conftest.py

# Configuration for pytest to automatically collect types.
# Thanks to Guilherme Salgado.
import pytest

try:
    import pyannotate_runtime
    PYANOTATE_PRESENT = True
except ImportError:
    PYANOTATE_PRESENT = False

if PYANOTATE_PRESENT:
    def pytest_collection_finish(session):
        """Handle the pytest collection finish hook: configure pyannotate.
        Explicitly delay importing `collect_types` until all tests have
        been collected.  This gives gevent a chance to monkey patch the
        world before importing pyannotate.
        """
        from pyannotate_runtime import collect_types
        collect_types.init_types_collection()

    @pytest.fixture(autouse=True)
    def collect_types_fixture():
        from pyannotate_runtime import collect_types
        collect_types.resume()
        yield
        collect_types.pause()

    def pytest_sessionfinish(session, exitstatus):
        from pyannotate_runtime import collect_types
        collect_types.dump_stats("type_info.json")