Shouldn't this path just be ../jest/business-logic.md?

Yes. Fixed.

Claude is flagging this as bad code example because it's missing error handling and cleanup, which could encourage an LLM to use this. Here's the recommended code.

// ❌ Custom hook with async logic but no tests
  const useCustomFetch = <T,>(url: string): T | null => {
      const [data, setData] = useState<T | null>(null);
      useEffect(() => {
          const controller = new AbortController();
          fetch(url, { signal: controller.signal })
              .then(res => res.json())
              .then(setData)
              .catch(() => { /* ignore aborts/errors for brevity */ });
          return () => controller.abort();
      }, [url]);
      return data;
  };

This is interesting. It IS a bad code example, though its intent is to be bad in a different way (lacking tests, not bad error handling).

Do we need our examples of bad code to be good in ways other than the specific problem they're intending to call out? The downside is overly verbose examples and token bloat.

I am not sure how useful these code examples are because we cannot use fetch anywhere, and as a result cannot use AbortControllers. We'd need to release a 2.x version of @labkey/api for this to be relevant to us. This is something we should do, and I was just talking with Nick about it the other day because I want to use AbortControllers, but there isn't really a path forward for us to use either because all of our API requests are done via Ajax.request

This was a low priority call out by claude, but I suspect what you might get is an LLM adds tests to the bad example and thinks it is now good code to use as a reference. Even though it has other issues. Maybe something to research further.