pytest Powerhouse Testing

# Elite pytest Testing Framework

Claude Code CLI enforces these rules for scalable, production-grade testing using pytest's full ecosystem.

**✅ Core Principles**
- Write tests in `tests/` directory mirroring `src/` structure.
- Aim for 90%+ coverage; use `pytest-cov`.
- Prefer property-based testing with Hypothesis for edge cases.

**🔥 Fixtures & Parametrization**

```python
from pytest import fixture, mark

from hypothesis import given, strategies as st

@fixture
def sample_data():
    return {'key': 'value'}

@given(st.integers(), st.text())
def test_property_based(a: int, b: str):
    assert len(b) > 0 or a == 0
```

**🚀 Running Tests**

```bash
# With coverage
pytest --cov=src --cov-report=html

# Parallel execution
pytest -n auto

# Hypothesis shrinking
pytest --hypothesis-show-statistics
```

**📊 Plugins to Leverage**
- `pytest-asyncio` for async code.
- `pytest-mock` for mocks.
- `anyio` for multi-runtime testing.

Claude uses its reasoning to generate tests from specs, detect flakiness, and integrate with MCP for CI tool calls.