Google's John Mueller confirmed on Twitter that Google does cache your JavaScript and CSS files for a "fairly long" time and thus, if those files change what content shows up on the page or what new URLs you produce, then that might be an issue for your SEO strategy.
John said "Yes - we cache these files [JavaScript and CSS] fairly long, so if you rely on them changing (content or URL) frequently, that might make rendering impossible or at least hard."
Here are the tweets:
Yes - we cache these files fairly long, so if you rely on them changing (content or URL) frequently, that might make rendering impossible or at least hard.
— 🍌 John 🍌 (@JohnMu) October 18, 2018
So if you use these files to show Google specific fresh content or new URLs, try to think about how you can give them this new content and URLs other ways. If Google caches these files for a long time, it may delay how quickly they can pick up new content and URLs on your site.
Forum discussion at Twitter.
