wrapping webdriverjs's waitFor to act differently if passed an instance of JQuerySelector.

jQuery-webdriverjs.js

(function () {
  var methods = ['children', 'closest', 'find',
      'next', 'nextAll', 'nextUntil',
      'offsetParent', 'parent', 'parents',
      'parentsUntil', 'prev', 'prevAll',
      'prevUntil', 'siblings'
  ];

  _.each(methods, function (method) {
      JQuerySelector.prototype[method] = function (selector) {
          this.methods.push({ method: method, selector: selector });
          return this;
      };
  });

    JQuerySelector.prototype._getMethods = function () {
        return _.map(this.methods, function (obj) {
            var selector = obj.selector ? '"' + obj.selector.replace(/"/g, '\\"') + '"' : '';
            return '.' + obj.method + '(' + selector + ')';
        });
    };

    JQuerySelector.prototype.toString = function () {
        return '$("' + this.selector + '")' + this._getMethods().join('');
    };

    webdriverjs.prototype.jQuerySelector = function (selector) {
        return new JQuerySelector(selector);
    };

    var oldElement = webdriverjs.prototype.element;
    webdriverjs.prototype.element = function (value, callback) {
        var methodCalls;
        if (value instanceof JQuerySelector) {            
            this.execute('return '+ value.toString() + '.get(0);', callback);
        } else {
            oldElement.apply(this, arguments);
        }
    };
})();

function JQuerySelector (selector) {
    this.selector = selector.replace(/"/g, '\\"');
    this.methods = [];
}

waitFor-jQuery-webdriverjs.js

(function () {
    var waitForOld = webdriverjs.prototype.waitFor;
    webdriverjs.prototype.waitFor = function (selector, ms, callback) {
        var wrappedCallback = function (err, result) {
            if (result) {
                if (! (result.value && result.value.ELEMENT) ) {
                    result = null;
                    err = 'Timed out waiting ' + ms + ' ms for element by selector: ' + selector;
                }
            }

            if (typeof callback === 'function') {
                callback.call(this, err, result);
            }
        };

        if (selector instanceof JQuerySelector) {
            var timeBetweenChecks = 50,
                timesToCheck = ms / timeBetweenChecks;

            this.timeouts('script', ms)
                .executeAsync(function (selector, timesToCheck, timeBetweenChecks, cb) {
                    var timesChecked = 0;
                    var handle = setInterval(function () {
                        timesChecked++;
                        var el = eval(selector);
                        el = el.get(0);
                        if (el) {
                            cb(el);
                        } else if (timesChecked >= timesToCheck) {
                            clearInterval(handle);
                        }
                    }, timeBetweenChecks);
                }, [selector.toString(), timesToCheck, timeBetweenChecks], wrappedCallback);
            return this;
        } else {
            return waitForOld.call(this, selector, ms, wrappedCallback);
        }
    };
})();