index.js

/*

This Google Script will auto-update the title of your
YouTube video based on the number of views and comments

Tutorial: www.labnol.org/update-youtube-title-200818

Author: Amit Agarwal https://digitalinspiration.com/

Original Idea by Tom Scott youtu.be/BxV14h0kFs0

*/

const updateYouTubeVideo = (e = null) => {
  const id = '<<Video Id>>';
  const template = 'This video has VIEWCOUNT views and COMMENTCOUNT comments';

  // The cron job is created only when the script is run manually
  if (e === null) {
    const triggerName = 'updateYouTubeVideo';
    const triggers = ScriptApp.getProjectTriggers().filter((trigger) => {
      return trigger.getHandlerFunction() === triggerName;
    });

    // If time based trigger doesn't exist, create one that runs every 5 minutes
    if (triggers.length === 0) {
      ScriptApp.newTrigger(triggerName).timeBased().everyMinutes(5).create();
    }
  }

  // Get the watch statistics of the video
  const { items: [video = {}] = [] } = YouTube.Videos.list('snippet,statistics', {
    id,
  });

  // Parse the YouTube API response to get views and comment count
  const { snippet: { title: oldTitle, categoryId } = {}, statistics: { viewCount, commentCount } = {} } = video;

  if (viewCount && commentCount) {
    const newTitle = template.replace('VIEWCOUNT', viewCount).replace('COMMENTCOUNT', commentCount);

    // If the video title has not changed, skip this step
    if (oldTitle !== newTitle) {
      YouTube.Videos.update({ id, snippet: { title: newTitle, categoryId } }, 'snippet');
    }
  }
};