I mean, there's no way to prove something is actually used in those cases except for actually running the thing.
Do you just rely (and hope) on tests across all projects?
It usually goes like this:
- You make your API backward compatible.
- You use grep to try and find all the ways people are using it.
- You write and run a codemod to convert 70-90% of the call sites mechanically.
- You manually fix the remaining ones. This is usually a good opportunity to throw a hackathon-style event where a bunch of people sit in a room for few hours and drive it down.
- You remove support for the previous version.
The mere thought of this makes me think of the dark ages and a time in my career that I'd rather forget. All hail statically typed languages. Or languages that can easily be tooled against.
I assume it's easier with RPC.