[feat] Allow to join several rooms at once (#2879)

docs/API.md

@@ -40,6 +40,7 @@
     - [socket.emit(eventName[, ...args][, ack])](#socketemiteventname-args-ack)
     - [socket.on(eventName, callback)](#socketoneventname-callback)
     - [socket.join(room[, callback])](#socketjoinroom-callback)
+    - [socket.join(rooms[, callback])](#socketjoinrooms-callback)
     - [socket.leave(room[, callback])](#socketleaveroom-callback)
     - [socket.to(room)](#sockettoroom)
     - [socket.in(room)](#socketinroom)
@@ -476,6 +477,14 @@ io.on('connection', function(client){
 });
 ```
 
+#### socket.join(rooms[, callback])
+
+  - `rooms` _(Array)_
+  - `callback` _(Function)_
+  - **Returns** `Socket` for chaining
+
+Adds the client to the list of room, and fires optionally a callback with `err` signature (if any).
+
 #### socket.leave(room[, callback])
 
   - `room` _(String)_

lib/socket.js

@@ -223,23 +223,31 @@ Socket.prototype.packet = function(packet, opts){
 /**
  * Joins a room.
  *
- * @param {String} room
+ * @param {String|Array} room or array of rooms
  * @param {Function} fn optional, callback
  * @return {Socket} self
  * @api private
  */
 
-Socket.prototype.join = function(room, fn){
-  debug('joining room %s', room);
+Socket.prototype.join = function(rooms, fn){
+  debug('joining room %s', rooms);
   var self = this;
-  if (this.rooms.hasOwnProperty(room)) {
+  if (!Array.isArray(rooms)) {
+    rooms = [rooms];
+  }
+  rooms = rooms.filter(function (room) {
+    return !self.rooms.hasOwnProperty(room);
+  });
+  if (!rooms.length) {
     fn && fn(null);
     return this;
   }
-  this.adapter.add(this.id, room, function(err){
+  this.adapter.addAll(this.id, rooms, function(err){
     if (err) return fn && fn(err);
-    debug('joined room %s', room);
-    self.rooms[room] = room;
+    debug('joined room %s', rooms);
+    rooms.forEach(function (room) {
+      self.rooms[room] = room;
+    });
     fn && fn(null);
   });
   return this;

package.json

@@ -28,7 +28,7 @@
     "engine.io": "2.0.2",
     "has-binary": "0.1.7",
     "object-assign": "4.1.0",
-    "socket.io-adapter": "1.0.0",
+    "socket.io-adapter": "~1.1.0",
     "socket.io-client": "socketio/socket.io-client",
     "socket.io-parser": "2.3.1"
   },

test/socket.io.js

@@ -2083,6 +2083,21 @@ describe('socket.io', function(){
         });
       });
     });
+
+    it('allows to join several rooms at once', function(done) {
+      var srv = http();
+      var sio = io(srv);
+
+      srv.listen(function(){
+        var socket = client(srv);
+        sio.on('connection', function(s){
+          s.join(['a', 'b', 'c'], function(){
+            expect(Object.keys(s.rooms)).to.eql([s.id, 'a', 'b', 'c']);
+            done();
+          });
+        });
+      });
+    });
   });
 
   describe('middleware', function(done){