[i_v]

Sorbet[1] is currently the most robust tooling available. It has a few rough edges and limitations but it otherwise works great for 90% of use cases.

[1]: https://sorbet.org

[aledalgrande]

Add tapioca and it's much smoother

[berkes]

But Sorbet is also not part of the language, not part of the std-lib, and AFAIK there aren't plans to make it that.

[_joel]

Oh lovely, there's this morning wasted :)