The most unexpected unit test I have seen from my AI agents today is a check that a push notification in a video cannot appear before the price in its animated chart reaches its target.
I needed a 15-second promotional video for my side project Petroly, a fuel-price app. Claude Code went ahead and wrote a JavaScript renderer that reuses my app’s design. I could then describe a change in plain language, watch the result and refine it.
The chart, the notification, the sorting animation and the transitions all live in the source. I can change them, review a diff and render again. The more we worked on it, the more possibilities I saw: tests for the timing, translations from the app, even a video with transparent corners.
