bump-version.yml

# Source: https://github.com/joaomcteixeira/python-project-skeleton/blob/main/.github/workflows/version-bump-and-package.yml
#         and https://github.community/t/trigger-workflow-only-on-pull-request-merge/17359/9

# taken and upgraded from:
# https://github.com/haddocking/pdb-tools/blob/f019d163d8f8cc5a0cba288e02f5a63a969719f6/.github/workflows/bump-version-on-push.yml
name: Bump version

# Bump version only when closed Pull Requests to main
on:
  pull_request:
    branches:
      - main
    types: [closed]

jobs:
  bump-version:

    runs-on: ubuntu-latest
    if: "github.event.pull_request.merged == true &&
        !startsWith(github.head_ref, 'SKIP')"

    steps:

    - uses: actions/checkout@v2
      with:
        # I setup a new token for my GitHub user and added that token
        # to the secrets in the repository
        # When I tried
        # https://docs.github.com/en/actions/reference/authentication-in-a-workflow
        # I had some problems, they could be my fault, but yet, I felt using a
        # dedicated token would be better and enough
        token: ${{ secrets.CICD_TOKEN }}

    - name: Set up Python
      uses: actions/setup-python@v2
      with:
        python-version: '3.x'

    - name: Setup Git
      env:
        GH_USER: ${{ github.actor }}
        GH_TOKEN: ${{ secrets.CICD_TOKEN }}
        PR_TARGET_BRANCH: ${{ github.base_ref }}
      run: |
        git config user.name "${GH_USER}"
        git config user.email "${GH_USER}@users.noreply.github.com"
        git remote set-url origin https://x-access-token:${{ secrets.CICD_TOKEN }}@github.com/$GITHUB_REPOSITORY
        git checkout "${PR_TARGET_BRANCH}"
    - name: Setup env variables
      run: |
        echo "SKIPBUMP=FALSE" >> $GITHUB_ENV
    - name: Install dependencies
      run: |
        python -m pip install --upgrade pip
        pip install bump2version
    # If a commit starts with [MAJOR] a new major verion upgrade will be
    # triggered. Use with caution as Major upgrades denote backwards
    # incompatibility. Yet I like it to be integrated in the CI
    - name: Bump Major Version
      env:
        PR_SOURCE_BRANCH: ${{ github.head_ref }}
      run: |
        bump2version major
        echo "SKIPBUMP=TRUE" >> $GITHUB_ENV
      if: "startsWith(github.head_ref, 'MAJOR') || 
          startsWith(github.head_ref, 'BREAK')"

    - name: Bump Minor Version
      env:
        PR_SOURCE_BRANCH: ${{ github.head_ref }}
      run: |
        bump2version minor
        echo "SKIPBUMP=TRUE" >> $GITHUB_ENV
      if: "startsWith(github.head_ref, 'MINOR') || 
          startsWith(github.head_ref, 'FEAT')"

    # Default action
    - name: Bump Patch Version
      env:
        PR_SOURCE_BRANCH: ${{ github.head_ref }}
      run: |
        bump2version patch
      if: env.SKIPBUMP == 'FALSE'

    - name: Commit version change to master
      run: |
        git push --follow-tags