“Refactor”

Original Author: Rob-Galanakis

Refactoring is defined as a “disciplined technique for restructuring an existing body of code, altering its internal structure without changing its external behavior” by Martin Fowler.

But its everyday usage takes a very different meaning. We use the word refactor to everything from the original meaning, to a complete side-by-side rewrite of a barely-functional system. How can you use the same word to refer to something that does not change external behavior, with building an entirely new replacement system?

More than once, I’ve elicited sighs for my efforts to clarify the language we use. But when you have people that use wildly different vocabularies- artists, programmers, project managers- this is of paramount importance. So the fact that we say ‘refactor’ to meaning any type of rewriting of code or functionality irks me.

So recently I’ve begun a dictionary in my head for the type of tasks we do.

Refactor: The original and ‘precise’ meaning of restructuring a module without altering external behavior, up to a rewrite of parts of a larger system, that may change internal behavior of the system (including the external behavior of large internal components). While I’d love to keep only the more limited original meaning, when we’re dealing with large legacy codebases that often have zero tests, the original meaning doesn’t apply often enough.

Renovate: Rewriting a system so that its external behavior changes considerably but it still fulfills the same purpose (obviously). I name it as such because it is like renovating a building- the exterior and interior may greatly change, but what goes on inside may stay the same. Similar to ‘Rewrite’ but generally applies to a smaller (module/system) scale. An example would be, if you have a library for dealing with source control, and you no longer like the API. So you greatly change how the module works, and it still fulfills its fundamental purpose of dealing with source control.

Recycle: Writing a replacement system side-by-side with the old system, using components from the old system (by either referencing or copy/pasting), with the goal that once the new system is working, the old system will be shut down. The goal is a replacement that is easier to use but fulfills similar requirements. An example would be replacing legacy procedures for data transformations, that may have a lot of imperative code and poor reuse. You would replace the system with something better written, often taking chunks of logic from the old system, or writing tests that verify it produces the same results, then hook up calling code to use the new system, then delete the old one entirely.

Rewrite/Rebuild: When a system is to be written from the ground up, using the original implementation as an example or in a prototype role only, resulting in a system that fulfills the business requirements of the original system but does not necessarily preserve anything else about it. Similar to ‘Renovating’ but generally applies to a larger (application) scale. An example would be, if you have a website/game feature that you want to replace, you’d build the new one to fulfill the same business requirement (we need a website/some feature), but the features may be completely different.

So that’s my personal language right now. My hope is that it will expand to my team and then out from there. I don’t know if I’ll refine it much more- too granular and it would become unwieldy. Do you have suggestions or a language of your own?