Deprecate zope.testing.doctestcase in favour of plain doctest.

Points users to doctest.DocTestSuite/DocFileSuite as the migration path.

Author: icemac

CHANGES.rst

@@ -7,6 +7,9 @@
 
 - Add support for Python 3.15.
 
+- Deprecate ``zope.testing.doctestcase`` in favour of plain ``doctest``
+  (e.g. ``doctest.DocTestSuite`` or ``doctest.DocFileSuite``).
+
 - Move package metadata from setup.py to pyproject.toml.
 
 

src/zope/testing/doctestcase.py

@@ -9,6 +9,15 @@
 import sys
 import types
 import unittest
+import warnings
+
+
+warnings.warn(
+    'zope.testing.doctestcase is deprecated and will be removed in a '
+    'future release. Use plain doctest (e.g. doctest.DocTestSuite or '
+    'doctest.DocFileSuite) instead.',
+    DeprecationWarning,
+    stacklevel=2)
 
 
 __all__ = [