[Sub] Add CI/CD Workflow with Automated Testing and Coverage Reporting

[switch180]

Parent Issue: #4 Zero Test Coverage

Objective

Set up GitHub Actions CI/CD workflow to run tests automatically on every push/PR with coverage reporting.

Workflow Requirements

Test Execution

• Run on push to main branch
• Run on all pull requests
• Test against multiple Python versions (3.11, 3.12, 3.13)
• Test against multiple HA versions (latest stable + beta)

Coverage Reporting

• Generate coverage report with pytest-cov
• Upload coverage to Codecov or similar
• Fail if coverage drops below threshold (e.g., 80%)
• Display coverage badge in README

Code Quality Checks

• Run ruff linting
• Run type checking (mypy/pyright)
• Check code formatting
• Validate manifest.json

Workflow Configuration

# .github/workflows/test.yml
name: Test

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  test:
    runs-on: ubuntu-latest
    strategy:
      matrix:
        python-version: ["3.11", "3.12", "3.13"]
    steps:
      - uses: actions/checkout@v4
      - name: Set up Python
        uses: actions/setup-python@v5
        with:
          python-version: ${{ matrix.python-version }}
      - name: Install dependencies
        run: |
          pip install -r requirements.txt
          pip install pytest pytest-cov pytest-homeassistant-custom-component
      - name: Run tests
        run: pytest --cov=custom_components.riverlink --cov-report=xml
      - name: Upload coverage
        uses: codecov/codecov-action@v4

Additional Workflows

Release Workflow

• Automatic version tagging
• Generate release notes from commits
• Validate HACS compatibility

Lint Workflow

• Run ruff on every PR
• Auto-format suggestions

Success Criteria

• All tests pass on CI
• Coverage report generated and uploaded
• Badge displays in README
• Workflow runs on every PR
• Fast execution (<5 minutes)

References

• GitHub Actions Documentation
• pytest-cov Documentation
• Parent Issue: Zero Test Coverage - Critical Testing Infrastructure Gap #4
• Depends on: Issues [Sub] Set up Test Infrastructure with pytest-homeassistant-custom-component #14-[Sub] Write Integration Tests #18

Priority

🟡 Medium - Automation infrastructure