validate-action_yml.yml

name: Validate action.yml

on:
  pull_request:
    paths:
      - ".github/workflows/validate-action_yml.yml"
      - "action.yml"
  push:
    paths:
      - ".github/workflows/validate-action_yml.yml"
      - "action.yml"
  # Scheduled trigger to catch workflow failure resulting from changes to the JSON schema
  schedule:
    # run every Tuesday at 3 AM UTC
    - cron: "0 3 * * 2"
  # See: https://docs.github.com/en/actions/reference/events-that-trigger-workflows#workflow_dispatch
  workflow_dispatch:
  # See: https://docs.github.com/en/actions/reference/events-that-trigger-workflows#repository_dispatch
  repository_dispatch:

jobs:
  validate:
    runs-on: ubuntu-latest

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

    steps:
      - name: Checkout local repository
        uses: actions/checkout@v2

      # See: https://github.com/carlosperate/download-file-action/blob/master/README.md
      - name: Download JSON schema for action.yml
        uses: carlosperate/download-file-action@v1.0.3
        with:
          # See: https://github.com/SchemaStore/schemastore/blob/master/src/schemas/json/github-action.json
          file-url: https://json.schemastore.org/github-action
          location: ${{ env.JSON_SCHEMA_FOLDER }}
          file-name: ${{ env.JSON_SCHEMA_FILENAME }}

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

      # See: https://github.com/ajv-validator/ajv-cli/blob/master/README.md
      - name: Validate action.yml
        run: ajv -s "${{ env.JSON_SCHEMA_FOLDER }}/${{ env.JSON_SCHEMA_FILENAME }}" -d action.yml