What do you mean? It's the typescript compiler that catches your errors. The IDE stuff is nice to have, but it's not the main benefit typescript adds to refactoring. Typescript doesn't rely on an IDE.

Apologies, as I am going to make a few assumptions.

If you write fewer classes and class hierarchies, and use higher order functions (see also - partial function application), you will have much less "refactoring" to do - often, simply small changes such as to increase the visible scope of a function you now want to reuse elsewhere, or to "pre bind" another argument to a function so the caller(s) don't need to know a particular detail.

This probably has a lot to do with why the static OOP people think the dynamic FP people are insane: they have no idea how we really work.

We have garbage collectors and closures now. Stop writing code as if in some crippled version of Simula 67 :-)

I work with a typescript project, and the classes of errors that are caught by the TS compiler are not worth the hassle of having to use typescript.