Code RoomDate library migration risk
MediumPrep Room Coding #4234

Date library migration risk

Vibe & agenticCode quality & reviewMid–Senior~20 min

Your TypeScript codebase uses the deprecated Moment.js for all date handling. You ask an AI agent to swap it for a modern library (date-fns / Luxon / Temporal). The agent does a clean find-and-replace and the build is green. Why is a green build dangerous here, and what do you verify before shipping?

Implement
normalize_dates_strict(raw_dates: list[str]) → list[str]
Examples
in[["2026-01-31","2026-1-31","03/14/2026"]]out["2026-01-31","Invalid Date","Invalid Date"]
in[["2024-02-29","2026-02-29"]]out["2024-02-29","Invalid Date"]
in[[]]out[]
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.

0:00 of about 20 min

Vibe & agentic: describe the solution in plain language (or narrate it) and the coach grades your approach.

Which questions mattered is sealed until you submit. Telling you now would just be handing over the edge cases.