Ask HN: Programmer Focused Programming Language?

Is there a programming language designed explicitly with some of these in mind:

Troubleshooting and debugging as first class citizens

Testing baked into the language

Refactoring and legacy code friendly

Designed for tooling, IDE integration, code generation, analyzers etc.

I find most of the discussion around PLs focus more on the technical and theoretical side of things, and less on the hands on and practical.