publish.yaml

name: Publish

on:
  push:
    branches:
      - main
  workflow_dispatch:

concurrency: rubygems

jobs:
  pre:
    name: Pre-flight checks
    runs-on: ubuntu-latest
    outputs:
      go: ${{ steps.gem_version.outputs.new_version }}

    steps:
      - uses: actions/checkout@v3

      - uses: ruby/setup-ruby@v1
        with:
          ruby-version: '3'

      - name: Check if new version to release
        id: gem_version
        run: |
          gem_version=$(ruby -r rubygems -e "puts Gem::Specification::load('govuk_tech_docs.gemspec').version")
          echo "gem_version=$gem_version" >> "$GITHUB_OUTPUT"

          if git fetch origin "refs/tags/v${gem_version}" >/dev/null 2>&1
          then
            echo "Tag 'v$gem_version' already exists"
            echo "new_version=false" >> "$GITHUB_OUTPUT"
          else
            echo "new_version=true" >> "$GITHUB_OUTPUT"
          fi

  deploy:
    name: Publish Ruby Gem
    environment: github-package-registry
    permissions:
      contents: write  # needed to be able to tag the release
      packages: write  # needed to be able to publish the gem
    runs-on: ubuntu-latest
    needs: pre
    if: ${{ needs.pre.outputs.go == 'true' }}

    steps:
      - uses: actions/checkout@v3

      - uses: actions/setup-node@v3
        with:
          node-version-file: '.nvmrc'
          cache: 'npm'

      - uses: ruby/setup-ruby@v1
        with:
          ruby-version: '3'
          bundler-cache: true

      - name: Publish
        uses: dawidd6/action-publish-gem@v1
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}