Just because something works, does it mean you don't have to refactor?

Question

I just saw this line of code in the WP codebase.

if ( $user_id = wp_validate_auth_cookie( '', apply_filters( 'auth_redirect_scheme', '' ) ) ) {
}

Um. Yeah. two method calls and an assignment statement in an if statement.

So, my guess is, nobody is refactoring this.

Are there any reasons why?

Answer 1

To answer the question in your title:

Just because something works, does it mean you don't have to refactor?

If it did, we'd never refactor. Because refactoring happens on green. That is, it happens when all tests are passing, when - by definition - the code works. If you "refactor" on red, you're not refactoring. You're playing with your code. You're taking risks that you probably shouldn't be taking. Refactoring is improving the design of existing code, without changing its behavior. If your code isn't working, if you don't have tests that demonstrate that it's working, then the changes you make could be changing its behavior.