express cors

not-working.js

var express = require('express')
  , cors = require('connect-xcors')({
      headers: ['X-Requested-With', 'X-HTTP-Method-Override', 'Content-Type', 'Accept', 'Authorization']
    })

var app = express()

// OPTIONS requests don't get handled because 
// cors is hidden behind the routing middleware 
// and '/' is only accessible via GET

// NOTE: using `app.all` here makes this work 
// as intended. the other option is to use an
// empty OPTIONS request: `app.options('/', [cors], function(req, res) { })`
app.get('/', [cors], function(req, res) {
  res.end('ok')
})

app.listen(3000)

working.js

var express = require('express')
  , cors = require('connect-xcors')({
      headers: ['X-Requested-With', 'X-HTTP-Method-Override', 'Content-Type', 'Accept', 'Authorization']
    })

var app = express()

app.use(cors)

app.get('/', function(req, res) {
  res.end('ok')
})

app.listen(3000)