Side quest: creating a "main" tool

I like Simon Willison's framing of using large language models (aka LLMs, aka "AI") to enable side quests of things you wouldn't normally do.

Could I have done this without LLM assistance? Yes, but not nearly as quickly. And this was not a task on my critical path for the day—it was a sidequest at best and honestly more of a distraction.

So, yesterday's side quest: writing a tool that checks out the default branch of a Git repository, regardless of what it's named.

Context: most of my work these days happens on GitHub, which involves creating PRs off the main branch, which means I'm frequently going back to it, via git checkout main and then usually a git pull to fast-forward the branch.

But just to make things a little more interesting, the SecureDrop server Git repository's main branch is named develop, which entirely screws with muscle memory and autocomplete. Not to mention all the older projects that still use a master branch.

For a while now I've wanted a tool that just checks out the main branch, regardless of what it's actually named, and optionally pulls it and stashes pending changes.

I asked Claude 3.5 Sonnet for exactly that:

I want a Rust program named "main" that primarily checks out the main branch of a Git repository (or master if it's called that).

I want to invoke it as:

• main - just checkout the main branch
• main stash - stash changes, then checkout main, then pop the stash
• main pull - checkout main and then git pull
• main stash pull or main pull stash - stash changes, checkout main, then pull, then pop the stash

It was mostly there, except it hardcoded the main and master branches intead of looking it up via Git. I asked:

Is there a smarter way to determine the main branch? What if it's called something other than main or master?

And it adjusted to checking git symbolic-ref refs/remotes/origin/HEAD, which I didn't know about.

I cleaned up the argument handling a little bit, added --version and published it on Salsa.

It took me about 5-10 minutes for this whole process, which according to xkcd is an efficiency positive (saves 1 second, but I do it ~5 times a day) over 5 years.

It probably would've taken me 2-3x as long without using an LLM, but honestly, I'm not sure I would've ever overcome the laziness to write something so small.

Anyways, so far I haven't really gotten around to writing about my experiences and feelings about LLMs yet, so here's literally the smallest piece of work to kick that off.