June 11, 2017
Write programs that do one thing and do it well. –The Unix Philosophy
I love small Git commits. When I commit, I like a short message. The code should only do what’s described by that message, in one or two migrations, each of which can be rolled back. The changes should touch a limited number of files, and leave a green test suite. Everything should be reversible without side effects.
Whenever I’m pair programming, I’m quick to say: “Can we commit this?“. I want to commit as soon as the tests are green, as soon as I have an inkling that refactoring or optimization is imminent, the moment we let our attention drift, the second anything other than the current feature is up for discussion.
I call this philosophy ‘Work Small’.
Obsess about the task at hand. Measure and remeasure, discuss edge cases, ponder if you are using the right tools, sharpen them. Pick the smallest part of the problem you can solve and solve it. Don’t stop until it’s perfect. When it’s perfect, sand the splinters away, cast it in lacquer, put it in a glass case.
A few great programmers I’ve met can carry entire wings of a codebase in their heads. They are happy when their Git log is dirty, their Vim buffers are full, and they are walking above the ground on a tightrope with no harness. They know what they want and they are driving toward it with total focus. They finish their thought process with a complex commit process, divvying up hours of work into a series of changes.
I am not such a programmer.
Pausing to think, to commit to your work, to ship what you have, to deliver where you are, is the heart of Agile. I admire those programmers–- they often ship great work. But they take a risk, too: that their work will never be finished, that it’s irreversible, that future maintainers will not understand their thought process and delete or hack apart their code.
Don’t want to work small? No problem; go ahead and open a pull request that changes forty files, has six commits that break the build, and migrates the database five times. It takes a brave soul to read that pull request, an even braver one to ask a question or push back. You’re most likely to get silence or a token ‘looks good’. Merge it in on a Friday if you want an excuse to cancel your weekend plans!
As an OSS maintainer, small is everything. Your commits tell the story. I’ll take four commits (‘add the library, add a column to the table, implement the form, and optimize the query’) over something less expository every time. I understand each step, and can revert them someday. We can always squash the pull request once everyone approves the change.