Make a Facebook post with a DataURI image using Rem

post_data_uri.js

var fs = require('fs')
  , path = require('path');

var rem = require('rem')
  , FormData = require('form-data');

rem.connect('facebook.com').prompt({
  scope: ['publish_stream']
}, function (err, user) {
  var form = new FormData();
  form.append('message', 'Testing from Rem');
  var datauri = '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';
  var b = new Buffer(datauri, 'base64');
  b.path = "image.png";
  form.append('source', b)

  user.debug = true;
  form.pipe(user('me/photos').post(form.getHeaders()['content-type'], function (err, json) {
    console.log('After upload:', err, json);
  }));
});