create-merge-release-into-dev-pr.yml

name: create-merge-release-into-dev-pr
on:
  workflow_dispatch:
  schedule:
    - cron: '30 3 * * *' # Daily at 03:30

env:
  BASE_BRANCH: dev

permissions: {}
jobs:
  setup:
    runs-on: ubuntu-latest
    outputs:
      latest_release_branch: ${{ steps.find_latest_release.outputs.branch }}
    steps:
    - id: find_latest_release
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        GITHUB_REPOSITORY: ${{ github.repository }}
      run: |
        BRANCH=$(curl -H "Authorization: token $GITHUB_TOKEN" \
          https://api.github.com/repos/$GITHUB_REPOSITORY/branches?protected=true | \
          jq -r '.[].name' | grep '^release/' | sort --version-sort | tail -1
        )
        if [ "$BRANCH" = "" ]; then
          echo "Invalid release branch found: $BRANCH"
          exit 1
        fi

        echo "branch=${BRANCH}" >> $GITHUB_OUTPUT

  merge-or-create-pr:
    env:
      RELEASE_BRANCH: ${{ needs.setup.outputs.latest_release_branch }}

    permissions:
      contents: write # for git push
      pull-requests: write # for creating pull request

    runs-on: ubuntu-latest
    needs: setup
    timeout-minutes: 5
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          ref: ${{ env.BASE_BRANCH }}

      - name: Fetch dev branch upto release branch
        run: git fetch --shallow-exclude "$RELEASE_BRANCH" origin "$BASE_BRANCH" || git fetch --depth 1 origin "$BASE_BRANCH"

      - name: Fetch release branch upto dev branch
        run: git fetch --shallow-exclude "$BASE_BRANCH" origin "$RELEASE_BRANCH" || git fetch --depth 1 origin "$RELEASE_BRANCH"

      - name: Resolve bug in git https://stackoverflow.com/a/63879454/96823
        run: git repack -d

      - name: Get one commit more to connect the history of dev and release branches
        run: git fetch --deepen 1 origin "$BASE_BRANCH" "$RELEASE_BRANCH"

      - name: Create branch without checkout just to have shorter automatic commit message
        run: git branch "$RELEASE_BRANCH" origin/"$RELEASE_BRANCH"

      - name: Required git config
        run: |
          git config user.name "OpenProject Actions CI"
          git config user.email "operations+ci@openproject.com"

      - name: Show diff
        run: git diff ..."$RELEASE_BRANCH"

      - name: Try merging or create a PR
        run: |
          if git diff --exit-code --quiet ..."$RELEASE_BRANCH"; then
            echo "Nothing to merge from $RELEASE_BRANCH into $BASE_BRANCH"
          else
            if git merge --no-edit --no-ff "$RELEASE_BRANCH" && git push origin "$BASE_BRANCH"; then
              echo "Successfully merged $RELEASE_BRANCH into $BASE_BRANCH and pushed"
            else
              # Close all previous PRs with label
              for pr_number in $(gh pr list --label create-merge-release-into-dev-pr --json number --jq='.[].number'); do
                gh pr close "$pr_number"
              done

              TEMP_BRANCH="$RELEASE_BRANCH-$(date "+%Y%m%d%H%M%S")"

              git branch "$TEMP_BRANCH" "$RELEASE_BRANCH"

              git push origin "$TEMP_BRANCH"

              gh pr create \
                --base "$BASE_BRANCH" \
                --head "$TEMP_BRANCH" \
                --title "Merge $RELEASE_BRANCH into $BASE_BRANCH" \
                --body 'Created by GitHub action' \
                --label create-merge-release-into-dev-pr
              echo "Created a PR to merge $RELEASE_BRANCH ($TEMP_BRANCH) into $BASE_BRANCH"
            fi
          fi
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}