Great loop spotting!

Recently I was messing around with parquet files in Python and ended up needing to ship the results on Windows, without a Windows machine to test on.

Shipping Python to end users is half mad already, and doing it on Windows is exactly the kind of thing I don't want to spend my life maintaining.

So I figured I'd rewrite it in Go. But that meant embedding a DLL, and how would I test it? I could spin up a VM, sure. But GitHub Actions already has a Windows environment, and there was my loop: let the agent push to the repo, run tests in GHA, rinse and repeat.

In under an hour it had a full rewrite of my Python, passing every test and producing row-for-row copies of my Parquet output. And it does work on the user machine!

Spotting a loop like that is as satisfying as noticing you can walk your chess opponent into a smothered mate. Truly empowering.

DuckDB

Also Windows used to have a free VHD with a trial license you could download (and convert to different format with qemu-img)