Some people are comfortable offloading mental effort to a compiler. Others suffer from anxiety at the suggestion.
Last week I deployed a Ruby change where a missed comma between two strings in an array did not get picked up by any of the automated tooling or by 3 other team members who code reviewed my change, and ended up cutting 50+ sev2s at 10pm.
AWS folks can probably guess which internal tool I had to touch that requires Ruby.
(I was on call, fun times)
> anxiety when I'm forced to touch fragile bits written in Ruby
Wild, because the first sentiment is exactly how I feel about Ruby.
I resonate with you even with TypeScript, since it's just annotating types but not the true value under the variable. You would have to go to a greater extent to make sure that everything from outside (library code, parsing HTTP responses, database queries, etc.) conforms to your annotated types. Even in the same project code created by other people, I often doubt the validity of the types, asking myself questions like: Should I validate this? What if this has already been validated, thus making mine a performance waste? Does this object contain extra sensitive information that could be leaked when used in a logger?
After having experience with Rust, working with TS feels like navigating a minefield where every refactor could detonate hidden bugs or behavior collectively accumulated by all the historic code and dependencies, small or large.