I have just received an email regarding Index coverage issues for my site. The following file is indexed by the Google:
root-of-my-site/files/custom.js
Please note that I have disallowed /files folder in my .htaccess though Google has indexed a URL from that folder.
Please let me know how should I de-index my URL forever!
Please read this article from Goole itself: https://support.google.com/webmasters/answer/7440203?hl=en
Some from there:
Indexed, though blocked by robots.txt: The page was indexed, despite being blocked by robots.txt (Google always respects robots.txt, but this doesn't help if someone else links to it). This is marked as a warning because we're not sure if you intended to block the page from search results. If you do want to block this page, robots.txt is not the correct mechanism to avoid being indexed. To avoid being indexed you should either use 'noindex' or prohibit anonymous access to the page using auth. You can use the robots.txt tester to determine which rule is blocking this page. Because of the robots.txt, any snippet shown for the page will probably be sub-optimal. If you do not want to block this page, update your robots.txt file to unblock your page.
You can watch this video for more details: https://www.youtube.com/watch?v=WlniBqL_0Zc