Merge Check

Merge Check

Predicts whether a GitHub PR will get merged by analyzing it against a comprehensive rejection vector taxonomy. Not a generic code quality tool — this answers: "Will this PR get merged by the maintainer?"

Quick Start

Run the data gathering script: bash skills/merge-check/scripts/merge-check.sh owner/repo#123 # or bash skills/merge-check/scripts/merge-check.sh https://github.com/owner/repo/pull/123 Parse the JSON output Analyze against the dimensions below Produce the mergeability report

Analysis Dimensions

After gathering data, analyze across ALL of these dimensions. Load skills/merge-check/references/rejection-taxonomy.md for the detailed rejection vector framework.

1. Technical Signals (Automated Gates)

CI status: Are all checks passing? Any failed or pending? Build status: Does it compile/build? Coverage: Any coverage regression indicated?

2. PR Hygiene

Size (most predictive single factor): 🟢 <400 LOC changed — ideal, easy to review 🟡 400–1000 LOC — risky, reviewer fatigue 🔴 >1000 LOC — danger zone, likely to stall or get rejected File spread: Concentrated in one area or scattered across directories? Single concern: Does it do one thing, or is it a kitchen-sink PR? Title & description: Clear, descriptive? Or vague/empty? Linked issue: Does it reference an issue? (Signals intentionality) Commit hygiene: Clean messages? Reasonable count? Squash-ready?

3. Architectural Fit

Pattern consistency: Does it follow repo conventions? (language, directory structure, naming) Dependencies: New dependencies introduced? (High friction signal) Scope creep: Does it touch things outside its stated purpose? File types: Consistent with repo's tech stack?

4. Review Status

Approvals: Any already? How many required? Changes requested: Outstanding and unaddressed? (Strong rejection signal) Reviewer assignment: Are required reviewers assigned? Review comment sentiment: Positive, neutral, or adversarial? CODEOWNERS: Does the PR touch files with code owners? Are they reviewing?

5. Process Compliance

Draft status: Draft PRs won't merge Blocking labels: WIP, do-not-merge, needs-work, etc. PR template: Was it followed? (Empty template = red flag) CLA/DCO: If repo requires it, is it signed?

6. Social/Meta Signals

Author merge history: What % of this author's recent PRs were merged in this repo? Staleness: How long has it been open? (>2 weeks = concern, >30 days = likely abandoned) Activity level: Recent comments/updates, or radio silence? First-time contributor: Higher rejection rate for newcomers

Output Format

Produce a structured report:

Mergeability Score

🟢 High (>80% likely to merge) — No blockers, reviews positive, CI green 🟡 Medium (40–80%) — Some concerns but addressable 🔴 Low (<40%) — Significant blockers present

Report Sections

Mergeability Score: 🟢/🟡/🔴 with percentage estimate Risk Factors: Bullet list of specific concerns, ordered by severity Strengths: What's working in the PR's favor Recommendations: Actionable steps to improve mergeability (if not already 🟢) Verdict: One-sentence summary

Example Output

• ## PR Mergeability Report: owner/repo#123
• **Score: 🟡 Medium (~55%)**
• ### Risk Factors
• ⚠️ 847 lines changed — approaching reviewer fatigue threshold
• ⚠️ Changes requested by @maintainer not yet addressed
• ⚠️ Touches 12 files across 6 directories — scattered scope
• ℹ️ No linked issue
• ### Strengths
• ✅ All 14 CI checks passing
• ✅ Clear title and detailed description
• ✅ Author has 73% merge rate in this repo (8/11 recent PRs)
• ✅ Active discussion — last update 2 hours ago
• ### Recommendations
• 1. Address @maintainer's review comments before requesting re-review
• 2. Consider splitting into smaller PRs (config changes vs logic changes)
• 3. Link the relevant issue for traceability
• ### Verdict
• Solid PR with passing CI and an active author, but stalled on unaddressed review feedback — resolving those comments is the critical path to merge.

Script Reference

The script (scripts/merge-check.sh) gathers all data via gh CLI and outputs a single JSON object with these keys: KeyContentsprFull PR metadata (title, body, author, state, draft, labels, reviewers)filesList of changed files with patch statsdiff_statsTotal additions, deletions, changed files countchecksCI/check run results for the head commitreviewsAll reviews (approved, changes_requested, commented)review_commentsInline review commentsissue_commentsPR conversation commentscommitsCommit list with messagesrepoRepository metadata (language, size, defaults)author_historyAuthor's recent closed PRs and merge ratehas_codeownersBooleanhas_contributingBoolean

Error Handling

The script outputs "error" fields when individual API calls fail (e.g., rate limits, 404s). Analyze what's available and note any missing data in the report.