._reconnectionDelayMax = v;
-        this.backoff && this.backoff.setMax(v);
-        return this;
-    }
-    /**
-     * Sets the connection timeout. `false` to disable
-     *
-     * @return {Manager} self or value
-     * @api public
-     */
-    timeout(v) {
-        if (!arguments.length)
-            return this._timeout;
-        this._timeout = v;
-        return this;
-    }
-    /**
-     * Starts trying to reconnect if reconnection is enabled and we have not
-     * started reconnecting yet
-     *
-     * @api private
-     */
-    maybeReconnectOnOpen() {
-        // Only try to reconnect if it's the first time we're connecting
-        if (!this.reconnecting &&
-            this._reconnection &&
-            this.backoff.attempts === 0) {
-            // keeps reconnection from firing twice for the same reconnection loop
-            this.reconnect();
-        }
-    }
-    /**
-     * Sets the current transport `socket`.
-     *
-     * @param {Function} optional, callback
-     * @return {Manager} self
-     * @api public
-     */
-    open(fn, opts) {
-        debug("readyState %s", this.readyState);
-        if (~this.readyState.indexOf("open"))
-            return this;
-        debug("opening %s", this.uri);
-        this.engine = engine_io_client_1.default(this.uri, this.opts);
-        const socket = this.engine;
-        const self = this;
-        this.readyState = "opening";
-        this.skipReconnect = false;
-        // emit `open`
-        const openSub = on_1.on(socket, "open", function () {
-            self.onopen();
-            fn && fn();
-        });
-        // emit `connect_error`
-        const errorSub = on_1.on(socket, "error", (err) => {
-            debug("connect_error");
-            self.cleanup();
-            self.readyState = "closed";
-            super.emit("connect_error", err);
-            if (fn) {
-                fn(err);
-            }
-            else {
-                // Only do this if there is no fn to handle the error
-                self.maybeReconnectOnOpen();
-            }
-        });
-        // emit `connect_timeout`
-        if (false !== this._timeout) {
-            const timeout = this._timeout;
-            debug("connect attempt will timeout after %d", timeout);
-            if (timeout === 0) {
-                openSub.destroy(); // prevents a race condition with the 'open' event
-            }
-            // set timer
-            const timer = setTimeout(() => {
-                debug("connect attempt timed out after %d", timeout);
-                openSub.destroy();
-                socket.close();
-                socket.emit("error", "timeout");
-                super.emit("connect_error", new Error("timeout"));
-            }, timeout);
-            this.subs.push({
-                destroy: function () {
-                    clearTimeout(timer);
-                },
-            });
-        }
-        this.subs.push(openSub);
-        this.subs.push(errorSub);
-        return this;
-    }
-    connect(fn, opts) {
-        return this.open(fn, opts);
-    }
-    /**
-     * Called upon transport open.
-     *
-     * @api private
-     */
-    onopen() {
-        debug("open");
-        // clear old subs
-        this.cleanup();
-        // mark as open
-        this.readyState = "open";
-        super.emit("open");
-        // add new subs
-        const socket = this.engine;
-        this.subs.push(on_1.on(socket, "data", component_bind_1.default(this, "ondata")));
-        this.subs.push(on_1.on(socket, "ping", component_bind_1.default(this, "onping")));
-        this.subs.push(on_1.on(socket, "error", component_bind_1.default(this, "onerror")));
-        this.subs.push(on_1.on(socket, "close", component_bind_1.default(this, "onclose")));
-        this.subs.push(on_1.on(this.decoder, "decoded", component_bind_1.default(this, "ondecoded")));
-    }
-    /**
-     * Called upon a ping.
-     *
-     * @api private
-     */
-    onping() {
-        super.emit("ping");
-    }
-    /**
-     * Called with data.
-     *
-     * @api private
-     */
-    ondata(data) {
-        this.decoder.add(data);
-    }
-    /**
-     * Called when parser fully decodes a packet.
-     *
-     * @api private
-     */
-    ondecoded(packet) {
-        super.emit("packet", packet);
-    }
-    /**
-     * Called upon socket error.
-     *
-     * @api private
-     */
-    onerror(err) {
-        debug("error", err);
-        super.emit("error", err);
-    }
-    /**
-     * Creates a new socket for the given `nsp`.
-     *
-     * @return {Socket}
-     * @api public
-     */
-    socket(nsp, opts) {
-        let socket = this.nsps[nsp];
-        if (!socket) {
-            socket = new socket_1.Socket(this, nsp, opts);
-            this.nsps[nsp] = socket;
-            var self = this;
-            socket.on("connecting", onConnecting);
-            if (this.autoConnect) {
-                // manually call here since connecting event is fired before listening
-                onConnecting();
-            }
-        }
-        function onConnecting() {
-            if (!~indexof_1.default(self.connecting, socket)) {
-                self.connecting.push(socket);
-            }
-        }
-        return socket;
-    }
-    /**
-     * Called upon a socket close.
-     *
-     * @param {Socket} socket
-     */
-    destroy(socket) {
-        const index = indexof_1.default(this.connecting, socket);
-        if (~index)
-            this.connecting.splice(index, 1);
-        if (this.connecting.length)
-            return;
-        this.close();
-    }
-    /**
-     * Writes a packet.
-     *
-     * @param {Object} packet
-     * @api private
-     */
-    packet(packet) {
-        debug("writing packet %j", packet);
-        if (packet.query && packet.type === 0)
-            packet.nsp += "?" + packet.query;
-        const encodedPackets = this.encoder.encode(packet);
-        for (let i = 0; i < encodedPackets.length; i++) {
-            this.engine.write(encodedPackets[i], packet.options);
-        }
-    }
-    /**
-     * Clean up transport subscriptions and packet buffer.
-     *
-     * @api private
-     */
-    cleanup() {
-        debug("cleanup");
-        const subsLength = this.subs.length;
-        for (let i = 0; i < subsLength; i++) {
-            const sub = this.subs.shift();
-            sub.destroy();
-        }
-        this.decoder.destroy();
-    }
-    /**
-     * Close the current socket.
-     *
-     * @api private
-     */
-    close() {
-        debug("disconnect");
-        this.skipReconnect = true;
-        this.reconnecting = false;
-        if ("opening" === this.readyState) {
-            // `onclose` will not fire because
-            // an open event never happened
-            this.cleanup();
-        }
-        this.backoff.reset();
-        this.readyState = "closed";
-        if (this.engine)
-            this.engine.close();
-    }
-    disconnect() {
-        debug("disconnect");
-        this.skipReconnect = true;
-        this.reconnecting = false;
-        if ("opening" === this.readyState) {
-            // `onclose` will not fire because
-            // an open event never happened
-            this.cleanup();
-        }
-        this.backoff.reset();
-        this.readyState = "closed";
-        if (this.engine)
-            this.engine.close();
-    }
-    /**
-     * Called upon engine close.
-     *
-     * @api private
-     */
-    onclose(reason) {
-        debug("onclose");
-        this.cleanup();
-        this.backoff.reset();
-        this.readyState = "closed";
-        super.emit("close", reason);
-        if (this._reconnection && !this.skipReconnect) {
-            this.reconnect();
-        }
-    }
-    /**
-     * Attempt a reconnection.
-     *
-     * @api private
-     */
-    reconnect() {
-        if (this.reconnecting || this.skipReconnect)
-            return this;
-        const self = this;
-        if (this.backoff.attempts >= this._reconnectionAttempts) {
-            debug("reconnect failed");
-            this.backoff.reset();
-            super.emit("reconnect_failed");
-            this.reconnecting = false;
-        }
-        else {
-            const delay = this.backoff.duration();
-            debug("will wait %dms before reconnect attempt", delay);
-            this.reconnecting = true;
-            const timer = setTimeout(() => {
-                if (self.skipReconnect)
-                    return;
-                debug("attempting reconnect");
-                super.emit("reconnect_attempt", self.backoff.attempts);
-                super.emit("reconnecting", self.backoff.attempts);
-                // check again for the case socket closed in above events
-                if (self.skipReconnect)
-                    return;
-                self.open((err) => {
-                    if (err) {
-                        debug("reconnect attempt error");
-                        self.reconnecting = false;
-                        self.reconnect();
-                        super.emit("reconnect_error", err);
-                    }
-                    else {
-                        debug("reconnect success");
-                        self.onreconnect();
-                    }
-                });
-            }, delay);
-            this.subs.push({
-                destroy: function () {
-                    clearTimeout(timer);
-                },
-            });
-        }
-    }
-    /**
-     * Called upon successful reconnect.
-     *
-     * @api private
-     */
-    onreconnect() {
-        const attempt = this.backoff.attempts;
-        this.reconnecting = false;
-        this.backoff.reset();
-        super.emit("reconnect", attempt);
-    }
-}
-exports.Manager = Manager;
diff --git a/build/on.d.ts b/build/on.d.ts
deleted file mode 100644
index add15fead..000000000
--- a/build/on.d.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-export declare function on(obj: any, ev: any, fn: any): {
-    destroy: () => void;
-};
diff --git a/build/on.js b/build/on.js
deleted file mode 100644
index c18ba5af5..000000000
--- a/build/on.js
+++ /dev/null
@@ -1,12 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.on = void 0;
-function on(obj, ev, fn) {
-    obj.on(ev, fn);
-    return {
-        destroy: function () {
-            obj.removeListener(ev, fn);
-        },
-    };
-}
-exports.on = on;
diff --git a/build/socket.d.ts b/build/socket.d.ts
deleted file mode 100644
index 743e100f9..000000000
--- a/build/socket.d.ts
+++ /dev/null
@@ -1,148 +0,0 @@
-import Emitter from "component-emitter";
-import { Manager } from "./manager";
-export declare class Socket extends Emitter {
-    readonly io: Manager;
-    id: string;
-    connected: boolean;
-    disconnected: boolean;
-    private readonly nsp;
-    private readonly auth;
-    private ids;
-    private acks;
-    private receiveBuffer;
-    private sendBuffer;
-    private flags;
-    private subs;
-    /**
-     * `Socket` constructor.
-     *
-     * @api public
-     */
-    constructor(io: any, nsp: any, opts: any);
-    /**
-     * Subscribe to open, close and packet events
-     *
-     * @api private
-     */
-    subEvents(): void;
-    /**
-     * "Opens" the socket.
-     *
-     * @api public
-     */
-    open(): this;
-    connect(): this;
-    /**
-     * Sends a `message` event.
-     *
-     * @return {Socket} self
-     * @api public
-     */
-    send(): this;
-    /**
-     * Override `emit`.
-     * If the event is in `events`, it's emitted normally.
-     *
-     * @param {String} event name
-     * @return {Socket} self
-     * @api public
-     */
-    emit(ev: any): this;
-    /**
-     * Sends a packet.
-     *
-     * @param {Object} packet
-     * @api private
-     */
-    packet(packet: any): void;
-    /**
-     * Called upon engine `open`.
-     *
-     * @api private
-     */
-    onopen(): void;
-    /**
-     * Called upon engine `close`.
-     *
-     * @param {String} reason
-     * @api private
-     */
-    onclose(reason: any): void;
-    /**
-     * Called with socket packet.
-     *
-     * @param {Object} packet
-     * @api private
-     */
-    onpacket(packet: any): void;
-    /**
-     * Called upon a server event.
-     *
-     * @param {Object} packet
-     * @api private
-     */
-    onevent(packet: any): void;
-    /**
-     * Produces an ack callback to emit with an event.
-     *
-     * @api private
-     */
-    ack(id: any): () => void;
-    /**
-     * Called upon a server acknowlegement.
-     *
-     * @param {Object} packet
-     * @api private
-     */
-    onack(packet: any): void;
-    /**
-     * Called upon server connect.
-     *
-     * @api private
-     */
-    onconnect(id: string): void;
-    /**
-     * Emit buffered events (received and emitted).
-     *
-     * @api private
-     */
-    emitBuffered(): void;
-    /**
-     * Called upon server disconnect.
-     *
-     * @api private
-     */
-    ondisconnect(): void;
-    /**
-     * Called upon forced client/server side disconnections,
-     * this method ensures the manager stops tracking us and
-     * that reconnections don't get triggered for this.
-     *
-     * @api private.
-     */
-    destroy(): void;
-    /**
-     * Disconnects the socket manually.
-     *
-     * @return {Socket} self
-     * @api public
-     */
-    close(): this;
-    disconnect(): this;
-    /**
-     * Sets the compress flag.
-     *
-     * @param {Boolean} if `true`, compresses the sending data
-     * @return {Socket} self
-     * @api public
-     */
-    compress(compress: any): this;
-    /**
-     * Sets the binary flag
-     *
-     * @param {Boolean} whether the emitted data contains binary
-     * @return {Socket} self
-     * @api public
-     */
-    binary(binary: any): this;
-}
diff --git a/build/socket.js b/build/socket.js
deleted file mode 100644
index b59460bde..000000000
--- a/build/socket.js
+++ /dev/null
@@ -1,388 +0,0 @@
-"use strict";
-var __importDefault = (this && this.__importDefault) || function (mod) {
-    return (mod && mod.__esModule) ? mod : { "default": mod };
-};
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.Socket = void 0;
-const socket_io_parser_1 = require("socket.io-parser");
-const component_emitter_1 = __importDefault(require("component-emitter"));
-const to_array_1 = __importDefault(require("to-array"));
-const on_1 = require("./on");
-const component_bind_1 = __importDefault(require("component-bind"));
-const has_binary2_1 = __importDefault(require("has-binary2"));
-const debug = require("debug")("socket.io-client:socket");
-/**
- * Internal events.
- * These events can't be emitted by the user.
- *
- * @api private
- */
-const RESERVED_EVENTS = {
-    connect: 1,
-    disconnect: 1,
-    disconnecting: 1,
-    error: 1,
-    // EventEmitter reserved events: https://nodejs.org/api/events.html#events_event_newlistener
-    newListener: 1,
-    removeListener: 1,
-};
-class Socket extends component_emitter_1.default {
-    /**
-     * `Socket` constructor.
-     *
-     * @api public
-     */
-    constructor(io, nsp, opts) {
-        super();
-        this.ids = 0;
-        this.acks = {};
-        this.receiveBuffer = [];
-        this.sendBuffer = [];
-        this.flags = {};
-        this.io = io;
-        this.nsp = nsp;
-        this.ids = 0;
-        this.acks = {};
-        this.receiveBuffer = [];
-        this.sendBuffer = [];
-        this.connected = false;
-        this.disconnected = true;
-        this.flags = {};
-        if (opts && opts.auth) {
-            this.auth = opts.auth;
-        }
-        if (this.io.autoConnect)
-            this.open();
-    }
-    /**
-     * Subscribe to open, close and packet events
-     *
-     * @api private
-     */
-    subEvents() {
-        if (this.subs)
-            return;
-        const io = this.io;
-        this.subs = [
-            on_1.on(io, "open", component_bind_1.default(this, "onopen")),
-            on_1.on(io, "packet", component_bind_1.default(this, "onpacket")),
-            on_1.on(io, "close", component_bind_1.default(this, "onclose")),
-        ];
-    }
-    /**
-     * "Opens" the socket.
-     *
-     * @api public
-     */
-    open() {
-        if (this.connected)
-            return this;
-        this.subEvents();
-        if (!this.io.reconnecting)
-            this.io.open(); // ensure open
-        if ("open" === this.io.readyState)
-            this.onopen();
-        return this;
-    }
-    connect() {
-        if (this.connected)
-            return this;
-        this.subEvents();
-        if (!this.io.reconnecting)
-            this.io.open(); // ensure open
-        if ("open" === this.io.readyState)
-            this.onopen();
-        return this;
-    }
-    /**
-     * Sends a `message` event.
-     *
-     * @return {Socket} self
-     * @api public
-     */
-    send() {
-        const args = to_array_1.default(arguments);
-        args.unshift("message");
-        this.emit.apply(this, args);
-        return this;
-    }
-    /**
-     * Override `emit`.
-     * If the event is in `events`, it's emitted normally.
-     *
-     * @param {String} event name
-     * @return {Socket} self
-     * @api public
-     */
-    emit(ev) {
-        if (RESERVED_EVENTS.hasOwnProperty(ev)) {
-            throw new Error('"' + ev + '" is a reserved event name');
-        }
-        const args = to_array_1.default(arguments);
-        const packet = {
-            type: (this.flags.binary !== undefined ? this.flags.binary : has_binary2_1.default(args))
-                ? socket_io_parser_1.PacketType.BINARY_EVENT
-                : socket_io_parser_1.PacketType.EVENT,
-            data: args,
-        };
-        packet.options = {};
-        packet.options.compress = !this.flags || false !== this.flags.compress;
-        // event ack callback
-        if ("function" === typeof args[args.length - 1]) {
-            debug("emitting packet with ack id %d", this.ids);
-            this.acks[this.ids] = args.pop();
-            packet.id = this.ids++;
-        }
-        if (this.connected) {
-            this.packet(packet);
-        }
-        else {
-            this.sendBuffer.push(packet);
-        }
-        this.flags = {};
-        return this;
-    }
-    /**
-     * Sends a packet.
-     *
-     * @param {Object} packet
-     * @api private
-     */
-    packet(packet) {
-        packet.nsp = this.nsp;
-        this.io.packet(packet);
-    }
-    /**
-     * Called upon engine `open`.
-     *
-     * @api private
-     */
-    onopen() {
-        debug("transport is open - connecting");
-        if (typeof this.auth == "function") {
-            this.auth((data) => {
-                this.packet({ type: socket_io_parser_1.PacketType.CONNECT, data });
-            });
-        }
-        else {
-            this.packet({ type: socket_io_parser_1.PacketType.CONNECT, data: this.auth });
-        }
-    }
-    /**
-     * Called upon engine `close`.
-     *
-     * @param {String} reason
-     * @api private
-     */
-    onclose(reason) {
-        debug("close (%s)", reason);
-        this.connected = false;
-        this.disconnected = true;
-        delete this.id;
-        super.emit("disconnect", reason);
-    }
-    /**
-     * Called with socket packet.
-     *
-     * @param {Object} packet
-     * @api private
-     */
-    onpacket(packet) {
-        const sameNamespace = packet.nsp === this.nsp;
-        const rootNamespaceError = packet.type === socket_io_parser_1.PacketType.ERROR && packet.nsp === "/";
-        if (!sameNamespace && !rootNamespaceError)
-            return;
-        switch (packet.type) {
-            case socket_io_parser_1.PacketType.CONNECT:
-                const id = packet.data.sid;
-                this.onconnect(id);
-                break;
-            case socket_io_parser_1.PacketType.EVENT:
-                this.onevent(packet);
-                break;
-            case socket_io_parser_1.PacketType.BINARY_EVENT:
-                this.onevent(packet);
-                break;
-            case socket_io_parser_1.PacketType.ACK:
-                this.onack(packet);
-                break;
-            case socket_io_parser_1.PacketType.BINARY_ACK:
-                this.onack(packet);
-                break;
-            case socket_io_parser_1.PacketType.DISCONNECT:
-                this.ondisconnect();
-                break;
-            case socket_io_parser_1.PacketType.ERROR:
-                super.emit("error", packet.data);
-                break;
-        }
-    }
-    /**
-     * Called upon a server event.
-     *
-     * @param {Object} packet
-     * @api private
-     */
-    onevent(packet) {
-        const args = packet.data || [];
-        debug("emitting event %j", args);
-        if (null != packet.id) {
-            debug("attaching ack callback to event");
-            args.push(this.ack(packet.id));
-        }
-        if (this.connected) {
-            super.emit.apply(this, args);
-        }
-        else {
-            this.receiveBuffer.push(args);
-        }
-    }
-    /**
-     * Produces an ack callback to emit with an event.
-     *
-     * @api private
-     */
-    ack(id) {
-        const self = this;
-        let sent = false;
-        return function () {
-            // prevent double callbacks
-            if (sent)
-                return;
-            sent = true;
-            const args = to_array_1.default(arguments);
-            debug("sending ack %j", args);
-            self.packet({
-                type: has_binary2_1.default(args) ? socket_io_parser_1.PacketType.BINARY_ACK : socket_io_parser_1.PacketType.ACK,
-                id: id,
-                data: args,
-            });
-        };
-    }
-    /**
-     * Called upon a server acknowlegement.
-     *
-     * @param {Object} packet
-     * @api private
-     */
-    onack(packet) {
-        const ack = this.acks[packet.id];
-        if ("function" === typeof ack) {
-            debug("calling ack %s with %j", packet.id, packet.data);
-            ack.apply(this, packet.data);
-            delete this.acks[packet.id];
-        }
-        else {
-            debug("bad ack %s", packet.id);
-        }
-    }
-    /**
-     * Called upon server connect.
-     *
-     * @api private
-     */
-    onconnect(id) {
-        this.id = id;
-        this.connected = true;
-        this.disconnected = false;
-        super.emit("connect");
-        this.emitBuffered();
-    }
-    /**
-     * Emit buffered events (received and emitted).
-     *
-     * @api private
-     */
-    emitBuffered() {
-        for (let i = 0; i < this.receiveBuffer.length; i++) {
-            super.emit.apply(this, this.receiveBuffer[i]);
-        }
-        this.receiveBuffer = [];
-        for (let i = 0; i < this.sendBuffer.length; i++) {
-            this.packet(this.sendBuffer[i]);
-        }
-        this.sendBuffer = [];
-    }
-    /**
-     * Called upon server disconnect.
-     *
-     * @api private
-     */
-    ondisconnect() {
-        debug("server disconnect (%s)", this.nsp);
-        this.destroy();
-        this.onclose("io server disconnect");
-    }
-    /**
-     * Called upon forced client/server side disconnections,
-     * this method ensures the manager stops tracking us and
-     * that reconnections don't get triggered for this.
-     *
-     * @api private.
-     */
-    destroy() {
-        if (this.subs) {
-            // clean subscriptions to avoid reconnections
-            for (let i = 0; i < this.subs.length; i++) {
-                this.subs[i].destroy();
-            }
-            this.subs = null;
-        }
-        this.io.destroy(this);
-    }
-    /**
-     * Disconnects the socket manually.
-     *
-     * @return {Socket} self
-     * @api public
-     */
-    close() {
-        if (this.connected) {
-            debug("performing disconnect (%s)", this.nsp);
-            this.packet({ type: socket_io_parser_1.PacketType.DISCONNECT });
-        }
-        // remove socket from pool
-        this.destroy();
-        if (this.connected) {
-            // fire events
-            this.onclose("io client disconnect");
-        }
-        return this;
-    }
-    disconnect() {
-        if (this.connected) {
-            debug("performing disconnect (%s)", this.nsp);
-            this.packet({ type: socket_io_parser_1.PacketType.DISCONNECT });
-        }
-        // remove socket from pool
-        this.destroy();
-        if (this.connected) {
-            // fire events
-            this.onclose("io client disconnect");
-        }
-        return this;
-    }
-    /**
-     * Sets the compress flag.
-     *
-     * @param {Boolean} if `true`, compresses the sending data
-     * @return {Socket} self
-     * @api public
-     */
-    compress(compress) {
-        this.flags.compress = compress;
-        return this;
-    }
-    /**
-     * Sets the binary flag
-     *
-     * @param {Boolean} whether the emitted data contains binary
-     * @return {Socket} self
-     * @api public
-     */
-    binary(binary) {
-        this.flags.binary = binary;
-        return this;
-    }
-}
-exports.Socket = Socket;
diff --git a/build/url.d.ts b/build/url.d.ts
deleted file mode 100644
index 80b1cf729..000000000
--- a/build/url.d.ts
+++ /dev/null
@@ -1,9 +0,0 @@
-/**
- * URL parser.
- *
- * @param {String} url
- * @param {Object} An object meant to mimic window.location.
- *                 Defaults to window.location.
- * @api public
- */
-export declare function url(uri: any, loc?: any): any;
diff --git a/build/url.js b/build/url.js
deleted file mode 100644
index 79065cfb5..000000000
--- a/build/url.js
+++ /dev/null
@@ -1,68 +0,0 @@
-"use strict";
-var __importDefault = (this && this.__importDefault) || function (mod) {
-    return (mod && mod.__esModule) ? mod : { "default": mod };
-};
-Object.defineProperty(exports, "__esModule", { value: true });
-exports.url = void 0;
-const parseuri_1 = __importDefault(require("parseuri"));
-const debug = require("debug")("socket.io-client:url");
-/**
- * URL parser.
- *
- * @param {String} url
- * @param {Object} An object meant to mimic window.location.
- *                 Defaults to window.location.
- * @api public
- */
-function url(uri, loc) {
-    let obj = uri;
-    // default to window.location
-    loc = loc || (typeof location !== "undefined" && location);
-    if (null == uri)
-        uri = loc.protocol + "//" + loc.host;
-    // relative path support
-    if ("string" === typeof uri) {
-        if ("/" === uri.charAt(0)) {
-            if ("/" === uri.charAt(1)) {
-                uri = loc.protocol + uri;
-            }
-            else {
-                uri = loc.host + uri;
-            }
-        }
-        if (!/^(https?|wss?):\/\//.test(uri)) {
-            debug("protocol-less url %s", uri);
-            if ("undefined" !== typeof loc) {
-                uri = loc.protocol + "//" + uri;
-            }
-            else {
-                uri = "https://" + uri;
-            }
-        }
-        // parse
-        debug("parse %s", uri);
-        obj = parseuri_1.default(uri);
-    }
-    // make sure we treat `localhost:80` and `localhost` equally
-    if (!obj.port) {
-        if (/^(http|ws)$/.test(obj.protocol)) {
-            obj.port = "80";
-        }
-        else if (/^(http|ws)s$/.test(obj.protocol)) {
-            obj.port = "443";
-        }
-    }
-    obj.path = obj.path || "/";
-    const ipv6 = obj.host.indexOf(":") !== -1;
-    const host = ipv6 ? "[" + obj.host + "]" : obj.host;
-    // define unique id
-    obj.id = obj.protocol + "://" + host + ":" + obj.port;
-    // define href
-    obj.href =
-        obj.protocol +
-            "://" +
-            host +
-            (loc && loc.port === obj.port ? "" : ":" + obj.port);
-    return obj;
-}
-exports.url = url;
diff --git a/lib/index.ts b/lib/index.ts
index 3a07830b4..69cde969a 100644
--- a/lib/index.ts
+++ b/lib/index.ts
@@ -1,6 +1,6 @@
 import { url } from "./url";
-import { Manager } from "./manager";
-import { Socket } from "./socket";
+import { Manager, ManagerOptions } from "./manager";
+import { Socket, SocketOptions } from "./socket";
 
 const debug = require("debug")("socket.io-client");
 
@@ -25,10 +25,14 @@ const cache = (exports.managers = {});
  * We reuse the existing instance based on same scheme/port/host,
  * and we initialize sockets for each namespace.
  *
- * @api public
+ * @public
  */
-
-function lookup(uri, opts): Socket {
+function lookup(opts?: Partial<ManagerOptions | SocketOptions>): Socket;
+function lookup(
+  uri: string,
+  opts?: Partial<ManagerOptions | SocketOptions>
+): Socket;
+function lookup(uri: any, opts?: any): Socket {
   if (typeof uri === "object") {
     opts = uri;
     uri = undefined;
@@ -68,7 +72,7 @@ function lookup(uri, opts): Socket {
 /**
  * Protocol version.
  *
- * @api public
+ * @public
  */
 
 export { protocol } from "socket.io-parser";
@@ -77,7 +81,7 @@ export { protocol } from "socket.io-parser";
  * `connect`.
  *
  * @param {String} uri
- * @api public
+ * @public
  */
 
 exports.connect = lookup;
@@ -85,8 +89,8 @@ exports.connect = lookup;
 /**
  * Expose constructors for standalone build.
  *
- * @api public
+ * @public
  */
 
 export { Manager } from "./manager";
-export { Socket } from "./socket";
+export { lookup as io };
diff --git a/lib/manager.ts b/lib/manager.ts
index 289a46d08..bace6061d 100644
--- a/lib/manager.ts
+++ b/lib/manager.ts
@@ -1,24 +1,271 @@
-import eio from "engine.io-client";
-import { Socket } from "./socket";
-import Emitter from "component-emitter";
+import * as eio from "engine.io-client";
+import { Socket, SocketOptions } from "./socket";
+import * as Emitter from "component-emitter";
 import * as parser from "socket.io-parser";
 import { Decoder, Encoder } from "socket.io-parser";
 import { on } from "./on";
-import bind from "component-bind";
-import indexOf from "indexof";
-import Backoff from "backo2";
+import * as bind from "component-bind";
+import * as indexOf from "indexof";
+import * as Backoff from "backo2";
 
 const debug = require("debug")("socket.io-client:manager");
 
-/**
- * IE6+ hasOwnProperty
- */
-const has = Object.prototype.hasOwnProperty;
+interface EngineOptions {
+  /**
+   * The host that we're connecting to. Set from the URI passed when connecting
+   */
+  host: string;
+
+  /**
+   * The hostname for our connection. Set from the URI passed when connecting
+   */
+  hostname: string;
+
+  /**
+   * If this is a secure connection. Set from the URI passed when connecting
+   */
+  secure: boolean;
+
+  /**
+   * The port for our connection. Set from the URI passed when connecting
+   */
+  port: string;
+
+  /**
+   * Any query parameters in our uri. Set from the URI passed when connecting
+   */
+  query: Object;
+
+  /**
+   * `http.Agent` to use, defaults to `false` (NodeJS only)
+   */
+  agent: string | boolean;
+
+  /**
+   * Whether the client should try to upgrade the transport from
+   * long-polling to something better.
+   * @default true
+   */
+  upgrade: boolean;
+
+  /**
+   * Forces JSONP for polling transport.
+   */
+  forceJSONP: boolean;
+
+  /**
+   * Determines whether to use JSONP when necessary for polling. If
+   * disabled (by settings to false) an error will be emitted (saying
+   * "No transports available") if no other transports are available.
+   * If another transport is available for opening a connection (e.g.
+   * WebSocket) that transport will be used instead.
+   * @default true
+   */
+  jsonp: boolean;
+
+  /**
+   * Forces base 64 encoding for polling transport even when XHR2
+   * responseType is available and WebSocket even if the used standard
+   * supports binary.
+   */
+  forceBase64: boolean;
+
+  /**
+   * Enables XDomainRequest for IE8 to avoid loading bar flashing with
+   * click sound. default to `false` because XDomainRequest has a flaw
+   * of not sending cookie.
+   * @default false
+   */
+  enablesXDR: boolean;
+
+  /**
+   * The param name to use as our timestamp key
+   * @default 't'
+   */
+  timestampParam: string;
+
+  /**
+   * Whether to add the timestamp with each transport request. Note: this
+   * is ignored if the browser is IE or Android, in which case requests
+   * are always stamped
+   * @default false
+   */
+  timestampRequests: boolean;
+
+  /**
+   * A list of transports to try (in order). Engine.io always attempts to
+   * connect directly with the first one, provided the feature detection test
+   * for it passes.
+   * @default ['polling','websocket']
+   */
+  transports: string[];
+
+  /**
+   * The port the policy server listens on
+   * @default 843
+   */
+  policyPost: number;
+
+  /**
+   * If true and if the previous websocket connection to the server succeeded,
+   * the connection attempt will bypass the normal upgrade process and will
+   * initially try websocket. A connection attempt following a transport error
+   * will use the normal upgrade process. It is recommended you turn this on
+   * only when using SSL/TLS connections, or if you know that your network does
+   * not block websockets.
+   * @default false
+   */
+  rememberUpgrade: boolean;
+
+  /**
+   * Are we only interested in transports that support binary?
+   */
+  onlyBinaryUpgrades: boolean;
+
+  /**
+   * Transport options for Node.js client (headers etc)
+   */
+  transportOptions: Object;
+
+  /**
+   * (SSL) Certificate, Private key and CA certificates to use for SSL.
+   * Can be used in Node.js client environment to manually specify
+   * certificate information.
+   */
+  pfx: string;
+
+  /**
+   * (SSL) Private key to use for SSL. Can be used in Node.js client
+   * environment to manually specify certificate information.
+   */
+  key: string;
+
+  /**
+   * (SSL) A string or passphrase for the private key or pfx. Can be
+   * used in Node.js client environment to manually specify certificate
+   * information.
+   */
+  passphrase: string;
+
+  /**
+   * (SSL) Public x509 certificate to use. Can be used in Node.js client
+   * environment to manually specify certificate information.
+   */
+  cert: string;
+
+  /**
+   * (SSL) An authority certificate or array of authority certificates to
+   * check the remote host against.. Can be used in Node.js client
+   * environment to manually specify certificate information.
+   */
+  ca: string | string[];
+
+  /**
+   * (SSL) A string describing the ciphers to use or exclude. Consult the
+   * [cipher format list]
+   * (http://www.openssl.org/docs/apps/ciphers.html#CIPHER_LIST_FORMAT) for
+   * details on the format.. Can be used in Node.js client environment to
+   * manually specify certificate information.
+   */
+  ciphers: string;
+
+  /**
+   * (SSL) If true, the server certificate is verified against the list of
+   * supplied CAs. An 'error' event is emitted if verification fails.
+   * Verification happens at the connection level, before the HTTP request
+   * is sent. Can be used in Node.js client environment to manually specify
+   * certificate information.
+   */
+  rejectUnauthorized: boolean;
+}
+
+export interface ManagerOptions extends EngineOptions {
+  /**
+   * Should we force a new Manager for this connection?
+   * @default false
+   */
+  forceNew: boolean;
+
+  /**
+   * Should we multiplex our connection (reuse existing Manager) ?
+   * @default true
+   */
+  multiplex: boolean;
+
+  /**
+   * The path to get our client file from, in the case of the server
+   * serving it
+   * @default '/socket.io'
+   */
+  path: string;
+
+  /**
+   * Should we allow reconnections?
+   * @default true
+   */
+  reconnection: boolean;
+
+  /**
+   * How many reconnection attempts should we try?
+   * @default Infinity
+   */
+  reconnectionAttempts: number;
+
+  /**
+   * The time delay in milliseconds between reconnection attempts
+   * @default 1000
+   */
+  reconnectionDelay: number;
+
+  /**
+   * The max time delay in milliseconds between reconnection attempts
+   * @default 5000
+   */
+  reconnectionDelayMax: number;
+
+  /**
+   * Used in the exponential backoff jitter when reconnecting
+   * @default 0.5
+   */
+  randomizationFactor: number;
+
+  /**
+   * The timeout in milliseconds for our connection attempt
+   * @default 20000
+   */
+  timeout: number;
+
+  /**
+   * Should we automatically connect?
+   * @default true
+   */
+  autoConnect: boolean;
+
+  /**
+   * the parser to use. Defaults to an instance of the Parser that ships with socket.io.
+   */
+  parser: any;
+}
 
 export class Manager extends Emitter {
-  public autoConnect: boolean;
-  public readyState: "opening" | "open" | "closed";
-  public reconnecting: boolean;
+  /**
+   * The Engine.IO client instance
+   *
+   * @public
+   */
+  public engine: any;
+  /**
+   * @private
+   */
+  _autoConnect: boolean;
+  /**
+   * @private
+   */
+  _readyState: "opening" | "open" | "closed";
+  /**
+   * @private
+   */
+  _reconnecting: boolean;
 
   private readonly uri: string;
   private readonly opts: object;
@@ -36,17 +283,18 @@ export class Manager extends Emitter {
   private connecting: Array<Socket> = [];
   private encoder: Encoder;
   private decoder: Decoder;
-  private engine: any;
   private skipReconnect: boolean;
 
   /**
    * `Manager` constructor.
    *
-   * @param {String} engine instance or engine uri/opts
-   * @param {Object} options
-   * @api public
+   * @param {String} uri - engine instance or engine uri/opts
+   * @param {Object} opts - options
+   * @public
    */
-  constructor(uri, opts) {
+  constructor(opts: Partial<ManagerOptions>);
+  constructor(uri?: string, opts?: Partial<ManagerOptions>);
+  constructor(uri?: any, opts?: any) {
     super();
     if (uri && "object" === typeof uri) {
       opts = uri;
@@ -67,23 +315,25 @@ export class Manager extends Emitter {
       jitter: this.randomizationFactor(),
     });
     this.timeout(null == opts.timeout ? 20000 : opts.timeout);
-    this.readyState = "closed";
+    this._readyState = "closed";
     this.uri = uri;
     const _parser = opts.parser || parser;
     this.encoder = new _parser.Encoder();
     this.decoder = new _parser.Decoder();
-    this.autoConnect = opts.autoConnect !== false;
-    if (this.autoConnect) this.open();
+    this._autoConnect = opts.autoConnect !== false;
+    if (this._autoConnect) this.open();
   }
 
   /**
    * Sets the `reconnection` config.
    *
-   * @param {Boolean} true/false if it should automatically reconnect
+   * @param {Boolean} v - true/false if it should automatically reconnect
    * @return {Manager} self or value
-   * @api public
+   * @public
    */
-  reconnection(v?) {
+  public reconnection(v: boolean): Manager;
+  public reconnection(): boolean;
+  public reconnection(v?: boolean): Manager | boolean {
     if (!arguments.length) return this._reconnection;
     this._reconnection = !!v;
     return this;
@@ -92,12 +342,14 @@ export class Manager extends Emitter {
   /**
    * Sets the reconnection attempts config.
    *
-   * @param {Number} max reconnection attempts before giving up
+   * @param {Number} v - max reconnection attempts before giving up
    * @return {Manager} self or value
-   * @api public
+   * @public
    */
-  reconnectionAttempts(v?) {
-    if (!arguments.length) return this._reconnectionAttempts;
+  public reconnectionAttempts(v: number): Manager;
+  public reconnectionAttempts(): number;
+  public reconnectionAttempts(v?: number): Manager | number {
+    if (v === undefined) return this._reconnectionAttempts;
     this._reconnectionAttempts = v;
     return this;
   }
@@ -105,19 +357,30 @@ export class Manager extends Emitter {
   /**
    * Sets the delay between reconnections.
    *
-   * @param {Number} delay
+   * @param {Number} v - delay
    * @return {Manager} self or value
-   * @api public
+   * @public
    */
-  reconnectionDelay(v?) {
-    if (!arguments.length) return this._reconnectionDelay;
+  public reconnectionDelay(v: number): Manager;
+  public reconnectionDelay(): number;
+  public reconnectionDelay(v?: number): Manager | number {
+    if (v === undefined) return this._reconnectionDelay;
     this._reconnectionDelay = v;
     this.backoff && this.backoff.setMin(v);
     return this;
   }
 
-  randomizationFactor(v?) {
-    if (!arguments.length) return this._randomizationFactor;
+  /**
+   * Sets the randomization factor
+   *
+   * @param {Number} v - the randomization factor
+   * @return {Manager} self or value
+   * @public
+   */
+  public randomizationFactor(v: number): Manager;
+  public randomizationFactor(): number;
+  public randomizationFactor(v?: number): Manager | number {
+    if (v === undefined) return this._randomizationFactor;
     this._randomizationFactor = v;
     this.backoff && this.backoff.setJitter(v);
     return this;
@@ -126,12 +389,14 @@ export class Manager extends Emitter {
   /**
    * Sets the maximum delay between reconnections.
    *
-   * @param {Number} delay
+   * @param {Number} v - delay
    * @return {Manager} self or value
-   * @api public
+   * @public
    */
-  reconnectionDelayMax(v?) {
-    if (!arguments.length) return this._reconnectionDelayMax;
+  public reconnectionDelayMax(v: number): Manager;
+  public reconnectionDelayMax(): number;
+  public reconnectionDelayMax(v?: number): Manager | number {
+    if (v === undefined) return this._reconnectionDelayMax;
     this._reconnectionDelayMax = v;
     this.backoff && this.backoff.setMax(v);
     return this;
@@ -141,9 +406,11 @@ export class Manager extends Emitter {
    * Sets the connection timeout. `false` to disable
    *
    * @return {Manager} self or value
-   * @api public
+   * @public
    */
-  timeout(v?) {
+  public timeout(v: number | boolean): Manager;
+  public timeout(): number | boolean;
+  public timeout(v?: number | boolean): Manager | number | boolean {
     if (!arguments.length) return this._timeout;
     this._timeout = v;
     return this;
@@ -153,12 +420,12 @@ export class Manager extends Emitter {
    * Starts trying to reconnect if reconnection is enabled and we have not
    * started reconnecting yet
    *
-   * @api private
+   * @private
    */
-  maybeReconnectOnOpen() {
+  private maybeReconnectOnOpen() {
     // Only try to reconnect if it's the first time we're connecting
     if (
-      !this.reconnecting &&
+      !this._reconnecting &&
       this._reconnection &&
       this.backoff.attempts === 0
     ) {
@@ -170,19 +437,19 @@ export class Manager extends Emitter {
   /**
    * Sets the current transport `socket`.
    *
-   * @param {Function} optional, callback
+   * @param {Function} fn - optional, callback
    * @return {Manager} self
-   * @api public
+   * @public
    */
-  open(fn?, opts?): Manager {
-    debug("readyState %s", this.readyState);
-    if (~this.readyState.indexOf("open")) return this;
+  public open(fn?: (err?: Error) => void): Manager {
+    debug("readyState %s", this._readyState);
+    if (~this._readyState.indexOf("open")) return this;
 
     debug("opening %s", this.uri);
     this.engine = eio(this.uri, this.opts);
     const socket = this.engine;
     const self = this;
-    this.readyState = "opening";
+    this._readyState = "opening";
     this.skipReconnect = false;
 
     // emit `open`
@@ -195,7 +462,7 @@ export class Manager extends Emitter {
     const errorSub = on(socket, "error", (err) => {
       debug("connect_error");
       self.cleanup();
-      self.readyState = "closed";
+      self._readyState = "closed";
       super.emit("connect_error", err);
       if (fn) {
         fn(err);
@@ -236,23 +503,29 @@ export class Manager extends Emitter {
     return this;
   }
 
-  connect(fn, opts): Manager {
-    return this.open(fn, opts);
+  /**
+   * Alias for open()
+   *
+   * @return {Manager} self
+   * @public
+   */
+  public connect(fn?: (err?: Error) => void): Manager {
+    return this.open(fn);
   }
 
   /**
    * Called upon transport open.
    *
-   * @api private
+   * @private
    */
-  onopen() {
+  private onopen() {
     debug("open");
 
     // clear old subs
     this.cleanup();
 
     // mark as open
-    this.readyState = "open";
+    this._readyState = "open";
     super.emit("open");
 
     // add new subs
@@ -267,36 +540,36 @@ export class Manager extends Emitter {
   /**
    * Called upon a ping.
    *
-   * @api private
+   * @private
    */
-  onping() {
+  private onping() {
     super.emit("ping");
   }
 
   /**
    * Called with data.
    *
-   * @api private
+   * @private
    */
-  ondata(data) {
+  private ondata(data) {
     this.decoder.add(data);
   }
 
   /**
    * Called when parser fully decodes a packet.
    *
-   * @api private
+   * @private
    */
-  ondecoded(packet) {
+  private ondecoded(packet) {
     super.emit("packet", packet);
   }
 
   /**
    * Called upon socket error.
    *
-   * @api private
+   * @private
    */
-  onerror(err) {
+  private onerror(err) {
     debug("error", err);
     super.emit("error", err);
   }
@@ -305,9 +578,9 @@ export class Manager extends Emitter {
    * Creates a new socket for the given `nsp`.
    *
    * @return {Socket}
-   * @api public
+   * @public
    */
-  socket(nsp, opts) {
+  public socket(nsp: string, opts?: SocketOptions): Socket {
     let socket = this.nsps[nsp];
     if (!socket) {
       socket = new Socket(this, nsp, opts);
@@ -315,7 +588,7 @@ export class Manager extends Emitter {
       var self = this;
       socket.on("connecting", onConnecting);
 
-      if (this.autoConnect) {
+      if (this._autoConnect) {
         // manually call here since connecting event is fired before listening
         onConnecting();
       }
@@ -334,22 +607,23 @@ export class Manager extends Emitter {
    * Called upon a socket close.
    *
    * @param {Socket} socket
+   * @private
    */
-  destroy(socket) {
+  _destroy(socket) {
     const index = indexOf(this.connecting, socket);
     if (~index) this.connecting.splice(index, 1);
     if (this.connecting.length) return;
 
-    this.close();
+    this._close();
   }
 
   /**
    * Writes a packet.
    *
    * @param {Object} packet
-   * @api private
+   * @private
    */
-  packet(packet) {
+  _packet(packet) {
     debug("writing packet %j", packet);
     if (packet.query && packet.type === 0) packet.nsp += "?" + packet.query;
 
@@ -362,9 +636,9 @@ export class Manager extends Emitter {
   /**
    * Clean up transport subscriptions and packet buffer.
    *
-   * @api private
+   * @private
    */
-  cleanup() {
+  private cleanup() {
     debug("cleanup");
 
     const subsLength = this.subs.length;
@@ -379,47 +653,42 @@ export class Manager extends Emitter {
   /**
    * Close the current socket.
    *
-   * @api private
+   * @private
    */
-  close() {
+  _close() {
     debug("disconnect");
     this.skipReconnect = true;
-    this.reconnecting = false;
-    if ("opening" === this.readyState) {
+    this._reconnecting = false;
+    if ("opening" === this._readyState) {
       // `onclose` will not fire because
       // an open event never happened
       this.cleanup();
     }
     this.backoff.reset();
-    this.readyState = "closed";
+    this._readyState = "closed";
     if (this.engine) this.engine.close();
   }
 
-  disconnect() {
-    debug("disconnect");
-    this.skipReconnect = true;
-    this.reconnecting = false;
-    if ("opening" === this.readyState) {
-      // `onclose` will not fire because
-      // an open event never happened
-      this.cleanup();
-    }
-    this.backoff.reset();
-    this.readyState = "closed";
-    if (this.engine) this.engine.close();
+  /**
+   * Alias for close()
+   *
+   * @private
+   */
+  private disconnect() {
+    return this._close();
   }
 
   /**
    * Called upon engine close.
    *
-   * @api private
+   * @private
    */
-  onclose(reason) {
+  private onclose(reason) {
     debug("onclose");
 
     this.cleanup();
     this.backoff.reset();
-    this.readyState = "closed";
+    this._readyState = "closed";
     super.emit("close", reason);
 
     if (this._reconnection && !this.skipReconnect) {
@@ -430,10 +699,10 @@ export class Manager extends Emitter {
   /**
    * Attempt a reconnection.
    *
-   * @api private
+   * @private
    */
-  reconnect() {
-    if (this.reconnecting || this.skipReconnect) return this;
+  private reconnect() {
+    if (this._reconnecting || this.skipReconnect) return this;
 
     const self = this;
 
@@ -441,12 +710,12 @@ export class Manager extends Emitter {
       debug("reconnect failed");
       this.backoff.reset();
       super.emit("reconnect_failed");
-      this.reconnecting = false;
+      this._reconnecting = false;
     } else {
       const delay = this.backoff.duration();
       debug("will wait %dms before reconnect attempt", delay);
 
-      this.reconnecting = true;
+      this._reconnecting = true;
       const timer = setTimeout(() => {
         if (self.skipReconnect) return;
 
@@ -460,7 +729,7 @@ export class Manager extends Emitter {
         self.open((err) => {
           if (err) {
             debug("reconnect attempt error");
-            self.reconnecting = false;
+            self._reconnecting = false;
             self.reconnect();
             super.emit("reconnect_error", err);
           } else {
@@ -481,11 +750,11 @@ export class Manager extends Emitter {
   /**
    * Called upon successful reconnect.
    *
-   * @api private
+   * @private
    */
-  onreconnect() {
+  private onreconnect() {
     const attempt = this.backoff.attempts;
-    this.reconnecting = false;
+    this._reconnecting = false;
     this.backoff.reset();
     super.emit("reconnect", attempt);
   }
diff --git a/lib/socket.ts b/lib/socket.ts
index 832c440e1..75c748c86 100644
--- a/lib/socket.ts
+++ b/lib/socket.ts
@@ -1,18 +1,22 @@
-import { PacketType } from "socket.io-parser";
-import Emitter from "component-emitter";
-import toArray from "to-array";
+import { Packet, PacketType } from "socket.io-parser";
+import * as Emitter from "component-emitter";
 import { on } from "./on";
-import bind from "component-bind";
-import hasBin from "has-binary2";
+import * as bind from "component-bind";
+import * as hasBin from "has-binary2";
 import { Manager } from "./manager";
 
 const debug = require("debug")("socket.io-client:socket");
 
+export interface SocketOptions {
+  /**
+   * the authentication payload sent when connecting to the Namespace
+   */
+  auth: object | ((cb: (data: object) => void) => void);
+}
+
 /**
  * Internal events.
  * These events can't be emitted by the user.
- *
- * @api private
  */
 
 const RESERVED_EVENTS = {
@@ -45,9 +49,9 @@ export class Socket extends Emitter {
   /**
    * `Socket` constructor.
    *
-   * @api public
+   * @public
    */
-  constructor(io, nsp, opts) {
+  constructor(io: Manager, nsp: string, opts?: Partial<SocketOptions>) {
     super();
     this.io = io;
     this.nsp = nsp;
@@ -61,15 +65,15 @@ export class Socket extends Emitter {
     if (opts && opts.auth) {
       this.auth = opts.auth;
     }
-    if (this.io.autoConnect) this.open();
+    if (this.io._autoConnect) this.open();
   }
 
   /**
    * Subscribe to open, close and packet events
    *
-   * @api private
+   * @private
    */
-  subEvents() {
+  private subEvents() {
     if (this.subs) return;
 
     const io = this.io;
@@ -83,34 +87,31 @@ export class Socket extends Emitter {
   /**
    * "Opens" the socket.
    *
-   * @api public
+   * @public
    */
-  open() {
+  public connect(): Socket {
     if (this.connected) return this;
 
     this.subEvents();
-    if (!this.io.reconnecting) this.io.open(); // ensure open
-    if ("open" === this.io.readyState) this.onopen();
+    if (!this.io._reconnecting) this.io.open(); // ensure open
+    if ("open" === this.io._readyState) this.onopen();
     return this;
   }
 
-  connect() {
-    if (this.connected) return this;
-
-    this.subEvents();
-    if (!this.io.reconnecting) this.io.open(); // ensure open
-    if ("open" === this.io.readyState) this.onopen();
-    return this;
+  /**
+   * Alias for connect()
+   */
+  public open(): Socket {
+    return this.connect();
   }
 
   /**
    * Sends a `message` event.
    *
    * @return {Socket} self
-   * @api public
+   * @public
    */
-  send() {
-    const args = toArray(arguments);
+  public send(...args: any[]) {
     args.unshift("message");
     this.emit.apply(this, args);
     return this;
@@ -120,16 +121,16 @@ export class Socket extends Emitter {
    * Override `emit`.
    * If the event is in `events`, it's emitted normally.
    *
-   * @param {String} event name
+   * @param {String} ev - event name
    * @return {Socket} self
-   * @api public
+   * @public
    */
-  emit(ev) {
+  public emit(ev: string, ...args: any[]) {
     if (RESERVED_EVENTS.hasOwnProperty(ev)) {
       throw new Error('"' + ev + '" is a reserved event name');
     }
 
-    const args = toArray(arguments);
+    args.unshift(ev);
     const packet: any = {
       type: (this.flags.binary !== undefined ? this.flags.binary : hasBin(args))
         ? PacketType.BINARY_EVENT
@@ -162,19 +163,19 @@ export class Socket extends Emitter {
    * Sends a packet.
    *
    * @param {Object} packet
-   * @api private
+   * @private
    */
-  packet(packet) {
+  private packet(packet: Partial<Packet>) {
     packet.nsp = this.nsp;
-    this.io.packet(packet);
+    this.io._packet(packet);
   }
 
   /**
    * Called upon engine `open`.
    *
-   * @api private
+   * @private
    */
-  onopen() {
+  private onopen() {
     debug("transport is open - connecting");
     if (typeof this.auth == "function") {
       this.auth((data) => {
@@ -189,9 +190,9 @@ export class Socket extends Emitter {
    * Called upon engine `close`.
    *
    * @param {String} reason
-   * @api private
+   * @private
    */
-  onclose(reason) {
+  private onclose(reason) {
     debug("close (%s)", reason);
     this.connected = false;
     this.disconnected = true;
@@ -203,9 +204,9 @@ export class Socket extends Emitter {
    * Called with socket packet.
    *
    * @param {Object} packet
-   * @api private
+   * @private
    */
-  onpacket(packet) {
+  private onpacket(packet) {
     const sameNamespace = packet.nsp === this.nsp;
     const rootNamespaceError =
       packet.type === PacketType.ERROR && packet.nsp === "/";
@@ -248,9 +249,9 @@ export class Socket extends Emitter {
    * Called upon a server event.
    *
    * @param {Object} packet
-   * @api private
+   * @private
    */
-  onevent(packet) {
+  private onevent(packet) {
     const args = packet.data || [];
     debug("emitting event %j", args);
 
@@ -269,16 +270,15 @@ export class Socket extends Emitter {
   /**
    * Produces an ack callback to emit with an event.
    *
-   * @api private
+   * @private
    */
-  ack(id) {
+  private ack(id) {
     const self = this;
     let sent = false;
-    return function () {
+    return function (...args: any[]) {
       // prevent double callbacks
       if (sent) return;
       sent = true;
-      const args = toArray(arguments);
       debug("sending ack %j", args);
 
       self.packet({
@@ -293,9 +293,9 @@ export class Socket extends Emitter {
    * Called upon a server acknowlegement.
    *
    * @param {Object} packet
-   * @api private
+   * @private
    */
-  onack(packet) {
+  private onack(packet) {
     const ack = this.acks[packet.id];
     if ("function" === typeof ack) {
       debug("calling ack %s with %j", packet.id, packet.data);
@@ -309,9 +309,9 @@ export class Socket extends Emitter {
   /**
    * Called upon server connect.
    *
-   * @api private
+   * @private
    */
-  onconnect(id: string) {
+  private onconnect(id: string) {
     this.id = id;
     this.connected = true;
     this.disconnected = false;
@@ -322,9 +322,9 @@ export class Socket extends Emitter {
   /**
    * Emit buffered events (received and emitted).
    *
-   * @api private
+   * @private
    */
-  emitBuffered() {
+  private emitBuffered() {
     for (let i = 0; i < this.receiveBuffer.length; i++) {
       super.emit.apply(this, this.receiveBuffer[i]);
     }
@@ -339,9 +339,9 @@ export class Socket extends Emitter {
   /**
    * Called upon server disconnect.
    *
-   * @api private
+   * @private
    */
-  ondisconnect() {
+  private ondisconnect() {
     debug("server disconnect (%s)", this.nsp);
     this.destroy();
     this.onclose("io server disconnect");
@@ -352,9 +352,9 @@ export class Socket extends Emitter {
    * this method ensures the manager stops tracking us and
    * that reconnections don't get triggered for this.
    *
-   * @api private.
+   * @private
    */
-  destroy() {
+  private destroy() {
     if (this.subs) {
       // clean subscriptions to avoid reconnections
       for (let i = 0; i < this.subs.length; i++) {
@@ -363,16 +363,16 @@ export class Socket extends Emitter {
       this.subs = null;
     }
 
-    this.io.destroy(this);
+    this.io._destroy(this);
   }
 
   /**
    * Disconnects the socket manually.
    *
    * @return {Socket} self
-   * @api public
+   * @public
    */
-  close() {
+  public disconnect(): Socket {
     if (this.connected) {
       debug("performing disconnect (%s)", this.nsp);
       this.packet({ type: PacketType.DISCONNECT });
@@ -388,30 +388,24 @@ export class Socket extends Emitter {
     return this;
   }
 
-  disconnect() {
-    if (this.connected) {
-      debug("performing disconnect (%s)", this.nsp);
-      this.packet({ type: PacketType.DISCONNECT });
-    }
-
-    // remove socket from pool
-    this.destroy();
-
-    if (this.connected) {
-      // fire events
-      this.onclose("io client disconnect");
-    }
-    return this;
+  /**
+   * Alias for disconnect()
+   *
+   * @return {Socket} self
+   * @public
+   */
+  public close(): Socket {
+    return this.disconnect();
   }
 
   /**
    * Sets the compress flag.
    *
-   * @param {Boolean} if `true`, compresses the sending data
+   * @param {Boolean} compress - if `true`, compresses the sending data
    * @return {Socket} self
-   * @api public
+   * @public
    */
-  compress(compress) {
+  public compress(compress: boolean) {
     this.flags.compress = compress;
     return this;
   }
@@ -419,11 +413,11 @@ export class Socket extends Emitter {
   /**
    * Sets the binary flag
    *
-   * @param {Boolean} whether the emitted data contains binary
+   * @param {Boolean} binary - whether the emitted data contains binary
    * @return {Socket} self
-   * @api public
+   * @public
    */
-  binary(binary) {
+  public binary(binary: boolean): Socket {
     this.flags.binary = binary;
     return this;
   }
diff --git a/lib/url.ts b/lib/url.ts
index ead8de9c1..4f22fc605 100644
--- a/lib/url.ts
+++ b/lib/url.ts
@@ -1,17 +1,17 @@
-import parseuri from "parseuri";
+import * as parseuri from "parseuri";
 
 const debug = require("debug")("socket.io-client:url");
 
 /**
  * URL parser.
  *
- * @param {String} url
- * @param {Object} An object meant to mimic window.location.
+ * @param {String} uri - url
+ * @param {Object} loc - An object meant to mimic window.location.
  *                 Defaults to window.location.
- * @api public
+ * @public
  */
 
-export function url(uri, loc?) {
+export function url(uri: any, loc?: Location) {
   let obj = uri;
 
   // default to window.location
diff --git a/package.json b/package.json
index 1f8af62d4..ea861dc97 100644
--- a/package.json
+++ b/package.json
@@ -27,6 +27,7 @@
   },
   "types": "./build/index.d.ts",
   "dependencies": {
+    "@types/component-emitter": "^1.2.10",
     "backo2": "1.0.2",
     "component-bind": "1.0.0",
     "component-emitter": "~1.3.0",
@@ -35,14 +36,14 @@
     "has-binary2": "~1.0.2",
     "indexof": "0.0.1",
     "parseuri": "0.0.6",
-    "socket.io-parser": "4.0.1-rc1",
-    "to-array": "0.1.4"
+    "socket.io-parser": "4.0.1-rc1"
   },
   "devDependencies": {
     "@babel/core": "^7.11.6",
     "@babel/plugin-transform-object-assign": "^7.10.4",
     "@babel/preset-env": "^7.11.5",
-    "@types/node": "^14.11.2",
+    "@types/mocha": "^8.0.3",
+    "@types/node": "^14.11.8",
     "babel-eslint": "^10.1.0",
     "babel-loader": "^8.1.0",
     "babel-preset-es2015": "6.24.1",
@@ -58,6 +59,8 @@
     "socket.io": "3.0.0-rc1",
     "socket.io-browsers": "^1.0.0",
     "text-blob-builder": "0.0.1",
+    "ts-loader": "^8.0.5",
+    "ts-node": "^9.0.0",
     "typescript": "^4.0.3",
     "webpack": "^4.44.2",
     "webpack-cli": "^3.3.12",
@@ -69,11 +72,11 @@
   "scripts": {
     "compile": "tsc",
     "test": "npm run format:check && npm run compile && if test \"$BROWSERS\" = \"1\" ; then npm run test:browser; else npm run test:node; fi",
-    "test:node": "mocha --reporter dot --require test/support/server.js test/index.js",
+    "test:node": "mocha --require ts-node/register --reporter dot --require test/support/server.js test/index.js",
     "test:browser": "zuul test/index.js",
     "build": "npm run compile && webpack --config ./support/webpack.config.js --config ./support/prod.config.js",
-    "format:check": "prettier --check 'lib/**/*.ts' 'test/**/*.js' 'support/**/*.js'",
-    "format:fix": "prettier --write 'lib/**/*.ts' 'test/**/*.js' 'support/**/*.js'",
+    "format:check": "prettier --check 'lib/**/*.ts' 'test/**/*.js' 'test/**/*.ts' 'support/**/*.js'",
+    "format:fix": "prettier --write 'lib/**/*.ts' 'test/**/*.js' 'test/**/*.ts' 'support/**/*.js'",
     "prepack": "npm run compile"
   },
   "contributors": [
diff --git a/test/connection.js b/test/connection.ts
similarity index 93%
rename from test/connection.js
rename to test/connection.ts
index 5234a886f..5d6c154f6 100644
--- a/test/connection.js
+++ b/test/connection.ts
@@ -1,8 +1,8 @@
-const expect = require("expect.js");
-const io = require("../");
-const hasCORS = require("has-cors");
-const textBlobBuilder = require("text-blob-builder");
-const env = require("./support/env");
+import * as expect from "expect.js";
+import { io, Manager } from "..";
+import * as hasCORS from "has-cors";
+import * as textBlobBuilder from "text-blob-builder";
+import * as env from "./support/env";
 
 describe("connection", function () {
   this.timeout(70000);
@@ -94,21 +94,21 @@ describe("connection", function () {
   });
 
   it("should connect to a namespace after connection established", (done) => {
-    const manager = new io.Manager();
+    const manager = new Manager();
     const socket = manager.socket("/");
     socket.on("connect", () => {
       const foo = manager.socket("/foo");
       foo.on("connect", () => {
         foo.close();
         socket.close();
-        manager.close();
+        manager._close();
         done();
       });
     });
   });
 
   it("should open a new namespace after connection gets closed", (done) => {
-    const manager = new io.Manager();
+    const manager = new Manager();
     const socket = manager.socket("/");
     socket
       .on("connect", () => {
@@ -118,7 +118,7 @@ describe("connection", function () {
         const foo = manager.socket("/foo");
         foo.on("connect", () => {
           foo.disconnect();
-          manager.close();
+          manager._close();
           done();
         });
       });
@@ -170,7 +170,7 @@ describe("connection", function () {
   });
 
   it("should attempt reconnects after a failed reconnect", (done) => {
-    const manager = new io.Manager({
+    const manager = new Manager({
       reconnection: true,
       timeout: 0,
       reconnectionAttempts: 2,
@@ -187,7 +187,7 @@ describe("connection", function () {
       manager.on("reconnect_failed", () => {
         expect(reconnects).to.be(2);
         socket.close();
-        manager.close();
+        manager._close();
         done();
       });
       socket.connect();
@@ -195,7 +195,7 @@ describe("connection", function () {
   });
 
   it("reconnect delay should increase every time", (done) => {
-    const manager = new io.Manager({
+    const manager = new Manager({
       reconnection: true,
       timeout: 0,
       reconnectionAttempts: 3,
@@ -225,7 +225,7 @@ describe("connection", function () {
       expect(reconnects).to.be(3);
       expect(increasingDelay).to.be.ok();
       socket.close();
-      manager.close();
+      manager._close();
       done();
     });
   });
@@ -283,7 +283,7 @@ describe("connection", function () {
   });
 
   it("should stop reconnecting on a socket and keep to reconnect on another", (done) => {
-    const manager = new io.Manager();
+    const manager = new Manager();
     const socket1 = manager.socket("/");
     const socket2 = manager.socket("/asd");
 
@@ -294,7 +294,7 @@ describe("connection", function () {
       socket2.on("connect", () => {
         setTimeout(() => {
           socket2.disconnect();
-          manager.disconnect();
+          manager._close();
           done();
         }, 500);
       });
@@ -307,7 +307,7 @@ describe("connection", function () {
   });
 
   it("should try to reconnect twice and fail when requested two attempts with immediate timeout and reconnect enabled", (done) => {
-    const manager = new io.Manager({
+    const manager = new Manager({
       reconnection: true,
       timeout: 0,
       reconnectionAttempts: 2,
@@ -324,7 +324,7 @@ describe("connection", function () {
     manager.on("reconnect_failed", () => {
       expect(reconnects).to.be(2);
       socket.close();
-      manager.close();
+      manager._close();
       done();
     });
 
@@ -332,7 +332,7 @@ describe("connection", function () {
   });
 
   it("should fire reconnect_* events on manager", (done) => {
-    const manager = new io.Manager({
+    const manager = new Manager({
       reconnection: true,
       timeout: 0,
       reconnectionAttempts: 2,
@@ -350,13 +350,13 @@ describe("connection", function () {
     manager.on("reconnect_failed", () => {
       expect(reconnects).to.be(2);
       socket.close();
-      manager.close();
+      manager._close();
       done();
     });
   });
 
   it("should fire reconnecting (on manager) with attempts number when reconnecting twice", (done) => {
-    const manager = new io.Manager({
+    const manager = new Manager({
       reconnection: true,
       timeout: 0,
       reconnectionAttempts: 2,
@@ -374,13 +374,13 @@ describe("connection", function () {
     manager.on("reconnect_failed", () => {
       expect(reconnects).to.be(2);
       socket.close();
-      manager.close();
+      manager._close();
       done();
     });
   });
 
   it("should not try to reconnect and should form a connection when connecting to correct port with default timeout", (done) => {
-    const manager = new io.Manager({
+    const manager = new Manager({
       reconnection: true,
       reconnectionDelay: 10,
     });
@@ -395,14 +395,14 @@ describe("connection", function () {
       // set a timeout to let reconnection possibly fire
       setTimeout(() => {
         socket.close();
-        manager.close();
+        manager._close();
         done();
       }, 1000);
     });
   });
 
   it("should connect while disconnecting another socket", (done) => {
-    const manager = new io.Manager();
+    const manager = new Manager();
     const socket1 = manager.socket("/foo");
     socket1.on("connect", () => {
       const socket2 = manager.socket("/asd");
@@ -415,7 +415,7 @@ describe("connection", function () {
   // `script.onerror` (see: http://requirejs.org/docs/api.html#ieloadfail)
   if (!global.document || hasCORS) {
     it("should try to reconnect twice and fail when requested two attempts with incorrect address and reconnect enabled", (done) => {
-      const manager = new io.Manager("http://localhost:3940", {
+      const manager = new Manager("http://localhost:3940", {
         reconnection: true,
         reconnectionAttempts: 2,
         reconnectionDelay: 10,
@@ -431,13 +431,13 @@ describe("connection", function () {
       manager.on("reconnect_failed", () => {
         expect(reconnects).to.be(2);
         socket.disconnect();
-        manager.close();
+        manager._close();
         done();
       });
     });
 
     it("should not try to reconnect with incorrect port when reconnection disabled", (done) => {
-      const manager = new io.Manager("http://localhost:9823", {
+      const manager = new Manager("http://localhost:9823", {
         reconnection: false,
       });
       const cb = () => {
@@ -450,7 +450,7 @@ describe("connection", function () {
         // set a timeout to let reconnection possibly fire
         setTimeout(() => {
           socket.disconnect();
-          manager.close();
+          manager._close();
           done();
         }, 1000);
       });
@@ -459,8 +459,8 @@ describe("connection", function () {
     });
 
     it("should still try to reconnect twice after opening another socket asynchronously", (done) => {
-      const manager = new io.Manager("http://localhost:9823", {
-        reconnect: true,
+      const manager = new Manager("http://localhost:9823", {
+        reconnection: true,
         reconnectionAttempts: 2,
       });
       let delay = Math.floor(
@@ -478,7 +478,7 @@ describe("connection", function () {
       manager.on("reconnect_failed", () => {
         expect(reconnects).to.be(2);
         socket.disconnect();
-        manager.close();
+        manager._close();
         done();
       });
 
diff --git a/test/index.js b/test/index.js
index bf69ccdcd..24113d388 100644
--- a/test/index.js
+++ b/test/index.js
@@ -5,8 +5,8 @@ if (global.mocha) {
   global.mocha.globals(["___eio", "eio_iframe_*"]);
 }
 
-require("./url");
+require("./url.ts");
 
 // browser only tests
-require("./connection");
-require("./socket");
+require("./connection.ts");
+require("./socket.ts");
diff --git a/test/socket.js b/test/socket.ts
similarity index 98%
rename from test/socket.js
rename to test/socket.ts
index c4b8a548a..09ce1b006 100644
--- a/test/socket.js
+++ b/test/socket.ts
@@ -1,5 +1,5 @@
-const expect = require("expect.js");
-const io = require("../");
+import * as expect from "expect.js";
+import { io } from "..";
 
 describe("socket", function () {
   this.timeout(70000);
diff --git a/test/url.js b/test/url.ts
similarity index 96%
rename from test/url.js
rename to test/url.ts
index 9462eb6e9..d2ac7cc3a 100644
--- a/test/url.js
+++ b/test/url.ts
@@ -1,6 +1,7 @@
-const loc = {};
-const { url } = require("../build/url");
-const expect = require("expect.js");
+import { url } from "../build/url";
+import * as expect from "expect.js";
+
+const loc: any = {};
 
 describe("url", () => {
   it("works with undefined", () => {
diff --git a/tsconfig.json b/tsconfig.json
index a29c767aa..bd40c1107 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -5,7 +5,7 @@
     "target": "es2017",
     "module": "commonjs",
     "declaration": true,
-    "esModuleInterop": true
+    "allowSyntheticDefaultImports": true
   },
   "include": [
     "./lib/**/*"
diff --git a/zuul.config.js b/zuul.config.js
index 1690a67a0..15e5a9565 100644
--- a/zuul.config.js
+++ b/zuul.config.js
@@ -1,12 +1,30 @@
 'use strict';
 
-var browsers = require('socket.io-browsers');
+const browsers = require('socket.io-browsers');
 
-var zuulConfig = module.exports = {
+const webpackConfig = require('./support/prod.config.js');
+
+webpackConfig.module.rules.push({
+  test: /\.tsx?$/,
+  use: [
+    {
+      loader: "ts-loader",
+      options: {
+        compilerOptions: {
+          target: "es5",
+        }
+      }
+    },
+  ],
+  exclude: /node_modules/,
+});
+
+const zuulConfig = module.exports = {
   ui: 'mocha-bdd',
 
   // test on localhost by default
   local: true,
+  open: true,
 
   concurrency: 2, // ngrok only accepts two tunnels by default
   // if browser does not sends output in 120s since last output:
@@ -18,7 +36,7 @@ var zuulConfig = module.exports = {
 
   server: './test/support/server.js',
   builder: 'zuul-builder-webpack',
-  webpack: require('./support/prod.config.js')
+  webpack: webpackConfig
 };
 
 if (process.env.CI === 'true') {
@@ -29,5 +47,5 @@ if (process.env.CI === 'true') {
   };
 }
 
-var isPullRequest = process.env.TRAVIS_PULL_REQUEST && process.env.TRAVIS_PULL_REQUEST !== 'false';
+const isPullRequest = process.env.TRAVIS_PULL_REQUEST && process.env.TRAVIS_PULL_REQUEST !== 'false';
 zuulConfig.browsers = isPullRequest ? browsers.pullRequest : browsers.all;