[quality] uncovered error branches in run.ts, utils/config.ts fetch paths, utils/comments.ts createCommentOnce and labels/prefixed.ts #207

Finding

Unit coverage (npx vitest run --coverage on origin/main @ 187c5e3) leaves these branches unexecuted; none of them is claimed by an open test PR (#173–#206 cover other modules):

• src/run.ts:40 — setFailed on a non-Error handler rejection (String(error) arm).
• src/utils/config.ts:254 — explicit owner/repo:path source answers non-404 → wrapped could not load prow config from ….
• src/utils/config.ts:280 — explicit source resolves to a directory / non-file → TypeError: <path> is not a file.
• src/utils/config.ts:292 — fetch() of an https:// source rejects (network error) → wrapped error.
• src/utils/comments.ts:58 — createCommentOnce with a bot comment whose body is null (?? '' arm).
• src/labels/prefixed.ts:146 — requireIssueNumber throw when the payload has no issue.
• src/labels/prefixed.ts:258 — currentIssueLabels wrapping a failed issues.get.

Evidence: unit — v8 text report from the command above (per-file: run.ts 83.33% branches, config.ts lines 254/280/292, comments.ts 87.5% branches, prefixed.ts lines 146/258). End-to-end — this repository has no end-to-end suite or coverage artifact beyond __tests__/workflows.test.ts and __tests__/bundle, which do not exercise these paths; no e2e coverage claim is made.

Recommendation

• __tests__/run.test.ts: non-Error rejection → setFailed('…')
• __tests__/utils/configLoader.test.ts: explicit repo 500, explicit repo directory, url HttpResponse.error()
• __tests__/utils/comments.test.ts (new): createCommentOnce null-body bot comment, marker dedup, human comment ignored
• __tests__/label/prefixed.test.ts (new): missing issue number for add/remove, issues.get failure wrapping

Priority

• Impact: medium — these are the error-reporting paths operators see when config or API calls fail
• Effort: low

Filed by quality agent (hold-gated mode)

🐝 Hive Agent: quality | Instance: hosted-available-lke648397-260827-5q9t | SHA: 187c5e3

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