Added: res.respondTo() defaults the content-type

lib/response.js

@@ -340,7 +340,8 @@ res.respondTo = function(obj){
   if (!accepted.length) key = keys.shift();
 
   if (key) {
-    obj[key](req, res, next);
+    this.set('Content-Type', key);
+    obj[key](req, this, next);
   } else {
     var err = new Error('Not Acceptable');
     err.status = 406;

test/res.respondTo.js

@@ -8,7 +8,7 @@ var app = express();
 app.use(function(req, res, next){
   res.respondTo({
     'text/plain': function(){
-      res.type('text').send('hey');
+      res.send('hey');
     },
 
     'text/html': function(){
@@ -41,6 +41,17 @@ describe('req', function(){
       .expect('{"message":"hey"}', done);
     })
 
+    it('should default the Content-Type', function(done){
+      request(app)
+      .get('/')
+      .set('Accept', 'text/html; q=.5, text/plain')
+      .end(function(res){
+        res.headers['content-type'].should.equal('text/plain');
+        res.body.should.equal('hey');
+        done();
+      });
+    })
+
     describe('when Accept is not present', function(){
       it('should invoke the first callback', function(done){
         request(app)