GitHub Action Validate Frontmatter - SSWConsulting/SSW.Rules.Content GitHub Wiki

This GitHub Action validates the YAML frontmatter in markdown (.md) files whenever a pull request is opened or updated. It checks for required fields, formatting issues, and schema violations to ensure content consistency across rules and categories.

When It Runs

  • On pull requests to main

  • Manually, via the "Run workflow" button in the Actions tab

What It Does

1. Checks out the PR branch

  • Pulls the full Git history (fetch-depth: 0)

  • Uses the PR branch as the ref to analyze changes

2. Sets up Node.js

  • Required for running the validation script

3. Gets changed files

  • Uses git diff against origin/main to collect the list of changed files

  • Stores the list as a comma-separated string (env.changed)

4. Runs the frontmatter validator script

5. Adds a summary (if validation fails)

  • Displays errors in the GitHub Actions summary view so contributors can easily review what's wrong

6. Leaves a comment on the PR (if from same repo)

  • If the validation fails and the PR is not from a fork, it will comment directly on the pull request with a list of the issues.