How to statically serve a single page web app?

What is the correct logic for statically serving a single page web app? It seems to me that any path with no extension should go to index.html and any path with an extension should be served up as-is (assumed to be a file in the directory)?

I was surprised that I couldn't find clear best-practice for this online. Perhaps I'm missing something obvious.

Note - my implicit assumption here is that the majority of singe page app framework implementations behave similarly enough that the server's static rules can be agnostic (angular, yew, etc). If this assumption is totally wrong that would be interesting to know as well.