tidaldb/.sdlc/features/m9-retroactive-purge/qa-results.md

QA Results — m9-retroactive-purge

Summary

All QA gates passed. The retroactive signal purge feature is verified correct across unit and integration test suites.

Test Execution

Library Unit Tests

cargo test --manifest-path tidal/Cargo.toml --lib

Result: 1299 passing, 0 failed, 0 ignored

Relevant unit test suites:

• cohort::purge::tests — 5 tests (purge_retracts_from_ledger, second_purge_noop, manifest_entries_correct, manifest_json_round_trip, purge_unknown_cohort_empty_manifest)
• cohort::contribution::tests — ContributionLog push/drain/eviction semantics
• cohort::ledger::tests — retract(), lambdas_for(), drain_community_into()
• signals::hot::tests — subtract_contribution floors at 0.0
• signals::warm::tests — subtract_bucket floors at 0

Integration Tests

cargo test --manifest-path tidal/Cargo.toml --test m9_retroactive_purge

Result: 8 passing, 0 failed

Test	Outcome
basic_purge_retracts_score	PASS — cohort score decreases after purge
second_purge_is_idempotent	PASS — empty contribution log on second purge; score unchanged
purge_does_not_affect_other_users	PASS — user B's contribution intact after purging user A
manifest_persisted_and_listable	PASS — manifest appears in list_purge_manifests; two purges = two manifests
purge_unknown_cohort_is_noop	PASS — empty manifest, no error
score_never_goes_negative	PASS — score >= 0.0 floored by subtract_contribution
multiple_items_purged_together	PASS — manifest contains entries for all signalled items
non_cohort_member_purge_is_noop	PASS — fr_user in en_users cohort is no-op; score unchanged

Code Quality

cargo fmt --manifest-path tidal/Cargo.toml -- --check

Result: Clean — no formatting issues

cargo clippy --manifest-path tidal/Cargo.toml -D warnings

Result: Clean — no warnings

cargo build --manifest-path tidal/Cargo.toml

Result: Clean — no errors or warnings

QA Plan Coverage

QA Scenario	Test	Result
QA-1: Contribution log populated on signal_with_context	basic_purge_retracts_score	PASS
QA-2: Purge retracts from live cohort ledger	basic_purge_retracts_score	PASS
QA-3: Score never goes negative	score_never_goes_negative	PASS
QA-4: Second purge is idempotent	second_purge_is_idempotent	PASS
QA-5: Only target user's contributions retracted	purge_does_not_affect_other_users	PASS
QA-6: Manifest persisted to durable storage	manifest_persisted_and_listable	PASS
QA-7: list_purge_manifests retrieves persisted manifests	manifest_persisted_and_listable	PASS
QA-8: Multiple items purged in one request	multiple_items_purged_together	PASS
QA-9: Unknown cohort returns empty manifest	purge_unknown_cohort_is_noop	PASS
QA-10: Non-member purge is no-op	non_cohort_member_purge_is_noop	PASS

Regression Check

All prior test suites remain green after this feature's changes to db/mod.rs, db/signals.rs, and cohort internals. The 1299 lib tests include all regression coverage from M1–M8.

Verdict

PASSED — Ready to merge.