[Sub] Set up Test Infrastructure with pytest-homeassistant-custom-component

[switch180]

Parent Issue: #4 Zero Test Coverage

Objective

Set up the foundational test infrastructure using pytest-homeassistant-custom-component to enable automated testing of the RiverLink integration.

Tasks

• Add pytest-homeassistant-custom-component to requirements.txt
• Create tests/ directory structure
• Set up conftest.py with common fixtures
• Configure pytest.ini or pyproject.toml
• Create fixture files for mock API responses
• Add pytest to CI/CD workflow
• Document test execution in CONTRIBUTING.md

Directory Structure

tests/
├── __init__.py
├── conftest.py           # Pytest fixtures
├── test_api.py           # API client tests
├── test_coordinator.py   # Coordinator tests
├── test_config_flow.py   # Config flow tests
├── test_sensor.py        # Sensor platform tests
├── test_binary_sensor.py # Binary sensor tests
├── test_select.py        # Select platform tests
└── fixtures/
    └── api_responses.json  # Mock API responses

References

• pytest-homeassistant-custom-component
• Parent Issue: Zero Test Coverage - Critical Testing Infrastructure Gap #4

Priority

🔴 High - Foundation for all other testing