Claude Code wrote unit tests for a 15-second video

My video has unit tests

For a Petroly promo video, Claude Code built a JavaScript renderer where each frame is a function of time: time goes in, an SVG comes out, sharp turns it into pixels, and FFmpeg encodes it. The agent then wrote automated tests asserting that the push notification can't appear before the price hits its target, that no frame contains NaN, and that the cheapest station's checkmark waits for the rows to settle. Twelve localized versions share one renderer.