check-workflows.yml

# Source: https://github.com/arduino/.github/blob/master/workflow-templates/check-workflows.yml
name: Check Workflows

# See: https://docs.github.com/en/free-pro-team@latest/actions/reference/events-that-trigger-workflows
on:
  push:
    paths:
      - ".github/workflows/*.yaml"
      - ".github/workflows/*.yml"
  pull_request:
    paths:
      - ".github/workflows/*.yaml"
      - ".github/workflows/*.yml"
  schedule:
    # Run every Tuesday at 8 AM UTC to catch breakage resulting from changes to the JSON schema.
    - cron: "0 8 * * TUE"
  workflow_dispatch:
  repository_dispatch:

jobs:
  validate:
    runs-on: ubuntu-latest

    env:
      JSON_SCHEMA_FOLDER: etc/github-workflow-json-schema
      JSON_SCHEMA_FILENAME: github-workflow.json

    steps:
      - name: Checkout local repository
        uses: actions/checkout@v3

      - name: Download JSON schema for GitHub Actions workflows
        uses: carlosperate/download-file-action@v2
        with:
          # See: https://github.com/SchemaStore/schemastore/blob/master/src/schemas/json/github-workflow.json
          file-url: https://json.schemastore.org/github-workflow
          location: ${{ env.JSON_SCHEMA_FOLDER }}
          file-name: ${{ env.JSON_SCHEMA_FILENAME }}

      - name: Install JSON schema validator
        run: sudo npm install --global ajv-cli

      - name: Validate GitHub Actions workflows
        run: |
          # See: https://github.com/ajv-validator/ajv-cli#readme
          ajv \
            --strict=false \
            -s "${{ env.JSON_SCHEMA_FOLDER }}/${{ env.JSON_SCHEMA_FILENAME }}" \
            -d "./.github/workflows/*.{yml,yaml}"