Code RoomYAML config parser with validation
MediumPrep Room Coding #5005

YAML config parser with validation

Vibe & agenticAlgorithms & data structuresMid–Senior~18 min

You're building a YAML config parser in Rust for a CLI tool: load a `config.yaml`, validate it against a schema, apply defaults, and surface clear errors with the offending field path and line. You'll delegate it to an AI agent. Write the prompt/spec — constraints, edge cases, acceptance criteria — for a first-try-correct result. What does a vague prompt ("parse the YAML config") get wrong in Rust specifically?

Implement
validate_config(known_keys: list[str], required_keys: list[str], lines: list[str]) → list[str]
Examples
in[["name","timeout","country","retries"],["name","timeout"],["name = svc","timeout = 30"]]out[]
in[["name","timeout","country","retries"],["name","timeout"],["name = svc","tieout = 30"]]out["line 2: unknown key 'tieout'","missing required key 'timeout'"]
in[["name","timeout","country","retries"],["name","timeout"],["name = svc","timeout = 30","country = NO"]]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 18 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.