Search engine optimization in Meta Tags (Custom Elements)

Well cool the question. I have been working with Javascript frameworks and I really see this question often. The bots are constantly evolving. There are several, not only google, but also other search engines and other crawlers. Google's is the most advanced and it ends yes by reading the javascript. But the not read the .js files and only the html files. This means that if you do not render the pages of a SPA or JS framework on the server you will not have a good indexation in general between search engines (SEO).