bump_version.yml

name: Bump version
on:
  pull_request:
    branches: [master]
    types: [closed]
  workflow_dispatch:
    inputs:
      version_part:
        description: >
          Version part to bump before deployment.
          Possible options {none, major, minor, patch}
        required: true
        default: 'patch'

jobs:
  get_version_part_manually:
    name: Bump version on manual workflow dispatch
    if: github.event.inputs.version_part
    runs-on: ubuntu-latest
    env:
      VERSION_PART: ${{ github.event.inputs.version_part }}
    outputs:
      # will be empty if validation fails
      version_part: ${{ steps.validated_input.outputs.version_part }}
    steps:
      - name: Cancel on invalid input
        if: >
          !(
            env.VERSION_PART == 'none' ||
            env.VERSION_PART == 'major' ||
            env.VERSION_PART == 'minor' ||
            env.VERSION_PART == 'patch'
          )
        run: |
          echo "::error:: \`$VERSION_PART\` is not a valid version part. Must be one of {none, major, minor, patch}"
          exit 1
      - name: Set version part based on manual input
        id: validated_input
        run: echo "::set-output name=version_part::$VERSION_PART"

  get_version_part_on_pr_merge:
    name: Bump version on pull reuqest merge
    if: github.event.pull_request.merged == true
    runs-on: ubuntu-latest
    outputs:
      version_part: ${{ join(steps.*.outputs.version_part, '') }}
    steps:
      - name: Cancel on bump:none
        id: bump_none
        if: contains(github.event.pull_request.labels.*.name, 'bump:none')
        run: echo "::set-output name=version_part::none"
      - name: Bump major
        id: bump_major
        if: >
          steps.bump_none.conclusion == 'skipped' &&
          contains(github.event.pull_request.labels.*.name, 'bump:major')
        run: echo "::set-output name=version_part::major"
      - name: Bump minor
        id: bump_minor
        if: >
          steps.bump_none.conclusion == 'skipped' &&
          steps.bump_major.conclusion == 'skipped' &&
          contains(github.event.pull_request.labels.*.name, 'bump:minor')
        run: echo "::set-output name=version_part::minor"
      - name: Bump patch
        id: bump_patch
        if: >
          steps.bump_none.conclusion == 'skipped' &&
          steps.bump_major.conclusion == 'skipped' &&
          steps.bump_minor.conclusion == 'skipped'
        run: echo "::set-output name=version_part::patch"

  bump_version:
    name: Bump version
    needs: [get_version_part_on_pr_merge, get_version_part_manually]
    # always() needed to not automatically skip this job due to one of the
    # get_version_part_* jobs being skipped and bump_version depending on both.
    if: >
      always() &&
      (
        needs.get_version_part_on_pr_merge.result == 'success' ||
        needs.get_version_part_manually.result == 'success'
      ) &&
      join(needs.*.outputs.version_part, '') != 'none'
    env: 
      VERSION_PART: ${{ join(needs.*.outputs.version_part, '') }}
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v2
      - uses: actions/setup-python@v1
        with:
          python-version: 3.7
      - name: Install bump2version
        run: pip install bump2version
      - uses: oleksiyrudenko/gha-git-credentials@v2-latest
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
      - name: Bump version
        run: bump2version --verbose "$VERSION_PART"
      - name: Push changes
        uses: ad-m/github-push-action@master
        with:
          tags: true
          branch: ${{ github.ref }}
          github_token: ${{ secrets.PERSONAL_ACCESS_TOKEN }}