Show asyncio mode in pytest report headers (#266)

Author: asvetlov

README.rst

@@ -261,6 +261,7 @@ Changelog
 - Fixes a bug that prevents async Hypothesis tests from working without explicit ``asyncio`` marker when ``--asyncio-mode=auto`` is set. `#258 <https://github.com/pytest-dev/pytest-asyncio/issues/258>`_
 - Fixed a bug that closes the default event loop if the loop doesn't exist `#257 <https://github.com/pytest-dev/pytest-asyncio/issues/257>`_
 - Added type annotations. `#198 <https://github.com/pytest-dev/pytest-asyncio/issues/198>`_
+- Show asyncio mode in pytest report headers. `#266 <https://github.com/pytest-dev/pytest-asyncio/issues/266>`_
 
 0.17.0 (22-01-13)
 ~~~~~~~~~~~~~~~~~~~

pytest_asyncio/plugin.py

@@ -187,6 +187,13 @@ def pytest_configure(config: Config) -> None:
         config.issue_config_time_warning(LEGACY_MODE, stacklevel=2)
 
 
+@pytest.mark.tryfirst
+def pytest_report_header(config: Config) -> List[str]:
+    """Add asyncio config to pytest header."""
+    mode = _get_asyncio_mode(config)
+    return [f"asyncio: mode={mode}"]
+
+
 @pytest.mark.tryfirst
 def pytest_pycollect_makeitem(
     collector: Union[pytest.Module, pytest.Class], name: str, obj: object