Exterminators Week 9 - The Wrong Time To Refactor

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This week I picked the wrong time to refactor. It was the day before our release was due and we needed to wrap things up. We decided to not ship my changes and I think waiting was the right choice.

We were fixing a bug. The problem affected multiple areas. You could use roughly the same fix in each spot. What do you do?

  1. Consolidate logic for the fix in one place, and then call the updated logic as needed. (Left)
  2. Repeat the fix as needed in each area. (Right)
On the left a circle encircled ny eight smaller circles. On the right there is a circle of eight circles larger than those on the left.

Normally, I would try to pick option 1. You can test the change better and make updates easier in the future. Code reviews can be a little cleaner since you can consolidate the logic required for the change. Either option involves a small change in the places affected by the issue with more changes to the affected areas with option 2.

I say normally because this week the normal decision making did apply. People get tense and uptight the closer the release deadline nears. They want to slow down what changes are being made and be confident no last minute bugs are introduced. This is a good idea. Rushing code in at the last minute you think is amazing can blind you to the fact it is secretly carrying the plague.

We had option 2. ready to go with a few days to spare and were happily reviewing it. It fixed an important defect we wanted to ship on time. The change was ready to be merged and all our initial testing looked good.

I decided I would try to refactor the fix to be closer to option 1. and beat the release deadline. There were some opportunities for consolidating the fix and reduce duplication. Within a short while I had a pull request ready for review. The release deadline was approaching fast.

A picture of numbers at a finishline
Project 365 #200: 190713 The Finishing Line by Pete, used under Creative Commons 2.0 BY

My code review looked okay on the surface, but was more complicated than the previous fix. There were unit tests covering my pull request and the consolidated code, but no tests covering the individual areas changed. Even though the previous fix did not have tests, we felt confident any issues would be isolated to the updated areas. Each of the affected areas could be tested manually.

We liked how my new change had more tests. Our major concern was how close the deadline was and whether we had enough time for thorough testing.

We decided not to ship my updated code. Rather than put the release at risk we decided to wait and do the refactoring in the next release. This meant we could calmly make all the changes we wanted to without the pressure of an imminent release looming over us.

I think this was the right decision and would do it again in the heartbeat. While I think craftsmanship and clean code are important I value shipping solid releases without drama more. Do your customers care if you have the perfect unit tests? No! They care when you break things. We already had the defect fixed and did not need my extra refactoring.

Several weeks later we went back and revisited the code. We added something like my refactoring. The second time we reviewed the code we found better ways to break down the duplication than my rushed first attempt.

From this experience, I learnt there are wrong times to refactor based on release timing and the business needs. Next time your reach the end of the release and have an amazing idea for how to clean up the code, please wait until the next release.

I would like to thank my fellow exterminator, Vlad, for the original fix, reviewing with my attempted refactoring and patiently consolidating the code in the next release.

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