Update routes formatter to use Parlour about sorbet-rails HOT 2 CLOSED

I tried doing this, and boy that is a lot more complex than I anticipated. Right now, it uses a RouteInspector that's technically supposed to be a private API, and it abuses some formatting tricks to output an RBI. I couldn't find a good (public API) way to consistently, programatically get all the routes available in a Rails app, unfortunately. :/

from sorbet-rails.

I don't think you need to find a different way to get routes. The route inspector will call the formatter for each route that it has. The RouteRbiFormatter can assume the methods are called correctly. Essentially @buffer can be replaced with a Parlour::RbiGenerator and every time a section is called, we insert new methods to the generator. When result is called, outout the generated rbi.

This is the code in rails source code that I modeled after
https://github.com/rails/rails/blob/0196551e6039ca864d1eee1e01819fcae12c1dc9/actionpack/lib/action_dispatch/routing/inspector.rb#L234

from sorbet-rails.