My Task

Mocking some API responses with grunt-contrib-connect and some custom middleware functions.

My Problem

405 Method not allowed responses for POST requests

Let's get the party started.

First naive (search stackoverflow, c&p) approach:

• add a function that sets all required HTTP headers

var enableREST = function(req, res, next){
  res.setHeader('Access-Control-Allow-Origin',          req.headers.origin);
  res.setHeader('Access-Control-Allow-Credentials', true);
  res.setHeader('Access-Control-Allow-Methods',     'GET,HEAD,PUT,PATCH,POST,DELETE');
  res.setHeader('Access-Control-Allow-Headers',      req.headers['access-control-request-headers']);

  return next();
};

• add that function to grunt-contrib-connect middlewares

connect: {
  server: {
    options: {
      middleware: function(connect, options, middlewares) {
        middlewares.push(enableREST);
      }
    }
  }
 }

Didn't turned out so well. Even various other header combinations didn't work. Still the same response: 405 Method not allowed.

My Solution

After a while and some code reviews I found this 'little return; trap' in expressjs/serve-index bypassing my custom middleware.

All I had to do was queueing enableREST() in front of serveIndex() by unshifting instead of pushing it to the middlewares array:

connect: {
  server: {
    options: {
      middleware: function(connect, options, middlewares) {
        middlewares.unshift(enableREST);
      }
    }
  }
 }

Response: 200 OK