Find da memory leak

origin.js

// `domains` is a global containing valid domains grouped by keys
// this module is instantiated via require at the top of some file and
// the following is run once per request:
// Origin.foundKey(blah, blah);


// some origin stuff

var _ = require('underscore');

module.exports = {

  list: function (arr) {
    var result = [];
    _.each(arr || [], function (domain) {
      result.push('http://' + domain);
      result.push('https://' + domain);
      result.push('http://www.' + domain);
      result.push('https://www.' + domain);
    });
    return result;
  },
  foundKey: function (key, origin) {
    return _.contains(this.list(domains[key]), origin);
  }

};