remove-stale-branches.yml

name: Remove stale branches

on:
  schedule:
    - cron: "0 0 * * *"

  # Allow workflow to be manually run from the GitHub UI
  workflow_dispatch:

jobs:
  remove_stale_branches:
    runs-on: ubuntu-24.04
    name: remove stale branches
    steps:
      - name: remove stale branches
        uses: techdecember/github-action-inactive-branches@7aca3178001bdbff984c3eeb3eeb0f972bd75ae4 # 1.2.1
        id: deleted_branches
        with:
          github_token: ${{ github.token }}
          last_commit_age_days: 100
          dry_run: yes
          ignore_suffix: _keep_me

      - name: Get output
        run: "echo 'Stale branches: ${{ steps.deleted_branches.outputs.deleted_branches }}'"

      - name: Format output for Slack
        id: format_slack
        run: |
          {
            echo 'formatted_branches<<EOF'
            echo "${{ steps.deleted_branches.outputs.deleted_branches }}" | tr \' \" | jq -r .[] | awk '{printf("%s\\n", $0)}'
            echo ""
            echo EOF
          } >> $GITHUB_ENV

      - name: Send slack message with branches that can be deleted
        if: steps.deleted_branches.outputs.deleted_branches != '[]'
        uses: slackapi/slack-github-action@485a9d42d3a73031f12ec201c457e2162c45d02d # v2.0.0
        with:
          webhook-type: incoming-webhook
          webhook: ${{ secrets.SLACK_WEBHOOK_URL }}
          payload-templated: true
          payload: |
            "text": "Stale branches detected",
            "blocks": [
              {
                "type": "section",
                "text": {
                  "type": "mrkdwn",
                  "text": "Hi :wave:"
                }
              },
              {
                "type": "section",
                "text": {
                  "type": "mrkdwn",
                  "text": "I have identified some branches on `${{ github.event.repository.name }}` that seem stale and could probably be removed:"
                }
              },
              {
                "type": "section",
                "text": {
                  "type": "mrkdwn",
                  "text": "```${{ env.formatted_branches }}```"
                }
              },
              {
                "type": "context",
                "elements": [
                  {
                    "type": "mrkdwn",
                    "text": "I will only alert for an unprotected branch that has been abandonded for over a 100 days and without an open PR. If you want to keep a branch you might consider to add a `_keep_me` suffix to the branch name so I will ignore it."
                  }
                ]
              },
              {
                "type": "divider"
              },
              {
                "type": "context",
                "elements": [
                  {
                    "type": "mrkdwn",
                    "text": "Powered by GitHub Actions | <https://github.com/sbl/${{ github.event.repository.name }}|View Workflow>"
                  }
                ]
              }
            ]