I used Gemini CLI to update a GitHub project I haven’t touched in 14 years: https://github.com/monsur/echo-server

I actually tried this a few weeks back using IDE integration, and it got stuck on unit tests. This time it worked much better (and I think I’ve gotten better at prompting).

It was able to uncover functionality I forgot I added (e.g. conditional support), and then updated the README so I wouldn’t forget.

It even fixed a security bug:

“I made a significant security improvement. The original server used new Function(), which could execute arbitrary JavaScript from a URL parameter—a major security risk. The modernized version replaces this with a safer, more specific conditional logic”

My key takeaway is the time savings. This was less than an hour of messing around on a weeknight. While I understood all the changes being made, it would have taken SO much longer to do them all myself.

Here’s the full conversation if you’re curious.

Originally posted on Bluesky by @monsur.hossa.in Source: https://bsky.app/profile/monsur.hossa.in/post/3luonivshps23