This simple GitHub Action will delete branches and optionally tags that haven't received a commit recently. The time since last commit is configurable.

The default behaviour is to exclude the default branch (main or master) and the Github protected branches. Default branch(es) can be overriden using the default_branches variable (e.g. default_branches: develop or for multiple default branches default_branches: main,develop,my-default-branch).

Additional branches can be excluded using the extra_protected_branch_regex variable (see example below). Similarly, certain tags can be excluded using the extra_protected_tag_regex variable. Also, branches with open pull requests are being ignored by default (see example below).

Always run the GitHub action in dry-run mode to ensure that it will do the right thing before you actually let it do it. Also make sure that you have a full copy of the repository (git clone --mirror ...) in case something goes bad

name: Cleanup old branches
on:
  push:
    branches:
      - master
      - develop
jobs:
  housekeeping:
    name: Cleanup old branches
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v2
      - name: Run delete-old-branches-action
        uses: beatlabs/[email protected]
        with:
          repo_token: ${{ github.token }}
          date: '3 months ago'
          dry_run: true
          delete_tags: true
          minimum_tags: 5
          extra_protected_branch_regex: ^(foo|bar)$
          extra_protected_tag_regex: '^v.*'
          exclude_open_pr_branches: true

Once you are happy switch, dry_run to false so the action actually does the job

Happy cleaning!