name: Validate 'versions-manifest.json' file
on: 
  push:
    branches:
      - main
    paths:
      - 'versions-manifest.json'

jobs:
  setup-versions-from-manifest:
    name: Setup ${{ matrix.python }} ${{ matrix.os }}
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        os: [macos-latest, windows-latest, ubuntu-16.04, ubuntu-18.04, ubuntu-20.04]
        python: [3.5.4, 3.6.7, 3.7.5, 3.8.1]
    steps:
    - name: setup-python ${{ matrix.python }}
      uses: actions/setup-python@v2
      with:
        python-version: ${{ matrix.python }}

    - name: Validate version
      run: |
        $pythonVersion = (python --version)
        if ("Python ${{ matrix.python }}" -ne "$pythonVersion"){
          Write-Host "The current version is $pythonVersion; expected version is ${{ matrix.python }}"
          exit 1
        }
        $pythonVersion
      shell: pwsh

    - name: Run simple code
      run: python -c 'import math; print(math.factorial(5))'