Hide watched YouTube videos

youtube-hidewatchedvideos.js

// example data
var selector = '.ytd-thumbnail-overlay-resume-playback-renderer'; // CSS selector for red bar indicating video has been watched
var exampleUrl = 'https://www.youtube.com/channel/UCN64HIrZNqFQYZ2BuyY-4zg'; // example URL for text
var jQueryInjectorExtension = 'https://chrome.google.com/webstore/detail/jquery-injector/ekkjohcjbjcjjifokpingdbdlfekjcgi?hl=en'; // url for chrome extension to inject jQuery into page for code below to run

$(selector)
  .parent()  // ytd-thumbnail-overlay-resume-playback-renderer.style-scope.ytd-thumbnail
  .parent()  // div#overlays.style-scope.ytd-thumbnail
  .parent()  // a#thumbnail.yt-simple-endpoint.inline-block.style-scope.ytd-thumbnail
  .parent()  // ytd-thumbnail.style-scope.ytd-grid-video-renderer
  .parent()  // div#dismissable.style-scope.ytd-grid-video-renderer
  .parent()  // ytd-grid-video-renderer.style-scope.yt-horizontal-list-renderer
  .hide();