Agree with this. I recently refactored a TypeScript code base for around 3 hours (renaming things, moving functionality into new classes, reducing duplication)

Agree with this. I recently refactored a TypeScript code base for around 3 hours (renaming things, moving functionality into new classes, reducing duplication) without running the code once and it nearly worked first time. Simply renaming a variable in plain JavaScript can be a challenging refactor in comparison.