Phy Pre Commit Gen

SKILL.md

---
name: Pre Commit Gen
description: Generates a tailored .pre-commit-config.yaml by analyzing your project's language stack, existing linting tools, and CI setup. Detects Python/JS/TS/Go/Rust/Terraform/Docker/Shell/SQL and picks the right hooks (Ruff vs Black vs ESLint vs Prettier, etc.) based on what's already configured. Also audits existing pre-commit configs for unpinned revs and missing security hooks. Zero external dependencies — pure Python stdlib. The only pre-commit config generator on ClawHub.
license: Apache-2.0
homepage: https://canlah.ai
metadata:
  author: Canlah AI
  version: "1.0.3"
tags:
  - git
  - pre-commit
  - dx
  - linting
  - code-quality
  - automation
  - developer-experience
---

# phy-pre-commit-gen — Pre-commit Config Generator

Analyzes your project and generates a `.pre-commit-config.yaml` with the right hooks for your specific stack. No generic templates — actual configuration based on what your project uses.

## Quick Start

```bash
# Generate config for the current directory
python3 ~/.claude/skills/phy-pre-commit-gen/scripts/pre_commit_gen.py .

# Preview without writing
python3 ~/.claude/skills/phy-pre-commit-gen/scripts/pre_commit_gen.py . --dry-run

# Audit an existing .pre-commit-config.yaml
python3 ~/.claude/skills/phy-pre-commit-gen/scripts/pre_commit_gen.py . --audit

# Overwrite an existing config
python3 ~/.claude/skills/phy-pre-commit-gen/scripts/pre_commit_gen.py . --overwrite

# Write to a specific path
python3 ~/.claude/skills/phy-pre-commit-gen/scripts/pre_commit_gen.py . --output .pre-commit-config.yaml
```

Then activate:
```bash
pip install pre-commit
pre-commit install          # activate for this repo
pre-commit autoupdate       # update all hook revs to latest
pre-commit run --all-files  # run on existing code
```

## What It Detects

| Detection | Signal Files |
|-----------|-------------|
| Python | `*.py`, `pyproject.toml`, `requirements.txt`, `setup.py` |
| JavaScript/TypeScript | `package.json`, TypeScript in deps |
| Go | `go.mod` |
| Rust | `Cargo.toml` |
| Terraform | `*.tf` files |
| Docker | `Dockerfile*`, `*.dockerfile` |
| Shell | `*.sh`, `*.bash` |
| SQL | `*.sql`, `migrations/` directory |
| YAML/CI | `.github/workflows/`, `.gitlab-ci.yml` |
| Ruff | `ruff.toml`, `.ruff.toml`, `[tool.ruff]` in pyproject.toml |
| Black | `[tool.black]` in pyproject.toml |
| ESLint | `eslint` in package.json deps |
| Prettier | `prettier` in package.json deps |
| Commitizen | `commitizen` or `@commitlint/cli` in package.json |
| Existing pre-commit | Reads existing hooks to avoid duplicates |

## Hook Selection Logic

**Python:**
- Has Ruff config → use `ruff` + `ruff-format` (replaces black+isort+flake8)
- Has Black config → use `black` + `isort` (if isort configured) + `flake8` (if configured)
- Neither → add Ruff as recommended default

**JS/TypeScript:**
- Has ESLint → use `eslint` mirror hook
- Has Prettier → use `prettier` mirror hook
- Neither → add Prettier as baseline

**Always included:**
- `pre-commit-hooks` — trailing whitespace, EOF fixer, YAML/JSON/TOML check, large files, merge conflict detection, no-commit-to-branch (main/master)
- `detect-secrets` — secret baseline scanning
- `markdownlint-cli` — Markdown quality

**Conditionally included:**
- Go → `go-fmt`, `go-vet`, `go-unit-tests`
- Rust → `rustfmt` (local), `clippy` (local)
- Terraform → `terraform_fmt`, `terraform_validate`, `terraform_tflint`
- Docker → `hadolint` (Dockerfile security)
- Shell → `shellcheck`
- SQL → `sqlfluff`
- YAML CI present → `yamllint`
- Commitizen/commitlint detected → `commitizen` (commit-msg stage)

## Audit Mode

Checks an existing `.pre-commit-config.yaml` for:
- Unpinned revs (`latest`, `main`, `HEAD`) — can break unexpectedly
- No secret detection hook (detect-secrets or gitleaks)
- Missing trailing-whitespace hook
- Local hooks that may not work cross-platform

```bash
python3 ~/.claude/skills/phy-pre-commit-gen/scripts/pre_commit_gen.py . --audit
```

Output:
```
📋  Auditing: .pre-commit-config.yaml

  🔴 Unpinned rev 'main' — pre-commit hooks should be pinned to a specific tag
  🟠 No secret detection hook — add detect-secrets or gitleaks
  ✅ trailing-whitespace present
```

## Example Outputs

### Python + Ruff project

```yaml
# Generated by phy-pre-commit-gen
# Run: pre-commit install && pre-commit autoupdate

repos:

  # Universal quality checks
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.6.0
    hooks:
      - id: trailing-whitespace
      - id: end-of-file-fixer
      - id: check-yaml
      - id: check-json
      - id: check-toml
      - id: check-merge-conflict
      - id: check-added-large-files
        args: [--maxkb=1000]
      - id: mixed-line-ending
      - id: no-commit-to-branch
        args: [--branch, main, --branch, master]

  # Secret detection
  - repo: https://github.com/Yelp/detect-secrets
    rev: v1.5.0
    hooks:
      - id: detect-secrets
        args: [--baseline, .secrets.baseline]

  # Python — Ruff (linter + formatter)
  - repo: https://github.com/astral-sh/ruff-pre-commit
    rev: v0.4.7
    hooks:
      - id: ruff
        args: [--fix]
      - id: ruff-format

  # Markdown
  - repo: https://github.com/igorshubovych/markdownlint-cli
    rev: v0.41.0
    hooks:
      - id: markdownlint
```

### Full-stack polyglot (JS + Python + Terraform + Docker)

```yaml
# Generated by phy-pre-commit-gen

repos:

  # Universal
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.6.0
    hooks:
      - id: trailing-whitespace
      - id: end-of-file-fixer
      ... (+ 6 more)

  # Secret detection
  - repo: https://github.com/Yelp/detect-secrets
    rev: v1.5.0
    hooks:
      - id: detect-secrets

  # Python — Ruff
  - repo: https://github.com/astral-sh/ruff-pre-commit
    rev: v0.4.7
    hooks:
      - id: ruff
        args: [--fix]
      - id: ruff-format

  # JS/TS — ESLint
  - repo: https://github.com/pre-commit/mirrors-eslint
    rev: v9.7.0
    hooks:
      - id: eslint

  # JS/TS — Prettier
  - repo: https://github.com/pre-commit/mirrors-prettier
    rev: v3.3.2
    hooks:
      - id: prettier

  # Terraform
  - repo: https://github.com/antonbabenko/pre-commit-terraform
    rev: v1.92.1
    hooks:
      - id: terraform_fmt
      - id: terraform_validate
      - id: terraform_tflint

  # Dockerfile security
  - repo: https://github.com/hadolint/hadolint
    rev: v2.13.0-beta
    hooks:
      - id: hadolint-docker

  # Shell
  - repo: https://github.com/shellcheck-py/shellcheck-py
    rev: v0.10.0.1
    hooks:
      - id: shellcheck

  # YAML
  - repo: https://github.com/adrienverge/yamllint
    rev: v1.35.1
    hooks:
      - id: yamllint
        args: [-d, relaxed]

  # Markdown
  - repo: https://github.com/igorshubovych/markdownlint-cli
    rev: v0.41.0
    hooks:
      - id: markdownlint
```

## Hook Revisions

All revisions are pinned to stable releases as of early 2026. Always run `pre-commit autoupdate` after generating to get the latest pinned versions:

```bash
pre-commit autoupdate
git add .pre-commit-config.yaml
git commit -m "chore: update pre-commit hook revisions"
```

## Integration with CI

```yaml
# GitHub Actions — run pre-commit on all files
- uses: pre-commit/action@v3.0.1
  with:
    extra_args: --all-files

# Or manual:
- name: pre-commit
  run: |
    pip install pre-commit
    pre-commit run --all-files
```

## Technical Notes

- **Zero external dependencies** — pure Python 3.7+ stdlib
- **Duplicate detection** — reads existing `.pre-commit-config.yaml` to avoid adding already-present hooks
- **Idempotent** — running on a project with existing config uses `--overwrite` flag; safe default is to not overwrite
- **YAML output** — valid YAML, human-readable comments, standard pre-commit format

## Companion Skills

| Skill | Relationship |
|-------|-------------|
| `phy-dep-upgrade` | Keeps dependencies up-to-date (pre-commit hooks check quality) |
| `phy-dockerfile-audit` | Hadolint is included as a pre-commit hook when Dockerfiles detected |
| `phy-lock-file-auditor` | Detects lock file issues (complementary to pre-commit integrity checks) |
| `phy-env-doctor` | Discovers .env refs — pairs with detect-secrets hook |

---

## Author

**[Canlah AI](https://canlah.ai)** — Run performance marketing without breaking your brand.

- GitHub: [github.com/PHY041](https://github.com/PHY041)
- All Skills: [clawhub.ai/PHY041](https://clawhub.ai/PHY041)