I saw no mention of RBS+Steep, the latter providing a LSP. I use it a lot and very much like it, although it's still young and needs love, but it's making good, steady progress! I've been very pleasantly surprised by some of the crazy things Steep can catch, completely statically!
You appear to be working on projects with Sorbet (which I tried to like but found it fell short in practice, notably outside of the app use case i.e it's mostly useless when authoring a gem) so it may be a tall order to try on those. Maybe you can give RBS+Steep a shot on some small project?
If you want good results with intellisense/omnicomplete you need sigs. Steep does some type synthesis but giben Runy's very dynamic nature it's going to be hit and miss, so that's mostly for progressive typing. It really aims at leveraging static information.
The process is basically `rbs prototype` or `typeprof` to generate a sig file and steep then uses that. TBH it's not that much of a chore as it sounds and already gives you good-ish results. That gives you a bunch of material to work from and progressively refine types.
Speed is very good, I didn't notice anything slow.
For context, the reason I ask is that I am developing some Ruby gems, and considering whether it's worth adding .rbs files.
In the Python libraries I maintain, types are useful to anyone who installs the default Python VS Code plugin, because it gives them intellisense (but doesn't give them red squiggly lines for type errors) even if they do nothing to set up types or a typechecker.
You appear to be working on projects with Sorbet (which I tried to like but found it fell short in practice, notably outside of the app use case i.e it's mostly useless when authoring a gem) so it may be a tall order to try on those. Maybe you can give RBS+Steep a shot on some small project?
RBS: https://github.com/ruby/rbs
RBS collection (for those gems that don't ship RBS signatures in `sig`, integrates with bundler): https://github.com/ruby/gem_rbs_collection
Steep: https://github.com/soutaro/steep
VS Code: https://github.com/soutaro/steep-vscode
Sublime Text: https://github.com/sublimelsp/LSP
Vim (I'm working on it): https://github.com/dense-analysis/ale/pull/4671