update-feature-branches.yml

name: Update Feature Branches
on:
  workflow_dispatch:
    inputs:
      branch_patterns:
        description: 'Space-separated list of feature branch patterns'
        default: 'feature_branch/*'
        required: true
      main_branch:
        description: 'Main branch to merge'
        default: 'main'
        required: true
  schedule:
    - cron: "0 16 * * 1"  # Mondays, 4pm UTC = 9am PST / 10am PDT

env:
  defaultBranchPattern: "feature_branch/*"
  defaultMainBranch: "main"
  triggerTestsLabel: "tests-requested: quick"
  branchPrefix: "workflow/auto-merge-feature-branch-"


jobs:
  list_feature_branches:
    name: list-feature-branches
    runs-on: ubuntu-20.04
    outputs:
      branch_list: ${{ steps.get-branches.outputs.branch_list }}
    steps:
      - name: Check out repo (if needed)
        if: ${{ github.event.inputs.branch_list == '' }}
        uses: actions/checkout@v3

      - name: Get list of feature branches
        id: get-branches
        run: |
            branch_pattern='origin/${{ env.defaultBranchPattern }}'
            if [[ -n '${{ github.event.inputs.branch_patterns }}' ]]; then
              branch_pattern=origin/$(echo '${{ github.event.inputs.branch_patterns }}' | sed 's| | origin/|g')
            fi
            git remote update
            echo "Branch pattern: ${branch_pattern}"
            branch_list=$(git branch --list --all "${branch_pattern}")
            if [[ -n ${branch_list} ]]; then
              # If there's at least one entry, process the list.
              echo "Remote branch list: ${branch_list}"
              # Remove remotes/origin/ from each branch.
              branch_list=$(echo ${branch_list} | sed 's| remotes/origin/| |g' | sed 's|^remotes/origin/||')
              # Change spaces to commas.
              branch_list=$(echo ${branch_list} | sed 's/ /,/g')
              # Add quotes around each branch name.
              branch_list='"'$(echo ${branch_list} | sed 's/,/","/g')'"'
            fi
            echo "::warning ::Branch list: [${branch_list}]"
            echo "branch_list=[${branch_list}]" >> $GITHUB_OUTPUT

  create_merge_prs:
    name: create-merge-pr-${{ matrix.branch_name }}
    needs: [ list_feature_branches ]
    runs-on: ubuntu-20.04
    if: ${{ needs.list_feature_branches.outputs.branch_list != '[]' }}
    strategy:
      fail-fast: false
      matrix:
        branch_name: ${{ fromJson(needs.list_feature_branches.outputs.branch_list) }}
    steps:
      - name: Get token for firebase-workflow-trigger
        uses: tibdex/github-app-token@v1
        id: generate-token
        with:
          app_id: ${{ secrets.WORKFLOW_TRIGGER_APP_ID }}
          private_key: ${{ secrets.WORKFLOW_TRIGGER_APP_PRIVATE_KEY }}

      - name: Setup python
        uses: actions/setup-python@v4
        with:
          python-version: 3.8

      - uses: actions/checkout@v3
        with:
          ref: ${{ matrix.branch_name }}
          fetch-depth: 0
          submodules: false

      - name: Install prerequisites
        run: |
          python scripts/gha/install_prereqs_desktop.py
          python -m pip install requests

      - name: Name new branch
        run: |
          date_str=$(date "+%Y%m%d-%H%M%S")
          echo "NEW_BRANCH=${{env.branchPrefix}}${{github.run_number}}-${date_str}" >> $GITHUB_ENV

      - name: Create merge PR
        id: create-pr
        run: |
            git config user.email "firebase-workflow-trigger-bot@google.com"
            git config user.name "firebase-workflow-trigger-bot"
            git config core.commentChar "%"  # so we can use # in git commit messages

            main_branch='${{ env.defaultMainBranch }}'
            if [[ -n '${{ github.event.inputs.main_branch }}' ]]; then
              main_branch='${{ github.event.inputs.main_branch }}'
            fi
            # Attempt a merge, then check if any files changed.
            git merge --no-commit --no-ff "origin/${main_branch}" || true
            if git diff --quiet ${{ matrix.branch_name }}; then
              # No merge necessary.
              echo "::warning ::No merge needed for ${{ matrix.branch_name }}, won't create pull request."
              echo "created_pr_number=0" >> $GITHUB_OUTPUT
              exit 0
            fi

            # Undo the actual merge. Let the PR creation handle it.
            git merge --abort

            date_str=$(date "+%b %d, %Y")

            pr_title="Automatic merge of ${main_branch} into ${{ matrix.branch_name }} - ${date_str}"
            pr_body="Automatic merge of ${main_branch} into ${{ matrix.branch_name }}.

            > Created on ${date_str} by [${{github.workflow}} workflow]($GITHUB_SERVER_URL/$GITHUB_REPOSITORY/actions/runs/$GITHUB_RUN_ID).
            "
            git checkout main
            git checkout -b "${NEW_BRANCH}"
            git push --set-upstream origin "${NEW_BRANCH}"
            pr_number=$(python scripts/gha/create_pull_request.py --token ${{ steps.generate-token.outputs.token }} --base "${{ matrix.branch_name }}" --head "${NEW_BRANCH}" --title "${pr_title}" --body "${pr_body}")
            echo "created_pr_number=${pr_number}" >> $GITHUB_OUTPUT

      - name: Set test trigger label.
        uses: actions-ecosystem/action-add-labels@v1
        if: ${{ steps.create-pr.outputs.created_pr_number }}
        with:
          github_token: ${{ steps.generate-token.outputs.token }}
          number: ${{ steps.create-pr.outputs.created_pr_number }}
          labels: "${{ env.triggerTestsLabel }}"