PR Comparator
Picks the merge winner among competing PRs for a single issue. Tier 0 gates eliminate plumbing failures; Tiers 1-2 score correctness and quality; Tier 3 applies deterministic tiebreakers. Degraded mode handles the case where no PR passes gates.
Prerequisites
- CLI installed and authenticated
- A target repository with an issue that has 2+ open PRs
Repo policy
Defaults assume NemoClaw conventions (security CODEOWNERS, DCO, CodeRabbit,
directory). For other repos, edit
to override.
Workflow
Copy this checklist into your response and check off each step:
text
PR Comparison Progress:
- [ ] Step 1: Parse issue (body + comments) for acceptance criteria
- [ ] Step 2: Discover candidate PRs (default-order search with stop conditions)
- [ ] Step 3: Detect supersession (parse PR bodies)
- [ ] Step 4: Run Tier 0 gates per PR
- [ ] Step 5: Run Tier 1 correctness checks per PR
- [ ] Step 6: Run Tier 2 quality checks per PR
- [ ] Step 7: Compute weighted scores
- [ ] Step 8: Apply Tier 3 ranking (happy path or degraded mode)
- [ ] Step 9: Emit verdict using templates/verdict.md
Step 1: Parse issue
Extract acceptance criteria from issue body and all comments:
bash
gh issue view <issue-number> --json title,body,comments
Read every comment — commenters often add asks the body doesn't capture.
Step 2: Discover candidate PRs
bash
scripts/find-candidates.sh <issue-number>
Applies a single default order with stop conditions.
Step 3: Detect supersession
bash
scripts/parse-supersession.sh <pr-number-1> <pr-number-2> ...
Parses each PR body for
,
,
,
. A PR that supersedes another wins ties immediately.
Step 4: Tier 0 gates
bash
scripts/collect-gates.sh <pr-number>
scripts/check-coderabbit-threads.sh <pr-number>
Five gates, all mandatory. See
for the full list and interpretation.
Step 5: Tier 1 correctness
Six checks, all LLM judgments. See
checks/tier-1-correctness.md
for evidence requirements per check.
Step 6: Tier 2 quality
Three checks, all LLM judgments. See
.
Step 7: Weighted score
- Each pass = full points
- Each yellow = half points
- Each fail = zero
- Tier 1 weight: 2.0× per check
- Tier 2 weight: 1.0× per check
Step 8: Tier 3 ranking
Branch on whether any PR passes all Tier 0 gates. See
for happy-path tiebreakers, degraded-mode distance-to-ready ranking, and the behavior-coverage matrix.
Step 9: Emit verdict
Use
. Every judgment must carry evidence (file:line refs, diff snippets), reasoning chain, and the score it contributed.
Reference files
- — configurable defaults per target repo
- — plumbing gates
checks/tier-1-correctness.md
- — three quality checks
- — Tier 3 ranking and degraded mode
- — output template
- — backtest the skill against historical cases
Scripts (execute, do not read)
scripts/find-candidates.sh
- — Tier 0 gate evaluation
scripts/check-coderabbit-threads.sh
scripts/parse-supersession.sh
scripts/render-verdict.py
What this skill does NOT do
These require infrastructure beyond GitHub API + LLM and are deferred to v2 modules:
- Running each PR's code against adversarial inputs (sandboxed execution)
- Cross-issue regression sweep (separate skill)
- Revert simulation against neighbor PRs
- Static analyzer integration (CodeQL, Semgrep)