Added req.subdomains

lib/request.js

@@ -311,6 +311,23 @@ req.__defineGetter__('secure', function(){
   return this.connection.encrypted;
 });
 
+/**
+ * Return subdomains as an array.
+ *
+ * For example "tobi.ferrets.example.com"
+ * would provide `["ferrets", "tobi"]`.
+ *
+ * @return {Array}
+ * @api public
+ */
+
+req.__defineGetter__('subdomains', function(){
+  return this.get('Host')
+    .split('.')
+    .slice(0, -2)
+    .reverse();
+});
+
 /**
  * Short-hand for `require('url').parse(req.url).pathname`.
  *

test/req.subdomains.js

@@ -0,0 +1,43 @@
+
+var express = require('../')
+  , request = require('./support/http');
+
+describe('req', function(){
+  describe('.subdomains', function(){
+    describe('when present', function(){
+      it('should return an array', function(done){
+        var app = express();
+
+        app.use(function(req, res){
+          res.send(req.subdomains);
+        });
+
+        request(app)
+        .get('/')
+        .set('Host', 'tobi.ferrets.example.com')
+        .end(function(res){
+          res.body.should.equal('["ferrets","tobi"]');
+          done();
+        })
+      })
+    })
+
+    describe('otherwise', function(){
+      it('should return an empty array', function(done){
+        var app = express();
+
+        app.use(function(req, res){
+          res.send(req.subdomains);
+        });
+
+        request(app)
+        .get('/')
+        .set('Host', 'example.com')
+        .end(function(res){
+          res.body.should.equal('[]');
+          done();
+        })
+      })
+    })
+  })
+})