publish-a-release.yml

name: Publish Release to GitHub

on:
  pull_request:
    branches:
      - master
    types:
      - closed

jobs:
  publish-a-release:
    runs-on: ubuntu-latest
    if: github.event.pull_request.merged == true && startsWith(github.event.pull_request.head.ref, 'release/')
    steps:
      - name: Extract version from branch name
        run: |
          set -x
          branchName="${{ github.event.pull_request.head.ref }}"
          version=${branchName#release/}
          if [[ "$version" =~ ^([0-9]+)\.([0-9]+)\.([0-9]+)(-rc\.([0-9]+))?$ ]]; then
            echo "TAG=$version" >> $GITHUB_ENV
          else
            echo "$version is not a supported semver." >&2
            exit 1
          fi 
      
      - name: Create Release to GitHub
        uses: actions/github-script@v6
        env: 
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          script: |
            const { owner, repo } = context.repo;
            const target_commitish = context.sha;

            github.rest.repos.createRelease({
              owner,
              repo,
              tag_name: process.env.TAG,
              target_commitish,
              name: `v${process.env.TAG}`,
              generate_release_notes: true,
              draft: process.env.TAG.includes('-rc'),
              prerelease: false
            });

      - name: Create a PR to merge master back into develop branch
        uses: actions/github-script@v6
        env: 
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          script: |
            const { owner, repo } = context.repo;
            const title = `Merge master into develop after publishing release ${process.env.TAG}`;
            const body = 'Created by GitHub Actions';
            const base = 'develop';
            const head = 'master';

            github.rest.pulls.create({
              owner,
              repo,
              title,
              body,
              base,
              head
            });