name: Auto-merge master/main back to dev branch

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

jobs:
  merge-master-back-to-dev:
    if: github.event.pull_request.merged == true
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - name: Set Git config
        run: |
          git config --local user.email "actions@github.com"
          git config --local user.name "Github Actions"
      - name: Merge master back to dev
        run: |
          git fetch --unshallow
          git checkout dev
          git pull
          git merge --no-ff main -m "Auto-merge master/main branch back to dev"
          git push