# Pre Commit > Configure pre-commit hooks for code quality, linting, formatting, and security checks. Automate code standards with Git hooks. Use for code quality enforcement, automated formatting, or security scanning before commits. Triggers on pre-commit, git hooks, husky, lint-staged. Use when this capability is needed. - Skill: `tomevault-io/pre-commit` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/pre-commit` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/pre-commit/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Security - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/pre-commit --- # Pre-commit Hooks Automate code quality checks with pre-commit hooks. ## Quick Reference | Tool | Language | Purpose | |------|----------|---------| | `pre-commit` | Python | Multi-language hook framework | | `husky` | JavaScript | Git hooks for Node.js projects | | `lint-staged` | JavaScript | Run linters on staged files | | `lefthook` | Go | Fast, polyglot Git hooks | ## 1. Pre-commit (Python Framework) ### Installation ```bash # Install pre-commit pip install pre-commit # Install hooks in repository pre-commit install # Install commit-msg hook (for conventional commits) pre-commit install --hook-type commit-msg ``` ### Configuration (.pre-commit-config.yaml) ```yaml repos: # General hooks - repo: https://github.com/pre-commit/pre-commit-hooks rev: v4.5.0 hooks: - id: trailing-whitespace - id: end-of-file-fixer - id: check-yaml - id: check-json - id: check-added-large-files args: ['--maxkb=500'] - id: check-merge-conflict - id: detect-private-key - id: check-case-conflict # Python - repo: https://github.com/psf/black rev: 24.1.1 hooks: - id: black - repo: https://github.com/astral-sh/ruff-pre-commit rev: v0.1.14 hooks: - id: ruff args: [--fix] - id: ruff-format - repo: https://github.com/pre-commit/mirrors-mypy rev: v1.8.0 hooks: - id: mypy additional_dependencies: [types-requests] # JavaScript/TypeScript - repo: https://github.com/pre-commit/mirrors-eslint rev: v8.56.0 hooks: - id: eslint files: \.[jt]sx?$ types: [file] additional_dependencies: - eslint@8.56.0 - typescript - '@typescript-eslint/parser' - '@typescript-eslint/eslint-plugin' - repo: https://github.com/pre-commit/mirrors-prettier rev: v4.0.0-alpha.8 hooks: - id: prettier types_or: [javascript, jsx, ts, tsx, json, yaml, markdown] # Security - repo: https://github.com/Yelp/detect-secrets rev: v1.4.0 hooks: - id: detect-secrets args: ['--baseline', '.secrets.baseline'] - repo: https://github.com/gitleaks/gitleaks rev: v8.18.1 hooks: - id: gitleaks # Conventional commits - repo: https://github.com/compilerla/conventional-pre-commit rev: v3.1.0 hooks: - id: conventional-pre-commit stages: [commit-msg] default_language_version: python: python3.11 node: 20.10.0 ci: autofix_prs: true autoupdate_schedule: weekly ``` ### Commands ```bash # Run on all files pre-commit run --all-files # Run specific hook pre-commit run black --all-files # Update hooks to latest versions pre-commit autoupdate # Skip hooks temporarily git commit --no-verify -m "message" # or SKIP=black,ruff git commit -m "message" # Clean cache pre-commit clean pre-commit gc ``` ## 2. Husky + lint-staged (Node.js) ### Installation ```bash # Install husky npm install -D husky lint-staged npx husky init # This creates .husky directory with pre-commit hook ``` ### Configuration ```json // package.json { "scripts": { "prepare": "husky" }, "lint-staged": { "*.{js,jsx,ts,tsx}": [ "eslint --fix", "prettier --write" ], "*.{json,md,yml,yaml}": [ "prettier --write" ], "*.css": [ "stylelint --fix", "prettier --write" ] } } ``` ```bash # .husky/pre-commit npx lint-staged ``` ### Commit Message Hook ```bash # .husky/commit-msg npx --no -- commitlint --edit $1 ``` ```javascript // commitlint.config.js module.exports = { extends: ['@commitlint/config-conventional'], rules: { 'type-enum': [ 2, 'always', ['feat', 'fix', 'docs', 'style', 'refactor', 'test', 'chore', 'ci'] ], 'subject-case': [2, 'always', 'lower-case'], 'header-max-length': [2, 'always', 72] } }; ``` ## 3. Common Hook Configurations ### Python Project ```yaml # .pre-commit-config.yaml repos: - repo: https://github.com/pre-commit/pre-commit-hooks rev: v4.5.0 hooks: - id: trailing-whitespace - id: end-of-file-fixer - id: check-yaml - id: check-toml - id: check-added-large-files - repo: https://github.com/astral-sh/ruff-pre-commit rev: v0.1.14 hooks: - id: ruff args: [--fix, --exit-non-zero-on-fix] - id: ruff-format - repo: https://github.com/pre-commit/mirrors-mypy rev: v1.8.0 hooks: - id: mypy additional_dependencies: - types-requests - pydantic - repo: https://github.com/python-poetry/poetry rev: 1.7.0 hooks: - id: poetry-check - id: poetry-lock args: [--check] - repo: local hooks: - id: pytest name: pytest entry: pytest language: system pass_filenames: false always_run: true stages: [push] ``` ### JavaScript/TypeScript Project ```yaml repos: - repo: https://github.com/pre-commit/pre-commit-hooks rev: v4.5.0 hooks: - id: trailing-whitespace - id: end-of-file-fixer - id: check-json - id: check-yaml - repo: local hooks: - id: eslint name: eslint entry: npx eslint --fix language: system files: \.[jt]sx?$ pass_filenames: true - id: prettier name: prettier entry: npx prettier --write language: system files: \.(js|jsx|ts|tsx|json|md|yml|yaml)$ - id: tsc name: typescript entry: npx tsc --noEmit language: system files: \.tsx?$ pass_filenames: false - id: test name: tests entry: npm test language: system pass_filenames: false stages: [push] ``` ### Go Project ```yaml repos: - repo: https://github.com/pre-commit/pre-commit-hooks rev: v4.5.0 hooks: - id: trailing-whitespace - id: end-of-file-fixer - id: check-yaml - repo: https://github.com/dnephin/pre-commit-golang rev: v0.5.1 hooks: - id: go-fmt - id: go-vet - id: go-imports - id: go-cyclo args: [-over=15] - id: golangci-lint - id: go-build - id: go-mod-tidy ``` ### Terraform/IaC Project ```yaml repos: - repo: https://github.com/pre-commit/pre-commit-hooks rev: v4.5.0 hooks: - id: trailing-whitespace - id: end-of-file-fixer - id: check-yaml - id: check-json - repo: https://github.com/antonbabenko/pre-commit-terraform rev: v1.86.0 hooks: - id: terraform_fmt - id: terraform_validate - id: terraform_tflint - id: terraform_docs args: - --hook-config=--path-to-file=README.md - --hook-config=--add-to-existing-file=true - --hook-config=--create-file-if-not-exist=true - id: terraform_checkov args: - --args=--skip-check CKV_AWS_1 - repo: https://github.com/bridgecrewio/checkov.git rev: 3.1.50 hooks: - id: checkov ``` ## 4. Security Hooks ```yaml repos: # Detect secrets - repo: https://github.com/Yelp/detect-secrets rev: v1.4.0 hooks: - id: detect-secrets args: ['--baseline', '.secrets.baseline'] exclude: package-lock\.json$ # Gitleaks - repo: https://github.com/gitleaks/gitleaks rev: v8.18.1 hooks: - id: gitleaks # Trivy - repo: https://github.com/aquasecurity/trivy rev: v0.48.3 hooks: - id: trivy-config - id: trivy-fs args: ['--scanners', 'vuln,secret'] # Bandit (Python security) - repo: https://github.com/PyCQA/bandit rev: 1.7.7 hooks: - id: bandit args: ['-c', 'pyproject.toml'] additional_dependencies: ['bandit[toml]'] ``` ## 5. CI Integration ### GitHub Actions ```yaml name: Pre-commit on: pull_request: push: branches: [main] jobs: pre-commit: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 - uses: actions/setup-python@v5 with: python-version: '3.11' - uses: pre-commit/action@v3.0.1 with: extra_args: --all-files ``` ### pre-commit.ci ```yaml # .pre-commit-config.yaml ci: autofix_prs: true autofix_commit_msg: 'style: auto fixes from pre-commit.ci' autoupdate_schedule: weekly autoupdate_commit_msg: 'chore: pre-commit autoupdate' skip: [pytest] # Skip slow hooks in CI ``` ## 6. Lefthook (Alternative) ### Installation ```bash # Install npm install -D lefthook # or brew install lefthook # Initialize lefthook install ``` ### Configuration (lefthook.yml) ```yaml pre-commit: parallel: true commands: lint: glob: "*.{js,ts,jsx,tsx}" run: npx eslint --fix {staged_files} format: glob: "*.{js,ts,jsx,tsx,json,md}" run: npx prettier --write {staged_files} test: run: npm test -- --passWithNoTests skip: - merge - rebase commit-msg: commands: commitlint: run: npx commitlint --edit {1} pre-push: commands: typecheck: run: npx tsc --noEmit ``` ## Best Practices 1. **Fast hooks** - Keep pre-commit hooks under 5 seconds 2. **Staged files only** - Use lint-staged for efficiency 3. **Skip for emergencies** - `--no-verify` when needed 4. **CI verification** - Run hooks in CI as backup 5. **Auto-fix when possible** - `--fix` flags 6. **Push hooks for slow checks** - Tests, type checking 7. **Baseline secrets** - Track known false positives 8. **Pin versions** - Reproducible environments 9. **Documentation** - README for setup instructions 10. **Team alignment** - Everyone uses same hooks --- > Converted and distributed by [TomeVault](https://tomevault.io/claim/housegarofalo) — claim your Tome and manage your conversions.