[node] Use express's built-in json headers, set no cache on GET

server.js

@@ -24,8 +24,8 @@ app.use(bodyParser.urlencoded({extended: true}));
 
 app.get('/comments.json', function(req, res) {
   fs.readFile('comments.json', function(err, data) {
-    res.setHeader('Content-Type', 'application/json');
-    res.send(data);
+    res.setHeader('Cache-Control', 'no-cache');
+    res.json(JSON.parse(data));
   });
 });
 
@@ -34,9 +34,8 @@ app.post('/comments.json', function(req, res) {
     var comments = JSON.parse(data);
     comments.push(req.body);
     fs.writeFile('comments.json', JSON.stringify(comments, null, 4), function(err) {
-      res.setHeader('Content-Type', 'application/json');
       res.setHeader('Cache-Control', 'no-cache');
-      res.send(JSON.stringify(comments));
+      res.json(comments);
     });
   });
 });