When to Write Tests for AI Features (Almost Never)

Non-deterministic outputs make unit tests useless. Model responses shift with every update or temperature setting, so your assertions fail randomly. Focus effort on the deterministic wrapper instead. The code that calls the API, handles errors, and formats results stays stable and deserves the tests. Prompt changes break tests faster than code does. Tweaking instructions happens daily, turning test maintenance into busywork. Run manual checks on high-stakes features only. For an AI product…