Query string to Object conversion in JavaScript

queryString.js

define([], function() {
  /*
    Public: Returns the query string decoded as an Object

    queryArg - a String that is a query string. eg: "one=1&two=2&three"

    Returns an Object
  */
  return function(queryArg) {
    var query = queryArg || window.location.search.substring(1);
    var vars = query.split('&');
    var retval = {};

    for(var i = 0; i < vars.length; i++) {
      var arg = vars[i];

      if(arg.indexOf('=') == -1) {
        retval[decodeURIComponent(arg)] = true;
      } else {
        var pair = arg.split('=')

        retval[decodeURIComponent(pair[0])] = decodeURIComponent(pair[1]);
      }
    }

    return retval;
  }
})

tests.js

define(function() {
  QUnit.start();
  /*
    ======== A Handy Little QUnit Reference ========
    http://api.qunitjs.com/

    Test methods:
      module(name, {[setup][ ,teardown]})
      test(name, callback)
      expect(numberOfAssertions)
      stop(increment)
      start(decrement)
    Test assertions:
      ok(value, [message])
      equal(actual, expected, [message])
      notEqual(actual, expected, [message])
      deepEqual(actual, expected, [message])
      notDeepEqual(actual, expected, [message])
      strictEqual(actual, expected, [message])
      notStrictEqual(actual, expected, [message])
      throws(block, [expected], [message])
  */

  /* require your app components
   * for example, if you have /app/modules/doSomething.js, you can
   * require(['modules/doSomething'], function(theModule) {
   *   // test the things
   * });
   */

  require(["lib/queryString"], function(queryString) {
    module("queryString");

    test('returns an object that represents the query string', function() {
      deepEqual(queryString("one=1&two=2&three"), {one: "1", two: "2", three: true});
    });

    test("it uses the window.location.search.substring(1) by default", function() {
      var customWindow = {
        location: {
          search: "?one=1&two=2&three"
        }
      };

      (function(window) {
        deepEqual(queryString(), {one: "1", two: "2", three: true});
      })(customWindow);
    });
  })
});