We are testing a modal z-layer style popup (fancybox javascript implementation) on one of our content pages that blocks user interaction with the rest of the page without a signup. I am curious what factors this has on crawlers (googlebot). We are aware the modal popup has other behavioral impacts on ranking (e.g. bounce rate, etc). I am curious if the presence of modal javascript/html code adversely affects search ranking.
The other answers saying that crawler bots are not executing Javascript are wrong or out-of-date. Experiments have proven that the Google bots (2017) does follow links that are rendered using javascript, therfor they crawl somehow the websites with js enabled.
The following article is from 2015 and proves what I've said.
http://searchengineland.com/tested-googlebot-crawls-javascript-heres-learned-220157