Run pre-commit hooks + reviewdog diff

This GitHub Action runs one or more pre-commit hooks on a ref range and, if any of them fail or modify files, posts the resulting diff to the pull request as a review using reviewdog.

It’s designed as a lightweight “core hygiene” action for things like whitespace, merge conflicts, config checks, and large file detection.

Default hooks

By default, this action expects the following hooks to be configured in your .pre-commit-config.yaml:

repos:
  - repo: https://github.com/pre-commit/pre-commit-hooks
    rev: v6.0.0
    hooks:
      - id: check-merge-conflict
      - id: end-of-file-fixer
      - id: trailing-whitespace
      - id: check-yaml
      - id: check-json
      - id: check-toml
      - id: check-added-large-files

If you don’t override the hooks input, these hook IDs will be used.

Requirements

You need:

• GitHub Actions enabled on the repository
• secrets.GITHUB_TOKEN available (default on GitHub-hosted runners)
• actions/checkout fetching enough history to include both from-ref and to-ref, for example:

- uses: actions/checkout@v4
  with:
    fetch-depth: 0

Inputs

Name	Required	Default	Description
from-ref	✅	–	Base git ref (e.g. PR base SHA)
to-ref	✅	–	Head git ref (e.g. PR head SHA)
github-token	✅	–	GitHub token for reviewdog (secrets.GITHUB_TOKEN)
hooks	❌	The default list of core hooks shown above (newline-separated hook IDs)	Newline-separated list of pre-commit hook IDs to run. Empty lines and # comments are ignored.

Customizing the hooks

You can override the default list and provide your own set of hooks:

      - name: Run pre-commit hooks + reviewdog diff
        uses: leinardi/gha-pre-commit-hooks-reviewdog@v1
        with:
          from-ref: ${{ github.event.pull_request.base.sha }}
          to-ref: ${{ github.event.pull_request.head.sha }}
          github-token: ${{ secrets.GITHUB_TOKEN }}
          hooks: |
            check-merge-conflict
            end-of-file-fixer
            trailing-whitespace
            check-yaml
            check-json
            # Custom extra hook:
            detect-private-key

The action will:

• Run each listed hook ID via pre-commit run <hook> on the diff between from-ref and to-ref.

Outputs

Name	Description
exitcode	1 if any hook failed or modified files, 0 otherwise

Usage

Basic example for pull requests using the default hook list:

name: pre-commit hooks

on:
  pull_request:

jobs:
  pre-commit-hooks:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Run pre-commit hooks + reviewdog diff
        uses: leinardi/gha-pre-commit-hooks-reviewdog@v1
        with:
          from-ref: ${{ github.event.pull_request.base.sha }}
          to-ref: ${{ github.event.pull_request.head.sha }}
          github-token: ${{ secrets.GITHUB_TOKEN }}

This will:

1. Run all configured hooks on files changed between from-ref and to-ref.
2. If any hook fails or fixes files, capture the resulting git diff.
3. Post the diff as a review (pre-commit (fixes)) via reviewdog.
4. Fail the job if any hooks reported issues or made changes.

Versioning

It’s recommended to pin to the major version:

uses: leinardi/gha-pre-commit-hooks-reviewdog@v1

For fully reproducible behavior, pin to an exact tag:

uses: leinardi/[email protected]