* close clients with no namespace ([91cd255](https://github.com/socketio/socket.io/commit/91cd255ba76ff6a780c62740f9f5cd3a76f5d7c7))

* emit an Error object upon middleware error ([54bf4a4](https://github.com/socketio/socket.io/commit/54bf4a44e9e896dfb64764ee7bd4e8823eb7dc7b))

* serve msgpack bundle ([aa7574f](https://github.com/socketio/socket.io/commit/aa7574f88471aa30ae472a5cddf1000a8baa70fd))

* add support for catch-all listeners ([5c73733](https://github.com/socketio/socket.io/commit/5c737339858d59eab4b5ee2dd6feff0e82c4fe5a))

* make Socket#join() and Socket#leave() synchronous ([129c641](https://github.com/socketio/socket.io/commit/129c6417bd818bc8b4e1b831644323876e627c13))

* remove prod dependency to socket.io-client ([7603da7](https://github.com/socketio/socket.io/commit/7603da71a535481e3fc60e38b013abf78516d322))

* move binary detection back to the parser ([669592d](https://github.com/socketio/socket.io/commit/669592d120409a5cf00f128070dee6d22259ba4f))

* add ES6 module export ([8b6b100](https://github.com/socketio/socket.io/commit/8b6b100c284ccce7d85e55659e3397f533916847))

* do not reuse the Engine.IO id ([2875d2c](https://github.com/socketio/socket.io/commit/2875d2cfdfa463e64cb520099749f543bbc4eb15))

* remove Server#set() method ([029f478](https://github.com/socketio/socket.io/commit/029f478992f59b1eb5226453db46363a570eea46))

* remove Socket#rooms object ([1507b41](https://github.com/socketio/socket.io/commit/1507b416d584381554d1ed23c9aaf3b650540071))

* remove the 'origins' option ([a8c0600](https://github.com/socketio/socket.io/commit/a8c06006098b512ba1b8b8df82777349db486f41))

* remove the implicit connection to the default namespace ([3289f7e](https://github.com/socketio/socket.io/commit/3289f7ec376e9ec88c2f90e2735c8ca8d01c0e97))

* throw upon reserved event names ([4bd5b23](https://github.com/socketio/socket.io/commit/4bd5b2339a66a5a675e20f689fff2e70ff12d236))

* the Socket#use() method is removed (see [5c73733](https://github.com/socketio/socket.io/commit/5c737339858d59eab4b5ee2dd6feff0e82c4fe5a))

* Socket#join() and Socket#leave() do not accept a callback argument anymore.

Before:

socket.join("room1", () => {

io.to("room1").emit("hello");

});

After:

socket.join("room1");

io.to("room1").emit("hello");

* the "connected" map is renamed to "sockets"

* the Socket#binary() method is removed, as this use case is now covered by the ability to provide your own parser.

* the 'origins' option is removed

Before:

new Server(3000, {

origins: ["https://example.com"]

});

The 'origins' option was used in the allowRequest method, in order to

determine whether the request should pass or not. And the Engine.IO

server would implicitly add the necessary Access-Control-Allow-xxx

headers.

After:

new Server(3000, {

cors: {

origin: "https://example.com",

methods: ["GET", "POST"],

allowedHeaders: ["content-type"]

}

});

The already existing 'allowRequest' option can be used for validation:

new Server(3000, {

allowRequest: (req, callback) => {

callback(null, req.headers.referer.startsWith("https://example.com"));

}

});

* Socket#rooms is now a Set instead of an object

* Namespace#connected is now a Map instead of an object

* there is no more implicit connection to the default namespace:

const socket = io("/admin");

io.on("connect", socket => {

// not triggered anymore

})

io.use((socket, next) => {

// not triggered anymore

});

io.of("/admin").use((socket, next) => {

// triggered

});

* the Server#set() method was removed

This method was kept for backward-compatibility with pre-1.0 versions.

"version": "3.0.0",

"socket.io-adapter": "~2.0.3",

"socket.io-parser": "~4.0.1"

"socket.io-client": "3.0.0",