Code RoomExample code uses nonexistent APIs
HardPrep Room Coding #4442

Example code uses nonexistent APIs

Vibe & agenticAlgorithms & data structuresSenior–Staff~20 min

You ask an AI to write usage documentation, including code examples, for a Rust crate you maintain. The prose is excellent and the examples compile in your head — but one example calls `client.fetch_all().await?` and another uses a `RetryPolicy::exponential()` builder. Your crate has neither; the AI synthesized idiomatic-looking APIs that don't exist. How do you keep AI-generated example code in docs honest, at scale, across every release?

Implement
find_hallucinated_api_calls(known_symbols: list[str], example_lines: list[str]) → list[str]
Examples
in[["Client::connect","fetch_page","RetryPolicy::new","build"],["let client = Client::connect(url)?;","let all = client.fetch_all().await?;","let policy = RetryPolicy::exponential().build();"]]out["RetryPolicy::exponential","fetch_all"]
in[["fetch_page"],["let page = client.fetch_page(1)?;","println!(\"{}\", page);"]]out[]
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.