[paholg]

In emacs, there's robe mode which I found to work very well. It keeps a Ruby process running with your code loaded in it.

I wonder why no one's written a Ruby LSP with this approach rather than relying on static analysis.

https://github.com/dgutov/robe

[grncdr]

The ruby-lsp project made by Shopify has (or had...) a rails plugin that worked this way. It adds some routes to your server during development and uses them to introspect the running process.