test(conftest): Add pytester

Author: tony

src/libtmux/conftest.py

@@ -11,11 +11,14 @@
 if t.TYPE_CHECKING:
     from libtmux.session import Session
 
+pytest_plugins = ["pytester"]
+
 
 @pytest.fixture(autouse=True)
 def add_doctest_fixtures(
     request: pytest.FixtureRequest,
     doctest_namespace: t.Dict[str, t.Any],
+    pytester: pytest.Pytester,
 ) -> None:
     if isinstance(request._pyfuncitem, DoctestItem) and shutil.which("tmux"):
         request.getfixturevalue("set_home")
@@ -24,6 +27,7 @@ def add_doctest_fixtures(
         doctest_namespace["session"] = session
         doctest_namespace["window"] = session.attached_window
         doctest_namespace["pane"] = session.attached_pane
+        doctest_namespace["pytester"] = pytester
 
 
 @pytest.fixture(autouse=True, scope="function")