happier-testing

# Happier Testing And TDD Use this skill for behavior-changing work in this repository, especially when changes touch shared runtime contracts, CLI/server/UI flows, or any lane that historically accumulates stale fixtures. ## Goal Apply strict RED-GREEN-REFACTOR while following Happier-specific lane, fixture, and rerun rules so changes do not silently drift until a late pipeline sweep. ## Workflow 1. **Inventory first** - Search for existing tests by symbol, route, command, feature id, config key, component name, or error code. - Map the affected lane(s) and any shared/package-local harnesses the change can invalidate before editing code. - Update the most relevant existing test first when possible. - Consolidate overlapping tests instead of stacking new ones on top. 2. **Classify failures correctly** - `production bug`: runtime behavior is wrong - `test drift`: assertions/fixtures assume an obsolete contract - `harness drift`: helpers/mocks/testkit no longer match real runtime wiring - `infra/resource issue`: disk, Docker, stale child processes, or similar environment failures 3. **RED** - Write or update the smallest relevant test first. - Run only the smallest relevant slice and confirm it fails for the expected reason. 4. **GREEN** - Implement the smallest fix that satisfies the failing behavior. - Keep internal behavior real; mock only system boundaries. 5. **REFACTOR** - Extract shared helpers only when there is repeated real duplication or repeated stale drift...