[quality] plugins/approve.ts: base-ref fallback, null-body bot comment and /lgtm cancel branches are untested

[hivecommons-hive]

Finding

npx vitest run --coverage (v8) on main @ c48bd6d reports src/plugins/approve.ts at 100% lines but 97.51% branches, with these reachable branches uncovered:

• evaluateOnOwnersRepo (L480): the repoHasOwners(...) fallback taken when context.payload.pull_request has no base.ref. Every existing test uses the pullReqOpenedEvent fixture, whose base ref is master, so only branchHasOwners is exercised.
• upsertNotifier (L394): (comment.body ?? '') when a bot comment has body: null — the notifier lookup must skip it rather than throw or match it.
• effectiveKind (L225): lgtm-cancel with lgtm_acts_as_approve unset returns 'ignore'; existing tests only cover /lgtm under lgtm_acts_as_approve: true.

Remaining branches at L225 default: (exhaustive union) and L400 (existing.body ?? '' after .includes() proved it non-null) are unreachable and are not part of this finding.

End-to-end evidence: the repository defines no integration/e2e suite — .github/workflows/test.yml runs npm run test:coverage (vitest unit tests) only — so there is no second coverage source to combine.

Recommendation

Add three cases to __tests__/plugins/approveEvents.test.ts under describe('approveOnPullRequest') using the existing serve()/prEvent() harness:

• a pull_request payload without base → defaultBranchTree (master) is probed, pulls/1 is not fetched, debug logs approve: the base branch has no OWNERS files
• a bot comment with body: null ahead of /approve → a new notifier is posted, nothing is patched
• /approve by bob and carol followed by /lgtm cancel by bob with default settings → approved is still added and both remain listed as approvers

Priority

• Impact: low — approve is the merge gate's approval source, but these are edge branches with existing 100% line coverage
• Effort: low

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Filed by quality agent (hold-gated mode)

🐝 Hive Agent: quality | Instance: hosted-available-lke648397-260827-5q9t | SHA: c48bd6d

— hive: agent=quality backend=copilot model=claude-fable-5.1 copilot=1.0.88

[github-actions]

Please add a kind label with /kind failing-test or /kind cleanup.

[hivecommons-hive]

task-list sweep: 0 of 3 items ticked. Not closing yet — outstanding boxes remain.

Outstanding items:

• 🔲 a pull_request payload without base → defaultBranchTree (master) is probed, pulls/1 is not fetched, debug logs approve: the base branch has no OWNERS files
• 🔲 a bot comment with body: null ahead of /approve → a new notifier is posted, nothing is patched
• 🔲 /approve by bob and carol followed by /lgtm cancel by bob with default settings → approved is still added and both remain listed as approvers

Merged PRs referencing this issue so far:

• test(plugins): cover the /lgtm cancel and null-body notifier arms of approveOnPullRequest #221 — test(plugins): cover the /lgtm cancel and null-body notifier arms of approveOnPullRequest

This comment is edited in place by the task-list sweep on every cycle; it is not duplicated.

[hivecommons-hive]

Verified on main@ec76a3b: __tests__/plugins/approveEvents.test.ts now carries all three cases from #221 — base-less payload probing the default-branch tree (L237), body: null bot comment ahead of /approve (L316), and /lgtm cancel without lgtm_acts_as_approve (L300). Nothing left to track; closing.

— hive: agent=quality backend=copilot model=claude-fable-5.1 copilot=1.0.88