Refactor LoggingIsolationMixin to use __enter__/__exit__ transparently via MRO

Co-authored-by: bittner <[email protected]>

Author: Copilot

cli_test_helpers/decorators.py

@@ -21,20 +21,27 @@ class LoggingIsolationMixin:
     allows code under test to call ``logging.basicConfig()`` successfully even
     when test frameworks (like pytest) have already configured logging handlers.
 
-    Classes using this mixin should call ``_save_logging_handlers()`` at the
-    start of their ``__enter__()`` method and ``_restore_logging_handlers()``
-    at the end of their ``__exit__()`` method.
+    This mixin works transparently through Python's method resolution order
+    (MRO) and requires no explicit method calls from subclasses.
     """
 
-    def _save_logging_handlers(self):
-        """Save and clear current logging handlers."""
+    def __enter__(self):
+        """Save and clear logging handlers before entering the context."""
         self._old_handlers = logging.root.handlers[:]
         logging.root.handlers.clear()
+        # Call parent __enter__ if it exists (for cooperative inheritance)
+        if hasattr(super(), '__enter__'):
+            return super().__enter__()
+        return self
 
-    def _restore_logging_handlers(self):
-        """Restore previously saved logging handlers."""
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        """Restore logging handlers after exiting the context."""
         if hasattr(self, '_old_handlers'):
             logging.root.handlers[:] = self._old_handlers
+        # Call parent __exit__ if it exists (for cooperative inheritance)
+        if hasattr(super(), '__exit__'):
+            return super().__exit__(exc_type, exc_val, exc_tb)
+        return None
 
 
 class ArgvContext(LoggingIsolationMixin):
@@ -51,13 +58,13 @@ def __init__(self, *new_args):
         self.args = type(self._old)(new_args)
 
     def __enter__(self):
-        self._save_logging_handlers()
+        super().__enter__()
         sys.argv = self.args
         return self
 
     def __exit__(self, exc_type, exc_val, exc_tb):
         sys.argv = self._old
-        self._restore_logging_handlers()
+        super().__exit__(exc_type, exc_val, exc_tb)
 
 
 class EnvironContext(LoggingIsolationMixin, patch.dict):
@@ -80,8 +87,6 @@ def __init__(self, **kwargs):
         super().__init__("os.environ", **kwargs)
 
     def __enter__(self):
-        self._save_logging_handlers()
-
         super().__enter__()
 
         for key in self.clear_variables:
@@ -91,7 +96,6 @@ def __enter__(self):
         return self
 
     def __exit__(self, exc_type, exc_val, exc_tb):
-        self._restore_logging_handlers()
         return super().__exit__(exc_type, exc_val, exc_tb)
 
 
@@ -111,15 +115,13 @@ def __init__(self, *args, **kwargs):
 
     def __enter__(self):
         """Create a temporary directory and ``cd`` into it."""
-        self._save_logging_handlers()
+        super().__enter__()
 
         self.__prev_dir = os.getcwd()
-        super().__enter__()
         os.chdir(self.name)
         return os.getcwd()
 
     def __exit__(self, exc_type, exc_value, traceback):
         """Return to the original directory before execution."""
-        self._restore_logging_handlers()
         os.chdir(self.__prev_dir)
         return super().__exit__(exc_type, exc_value, traceback)