add a test for graceful shutdown

package.json

@@ -21,7 +21,7 @@
     "test": "mocha --reporter dot --slow 200ms --bail"
   },
   "dependencies": {
-    "engine.io": "1.6.7",
+    "engine.io": "nkzawa/engine.io#graceful-close",
     "socket.io-parser": "2.2.6",
     "socket.io-client": "1.4.4",
     "socket.io-adapter": "0.4.0",

test/fixtures/server-close.js

@@ -0,0 +1,11 @@
+var server = require('http').createServer();
+var ioc = require('socket.io-client');
+var io = require('../..')(server);
+
+var srv = server.listen(function() {
+  var socket = ioc('ws://localhost:' + server.address().port);
+  socket.on('connect', function() {
+    io.close();
+    socket.close();
+  });
+});

test/socket.io.js

@@ -3,6 +3,7 @@ var http = require('http').Server;
 var io = require('..');
 var fs = require('fs');
 var join = require('path').join;
+var exec = require('child_process').exec;
 var ioc = require('socket.io-client');
 var request = require('supertest');
 var expect = require('expect.js');
@@ -412,6 +413,16 @@ describe('socket.io', function(){
       });
     });
 
+    describe('graceful close', function(){
+      function fixture(filename) {
+        return process.execPath + ' ' +
+          join(__dirname, 'fixtures', filename);
+      }
+
+      it('should stop socket and timers', function(done){
+        exec(fixture('server-close.js'), done);
+      });
+    });
   });
 
   describe('namespaces', function(){