contribution-check

name	contribution-check
description	Pre-flight checklist for open source contributions. Validates code changes against project rules, PR size limits, commit format, linting, and type-checking. Does NOT push or create PRs — only reports issues.
argument-hint	["--skip-lint|--skip-types|--verbose"]
disable-model-invocation	true
allowed-tools	Bash, Read, Grep, Glob

Contribution Pre-Flight Check

Validates your working changes against common open-source contribution guidelines before you push. This skill is read-only — it never pushes code, creates PRs, or modifies anything on GitHub.

Instructions

Run each check below in order. Report results as a checklist with pass/fail status.

1. Diff Size Check

# Count changed lines (excluding lockfiles, generated files, docs)
git diff --stat HEAD | tail -1
git diff --numstat HEAD -- . ':!yarn.lock' ':!package-lock.json' ':!pnpm-lock.yaml' ':!*.generated.*' ':!*.lock' | awk '{ added += $1; removed += $2; files += 1 } END { print files " files, +" added " -" removed " lines" }'

Rules:

• WARN if >500 lines changed (excluding docs, lockfiles, auto-generated)
• WARN if >10 code files modified
• Suggest splitting if either limit exceeded

2. Commit Message Format

git log --format="%s" -5

Rules:

• Must follow Conventional Commits: feat:, fix:, refactor:, chore:, test:, docs:, perf:, ci:
• Must be specific, not generic
• FAIL if any recent commit doesn't follow the format

3. Issue Eligibility

If the user specified an issue number (via $ARGUMENTS or conversation context):

gh issue view <NUMBER> --json labels,state

Rules:

• Features with needs approval label: WARN — may need to wait for maintainer approval
• Closed issues: WARN
• Open bugs/security/docs: PASS — typically safe to start

4. File Naming Conventions

Scan changed files for naming violations:

git diff --name-only HEAD

Rules:

• Check for project-specific naming conventions (look for CONTRIBUTING.md or similar)
• kebab-case for files is a common convention
• WARN on any violations found

5. Code Quality Checks

Read each changed file and check for common issues:

• Early returns preferred over deep nesting
• No obvious security issues (hardcoded secrets, SQL injection, etc.)
• No circular references introduced
• No barrel file imports (index.ts re-exports) — if the project discourages them
• Appropriate error handling

6. Lint Check (unless --skip-lint)

Detect the project's linter and run it:

# Try common linters in order
# biome, eslint, prettier, etc.

FAIL if linting reports errors.

7. Type Check (unless --skip-types)

Detect the project's type checker and run it:

# Try common type checkers
# tsc, pyright, mypy, etc.

FAIL if type errors found.

8. Relevant Tests

Check if there are test files related to changed code. WARN if changed source files have no corresponding tests.

9. Summary Report

Present a final summary:

## Contribution Check Results

| Check                  | Status | Notes                          |
|------------------------|--------|--------------------------------|
| Diff size              | PASS   | 12 files, +234 -45 lines      |
| Commit format          | PASS   | feat: add timezone handling    |
| Issue eligibility      | PASS   | #123 - bug, safe to start     |
| File naming            | PASS   |                                |
| Code quality           | WARN   | 1 potential issue found        |
| Lint                   | PASS   |                                |
| Type check             | PASS   |                                |
| Tests                  | WARN   | 2 files missing test coverage  |

### Action Items
- [ ] Fix identified issues
- [ ] Add tests for uncovered files

IMPORTANT: This skill NEVER pushes code, creates branches, creates PRs, or modifies anything on GitHub. It only reads and reports.