What problem does it solve? Result-bearing scientific code — pipeline seams, null models, statistical calculations, provenance fields — often gets implemented before its governing contract exists, producing silently wrong outputs. This Skill enforces a contract-first TDD workflow where the governing contract is resolved before any implementation code is written, and every behaviour slice is tested through the public or scientific interface. ## Core Features & Use Cases - Contract Resolution Gate: Requires an upstream contract (or an explicit documented N/A) before writing result-bearing code; the implementer never authors its own contract. - Interface-Level Testing: Tests cross the public/scientific seam — input stage, seeds, null-model order, output schema, error modes — not private internals, so they survive refactors. - Control Classification: Classifies each new control as remediation-red (must fail on the parent) or preservation-green (must pass on both), bound to the seam it exercises. - Exact-Value Assertions: Contract-pinned fields are asserted by exact value and type (e.g. n == 711, family == "quasibinomial") with negative cases, never key-presence checks. - Use Case: When adding a new output field to a statistical pipeline, resolve the schema contract first, write one failing test against the public seam, implement the minimal slice, then run contract binding and provenance checks before proceeding. ## Quick Start Ask the agent to implement a new result-bearing pipeline behaviour using contract-first TDD, resolving the governing schema contract before writing any implementation code.
