Give me a short test case. Something small, yet 100% complete. Concise - but self contained. Remove anything not relevant to the problem.
Tiny is good, but complete is a requirement.
999 times out of 1,000 - when I build these myself - I find my own mistake or omission.
Test cases are so very important. And seriously - most of the times when I build them, I find my own mistake or find a workaround to the problem at hand.
And if I don't, someone else will see it - it will be digestible, small, easy enough to understand.