Ignore unavoidable warning about private pytest classes

README.rst

@@ -40,21 +40,6 @@ Requirements
 * ``Python`` >= 3.5.
 * ``pytest`` >= 5.3.
 
-pytest 6.2+
-^^^^^^^^^^^
-
-``pytest 6.2`` now issues a warning when internal classes are used by third-party code,
-which is the case for ``pytest-subtests`` which needs to use some internal classes
-to integrate with other pytest features (such as capturing and debugging).
-
-For now users can ignore those warnings by adding this to their configuration file:
-
-.. code-block:: ini
-
-    [pytest]
-    filterwarnings =
-        ignore:A private pytest class or function was used.:pytest.PytestDeprecationWarning
-
 Installation
 ------------
 

pytest_subtests.py

@@ -138,9 +138,11 @@ def _capturing_output(self):
             capture_fixture_active = getattr(capman, "_capture_fixture", None)
 
         if option == "sys" and not capture_fixture_active:
-            fixture = CaptureFixture(SysCapture, self.request)
+            with ignore_pytest_private_warning():
+                fixture = CaptureFixture(SysCapture, self.request)
         elif option == "fd" and not capture_fixture_active:
-            fixture = CaptureFixture(FDCapture, self.request)
+            with ignore_pytest_private_warning():
+                fixture = CaptureFixture(FDCapture, self.request)
         else:
             fixture = None
 
@@ -201,6 +203,19 @@ def make_call_info(exc_info, *, start, stop, duration, when):
         return CallInfo(None, exc_info, start=start, stop=stop, when=when)
 
 
+@contextmanager
+def ignore_pytest_private_warning():
+    import warnings
+
+    with warnings.catch_warnings():
+        warnings.filterwarnings(
+            "ignore",
+            "A private pytest class or function was used.",
+            category=pytest.PytestDeprecationWarning,
+        )
+        yield
+
+
 @attr.s
 class Captured:
     out = attr.ib(default="", type=str)

tests/test_subtests.py

@@ -3,20 +3,6 @@
 import pytest
 
 
-@pytest.fixture(autouse=True)
-def ignore_private_class_warning(testdir):
-    """
-    Make every test in this file ignore the warning about using private pytest classes;
-    It is a risk we are willing to take in this plugin.
-    """
-    testdir.makeini(
-        """
-        [pytest]
-        filterwarnings = ignore:A private pytest class
-        """
-    )
-
-
 @pytest.mark.parametrize("mode", ["normal", "xdist"])
 class TestFixture:
     """