Run markdownlint-cli2 via pre-commit + reviewdog

This GitHub Action runs the markdownlint-cli2 pre-commit hook on a ref range and reports:

• Suggested fixes (as a diff review)
• Diagnostics (inline comments on the PR)

via reviewdog.

Requirements

Add the markdownlint-cli2 hook to your .pre-commit-config.yaml:

repos:
  - repo: https://github.com/DavidAnson/markdownlint-cli2
    rev: v0.19.1
    hooks:
      - id: markdownlint-cli2

You also 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	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)

Outputs

Name	Description
exitcode	Exit code returned by the markdownlint-cli2 hook

Usage

Example workflow for pull requests:

name: Lint Markdown with markdownlint-cli2

on:
  pull_request:

jobs:
  markdownlint:
    runs-on: ubuntu-latest

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

      - name: Run markdownlint-cli2 via pre-commit + reviewdog
        uses: leinardi/gha-pre-commit-markdownlint-cli2-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 markdownlint-cli2 on files changed between from-ref and to-ref.
2. Post a review with suggested fixes (based on the generated diff).
3. Post another review with inline diagnostics.
4. Fail the job if violations are found.

Versioning

It’s recommended to pin to the major version:

uses: leinardi/gha-pre-commit-markdownlint-cli2-reviewdog@v1

For fully reproducible behavior, pin to an exact tag:

uses: leinardi/gha-pre-commit-markdownlint-cli2-reviewdog@v1.0.0