Version-controlled commented-out code

Today, whilst debugging some legacy code within an application, I found several blocks of commented-out code.

Some were previous debugging code which had been commented out, and some were old components or previous implementations - but instead of being removed when they were no longer needed, they remained in the codebase as commented-out lines - inactive but adding noise and complexity around the code that I was trying to understand and debug.

To make it easier for me to figure out this code, I’d like it to be as clean to read and as simple to understand as possible.

The codebase is version-controlled, so why would there be a need to comment out and keep the lines?

Version control systems have a log of each change, so if you need to see previous changes, you can view the log and see what changed, when, and by who.

You can also see any other files that were changed in the same commit, and usually, there will be a reference to the issue or ticket that required that change.

If you need to re-add a change that had been removed, you can either do this manually or by reverting the commit.

Should there be commented-out code within a codebase if it’s version controlled? I’d say no unless there’s a good reason for it to be there and it’s providing some additional context or for a specific purpose. If it’s an outdated implementation, some old debugging code, or a component that’s no longer needed, I think that it should be removed, and people can use version control tools to find or re-introduce those changes if needed.