auto-merge-branches.yml

# This workflow is intended to keep certain branches in sync and will automatically create PR's between 
# these branches. For now these PR's must be manually reviewed and merged. Consider if we should just 
# automatically do this if there are no conflicts. 
#
# This step will fail if a PR already exists, so we ignore failures. This also 
# mean that if some other error occur, the error will also be swallowed. This is acceptable.
name: Auto merge change between branches

on:
  push:
    branches:
      # List of "from" branches. Targets are defined by the `find-target-branch`-step below.
      - releases
      - main

jobs:
  main:
    name: Create PR with changes that should be merged into another branch
    runs-on: ubuntu-latest
    steps:
      - name: git checkout
        uses: actions/checkout@v3

      # Set the branch we want to merge changes into as step output. This step should list each branch name found in the `push`
      # trigger in the top of this file.
      - name: Set target branch
        id: find-target-branch
        shell: sh
        run: |
          if [ "${GITHUB_REF#refs/heads/}" = "main" ]; then echo '::set-output name=branch::releases/ktor2-support'; fi
          if [ "${GITHUB_REF#refs/heads/}" = "releases" ]; then echo '::set-output name=branch::${{ github.event.repository.default_branch }}'; fi

      # Unconditionally create a PR with the changes that needs to be manually reviewed. 
      # https://cli.github.com/manual/gh_pr_create
      - name: Create Pull Request
        id: open-pr
        run: |
          gh pr create \
          --base '${{ steps.find-target-branch.outputs.branch }}' \
          --head '${{ github.ref_name }}' \
          --title "[Automated] Merge ${{ github.ref_name }} into ${{ steps.find-target-branch.outputs.branch }}" \
          --body 'Automated Pull Request. Remember to choose "Create a merge commit" before merging.' \
          || true
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}