holocron/plugins/git/docs/research/docs/pre-commit/examples.md

topic, source_keys

topic	source_keys
examples	context7-pre-commit-com pre-commit-com context7-pre-commit-hooks

Starter config

pre-commit sample-config > .pre-commit-config.yaml
pre-commit validate-config
pre-commit install
pre-commit run --all-files

Common config patterns

File hygiene only

repos:
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.5.0
    hooks:
      - id: end-of-file-fixer
      - id: trailing-whitespace
      - id: check-yaml
      - id: check-json
      - id: check-toml
      - id: check-merge-conflict
      - id: detect-private-key

With auto-formatting

repos:
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.5.0
    hooks:
      - id: end-of-file-fixer
      - id: trailing-whitespace
      - id: pretty-format-json
        args: [--autofix]
      - id: mixed-line-ending
        args: [--fix=lf]

With branch protection and secret scanning

repos:
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.5.0
    hooks:
      - id: detect-private-key
      - id: detect-aws-credentials
      - id: no-commit-to-branch
        args: [--branch, main, --branch, master]
      - id: check-added-large-files
        args: [--maxkb=500]

Multi-stage config (pre-commit + pre-push + commit-msg)

default_install_hook_types: [pre-commit, pre-push, commit-msg]

repos:
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v4.5.0
    hooks:
      - id: end-of-file-fixer
        stages: [pre-commit]
      - id: check-yaml
        stages: [pre-commit]

  - repo: https://github.com/compilerla/conventional-pre-commit
    rev: v2.4.0
    hooks:
      - id: conventional-pre-commit
        stages: [commit-msg]

  - repo: local
    hooks:
      - id: run-tests
        name: Run test suite
        entry: bash tests/run-tests.sh
        language: unsupported_script
        pass_filenames: false
        always_run: true
        stages: [pre-push]

Kubernetes-style YAML (needs --unsafe for custom tags)

- id: check-yaml
  args: ['--unsafe']
  exclude: ^helm/templates/

Monorepo with subdirectory scope

- repo: local
  hooks:
    - id: validate-frontend
      name: Validate frontend
      entry: pre-commit hazmat cd frontend npm run lint --
      language: unsupported
      files: ^frontend/
      pass_filenames: false

Testing and validation workflow

# After writing a new config:
pre-commit validate-config

# Test all hooks against entire repo:
pre-commit run --all-files

# Test a single hook:
pre-commit run check-yaml --all-files

# Test a hook repo before adding it to config:
pre-commit try-repo https://github.com/psf/black --all-files

# Update all rev pins to latest tags:
pre-commit autoupdate

# Freeze revs to commit SHAs for reproducibility:
pre-commit autoupdate --freeze

# Skip a hook for one commit:
SKIP=check-yaml git commit -m "add yaml with custom tags"

# Run manually against a diff (CI):
pre-commit run --from-ref origin/main --to-ref HEAD

Local hook patterns

Forbidden file guard (cheapest possible hook)

- repo: local
  hooks:
    - id: no-env-files
      name: No .env files
      entry: .env files must not be committed — use environment variables
      language: fail
      files: \.env(\..+)?$

Run full test suite pre-push

- repo: local
  hooks:
    - id: run-tests
      name: Run test suite
      entry: bash tests/run-tests.sh
      language: unsupported_script
      pass_filenames: false
      always_run: true
      stages: [pre-push]

Adding meta-validation

Add after all other repos to catch dead hooks/excludes:

- repo: meta
  hooks:
    - id: check-hooks-apply
    - id: check-useless-excludes