fix: socket.io methods calling callbacks twice if method returns promise

src/socket.io/index.js

@@ -131,7 +131,6 @@ function onMessage(socket, payload) {
 		return socket.disconnect();
 	}
 
-	var cbCalled = false;
 	async.waterfall([
 		function (next) {
 			checkMaintenance(socket, next);
@@ -147,19 +146,20 @@ function onMessage(socket, payload) {
 			}
 		},
 		function (next) {
-			const returned = methodToCall(socket, params, next);
+			let callbackCalled = false;
+			function nextOnce(err, res) {
+				if (callbackCalled) { return; }
+				callbackCalled = true;
+				next(err, res);
+			}
+			const returned = methodToCall(socket, params, nextOnce);
 			if (returned && typeof returned.then === 'function') {
 				returned.then((payload) => {
-					next(null, payload);
+					nextOnce(null, payload);
 				}, next);
 			}
 		},
 	], function (err, result) {
-		if (cbCalled) {
-			return;
-		}
-
-		cbCalled = true;
 		callback(err ? { message: err.message } : null, result);
 	});
 }

test/socket.io.js

@@ -124,6 +124,14 @@ describe('socket.io', function () {
 		});
 	});
 
+	it('should get more unread topics', function (done) {
+		io.emit('topics.loadMoreSortedTopics', { after: 0, count: 10, direction: 1, sort: 'unread' }, function (err, result) {
+			assert.ifError(err);
+			console.log(result);
+			done();
+		});
+	});
+
 	it('should ban a user', function (done) {
 		var socketUser = require('../src/socket.io/user');
 		socketUser.banUsers({ uid: adminUid }, { uids: [regularUid], reason: 'spammer' }, function (err) {
@@ -182,7 +190,7 @@ describe('socket.io', function () {
 		});
 	});
 
-	describe('create/delete', function () {
+	describe('user create/delete', function () {
 		var uid;
 		it('should create a user', function (done) {
 			socketAdmin.user.createUser({ uid: adminUid }, { username: 'foo1' }, function (err, _uid) {