pr:review: accept a "Diff unchanged" correctness skip only when an earlier reviewed commit has the same patch-id

[thejackshelton]

AGENTS.md step 7 merges origin/master into a PR right before merging. When that merge leaves the PR's own diff unchanged, Macroscope skips the correctness check as "Diff unchanged". pr:review counted every skip as no review, so such a PR (for example #29) could never pass.

What changed:

• A correctness check skipped with output title exactly "Diff unchanged" now counts as passed only when both hold:

  • an earlier commit of the same PR has completed, successful correctness runs;
  • that commit's three-dot diff (against its merge-base with the base branch) has the same git patch-id --stable as the head's.

  pr:review prints the vouching commit and patch-id, or why nothing vouched.

• Missing commits are fetched. If a commit still can't be read, or a diff is empty, the check does not pass and the reason is printed.

• Every other skip reason still fails, including the cost limit and "Prerequisite check(s) not found". Unanswered findings still block.

• gh JSON (check runs, review comments, PR commits) and git output are validated; malformed input throws.

• The decision is a pure function in scripts/pr-review-vouch.ts. Unit tests in packages/parity/test/pr-review.test.ts cover the passing case, patch-id mismatch, no earlier success, other skip titles, an unfetchable commit and an empty diff, plus input parsing. No existing test or fixture changed.

What passed:

• pnpm typecheck
• pnpm test: 120 files, 2401 tests
• pnpm pr:review 29 exits 0, vouched by 0be4c3d with patch-id 0f7694f27ea03a5d17264fd9e6f7c733c619722b. ec15d1a, whose skip was "Prerequisite check(s) not found", correctly does not vouch.

🤖 Generated with Claude Code

Note

Accept a 'Diff unchanged' correctness skip only when an earlier reviewed commit has the same patch-id

• A completed 'Diff unchanged' correctness skip now passes only when an earlier commit of the same PR has a successful correctness review and the same non-empty git patch ID. The CLI computes stable patch IDs against the PR base branch, fetching missing commits from origin as needed.
• Adds a new module pr-review-vouch.ts with strict parsers for check runs, review comments, PR commits, and patch-id output. Malformed GitHub API data now throws instead of being silently flattened, and commit identifiers must be 40-char lowercase hex SHAs.
• The wait loop now uses a verdict-based settlement: failures settle immediately, and the review waits while any verdict is pending or no correctness check has started. Vouch results are cached per check-run URL, and the output reports the vouching commit or the failure reason for each skip.
• Extensive test coverage added in pr-review.test.ts.
• Behavioral Change: pr-review.ts no longer settles after unrelated checks finish unless a correctness check is present, and unvouched 'Diff unchanged' skips now fail the review.

^{Macroscope summarized 3fc2ccc.}

[macroscopeapp]

Approvability

Verdict: Approved at 3fc2ccc

Macroscope's review found this PR approvable — The changes affect only the developer-facing PR-review harness and add tested logic for validating and vouching “Diff unchanged” skips; no customer runtime or production deployment path is modified. The added GitHub/git history work changes review-tool behavior but remains isolated to that harness.

^{You can add or adjust custom eligibility rules. Learn more.}