Problems typing equality in Ruby – Jake Zimmerman

https://blog.jez.io/problems-typing-ruby-equality/ · TypeScript has this really handy error that flags when it looks like two values of unrelated types are getting compared. I would love to build the same error into Sorbet, but there are two features which make that hard: custom overrides of `==` and subtyping. Here are some heuristics we might consider building in Sorbet, and why they don't work.