Vint.ee threw away jQuery. And of course, it led to a major incident.

Hello,

jQuery is a timeless JavaScript library that we've been using since the beginning of vint.ee.
I've been planning to get rid of it and use pure JavaScript (VanillaJS) for a long time. The amount of work was quite decent (it could be measured in days) because jQuery was used on at least 30 pages. So it never got enough priority.

Yesterday I thought I would experiment with some AI tools and started using Github Copilot Agent mode. And I set out to get rid of jQuery. To my surprise, the AI agent was surprisingly good at generating code that would replace jQuery code.

The entire job was done in three hours instead of days!

The story could have ended happily at this point... but no!
After the changes were posted last night, today I started getting emails saying users can not log in anymore! A pretty critical incident.

Yes, jQuery was also used in login views, so the login issues were obviously related to my changes.
And of course, everything worked on my machine. The immediate thought is that people are using some weird browsers (like MS Edge ;)), but when one user claimed to have Google Chrome, things got more suspicious.

After some investigation, I understood that login was broken only in the gameroom and that I could reproduce this in the development environment. It turned out that AI had generated a window.onload function in all files.

As I use nested views, it led to multiple window.onload functions on one page which conflicted with eachother and broke the whole page. I had to revisit 30 files again and use the window.addEventListener("load", function() {}); function.

It happens.
 

sounds like rocket science to someone who is afraid of flying

Yesterday it turned out that sending messages to users' inboxes was broken for 2 weeks. This was also related to this change.

Sending messages should now work again!