> but I wish I could define in TypeScript “any object passed into this function is now typed _never_.

Having explicit language to differentiate between pass by reference and pass by value avoids this confusion. It requires a little more thought from the programmer but it’s really minimal once you internalize it.

Rust takes this a step further with an explicit ownership and borrowing model. The compiler will refuse your code if you try to write something that that violates the borrow checker. This is endlessly frustrating to beginners but after adapting your mind to ownership safety you find yourself thinking in the same way in other languages.

I always found real-world JavaScript codebases frustrating because there was so much sharing that wasn’t entirely intentionally. It only got fixed when someone recognized a bug as a result.