internal-check-python-venv-support.yml

name: Check Python venv virtual environment

on:
  pull_request:
    branches:
      - main
    # Only watch changes related to Python virtual environment venv
    paths:
      - 'requirements.txt'
      - 'scripts/activatePythonEnvironment.sh'
      - '.github/workflows/internal-check-python-venv-support.yml' # or when this file changed

jobs:
  check-python-venv-environment:
    runs-on: ubuntu-22.04
    strategy:
      matrix:
        include:
        - python: 3.12

    steps:
    - name: Checkout GIT Repository
      uses: actions/checkout@v6

    - name: (Python Setup) Use version ${{ matrix.python }} with venv environment management module
      uses: actions/setup-python@v6
      with:
        python-version: ${{ matrix.python }}
        cache: 'pip'
    
    - name: Activate virtual environment using venv and check if the required packages were installed
      env: 
        USE_VIRTUAL_PYTHON_ENVIRONMENT_VENV: "true"
      # 1.  Run the script under test to create, activate and install the virtual environment
      # 2.  Run pip install for the current environment in dry-mode with full output first to get all infos and fail on missing packages.
      # 3a. The leading exclamation mark tells the shell to invert the returned exit code. 
      #     Failing because "Would install" is missing leads to a successful execution. 
      # 3b. Run pip install for the current environment in dry-run mode without installing or resolving dependencies
      # 3c. Suppress all pip output (stderr)
      # 3d. Check if pip would install anything using grep
      # 3e. If there are missing dependencies and the environment is incomplete, 
      #     fail with code 1 (indicates all requirements already satisfied)
      #
      # Output installed dependencies for troubleshooting purposes:.venv/bin/pip freeze
      run: |
        source ./scripts/activatePythonEnvironment.sh
        .venv/bin/pip install --dry-run --quiet --requirement requirements.txt
        ! .venv/bin/pip install --dry-run --requirement requirements.txt 2>/dev/null | grep -q "Would install"