tdd

Instruction file imported from LuthienResearch/luthien_control (.cursor/rules/tdd.mdc). Copyright stays with the author.

These are the MANDATORY steps for test-driven development. You MUST write tests that initially fail, and only then implement the actual logic that solves the problem at hand and makes the tests pass.

1. Implement Skeleton: Create the necessary files, classes, function/method signatures, and other skeleton code without full implementation (e.g., using pass or NotImplementedError).
2. Write Unit Tests: Implement unit tests for the planned functionality before writing the implementation code. Ensure tests cover expected behavior and edge cases. These tests are expected to fail because the functionality isn't implemented yet.
3. Run Unit Tests (Expect Failures): Run the tests (poetry run pytest). They should fail for the unimplemented code. This verifies the tests are correctly targeting the new code.
4. Implement Solution: Write the actual code to implement the feature or fix (replacing the skeleton code).
5. Run Unit Tests (Verify Pass): Run the unit tests again. Iterate on the implementation until all unit tests pass.