Fix res.jsonp error if callback param is object

fixes #2104

History.md

@@ -2,6 +2,7 @@
 =====
 
  * fix `req.host` for IPv6 literals
+ * fix `res.jsonp` error if callback param is object
 
 3.5.2 / 2014-04-24
 ==================

lib/response.js

@@ -237,9 +237,13 @@ res.jsonp = function(obj){
   this.charset = this.charset || 'utf-8';
   this.set('Content-Type', 'application/json');
 
+  // fixup callback
+  if (Array.isArray(callback)) {
+    callback = callback[0];
+  }
+
   // jsonp
-  if (callback) {
-    if (Array.isArray(callback)) callback = callback[0];
+  if (callback && 'string' === typeof callback) {
     this.set('Content-Type', 'text/javascript');
     var cb = callback.replace(/[^\[\]\w$.]/g, '');
     body = 'typeof ' + cb + ' === \'function\' && ' + cb + '(' + body + ');';

test/res.jsonp.js

@@ -37,6 +37,22 @@ describe('res', function(){
           })
     })
 
+    it('should ignore object callback parameter with jsonp', function(done){
+      var app = express();
+
+      app.use(function(req, res){
+        res.jsonp({ count: 1 });
+      });
+
+      request(app)
+      .get('/?callback[a]=something')
+      .end(function(err, res){
+        res.headers.should.have.property('content-type', 'application/json; charset=utf-8');
+        res.text.should.equal('{"count":1}');
+        done();
+      })
+    })
+
     it('should allow renaming callback', function(done){
       var app = express();
 
@@ -212,7 +228,7 @@ describe('res', function(){
     })
   })
 
-  describe('.json(status, object)', function(){
+  describe('.jsonp(status, object)', function(){
     it('should respond with json and set the .statusCode', function(done){
       var app = express();
 
@@ -231,7 +247,7 @@ describe('res', function(){
     })
   })
 
-  describe('.json(object, status)', function(){
+  describe('.jsonp(object, status)', function(){
     it('should respond with json and set the .statusCode for backwards compat', function(done){
       var app = express();