Clean-room implementation workflow
Build a compatible implementation in small vertical slices from a frozen behaviour specification. Do not author a clone from copied source or promise completeness without measurements.
Procedure
- Select one requirement with a stable oracle and define the smallest useful slice.
- Create a clean fixture and a failing parity test before implementation; retain the RED result as evidence.
- Implement the narrowest public behaviour, with explicit error and state semantics. Keep reference observations out of source comments and runtime logs.
- Run focused parity tests, then normal/boundary/malformed/negative-control cases. Record byte or semantic comparison mode and tolerances.
- Add a second fixture before generalising. Track unsupported features rather than guessing.
- Run differential, property and round-trip checks where applicable; minimise failures to a reproducible fixture.
- Review dependency licences, generated artefacts and provenance before merging a slice.
Slice record
Requirement IDs; implementation commit; fixture hashes; environment; oracle; pass/fail; known divergence; performance/resource budget; reviewer; next slice.
Stop rules
Stop on contaminated inputs, unexplained parity failures, non-determinism, legal-scope uncertainty, or three identical failed approaches. Change the experiment, not the oracle. A high test count with weak oracles is not compatibility evidence.


