experiment.yaml

name: CI Unit
on:
  pull_request:
    branches: [ main, preview ]

concurrency:
  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
  cancel-in-progress: true

jobs:
  # ==========================================
  # 1. DISCOVERY & BUCKETING
  # ==========================================
  discover:
    runs-on: ubuntu-latest
    outputs:
      buckets: ${{ steps.generate-matrix.outputs.buckets }}
    steps:
      - uses: actions/checkout@v4
      
      - name: Detect Changed Packages
        id: changes
        uses: tj-actions/changed-files@v44
        with:
          files: packages/**
          dir_names: true               
          dir_names_max_depth: 2        
          matrix: false

      - name: Generate Balanced Buckets
        id: generate-matrix
        env:
          CHANGED_DIRS: ${{ steps.changes.outputs.all_changed_files }}
        run: python .github/scripts/matrix_generator.py --matrix-multiplier 6 --max-vms 40

  # ==========================================
  # 2. HORIZONTAL EXECUTION
  # ==========================================
  unit-tests:
    needs: discover
    if: ${{ needs.discover.outputs.buckets != '[]' }}
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      max-parallel: 60
      matrix:
        chunk: ${{ fromJSON(needs.discover.outputs.buckets) }}
        python: ["3.9", "3.10", "3.11", "3.12", "3.13", "3.14"]
        
    name: Unit (Py ${{ matrix.python }})
    steps:
      - uses: actions/checkout@v4
      - uses: astral-sh/setup-uv@v5
        with:
          python-version: ${{ matrix.python }}
          enable-cache: true

      - name: Optimize Core Dependencies
        run: git config --global url."${GITHUB_WORKSPACE}".insteadOf "https://github.com/googleapis/google-cloud-python"

      - name: Execute Chunk
        run: |
          # The Engine: uv handles virtualenvs, nox delegates to uv
          export NOX_DEFAULT_VENV_BACKEND=uv
          
          # The Fix: Forces uv to install `pip` in the venv so legacy `pip freeze` commands don't crash
          export UV_VENV_SEED=1 
          
          # Speed optimization: Pre-compile python bytecode
          export UV_COMPILE_BYTECODE=1
          
          FAILED=0
          
          for pkg in ${{ matrix.chunk }}; do
            echo "=========================================================="
            echo "🚀 TESTING: $pkg (Python ${{ matrix.python }})"
            echo "=========================================================="
            cd "$pkg"
            
            # Clean, readable bash: Check if the session exists before running it
            if uvx --with 'nox[uv]' nox -l | grep -q "unit-${{ matrix.python }}"; then
              # Run the test and stream logs directly to the UI
              uvx --with 'nox[uv]' nox -s "unit-${{ matrix.python }}" || FAILED=1
            else
              echo "⏭️ Session 'unit-${{ matrix.python }}' not defined for $pkg. Safely skipping."
            fi
            
            cd "$GITHUB_WORKSPACE"
          done
          
          exit $FAILED

  # ==========================================
  # 3. GATEKEEPER
  # ==========================================
  presubmit-passed:
    if: always() 
    needs: [discover, unit-tests]
    runs-on: ubuntu-latest
    steps:
      - name: Evaluate Pipeline Status
        run: |
          if [[ "${{ contains(needs.*.result, 'failure') }}" == "true" || "${{ contains(needs.*.result, 'cancelled') }}" == "true" ]]; then
            echo "::error::One or more required CI jobs failed or were cancelled."
            exit 1
          fi
          echo "All dynamically generated CI jobs completed successfully."