Vibe codingHardvc-g151

Subject Ai property testingLevel Senior–Staff~20 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

You asked an AI to write a Hypothesis property-based test for a serialize/deserialize pair for a config object. It produced:

python

1@given(st.dictionaries(st.text(), st.integers()))2def test_roundtrip(d):3    assert deserialize(serialize(d)) is not None

It passes thousands of cases. Why is this property nearly worthless, what is the property you actually want, and what subtlety must you get right for round-trip properties?

What a strong answer looks like

Treat the AI’s output as a draft to verify, not an answer to trust. Name the specific flaw and the input that triggers it, say how you’d catch it — tests, edge cases, reading critically — and how you’d re-prompt or decompose to get it right.

Learn the concepts

Describe your solution

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.