Catch an error

lib/document_handler.js

@@ -26,6 +26,7 @@ DocumentHandler.prototype.handlePost = function(request, response) {
   var key = '123';
   request.on('data', function(data) {
     if (!DocumentHandler.documents[key]) {
+      response.writeHead(200, { 'content-type': 'application/json' });
       DocumentHandler.documents[key] = '';
     } 
     DocumentHandler.documents[key] += data.toString();
@@ -35,7 +36,9 @@ DocumentHandler.prototype.handlePost = function(request, response) {
     response.end(JSON.stringify({ key: key }));
   });
   request.on('error', function(error) {
-    // TODO handle error
+    winston.error('connection error: ' + error.message);
+    response.writeHead(500, { 'content-type': 'application/json' });
+    response.end(JSON.stringify({ message: 'connection error' }));
   });
 };