python.yml

name: Python

# Builds and tests the Python wheels, and publishes them to PyPI every time the
# Build workflow succeeds on master (so a broken master never gets published).
# Each commit of master gets its own release: its version is the base version
# of 'python/packingsolver/_version.py' followed by the number of commits.
#
# Pull requests touching the bindings or their packaging only build and test
# the wheels.

on:
  workflow_run:
    workflows: ["Build"]
    branches: [master]
    types: [completed]
  pull_request:
    branches: [master]
    paths:
      - "python/**"
      - "pyproject.toml"
      - "CMakeLists.txt"
      - ".github/workflows/python.yml"
  workflow_dispatch:

# Cancel the run of a pull request when a new commit is pushed to it. Runs
# for master commits are never cancelled: each one publishes a release.
concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.event.workflow_run.head_sha || github.sha }}
  cancel-in-progress: ${{ github.event_name == 'pull_request' }}

jobs:

  version:
    # 'workflow_run' only filters on the branch name: also require a push to
    # this repository, so that a pull request from a fork's 'master' branch is
    # never built and published.
    if: >-
      github.event_name != 'workflow_run' ||
      (github.event.workflow_run.conclusion == 'success' &&
      github.event.workflow_run.event == 'push' &&
      github.event.workflow_run.head_repository.full_name == github.repository)
    runs-on: ubuntu-latest
    outputs:
      version: ${{ steps.version.outputs.version }}
    steps:
    - name: Checkout code
      uses: actions/checkout@v6
      with:
        ref: ${{ github.event.workflow_run.head_sha || github.sha }}
        fetch-depth: 0
        persist-credentials: false
    - name: Compute version
      id: version
      run: |
        base=$(sed -n 's/^__version__ = "\([0-9]*\.[0-9]*\)\..*"$/\1/p' python/packingsolver/_version.py)
        echo "version=${base}.$(git rev-list --count HEAD)" >> "$GITHUB_OUTPUT"

  build_wheels:
    needs: version
    name: Build wheels (${{ matrix.os }})
    runs-on: ${{ matrix.runs-on }}

    strategy:
      fail-fast: false
      matrix:
        include:
          - os: linux-x86_64
            runs-on: ubuntu-latest
          - os: linux-aarch64
            runs-on: ubuntu-24.04-arm
          - os: windows-x86_64
            runs-on: windows-latest
          - os: macos-x86_64
            runs-on: macos-15-intel
          - os: macos-arm64
            runs-on: macos-latest

    steps:
    - name: Checkout code
      uses: actions/checkout@v6
      with:
        ref: ${{ github.event.workflow_run.head_sha || github.sha }}
        persist-credentials: false
    - name: Set version
      shell: bash
      run: printf '__version__ = "%s"\n' "${{ needs.version.outputs.version }}" > python/packingsolver/_version.py
    - name: Build wheels
      uses: pypa/cibuildwheel@v4.2.1
      env:
        # One job per CPU: the Apple Silicon runners have 3 CPUs and 7 GB of
        # memory, and swap with more jobs.
        CMAKE_BUILD_PARALLEL_LEVEL: ${{ (runner.os == 'macOS' && runner.arch == 'ARM64') && 3 || 4 }}
        CIBW_ENVIRONMENT_PASS_LINUX: CMAKE_BUILD_PARALLEL_LEVEL
    - name: Upload wheels
      uses: actions/upload-artifact@v4
      with:
        name: cibw-wheels-${{ matrix.os }}
        path: ./wheelhouse/*.whl

  build_sdist:
    needs: version
    name: Build source distribution
    runs-on: ubuntu-latest
    steps:
    - name: Checkout code
      uses: actions/checkout@v6
      with:
        ref: ${{ github.event.workflow_run.head_sha || github.sha }}
        persist-credentials: false
    - name: Set version
      run: printf '__version__ = "%s"\n' "${{ needs.version.outputs.version }}" > python/packingsolver/_version.py
    - name: Build sdist
      run: pipx run build --sdist
    - name: Upload sdist
      uses: actions/upload-artifact@v4
      with:
        name: cibw-sdist
        path: dist/*.tar.gz

  publish:
    needs: [build_wheels, build_sdist]
    if: >-
      github.event_name == 'workflow_run' &&
      github.event.workflow_run.event == 'push' &&
      github.event.workflow_run.head_repository.full_name == github.repository
    runs-on: ubuntu-latest
    environment:
      name: pypi
      url: https://pypi.org/p/packingsolver
    permissions:
      id-token: write
    steps:
    - name: Download wheels and sdist
      uses: actions/download-artifact@v5
      with:
        pattern: cibw-*
        path: dist
        merge-multiple: true
    - name: Publish to PyPI
      uses: pypa/gh-action-pypi-publish@release/v1