No human maybe, but could an AI?
I fed the prompt for https://leetcode.com/problems/two-sum/ to ChatGPT, which generated code for an answer, and I then asked it for additional test cases, which it gave. What's mind blowing though is that it "reasoned" that:
> These test cases demonstrate that the twoSum() function can handle cases where the input array contains negative numbers, where the target is negative, where the indices of the two elements are not adjacent, and where the input array contains duplicate elements.
Full transcript: https://pastebin.com/BpdcuWEM