gistfile1.txt

function doTrafficLights() {
  turnOffLights();
  var activeLight = getActiveLight();
  if (activeLight === 'red') {
    turnRed();
  }
  if (activeLight === 'yellow') {
    turnYellow();
  }
  if (activeLight === 'green') {
    turnGreen();
  }
}



/* From here down, you are not expected to 
   understand.... for now :)  
   
   
   Nothing to see here!
   
*/


function turnOffLights() {
  $('.traffic-light').removeClass('yellow-on red-on green-on');
}

function turnGreen() {
  $('.green-light').addClass('green-on');
}

function turnYellow() {
 $('.yellow-light').addClass('yellow-on');
}

function turnRed() {
  $('.red-light').addClass('red-on');
}

function getActiveLight() {
  return (['red', 'green', 'yellow'])[Math.floor(Math.random() * 3)];
}

function handleClicks() {
  $('.js-control-lights').click(function() {
    doTrafficLights();
  });
}

$(function() {
  handleClicks();
})

gistfile2.txt

function main() {
  try {
    doAllTheThings();
  }
  catch(e) {
    console.error(e);
    reportError(e);
  }
}

function doAllTheThings() {
  throw {
    message: "Everything's ruined",
    name: "FatalException",
    toString: function(){return this.name + ": " + this.message;} 
  }
}




/* From here down, you are not expected to 
   understand.... for now :)  
   
   
   Nothing to see here!
   
*/


function reportError(e) {
  $('.js-error-report').text("Uh oh, something went wrong! Here's what we know: " + e.message);
}


$(main);