actions/python-version-detect/action.yml

# yaml-language-server: $schema=https://json.schemastore.org/github-action.json
# permissions:
#   - contents: read  # Required for reading version files
---
name: Python Version Detect
description: 'Detects Python version from project configuration files or defaults to a specified version.'
author: 'Ismo Vuorinen'

branding:
  icon: code
  color: blue

inputs:
  default-version:
    description: 'Default Python version to use if no version is detected.'
    required: false
    default: '3.12'
  token:
    description: 'GitHub token for authentication'
    required: false
    default: ''

outputs:
  python-version:
    description: 'Detected or default Python version.'
    value: ${{ steps.parse-version.outputs.detected-version }}

runs:
  using: composite
  steps:
    - name: Validate Inputs
      id: validate
      shell: bash
      env:
        DEFAULT_VERSION: ${{ inputs.default-version }}
      run: |
        set -euo pipefail

        # Validate default-version format
        if ! [[ "$DEFAULT_VERSION" =~ ^[0-9]+\.[0-9]+(\.[0-9]+)?$ ]]; then
          echo "::error::Invalid default-version format: '$DEFAULT_VERSION'. Expected format: X.Y or X.Y.Z (e.g., 3.12, 3.11.5)"
          exit 1
        fi

        # Check for reasonable version range (prevent malicious inputs)
        major_version=$(echo "$DEFAULT_VERSION" | cut -d'.' -f1)
        if [ "$major_version" -ne 3 ]; then
          echo "::error::Invalid default-version: '$DEFAULT_VERSION'. Python major version should be 3"
          exit 1
        fi

        # Check minor version range for Python 3
        minor_version=$(echo "$DEFAULT_VERSION" | cut -d'.' -f2)
        if [ "$minor_version" -lt 8 ] || [ "$minor_version" -gt 15 ]; then
          echo "::error::Invalid default-version: '$DEFAULT_VERSION'. Python 3 minor version should be between 8 and 15"
          exit 1
        fi

        echo "Input validation completed successfully"

    - name: Checkout Repository
      uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
      with:
        token: ${{ inputs.token || github.token }}

    - name: Parse Python Version
      id: parse-version
      uses: ivuorinen/actions/version-file-parser@7061aafd35a2f21b57653e34f2b634b2a19334a9
      with:
        language: 'python'
        tool-versions-key: 'python'
        dockerfile-image: 'python'
        version-file: '.python-version'
        validation-regex: '^[0-9]+\.[0-9]+(\.[0-9]+)?$'
        default-version: ${{ inputs.default-version }}