gistfile1.txt

function CasperSelector(casper, selector) {
  this.casper = casper;
  this.selector = selector;
}

CasperSelector.prototype.visible = function() {
  return this.casper.visible(this.selector);
};

Casper.prototype.find = function(selector) {
  return new CasperSelector(this, selector);
};

chai.Assertion.addProperty('visible', function () {
  this.assert(
      flag(this, 'object').visible(),
    , 'expected #{this} to be visible'
    , 'expected #{this} not to be visible');
});